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Related research: Public Health 101 for Informaticians (Koo 2001)

Public Health 101 for Informaticians
Denise Koo, MD, MPH, Patrick O'Carroll, MD, MPH, and Martin LaVenture, MPH
Affiliations of the authors: Centers for Disease Control and Prevention, Atlanta, Georgia (DK, PO'C); Minnesota Department of Health, Minneapolis, Minnesota (MLV).
Correspondence and reprints: Denise Koo, MD, MPH, Associate Director for Science, Epidemiology Program Office, Mailstop C-08, Centers for Disease Control and Prevention, 1600 Clifton Road NE, Atlanta, GA 30333; e-mail: <dkoo@cdc.gov>.
Received June 7, 2001; Accepted July 23, 2001.

Abstract

Public health is a complex discipline that has contributed substantially to improving the health of the population. Public health action involves a variety of interventions and methods, many of which are now taken for granted by the general public. The specific focus and nature of public health interventions continue to evolve, but the fundamental principles of public health remain stable. These principles include a focus on the health of the population rather than of individuals; an emphasis on disease prevention rather than treatment; a goal of intervention at all vulnerable points in the causal pathway of disease, injury, or disability; and operation in a governmental rather than a private context. Public health practice occurs at local, state, and federal levels and involves various professional disciplines. Public health principles and practice are illustrated by a case study example of neural tube defects and folic acid. The application of information science and technology in public health practice provides previously unfathomed opportunities to improve the health of the population. Clinical informaticians and others in the health care system are crucial partners in addressing the challenges and opportunities offered by public health informatics.

 

My list of the take-home points from this paragraph would include:

  • fundamental principles of public health:
    1. focus on the health of the population rather than of individuals;
      [RST: magnifying efforts beyond only the number of clients an individual practitioner can see]
    2. an emphasis on disease prevention rather than treatment;
      [RST: seems very compatible with our value of promoting wellness]
    3. a goal of intervention at all vulnerable points in the causal pathway of disease, injury, or disability;
      [RST: intervention in wellness/prevention as well as treatment after illness or injury occurs] and
    4. operation in a governmental rather than a private context.
      [RST: It's not clear how this can apply to us so much, as so few of us are in a governmental context, but maybe there is a role for exploring public-private partnerships. Let's see how they develop this point as we continue in the article.]
  • Public health practice occurs at local, state, and federal levels and involves various professional disciplines
    [RST: So do we fit into this picture anywhere, and if so, then how?]
  • Clinical informaticians and others in the health care system are crucial partners in addressing the challenges and opportunities offered by public health informatics
    [RST: In a similar way, is there an opportunity for MT as well to act as a partner in addressing public health challenges and opportunities?]

 

In this paper, we explain public health as a professional discipline to clinical informaticians. Defining public health presents a challenge, for two different but key reasons. First, public health as a discipline can be difficult to fathom because of the diverse range of problems it addresses and, consequently, the broad scope of activities. Second, many clinicians and other caregivers already have an idea of what public health is about, but that idea is typically limited in scope and is sometimes quite mistaken. At a minimum, it reflects and is constrained by the perspective that is inherent in the nature of clinical work. Yet understanding the discipline of public health is critical for informaticians. Through an understanding of public health and the developing specialty of public health informatics,1 their training, talents, creativity, and experience can be applied in new ways to the fundamental mission of public health—to promote physical and mental health and prevent disease, injury, and disability to realize the vision of healthy people in healthy communities.2

 

Hmmm, this sounds familiar--the diverse range of problems it addresses, and the broad scope of activities it encompasses makes public health a complex and challenging discipline to understand. And yet, people have developed methods for doing so.

Perhaps we can use some of those same methods to approach the complexity of understanding massage and its research in a similar way.

Clinicians and other caregivers have a limited and mistaken idea of what public health is about--yes, we've been there as well. Let's see how they address it; again, maybe we can use some of their ideas to tackle our similar problems.

The vision of public health is "healthy people in healthy communities"--that sounds like a vision MT could get behind, doesn't it?

In this paper, we explain the unique perspectives of public health as a discipline, broadly outline and discuss the fundamental nature of public health, present a case study to illustrate and amplify that discussion, and articulate several “grand challenges” for the new and evolving field of public health informatics.

 

I think we're pretty clear at this point what the authors intend to do in this paper. Let's see how they go about actually doing it.

 


Definition of Public Health

Tip of the Iceberg

Although the public health sector has protected and kept U.S. residents healthy, the majority of Americans have had limited direct exposure to the ways in which public health is practiced. Exposure to the public health system is typically confined to limited activities undertaken by local or state health departments. These activities might include the vaccination of children and the provision of official copies of birth certificates, among others. For years, public health hospitals have been counted among the most visible manifestations of the public health system, serving as “clinical care provider of last resort.” Indeed, many people equate public health solely with providing care to indigent populations. For others, public health involves routine restaurant inspections and investigations of food-borne epidemics in the community. For many clinicians, their primary (and generally one-way) interaction with public health involves submitting notifiable disease reports when they diagnose communicable diseases among their patients.

Certainly, public health agencies are involved in all of these activities. But to understand public health only in these terms is similar to understanding marine biology in terms of shells on the shore. It misses the broader, often invisible aspects of the discipline that have had and continue to have profound salutary effects on human health. For example, the majority of Americans take for granted certain aspects of daily life that exist because of the historical and continuing efforts of the public health sector, such as clean water, safe roads, a protected food supply, and proper disposal of solid and liquid waste.3,4 In addition, many of the fundamental processes of public health (e.g., ongoing disease surveillance, environmental monitoring, and prevention research) generally take place outside the public consciousness, although they are no less important for being invisible.

 

I like this analogy: "But to understand public health only in these terms is similar to understanding marine biology in terms of shells on the shore."

They've named a lot of things that public health is responsible for, yet those things they have listed seem as different from one another as the different shells you can find on the beach.

Can you see what all of these activities have in common, to make up a cohesive discipline called "public health"?

Let's see how they develop this point.

 

 


Shifting Priorities, Multiple Disciplines, Various Roles

Apart from limited exposure to the public health system, the discipline of public health can be difficult to grasp, in part because the focus of public health action has evolved over the past two centuries. This is because the activities of public health are primarily driven by its goal—to improve health and prevent disease, injury, and disability. Thus, as threats to human health vary with time and geography, so too do specific public health projects and efforts. For example, during the 18th and 19th centuries, yellow fever was a great scourge in America. In Philadelphia in 1793, for example, yellow fever killed 5,000 people in only three months—roughly 10 percent of the population.5 Today, this disease is essentially unknown in the United States, and it is not a current focus of public health action.

 

This clarifies the point to a degree: "[Public health's goal is] to improve health and prevent disease, injury, and disability. Thus, as threats to human health vary with time and geography, so too do specific public health projects and efforts."

That's what all these things have in common, and how they fit into the vision of healthy people in healthy communities. We specialize in musculoskeletal issues, for example, and infectious-disease specialists concentrate on communicable diseases, oncologists specialize in cancer, and so forth.

Public health's priorities, on the other hand, are driven by the needs of the particular community in question.

Occupational public health might have repetitive musculoskeletal injuries in assembly-line workers as a focus in one community.

In a different place, the spread of an infectious disease like whooping cough or hantavirus might be that community's highest health threat at a particular time, much as yellow fever used to be in 18th-century Philadelphia.

Yet another community may have much higher-than-expected cancer rates, and that might be the public health workers' focus as they try to figure out why that is, and what can be done to address the risk there.

So while we and other individual practitioners have particular specialties that we focus on, public health's priorities for focus is driven by the immediate needs of the community in question.

As progress was made against infectious diseases in the 20th century, the public health community expanded its focus to include other threats to human health (e.g., occupational illnesses, motor vehicle injuries, chronic diseases, exposures to toxic waste and other environmental hazards, interpersonal violence, and suicide).3,4 Of course, new or reemerging infectious disease threats (e.g., AIDS, hantavirus, and drug-resistant tuberculosis) continue to command the attention of public health officials.

Another aspect of public health that makes the concept hard to grasp derives from its varying interventions, which have involved diverse professional disciplines. Many activities—like road and building design, toxic waste disposal, water treatment, school safety, immigrant health, protection of the food supply, even municipal design to promote healthy lifestyles—have been key to promoting health and preventing disease and injury. In addition to nurses, physicians, epidemiologists, and statisticians, the public health system also relies on engineers, social workers, outreach workers, laboratory workers, health communication specialists, sanitarians, environmental specialists, nutritionists, lawyers, legislators, and others to apply efforts that promote health and prevent disease. The public health system comprises allied government, community, professional, voluntary, and academic institutions and organizations that might not be officially termed (or consider themselves) public health agencies. In this paper, we focus on governmental public health agencies.

Finally, public health as a discipline encompasses an amalgam of science, action, research, policy, advocacy, and government. Public health practitioners play each of these roles at different times, but as a professional discipline, public health is not adequately described by any one of them. If public health were simply a scientific enterprise, government function, or any one of the elements listed previously, the concept would be easier to grasp. But public health professionals do wear distinct hats according to the nature of the various threats to community health, the political and social context of the community, and the often incomplete scientific knowledge regarding available preventive interventions. This also makes understanding the extent and nature of public health as a discipline difficult.

 

The take-home point from this section is that when a focus is driven by a goal such as immediate health needs of a community, that goal is so open-ended and flexible that a variety of approaches and specialties are needed to address that goal.

So what role(s) might massage play in promoting healthy communities and healthy people? That's something to give serious consideration to, but not because it's so hard to fit massage in--it's not at all hard to envision multiple ways that massage could work with public health realize our commitment to wellness.

The real question is, with so many possibilities that can be imagined, where to start?

Coming up with specifics and prioritizing them would be a good next step. At the  May 2010 Seattle conference on Massage Therapy in Complementary and Integrative Medicine, there was a panel discussion: "The Role of Massage Therapy in Public Health". William Meeker, DC, MPH served as moderator, and the panel included Marissa Brooks, MPH, LMP; Cynthia Price, PhD, LMP; Deborah Senn, former Washington state Insurance Commissioner; and John Weeks, executive director of the Academic Consortium for Complementary and Alternative Health Care.

I've written to the Massage Therapy Foundation, who organized and put on the conference, to ask whether the video or proceedings from the panel are available. If they are, I will pass along the links so that you can see what points were raised in the discussion.

In addition, the problem of having to work in the here and now with incomplete scientific knowledge--of not being able to afford to wait until all the evidence is in, because people need relief right now--is certainly a familiar one to us, as well.

 

 


Defining Principles and Core Functions of Public Health

Although the focus of public health action and the nature of public health interventions continue to evolve, the fundamental principles of public health remain clear and stable. We previously stated four principles that define, guide, and provide the context for the types of activities and challenges that are undertaken in furtherance of public health.1 These principles derive from the scope and nature of public health itself and tend to distinguish public health from medicine and health care. These four principles can be useful as a guide to those attempting to understand public health.

  • The primary focus of public health is to promote the health of populations and not the health of specific individuals.
 
This may be something that we haven't considered before. The idea that there is a difference between individual health and population health may not have come up before, but it is true that often the whole is more than just the sum of its parts.
 
  • The primary strategy of public health is prevention of disease and injury by altering the conditions or the environment that put populations at risk.
 
Prevention and wellness go together nicely as goals. This can be a way for massage to express our stated commitment to wellness in concrete and doable ways.
 
  • Public health professionals explore the potential for prevention at all vulnerable points in the causal chains leading to disease, injury, or disability; public health activities are not restricted to particular social, behavioral, or environmental contexts.
 
 
We'll talk a bit later on about causal chains; the take-home point here is that anywhere there is an opportunity to break the cycle of problem ==> illness, that is a legitimate opportunity for a public-health intervention.
 
  • Public health interventions must reflect the governmental context in which public health is practiced.
 
 
This may seem like the least relevant point here for our purposes, since very few--if any--MTs practice in a governmental context. We'll talk more about what that means for us as it comes up in the following discussion.
 

With these four principles as guides, public health can be further defined and understood in terms of its core functions. In 1988, the Institute of Medicine (IOM) published The Future of Public Health,6 in which it articulated three activities that ideally comprise the core functions of an effective public health system—assessment, policy development, and assurance. The first core function refers to the assessment and monitoring of the health of communities and populations at risk, to identify health problems and priorities. Policy development involves formulating public policies, in collaboration with community and government leaders, that are designed to solve identified health problems. Assurance refers to the responsibility of the public health system to ensure that all populations have access to appropriate and cost-effective care, including health promotion and disease prevention services, and evaluation of the effectiveness of that care.

 

These points could be relevant to MT in the following ways, among other possibilities:

  • assessment: looking out for, and being able to recognize, problems in a community or a population. This point needs further exploration on how assessment systems in an MT's community can be relevant to the MT, and how the MT can support the system in promoting community health.
  • policy development: What are the identified health problems in our communities, and how can MTs participate in plans to address them?
  • assurance: What is MT doing to ensure that all populations have access to the care we offer? How do we evaluate the effectiveness of what we do, and how do we work to increase that effectiveness?

 

Information is central to each of these core functions. For example, the essence of community health assessment is the collection, analysis, interpretation, and communication of data and information. Timely and authoritative information is also central to the informed development of public health policy. Finally, the assurance function described in the IOM report moves public health away from “clinical care provider of last resort” toward the role of monitor and communicator of information about community access to critical health services. Thus, each of these core functions accentuates the importance of public health as information broker, directly underscoring the need for public health officials to be effective planners, developers, and users of health information systems.

 

Although this information is specific to the informatician audience this article is directed toward, it is not entirely irrelevant to us--certainly, our information needs are a very important component of our ability to participate in furthering the mission, objectives, and vision of healthy people in healthy communities.

 

 


People and Facilities

People

The governmental portion of the public health workforce embodies approximately 500,000 professionals, divided among federal, state, and local departments of health.7 As described previously, they practice many professions, including informatics. These public health practitioners operate within the political realities of government organizations and are constrained by limited budgets and inadequate information system resources. Despite these limitations, they are highly committed and dedicated, and their shared motivation is their belief in the power of prevention to ensure community health.
Public health professionals at the federal level frequently specialize or subspecialize in a narrow field, whereas those working on the front lines of public health (e.g., in local health departments) tend to be generalists with more diverse responsibilities. Depending on funding or need, state public health staff fall somewhere between. For example, an epidemiologist working at the Centers for Disease Control and Prevention (CDC) might focus on asthma or on monitoring the incidence and prevalence of asthma. A CDC health educator might develop training materials pertaining to influenza. In contrast, a state health department epidemiologist might focus on prevention of environmental illnesses, or a state health educator might concentrate on all diseases preventable by vaccine. In smaller cities or counties, a single local health department staff person may cover a wide range of programs; the same person might investigate infectious diseases, disseminate information about chronic diseases, manage the Women, Infants, and Children (WIC) and other direct-service programs, and communicate public health concerns to elected officials.
State and local public health staff and others in the health-care system rely on federal experts as a national resource, whereas federal and state public health departments produce much of the research, guidelines, and recommendations that local public health departments implement.
At all levels of public health, staff must build strong community collaboration, solicit and respond to the concerns of the public, and represent public health programs to elected officials.
Public health professionals adopt this challenging work despite liabilities—lack of academic preparation in public health, barriers to ongoing training, and low pay. As of 1997, 78 percent of local health department executives did not have graduate degrees in public health.8 Many state and federal public health executives are appointed by elected officials and are subject to political tides. Nationwide, a state's chief public health executive stays in the job an average of two years.7

 

As you can see, very few people, if any at all, go into public health for the money. And with states currently facing economic and budgetary shortfalls, public-health initiatives are often places where budget cuts can be made without a lot of awareness or protest from the public.

Remember, this article was written in 2001, well before the economic crisis that began in 2008. Everything they describe here was in a better economic situation than we now find ourselves in, and the economic constraints on public health are even tighter now than they were when the authors were writing this.

 

Ongoing training is essential in a field as broad and dynamic as public health, but the barriers to accessing needed training are formidable. For professionals practicing in a rural area, travel time to centralized training can be substantial. For instance, a public health professional from Kittson County in Minnesota, who attends a four-hour training session in Minneapolis, will spend approximately 12 hours commuting. Although public health personnel are taking increasing advantage of distance-learning technologies, for a professional to take the time away from daily work for training in the many areas for which highly technical expertise is required might be impossible.

 

We face some of the same issues in continuing professional education as public-health professionals do, and perhaps some of the same solutions that they have been exploring in this area could work for us as well.

 

Recruiting and retaining public health staff are also becoming increasingly difficult. The public health agency for Nobles-Rock counties in Minnesota offers a beginning registered nurse $12.54 per hour,9 while the regional hospital in the same town offers registered nurses $16.74 per hour as a starting wage.10 This disparity, more than $8,000 per nurse per year, is exacerbated for information technology professionals and is impossible for even the most fervent believer in the value of public health to ignore. Many agencies report positions that remain unfilled for months or years.

 

What does this mean for us for working with and supporting the vision of healthy people in healthy communities?

 

 


Facilities

Among the 59 U.S. state and territorial health departments and approximately 3,000 county and city health departments, facilities vary widely in size and resources, from new, state-of-the-art buildings to substandard portable trailers. Many outdated, crowded health department buildings are geographically separate from other government offices that have fast Internet connections and technical support.

Public health professionals are challenged to execute their broad responsibilities with limited electronic communication capacity, data systems, and other informatics tools. Examples include the following:

  • In 1999, an e-mail test message sent to local health departments showed that only 35 percent of the test e-mails were received.
  • Only 45 percent of the local agencies had the capacity to issue a broadcast facsimile.
  • Less than 50 percent had continuous high-speed (>56 KB) access to the Internet.7
  • In March 2001, 41 percent of Minnesota's local public health agencies reported that all managers had desktop access to the Internet; 31 percent reported that all support staff had desktop access; and only 19 percent reported that all professional staff (e.g., nurses, epidemiologists, sanitarians, and health educators) had desktop access to the Internet.11

Public health staff recognize that integrated, computerized information systems and the World Wide Web are critical tools, but these key components of public health infrastructure traditionally have not been funded by grants or new appropriations. Historically, the U. S. Congress has funded public health programs for disease prevention and control (e.g., cancer, tuberculosis, and sexually transmitted diseases), but such program-specific funding provides no incentives for developing integrated systems that would benefit multiple programs. Personnel at local and state health departments, therefore, are required to use distinct, incompatible applications to enter and analyze data; data cannot be easily exchanged, linked, or merged by different programs, or used to evaluate problems by person, across time or geographic area. (Additional discussion of public health informatics challenges appears below.)

 

This is informatics-specific information, tailored for the intended audience of this article, but you don't need to be an informatician to see some of the challenges faced by public-health workers in the age of information. Although this information is over 10 years old, and things have improved in the intervening decade, the budgetary constraints previously describe also act to discourage major infrastructure investments when direct community care is already so underfunded.


The authors turn next to a case study of information and neural tube defects in a population of newborn infants, and the public-health interventions taken against that problem. Interestingly, while case studies we read in the literature may usually, in our experience, be about people living with a particular condition, this case study is more abstract--it's about public-health approaches to a condition in a population, rather than clinical approaches to an individual.

While you're reading this, I'd like you to think about what might be a similar problem, where massage and public health could work as partners to address a community health issue, and work to promote better health in the members of that community.

 

 


Case Study: Neural Tube Defects

Epidemiology, the basic science of public health, is the study of the distribution and determinants of health-related states or events in specified populations and the application of this study to control health problems.12 An analogy heard in a medical school epidemiology course is that a clinician tries to decide what kind of disease a person has, whereas a public health practitioner tries to determine what kind of person has a disease or condition (i.e., what factors can be influenced to prevent that disease or condition). Through this case study, the clinical informatician will understand more about the practice of public health, where the patient is the population.

 

Another way of describing epidemiology is the study of health-related patterns in populations. Epidemiologists study what diseases occur in particular populations, and they look for cause-and-effect explanations why this particular condition is an issue for this particular population at this particular time and place.

For example, in the early 1980s, it was observed that numerous young gay men of all ethicities were showing up in physicians' offices with symptoms of Kaposi's sarcoma, a particular kind of tumor of connective tissue that previously had primarily been observed only occasionally, and typically in middle-aged men of Mediterranean, Southern European, and Jewish ancestry.

Source: http://upload.wikimedia.org/wikipedia/commons/3/3c/Kaposi%27s_Sarcoma.jpg accessed 2 July 2012

 

In trying to understand why the patterns of this disease had changed so dramatically, epidemiologists were a major part of the team that eventually discovered how the previously-unknown HIV/AIDS virus was causing such devastation in the community.

Other epidemiologists work on issues such as figuring out whether cancer clusters are occurring in particular neighborhoods (and--if-so--then why), or what it causing increases in infectious-disease incidence in certain regions, and similar pattern observation and figuring out the problem behind the pattern.

In the 1990s, as this newspaper article from the Spokane (Washington) Spokesman-Review describes, national attention was focused on why the small Western Washington Shoalwater Bay Tribe was suffering such a disproportionately high rate of miscarriage. The paper reports that "Out of 13 pregnancies in 1997 and 1998, only one Shoalwater baby is alive today [Jun 15, 1999].".

Source: Google news search, http://news.google.com/newspapers?nid=1314&dat=19990615&id=Io9XAAAAIBAJ&sjid=GvIDAAAAIBAJ&pg=5918,5084426 accessed 2 July 2012

 

The individual anguish to families that each of these miscarriages caused, and which is part of the issues that an individual clinician would work with those families about, is compounded by fears of the tribe going extinct, of environmental pesticides or other toxins that may be silently poisoning the community, of the effects that poverty, isolation, and health sequelae caused by socioeconomic status, as well as by many other issues.

That's what I was referring to earlier when I mentioned that the whole is often more than the sum of its parts. Certainly, 12 miscarriages out of 13 pregnancies are 12 family tragedies--there is no doubt about that. But, even more than that foundation, the community issues surrounding the complex causes and meaning of the deaths are what make it a community public health issue.

And trying--not always succeeding--to figure out what's going on, what pattern we are seeing, what meaning the pattern has, and what is causing the pattern is a job that falls, in large part, to epidemiologists.

In the case study in this article, the epidemiologists are trying to figure out a pattern of neural tube defects, another kind of tragedy that strikes developing fetuses, their mothers and fathers, and their entire families.

Before we continue, though, so that I don't leave you wondering what ultimately happened in the Shoalwater Bay Tribe, I found this update in the obituary of Herbert Whitish, the chairman of the tribe, who died in 2005.

Herbert "Ike" Whitish, 1955-2005: Native leader led Shoalwater Bay Tribe through crisis

By Paul Shukovsky, Seattle Post-Intelligencer Reporter

Published 10:00 p.m., Thursday, September 8, 2005

A Native American leader who played a central role in saving a tiny southwest Washington tribe from extinction has died after a lengthy illness. He was 50.

Herbert "Ike" Whitish grew up in Seattle before returning home and ultimately becoming chairman of his beloved Shoalwater Bay Tribe when it needed him the most. In the 1990s, the tribe's babies began dying, and no one knew why.

Always outspoken, Whitish used blunt language and media savvy to bring his tribe's troubles to the attention of the nation. Stories about the mysterious scourge of miscarriages, stillbirths and infant deaths ran in newspapers and on television stations across the country in the 1990s.

Whitish gave access to reporters who were specific in describing the tragedy engulfing the tiny tribe, which had about 200 members in the late 1990s. Whitish parlayed the attention into mobilizing politicians and government health officials, who sent in elite epidemiological teams from the U.S. Centers for Disease Control and Prevention to investigate.

No cause was ever uncovered, but Whitish prevailed on Congress to pay for a health care clinic and comprehensive program for pregnant women at the tribe's isolated reservation on the north end of Willapa Bay.

"He led his tribe through the crisis," said Kathy Spoor, Pacific County's public health director. "Through his efforts to assure better health care access and support services for his people, the situation has improved."

Spoor said the outcomes of pregnancies at the Shoalwater Bay reservation have been running at normal levels for at least the past two years.

...

 

So now that we have a clearer idea of what epidemiologists do, lets get back to the case report in this article.

The article assumes that we're all on the same page regarding our understanding of neural tube defects; let's briefly sum it up to make sure that that assumption will carry us through the rest of the article.

Neural tube defects (NTDs) are one of the most common birth defects, occurring in approximately one in 1,000 live births in the United States. An NTD is an opening in the spinal cord or brain that occurs very early in human development. In the 3rd week of pregnancy called gastrulation, specialized cells on the dorsal side of the fetus begin to fuse and form the neural tube. When the neural tube does not close completely, an NTD develops.

--Wikipedia: "Neural tube defect" accessed 2 July 2010

 

Take-home points:

  • a neural-tube defect (NTD) is a birth defect;
  • in the US, approximately one in every 1000 babies born alive will have some form of NTD;
  • NTDs occur when parts of the brain or spinal cord do not completely close as part of normal development, so that part of the baby's central nervous system is left open and exposed to the environment.

 

A severe NTD can be a life-threatening event, but mild or moderate NTDs can be repaired or managed.

Wikipedia lists a number of famous people who were born with spina bifida (one of the kinds of NTD that we will discuss in a bit); the ones I had heard of include musicians John Mellencamp, Lucinda Williams, and Hank Williams. They also list Karin Muraszko as the chair of the Department of Neurosurgery at University of Michigan, first female appointed to such a position in the US--evidence that being born with spina bifida is not necessarily an obstacle to succeeding at a demanding medical career.

That level of knowledge is enough for us to pick up reading the article and its discussion of the public health approach to NTDs.

 


Public Health Approach to a Problem

The public health approach to a problem is illustrated in Figure 1[triangle]. Public health surveillance is defined generally as the ongoing systematic collection, analysis, and interpretation of health-related data for use in planning, implementing, and evaluating public health practice.13,14 Surveillance is a key data-driven activity of public health and is crucial for the detection and description of problems. After a potential problem is recognized through surveillance, we identify risk factors to determine the cause of the problem. After risk factors have been characterized, we evaluate interventions to decide which ones work most effectively to prevent disease or illness. Subsequently, we implement programs that include such interventions. We then loop back to the beginning, to ongoing surveillance, to determine whether our programs have affected disease incidence.

Figure 1

Public health approach. Reproduced from materials used by the National Center for Injury Prevention and Control, Centers for Disease Control and Prevention, Atlanta, Georgia.

 

You can see how this approach is very similar to the scientific method of observation, forming and testing a hypothesis, and evaluating results.

It's also very similar to what we do with individual clients in practice--we observe, develop a treatment plan, and--based on how well that plan works--either keep going with it as it succeeds, or change it in response to feedback.

 

Not all conditions of interest are under public health surveillance, partly because no single source of data or system contains information for all diseases or conditions of interest. Public health surveillance information systems, like other distributed information systems, are resource-intensive. They use data from various sources, some of which are collected from health care providers, laboratories, or individuals or directly from medical records and birth and death certificates explicitly for surveillance purposes. Decisions about what conditions to monitor are made not by CDC but rather by the state health departments or state legislatures, who might also manage or appropriate specified funds for conducting surveillance activities. Thus, the conditions that are under public health surveillance vary by state.15,16

 

Take-home point--public health approaches and decisions are often made, necessarily on constrained or incomplete or politically-managed information.

In a perfect world, we'd have all the information we need to make out decisions; in the world we actually operate in, however, we recognize the limitations of the information available to us to rely upon.

 

Factors that influence what conditions are under surveillance in each state include the frequency of disease (i.e., incidence, prevalence, and mortality), the severity (i.e., hospitalization rate, case-fatality rate, years of potential life lost, and disability- and quality-adjusted life-years), the cost of caring for those with the condition, its preventability, its communicability, and the public interest in the condition.14 These criteria for surveillance show why public health officials monitor the occurrence of neural tube defects (NTDs). Neural tube defects affect 1 in every 1,000 pregnancies in the United States, or approximately 4,000 fetuses annually.17 Anencephalic infants are stillborn or die shortly after birth, and although many infants with spina bifida survive, they often suffer from severe lifelong disabilities. The total monetary cost of spina bifida over a lifetime has been calculated as $294,000 per infant (in 1992 dollars).17 It is now known that approximately 50 percent of NTDs can be prevented.18–23

 

Anencephalic (Ancient Greek ἀν- (an-) + ἐγκέφαλος (egkephalos, “within the head”) + -ia, from ἐν (en, “in”) + κεφαλή (kephalē, “head”)), meaning "without a brain", is a severe and fatal birth defect in which the brain simply fails to develop at the appropriate stage in the fetus. Infants born without a brain typically live a few hours--sometimes a few days--before dying; it's an extremely traumatic experience for a family to go through.

If it is any small consolation at all in a very painful situation to watch helplessly, the infants are typically not in pain from their condition. The damage, however, is often so severe that basic reflexes such as breathing and sucking/nursing are damaged or absent.

At the Wikipedia article on anencephaly, if you want to, you can see what anencephalic fetuses and newborns look like, but I'm not including those pictures here, because many people find them so distressing.

Spina bifida is--like anencephaly--an NTD, but a much less severe one, and one that occurs much more commonly than anencephaly does as well. Usually occurring in the lumbar or thoracic regions, spina bifida ("split", "divided into 2 branches, forked") is a condition where part of the spinal cord protrudes out through an opening where the neural tube failed to fully close.

 

Source: Centers for Disease Control http://www.cdc.gov/ncbddd/spinabifida/images/spina_bifida-web.jpg accessed 2 July 2012

 

Spina bifida can cause serious effects in severe cases--paralysis, other orthopedic issues, bowel and bladder control problems, just to name a few.

But it doesn't have to be that severe; it is possible to have a case of spina bifida so mild that the affected person doesn't even realize they have a condition. As I previously mentioned, Wikipedia has a list of notable people who were born with the condition, and for whom it did not prevent them from having successful careers, often grueling ones. Unlike anencephaly, which is not survivable, there is an entire spectrum of people's experience in living with spina bifida

That's the condition(s) that the case report here is about. Now, the authors explain how the incidence of NTDs get the epidemiologists' awareness in the first place.

 

 


Surveillance: What is the Problem?

A universally available source of data regarding the incidence of NTDs is the birth certificate, which is completed for all live births in the United States. A standardized format is used for birth certificates, the U.S. Standard Certificate of Birth (Figure 2[triangle]), which includes information about the parents, the month prenatal care began, the gestational age and Apgar scores of the infant, the mother's relevant medical and reproductive history, details about the labor and delivery, and check-boxes to indicate whether the newborn has certain congenital anomalies. This latter revision, introduced in 1989,24,25 lists anencephaly and spina bifida first and second, respectively.

 

Figure 2

U.S. Standard Certificate of Birth.

 

Since this article is written primarily for informaticians, an interesting side point here is that so much information is contained, not in modern computerized information systems (although, no doubt, later birth certificates are online), but for so many Americans, on paper birth certificates stored in the records area of public-health departments. It's an important point about our current dependence on computers to get information, yet so much vital information is not available on computers yet.

 

As with any other information system, however, birth certificate data have certain limitations. First, timeliness is an issue. A birth certificate generally must be completed, usually by a clerk at the hospital, and filed within five to ten days of birth. The local registrar forwards the information to the state department of health within one to four weeks and states send birth certificate data to the National Center for Health Statistics (NCHS) of CDC anytime, from daily to weekly to monthly. Most states send the data to NCHS within 60 days of birth. Finally, nationwide data are not usually available until a year after the calendar year in which birth occurred.

 

So if the epidemiologists want to know how many births in a certain area are recorded with the NTDs that they are tracking, there is a certain time lag that they have to take into account in their work--if they want nationwide data, for example, they have to work at least a year behind the year we are currently in.

It's an important point about the availability and accessibility of information that serves as the basis for public-health decisions--the information isn't, and can never be, perfect, and we have to make our decisions with that fact in mind.

 

Second, although the checkboxes for anencephaly and spina bifida appear on the birth certificate, a few states have not consistently required that congenital anomalies be reported.26 Third, even if congenital anomalies are supposed to be reported, they might not be recorded on the birth certificate. The sensitivity of the birth certificate for anencephaly has been documented at approximately 60 percent and for spina bifida at only 40 percent.27,28 Fortunately, given the relative clarity and ease of the diagnosis at birth, the positive predictive value or accuracy of the birth certificate for NTDs approaches 100 percent.27,28

 

The quality of the information on which public-health decisions are made is also an issue.

"Sensitivity" is the name that epidemiologists tend to use for the statistical measure that information scientists tend to refer to as "recall", but whichever name they use, they are both measuring the same thing: how good a job does their measuring instrument do of finding all of the relevant cases that are really there?

Or, how sure are they that they are not missing real cases, because whoever was responsible for entering the information on the birth certificate failed to do so for infants born alive with cases of anencephaly or spina bifida?

If the sensitivity of the birth certificate for anencephaly is about 60 percent, and for spina bifida is about 40 percent, that means that:

  • For every 100 babies born alive with anencephaly, about 60 of them will have a birth certificate that correctly records their condition, and
  • For every 100 babies born alive with spina bifida, about 40 of them will have a birth certificate that correctly records their condition.

 

If those numbers are making you wonder just how good the information that makes its way to you for you to make clinical decisions about may actually be--well, that is a very good question for all of us to be asking ourselves from time to time.

Fortunately, although a lot of relevant cases are missed when it comes to entering them on the birth certificate, the relevant cases that are not missed--the ones where they did correctly record the condition--are almost perfectly right. That's what it means to say that the positive predictive value approaches 100 percent.

It means that you can have almost absolute trust that, if these conditions are recorded on the birth certificate, that the infants really did have those conditions. There are almost no times when a normal healthy infant was mistakenly recorded as having one of these conditions, and there are also almost no instances where someone mistook some other condition for anencephaly or spina bifida.

A lot of real cases of NTDs at birth were missed when it came to recording them on the birth certificate (the 60% and 40% sensitivity rates).

But, if whoever was responsible for recording that information on the birth certificate did put one of those conditions, you can trust with almost perfect certainty that the baby actually does have that condition, and that the birth certificate does not mistakenly put anencephaly or spina bifida for infants who are normal, or who have different conditions present at birth.

 

Finally, however, a key limitation of using birth certificates for complete ascertainment or determination of NTDs is that they do not include fetuses that have been miscarried or terminated. Approximately 50 percent of fetuses with NTDs are diagnosed prenatally and aborted.29,30 Thus, in states where detection of all birth defects is a priority, additional resources are invested in gathering data from other sources in addition to the birth certificate.

Approximately 21 states or localities conduct active surveillance for birth defects.31 Active surveillance refers to the increased effort and resources invested by the health department to seek information on a regular basis from sources. Active surveillance, which is initiated primarily by a health department, differs from passive surveillance, which relies on providers to report to the health department.

These birth defects monitoring programs cover various fractions of their population and use various combinations of data sources, which include obstetric offices, prenatal diagnostic centers and laboratories, fetal and neonatal autopsy programs, outpatient perinatal centers, genetic service and other specialty clinics, hospital discharge data and medical records, vital records, ultrasonography records, and neonatal intensive care units; certain ones include passive reports from schools and community agencies. Data from each of these systems are useful for decision making and planning within a jurisdiction, providing information that facilitates understanding the incidence of a problem, the population affected, their rates of prenatal diagnosis and termination and, thus, the most useful points for and types of public health interventions.

 

An excellent point about the limitations of data from birth certificates--they only record the incidence of NTDs in babies who were born alive.

If the NTD is serious enough to kill the baby before it's born, or if parents decide to terminate the pregnancy because of the effects of the NTD, the cases where those happen are invisible if you rely only on birth certificates to understand what is really going on.

You need multiple sources of data to get closer to the entire picture.

Active surveillance is when the public-health agency reaches out and asks sources in the community for information about cases they are seeing.

Passive surveillance is when the public-health agency does not do its own outreach, but works on the data that providers and other community sources deliver to them.

You can see how those different methods of information collection might have an effect on how representative and thorough the collected data could turn out to be.

 

 

 


Risk Factor Identification: What is the Cause?

Diverse scientific investigations might prove useful to public health officials attempting to identify the etiology or cause of a problem or, at minimum, risk factors that influence the occurrence of a condition. For NTDs, such studies include basic or molecular research into the genetic and biochemical bases of NTDs. They also include clinical research such as that conducted among family planning clinic or prenatal care patients (e.g., case-control or cohort studies to evaluate risk factors and clinical trials to study patient interventions). Naturally, population-based research regarding diet or risk behaviors (e.g., ecologic studies of cultures or nations, state- or communitywide surveys, or case-control studies using cases identified through surveillance) also play a role in the public health understanding of the problem.

 

The best outcome is when public-health workers can determine exactly what causes a problem, and address it head on--such as in 1854 when the British physician John Snow demonstrated that cases in a London cholera outbreak were coming from a public drinking-water pump in Broad Street contaminated with human sewage, or when the human immunodeficiency virus was demonstrated to be the cause of AIDS.

However, we don't always get that best possible outcome. Sometimes, we have to settle only for correlations, or associations, rather than understanding cause and effect.

The best we get, in some cases, may be to recognize that certain populations are at higher risk for a particular condition than other populations are, without ever being able to exactly pin down the causality.

Wikipedia has an illustration that shows some of the different ways that epidemiologists can study these questions.

There are, essentially, 3 factors involved in these types of studies:

  • the exposure (or non-exposure) to the causative agent behind the condition;
  • whether or not members of that population actually get the condition; and
  • at what point the researcher gets involved in the investigation.

 

This diagram shows the interactions among those factors in different types of epidemiological studies:

Source: http://upload.wikimedia.org/wikipedia/en/b/b5/ExplainingCaseControlSJW.jpg accessed 3 July 2012

 

First of all, we are going to ignore the ORs and RRs in the captions, because the explanations of those statistics will get us rather far away from the topic of the article we are reading here. If you want to know more about them, you can look up "odds ratio" (OR) and "relative risk" (RR), and we'll also discuss them in other places here at POEM. But since the original article didn't bring them up, and since you've slogged through a lot of material already, we won't add a new pair of statistics on right here.

The key at the bottom of the diagram tells you how to read each part of the diagram. The green question mark is what we are trying to find out; the black dot is members of the population in which the condition is present; the white dot is members of the population in which the condition is absent, and the stick figure comes into the diagram at the point in which the researcher gets involved with the study.

So in the first one, the case-control study, the researcher enters the scene after the exposure, and after it is clear who has the condition (the "cases" of disease) and who doesn't have the condition (the "controls", no disease), and tries to investigate something about the exposure itself (the green question marks).

The next two are cohort studies over a long time period, where the condition--whether or not the different members of the population were exposed to the risk factor for the disease--is known, and the question the researcher is investigating is whether or not those different members of the population go on to develop the disease.

If the researcher gets involved before the diseases develop and studies them as they occur, then that is a prospective ("forward-looking") cohort study.

Working backwards (such as investigating birth certificates or other historical records) means that the researcher is conducting a retrospective ("backward-looking") cohort study.

These different kinds of studies shed different kinds of light on associations between exposure to some kind of disease-causing factor, and what really happens in terms of people going on to actually develop those conditions.

 

Public health officials might also learn more about the cause of a problem during the course of outbreak or cluster investigations. When a cluster of anencephaly occurred along the Texas–Mexico border several years ago,32 public health officials conducted an investigation because of concerns that the outbreak was related to environmental contamination either from the industrial plants along the Mexican border or from pesticide use and that the number of cases was not a statistical anomaly. However, they were unable to identify an etiologic association for this cluster.

 

In this case, like in the Shoalwater Bay case, they were able to figure out that this was a real pattern of more disease than you would expect in a population this size, rather than just a chance result that looked like a pattern.

But, also like in the Shoalwater Bay case, they did not succeed in finding out what the cause (or causes) of that increased disease rate was.

Sometimes, disappointingly, that's the best we're able to do.

However, the NTD case study in this report has a better outcome than those more intractable cases.

 

 

 


Folic Acid and Neural Tube Defects

In July 1991, the British Medical Research Council reported that daily consumption of dietary supplements containing 4 mg of folic acid produced a 72 percent reduction in the recurrence of NTDs.19 The results were so striking that the study was stopped early. This randomized trial supported earlier results by Smithells et al.18 that showed a similar effect with multivitamin supplements containing 0.36 mg of folic acid in a non-randomized intervention among women at high risk (i.e., women with a prior pregnancy resulting in an NTD18).

 

There are 2 reasons, basically, for interrupting a scientific study before it is completed according to the way it was designed.

One way is that the treatment under study is so clearly and obviously harmful to the people who are receiving it that the minute that that fact is known, it is not ethical to submit them to that harm for a moment longer.

The other way is that the treatment under study is so clearly and obviously beneficial to the people who are receiving it that the minute that that fact is known, it is not ethical to deprive the control participants in the study from thos benefits for a moment longer.

This 1991 study was cut short for that second reason.

Before the dietary supplements containing folic acid (one of the B vitamins) were given to pregnant women, the babies were expected to have the following rates of NTDs might have looked like the left side of the following illustration--based on previous history of similar populations out of some larger number of babies, 100 of them would be expected to have NTDs.

Rate of births with NTDs before folic acid dietary supplements ||| Rate of births with NTDs after folic acid dietary supplements

 

After intervention with the folic acid dietary supplements, the 100 babies who were expected to develop NTDs turned out to be 28 babies in reality.

That improvement was so dramatic that they didn't wait to finish the study as originally designed--they stopped it early, so that the controls could be given folic acid dietary supplements, and they could get the word out to the general public with their recommendations as soon as possible.

 

Officials at CDC determined that this information could prevent NTDs and published a special report in August 199133 that included interim recommendations that women with a history of an infant or fetus with an NTD take 4 mg/day of folic acid, starting when they planned to become pregnant. This amount was 10 times the current recommended daily allowance of folic acid for pregnant women. Given the compelling data from these studies and a sense of urgency about informing the public, this recommendation did not involve CDC's other partner federal agencies, particularly the Food and Drug Administration (FDA). The FDA was apprehensive about safety, about the possibility that taking this amount of folic acid would mask the ability to diagnose vitamin B12 deficiency through blood smears.

 

The CDC and the FDA had a genuine conflict over two good and desirable goals that conflicted with each other, so since they could not resolve it, the CDC pushed ahead without the FDA's participation--that's how important they saw this issue to be.

 

Soon after, however, another randomized clinical trial was also stopped early in Hungary after a protective effect was shown for women with no prior history of a pregnancy resulting in an NTD. In the Hungarian study, the women took a multivitamin containing only 0.8mg of folic acid.20 At this point, several studies documented a protective effect of taking folic acid in amounts ranging from 0.1 to 5.0mg.21–23,34 This time, CDC—working with the Office of the Assistant Secretary for Health, FDA, the Health Resources and Services Administration (HRSA), and the National Institutes of Health—developed a statement regarding folic acid for all women.

 

More trials, including another one in Hungary that was stopped early, persuaded the FDA and other agencies to sign on with the CDC to promote the recommendation that all pregnant women should take folic acid dietary supplements.

 

Thus, in 1992, the U.S. Public Health Service (PHS) recommended that all women consume 0.4 mg folic acid daily.34 The recommended daily consumption was directed at all women, not just women planning to become pregnant, because development and closure of the neural tube takes place within 28 days after conception, before the majority of women know they are pregnant; in addition, approximately 50 per cent of pregnancies in the United States are unplanned.35 The recommendation did not specify how the population might obtain the appropriate amount of folic acid, although it did describe three potential approaches—improvement of dietary habits, fortification of the U.S. food supply, and use of dietary supplements. The report stated that FDA would explore the issue of fortification of the food supply, balancing the goal of increasing folic acid intake with concerns about safety. This process required FDA to participate in federal rule making, which involved obstetric and other medical professionals, the scientific community, consumers, and industry as well as other PHS agencies, underscoring the governmental context of public health actions.

 

Two of the three potential approaches require the pregnant women to take active steps to change food habits, or to start taking vitamins. The third one is passive on the part of the woman, since it involves putting extra micronutrients in the food supply (fortification).

Part of the problem is that--even if you can reach the women, and if they are motivated to begin changing habits--the necessary process of development takes place so early that it is often finished--correctly or imperfectly--before the woman even realizes she is pregnant. So it's too late to change the outcome at that point.

Fortifying the common food supply that everyone--not only the pregnant women--eats from raises safety concerns, among others. These are some of the trade-offs involved in making that decision.

 

 

 


Evaluate Intervention: What Works?

Although science indicated that folic acid was effective in preventing certain NTDs, the question of how to implement effective programs to produce this outcome remained. First was the issue of ensuring that health care providers and consumers were aware of the recommendation, especially the need of women to take folic acid before becoming pregnant. Second, dietary changes are widely acknowledged as difficult to implement, even for a motivated, knowledgeable persons. And above all, the fact that half of pregnancies in this country are unplanned augmented the public health challenge. Clearly, the approach to this problem would have to be multi-pronged.

 

This is often what the findings of public-health studies reveal--very, very rarely is it a simple, 1-1 cause and effect, where one solution fits all.

Rather, as you might expect in a diverse population, a variety of different approaches is often more effective in promoting community health.

Another important point alluded to in this paragraph is that it's not just about what the science shows. Translating scientific findings into effective practices, and educating and encouraging practitioners and clients to make use of those effective practices, is a much bigger, and different, problem.

 

 


Implement Program: How Do You Do It?

As in the 1992 recommendation, FDA pursued the option of fortification of the food supply. They published a proposed rule in the Federal Register in 1993 and a final rule in March 1996.36 At that time, fortification was optional; however, the rule required fortification of enriched grain products (e.g., flours and pastas) with 140μg folic acid/100g grain beginning Jan 1, 1998. This action was expected to add 0.1mg of folate to the average person's daily diet and was intended to result in 50 percent of women of reproductive age receiving 0.4mg folate from all sources.37,38 Questions regarding whether more birth defects could be prevented with a larger dose of folic acid remain,39 but FDA wanted to balance this theoretic benefit with concerns about safety and masking vitamin B12 deficiency.

 

What does this mean for products that you purchase where you do your food shopping in the US?

What were the trade-offs involved in deciding on the final dose?

What is the effect of this intervention on the population?

 

Public health partners working together to disseminate information about folic acid included CDC, FDA, HRSA, and state health agencies, along with obstetric associations and other provider groups, health plans, maternal and child health advocacy groups, public school educators, and community organizations. A CDC publication, “Preventing Neural Tube Birth Defects: A Prevention Model and Resource Guide,” outlines ways to design, develop, deliver, and evaluate an NTD prevention program in a community by using folic acid promotion as a model.40 It includes informational materials targeted at the media, physician's offices, clinics, schools, and even health clubs. In addition, in 1999, CDC, the March of Dimes Birth Defects Foundation, and the National Council on Folic Acid began a national education campaign with materials targeted to women who are thinking about pregnancy, the contemplators, and women who are able to get pregnant even if not planning to in the near future, the non-contemplators. The “Before You Know It” and “Ready, Not” brochures produced for these two groups, respectively, along with other materials, were developed after focus groups were conducted with women who were contemplators and non-contemplators, including Spanish-speaking women from various countries of origin. These materials are readily available in English and Spanish from the CDC Web site and the CDC facsimile information service.

 

In addition to the food fortification prong of the approach, there is a provider and family education component as well.

 

 

 


Surveillance: How to Measure Impact?

As with any public health program, continual surveillance to determine whether these programs are having an effect on the incidence of NTDs is essential. However, with delays in the availability of birth certificate data and the utility of assessing more immediately the effects of these programs, evaluation also involves conducting surveillance for outcomes earlier in the causal pathway of disease ([triangle]). Thus, by analyzing the levels of folate in fortified grains, we can measure the effects of the fortification rule on the amount of folic acid in the environment.412

 

How were they going to tell whether their intervention was effective?

 

 

Figure 3

Causal pathway of disease.

 

This is a simplified representation of how cause and effect bring about disease.

What do the different stages in this pathway represent in the case of NTDs?

 

To estimate the effects of education campaigns, CDC partnered with the March of Dimes to survey women about their awareness of folic acid and its role in preventing birth defects. Folic acid awareness increased from 52 percent in 1995 to 75 percent in 2000, and the women surveyed also reported an increase in consumption of vitamins containing folic acid, from 28 percent in 1995 to 34 percent in 2000.42,43

 

Was the intervention effective in promoting awareness and in encouraging women to take vitamins containing folic acid?

 

 

We might also enumerate sales of folic acid–containing vitamins to discern whether behavior has changed. Results from the National Health and Nutrition Examination Survey (NHANES), conducted periodically by NCHS, provide another gauge of the increase in folic acid intake among women. Analysis of blood samples from NHANES 1999 demonstrated a substantial increase in serum and red blood cell folate concentrations among women between 1 and 44 years of age after folic acid fortification (Figure 4[triangle]).44 A similar increase in serum folate levels among clinical specimens from men and women supports the hypothesis that folic acid fortification and not dietary supplements might be contributing to this trend.45,46

Figure 4

Median serum folate concentrations among non-pregnant women between 15 and 44 years of age, from the National Health and Nutrition Examination Survey (NHANES) III, conducted 1988 to 1994.

 

Median is a kind of average measurement--the median of a set of data points is the number that exactly half of the data is higher than, and half of the data is lower than.

We'll explore this further in the research literacy book, so for the purposes of this article, it's enough to think of the median as a divider. It divides the data into a higher half and a lower half.

So, for example, if your data looked like this:

4,3,12,5,1,1,2,8,7

 

then 4 is the median. Half of the values (1,1,2,3) are less than 4, and half of the values (5,7,8,12) are more than 4. So 4 divides the data up exactly into a higher half and a lower half.

Percentile is a statistical measure that tells you how many of the data points fall beneath the one you are looking at.S

The 10th percentile of the pre-fortification measure of serum folate looks like it comes in at about 2 ng/ml. So we can say that 2 ng/ml is the 10th percentile of pre-fortification serum folate measurements, which means that 10% of the measurements of pre-fortification serum folate are less than 2 ng/ml.

The post-fortification 10th percentile for serum folate looks like about 6 ng/ml, so in a similar way, we can say that 10% of the measurements of post-fortification serum folate are less than 6 ng/ml.

What is the 25th percentile pre- and post-fortification?

What is the 50th percentile pre- and post-fortification?

Is the 50th percentile always going to be equal to the median value, or is that just a coincidence here? Why or why not?

What is the 75th percentile pre- and post-fortification?

What is the highest value pre- and post-fortification?

What do these trends tell you about whether the intervention was effective or not?

Was there anyone in the pre-intervention group who actually had higher folate than some people in the post-intervention group? How can you tell?

What do the authors mean by:

A similar increase in serum folate levels among clinical specimens from men and women supports the hypothesis that folic acid fortification and not dietary supplements might be contributing to this trend.

 

What leads them to say that?

 

Folic acid fortification might be having its intended effect on the incidence of NTDs. An analysis of birth certificate data through 1999 shows that the birth prevalence of NTDs decreased from 37.8 per 100,000 live births before fortification to 30.5 per 100,000 live births after fortification, a 19 percent decline (Figure 5[triangle]).26Analysis of data regarding births to women who received only third-trimester or no prenatal care, and thus could not have terminated a pregnancy with an NTD, demonstrates a similar decline (Figure 6[triangle]).26Data from the Metropolitan Atlanta Congenital Defects Program, which includes prenatally diagnosed cases, also exhibit a decline (Figure 7[triangle]). Factors other than folic acid fortification (e.g., increased vitamin supplementation) may also have contributed to this decline; public health officials will continue to monitor the occurrence of NTDs to further evaluate the effects of these public health interventions.

Figure 5

Trends in total neural tube defects (anencephaly and spina bifida) among all births, 1990–1999, for 45 U.S. states and Washington, DC. source: National Center for Health Statistics Vital Statistics Data. Adapted from Honein et al.26

 

What does the trend show?

 

Figure 6

Trends in total neural tube defects (anencephaly and spina bifida) among births to women who received no prenatal care or prenatal care in the third trimester only, 1990–1999, for 45 U.S. states and Washington, DC. source: National Center for (more ...)

 

What appears to have happened in the "Optional" period before fortification became mandatory?

Why do you think that's what happened?

 

Figure 7

Prevalence of anencephaly and spina bifida, Metropolitan Atlanta Congenital Defects Program, 1968– 2000. Dark bars indicate prenatally diagnosed cases; light bars, hospital-based cases, which include both liveborn and stillborn infants.

 
 
What does this trend show?
 
Do you see any missing data on this chart?
 
 
 
 

Grand Challenges of Public Health Informatics

As might be expected from the public health principles described above and illustrated by the case study, the nature of public health also defines a special set of informatics application challenges. For example, to assess the health and risk status of a a population, data must be obtained from multiple disparate sources (e.g., hospitals, social service agencies, police, departments of labor and industry, population surveys, and on-site inspections). Data about particular individuals from these sources must be accurately combined, then individual-level data must be compiled into usable, aggregate forms at the population level. This information must be presented in clear and compelling ways to legislators and other policymakers, scientists, advocacy groups, and the public while ensuring the confidentiality of the health information of specific individuals.

Although information science and technology can improve public health practice in various ways, three areas represent grand challenges for public health informatics—developing coherent, integrated national public health information systems, developing closer integration of public health and clinical care, and addressing pervasive concerns about the effects of information technology on confidentiality and privacy.

One goal of public health informatics is ensuring the capacity to assess community problems in a comprehensive manner through the development of integrated nationwide public health data systems. This will require a clear definition of public health data needs and the sources of these data, consensus on data and communication standards—to facilitate data quality, comparability, and exchange—with policies to support data sharing and mechanisms and tools for accessing and disseminating data and information in a useful manner. Because electronic reporting will increasingly form the basis for surveillance systems, developmental efforts must also address such concerns as unambiguously defining the specific medical conditions that trigger automated data transmissions, working with reporting organizations to ensure that they have appropriate software and electronic communication capabilities, and ensuring that adequate capacity exists for analysis of the increased volumes of public health data that are anticipated.

A second challenge for public health informatics is facilitating the improved exchange of information between public health and clinical care. Much of the data in public health information systems comes from forms that are filled out by hand and later computer-coded. Even where reporting is electronic, initial data entry is typically manual. This results in serious under-reporting of many reportable diseases and conditions.49–52

Data should flow automatically to public health from clinical and laboratory information systems. When these data are appropriately compiled by public health information systems, they should allow rapid and accurate assessments and disease control responses, as well as the formulation of improved clinical guidelines and interventions. Conversely, automated presentation to clinicians of prevention guidelines has been shown to improve clinical care, and there are other ways in which the skills and activities of the public health community (e.g., community outreach) could benefit clinical care. Electronic information sharing and data exchange provide the means by which we can better integrate public health and clinical care activities, but creativity and hard work are needed to take full advantage of these opportunities.

Finally, privacy, confidentiality, and security are pervasive and persistent challenges to progress in public health informatics. Information systems are correctly perceived by the public as being a double-edged sword: Whatever is done to make integrated, comprehensive information more easily available for laudable and worthwhile purposes must of necessity create new opportunities for misuse. Public health often collects extremely sensitive personal medical information that has the potential for tremendous harm if improperly disclosed. Federal legislation that provides a fair and workable balance between individual privacy and the common good is needed to reassure the public and establish legal guidelines for handling sensitive information.

The Health Insurance Portability and Accountability Act (HIPAA) of 1996 will result in both privacy and security standards for all health plans (including Medicare and Medicaid), clearinghouses, and providers who use electronic data. Public health has had an excellent record of information protection in the past; the recently published HIPAA Privacy Rule continues to permit disclosure of protected health information to public health authorities for public health activities.53 Public health agencies should adopt and enforce confidentiality policies that incorporate fair information practices and use state-of-the-art security measures to implement those policies.

To these three specific challenges for public health informatics,1 we can add another challenge, potentially more important (if less concrete) than the rest— to apply information technology in unanticipated ways to reengineer public health and invent new ways to protect and promote community health. If, as we have said, the goal of public health is to promote health and prevent unnecessary disease, injury, and disability and the means are open-ended, we suggest that unexplored and unimagined ways to promote and protect community health using the power of modern information technology still exist. We have briefly outlined and illustrated the complex, multidimensional nature of public health as a discipline; we anticipate working with our clinical informatics colleagues as critical partners in addressing these major public health informatics challenges.

 

If you have read this far with me, that is truly awesome! This was neither trivial nor easy, and it must have been a real slog at times. Nice job!

This part is tailored more for the informatician audience that the article is aimed at. Of course, issues of high-quality and validated information are of concern to us as well, but this part really is aimed at specialists other than ourselves.

But the authors patiently explained their work for this audience of informaticians, and we were able to benefit to some degree from those explanations.

Since we tend to focus on musculoskeletal issues, bearing in mind what we've learned about public health's mission and values, can you think of some populations and some specific conditions or problems where massage, partnered with public health, might productively address those challenges, and help realize the vision of healthy people in healthy communities?

How might such a partnership work?

What could it achieve?

How could we tell if it is effective?

 

 

 

 


Acknowledgments

The authors thank Dr. Dave Erickson and Dr. Joseph Mulinare, of the National Center on Birth Defects and Developmental Disabilities, CDC, for their insights and help with the folic acid case study (including the provision of Figures 4 through 7[triangle][triangle][triangle][triangle]), and Ms. Mary Anne Freedman, of the National Center for Health Statistics, CDC, for information about the vital statistics system.

 

 

 


Notes

This manuscript is based in part on presentations made by the authors at an orientation session entitled “Public Health for Informaticians” at the AMIA 2001 Spring Congress, May 15-17, 2001, in Atlanta, Georgia.
 

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