Population-Based Medicine:

AN Overview and Strategies for Implementation

 

Richard M. Carpiano, M.A.

 

 

INTRODUCTION

 

            With the focus towards managed care, health systems in the United States have begun to adopt strategies that address the health care of whole populations, rather than just individual patients.  The movement towards population-based medicine represents a community-based strategy for disease management and health promotion, moving away from traditional physician-patient-centered medicine.  This new approach places the individual within the context of the larger community that is composed of both sick and healthy patients.1  As a result, only a small number of people who consult a primary care physician are actually at risk for significant morbidity.1  While the physician remains the core person for delivering health care to the community at-large, population-based medicine promises a better use of resources and a more integrated systems approach to health care delivery.1, 2  Although the term “population-based medicine” has become quite a buzzword within the health care field, confusion still exists regarding what it actually means and how it can be used.3  The present chapter will explore the theories behind population-based medicine while detailing the strategies for using this approach.  In addition, the applications and implications of its implementation will be discussed.  

 


CONCEPTS AND BACKGROUND

Core Ideas

            The population-based medicine approach involves: (1) assessment of the health needs of a specific population, (2) implementation and evaluation of interventions designed to improve the health of that population, and (3) providing care for individual patients in the context of the culture, health status, and health needs of the populations of which that patient is a member.4  Upon initial examination of this definition, it is rather easy to think of the terms “population-based medicine” and “public health” as being synonymous.  However, while both areas are linked to epidemiologic foundations and applications, a difference exists in their respective overall goals.  The majority of population-based medicine programs is generally limited to medical (rather than social or hygienic) interventions and is confined to individuals who have their health care financed by particular payers.2  Generally, these programs consist of 4 basic steps: 

1.      Identifying the health and disease states that can be responsive to population-based care.

2.      Applying the principles of epidemiology to define the target population.

3.      Assembling a multidisciplinary team to gather input from multiple clinical providers of various levels (e.g., physicians, nurses, allied health providers) and administrative personnel.

4.      Creating information systems to support on-going surveillance of population-based care that will store, track, and monitor patient outcomes.1  

Care for the individual patient starts with one or more health risks before any care is sought and finishes with one or more outcomes after receiving care.2  The total amount of individual risks, demands, diseases, and outcomes of people within a population can be systematically addressed through interventions designed to initiate positive change in a population’s health and lower overall costs of the health care itself.2

Historical Background

While the central foundations of population-based medicine can be traced to the early practices of public health and the beginnings of epidemiology, Abraham Flexner was one of the first people in the medical profession in the 20th century to argue that the physician’s function was “fast becoming social and preventive, rather than individual and curative.”5  Despite this call for an evolving role, similar calls were still being made even in the 1980s, indicating that little had been accomplished in developing this function.6  Comparatively, physician training in Western Europe had been influenced by population-based trends initiated by innovators such as Rudolph Virchow, who proposed in the mid-1800s that a relationship existed between disease and the environmental circumstances in which it occurred.6  In the face of this resistance to changing the role of the US physician, research on the ecology of the medical practice by Kerr White et al. in the 1960s led to the contemporary US approach to population-based medicine.  White’s research resulted in a model explaining the primary care physician’s role in relation to the health care needs of the community.  His model placed primary, secondary, and tertiary care within the context of the community.1           

 

Doing Population-Based Medicine:

A Step-By-Step Approach

 

            In reviewing the literature on the implementation of population-based medicine, one cannot help but notice that most of the initiatives are conducted in large managed care environments.  However, this approach is not limited to such an environment and may also be applied in the individual or group practice setting.  So how can an individual or group medical practice “do” population-based medicine?  Putting theories of population-based medicine into practice involves the use of several systematic steps.  Employing a 5-step approach, Rust has outlined a particularly useful guide for implementing a population-based approach out of a traditional physician-patient model of primary care practice.7

The first step requires the use of epidemiological tools to define a particular patient population.7  This involves identifying risk factors that are responsible for significant levels of morbidity and mortality in patients; diagnoses common to patient subgroups of particular age, ethnicity, and gender; and health and disease states that are likely to be responsive to population-based care.  Patient records can be used to identify populations, patterns of risk factors, and frequencies of particular diagnoses and complaints.1

The second step is comprised of using a systems approach to track patients and assess outcomes.7  This includes the implementation of information technology to collect aggregate data on the patient population.  Examples of the application of information systems include using databases to determine what patients have family histories of cancer and generating a list of patients who need to be sent reminder letters to receive their flu shots.7

The third step requires the application of evidence-based medicine across an entire patient population instead of one patient at a time.7  This step involves identifying the percentage of patients who have treatment regimens that are less effective than current protocols or national guidelines and offering appropriate treatment options.7

Using health education is the fourth step.7  The practice should consider using all available tools, including appropriate printed brochures and self-instructional materials, audiovisual media, and recommending behavior modification groups.  Along with these materials, there is a need to consider how interactions with the patients’ families can be used to monitor and promote healthier lifestyles, what sociocultural values and beliefs underlie health behaviors in the population, and how alliances with the community can be arranged to prevent illness and promote health (e.g., reducing STD rates in a population).7 

The fifth and final step involves the team approach.7  Instead of handling patients alone, physicians need to coordinate patient care and health education with nurses, allied health professionals (e.g., nutritionists, certified health educators), social workers, and even behavioral scientists.  An integrated, interdependent group of providers (with a clearly delineated division of labor to facilitate transfer of care) needs to exist in providing the best possible care for the population.

Although Rust ends his plan at step 5, a sixth step, nevertheless, must be considered: continued monitoring and evaluation of programs and populations in order to be responsive to the needs of the population.  This step can be executed in several ways:

1.      Subjective impressions of the physicians or patient population

2.      Extrapolation of data from secondary data sources (e.g., data collected from local agencies)

3.      Data specific to the population (e.g., pre- and post-test data from a particular intervention or patient subgroup)

4.      Assessment of program impact (both positive and negative) with methods specific to objectives of interventions for specific target populations.8 

Applications and debates

            Many opportunities exist for applying population-based medicine strategies.  Nevertheless, like the traditional physician-patient-centered model, the population-based approach is far from being a perfect approach to health care.  While it does offer many potential improvements in health care delivery and cost containment, disadvantages exist as well.  This section will explore some of the applications and debates of population-based medicine.

Applications

There is no shortage of examples in the literature of population-based medicine principles being put into action.  Examples of these applications include:

1.      Diabetes care9

2.      Asthma10

3.      Vaccinations11, 12

4.      Cancer control13

5.      Gastrointestinal ulcers14

6.      Congestive heart failure15

7.      Maternal and child health services16

8.      Monitoring adverse outcomes of medical care.17

Among US health plans, Kaiser Permanente has extended its emphasis on population-based care through its national development of “care management”—an approach that groups members into disease-specific populations where prevention and health maintenance are the goals.3  Services are organized in a manner that allows for physician care when needed but also strongly focuses on patient education, thereby teaching patients how to care for themselves and when to contact the HMO.3   

However, the US is not the only country that has applied principles of population-based medicine to their health system.  Canadian researchers have designed a population-based health information system from administrative data collected for Canada’s national health insurance plan.18  This system has allowed decision-makers to make cross-regional comparisons of residents’ health status, socioeconomic risk factors, and health care utilization in order to assess issues such as high-risk populations and which groups need more physician services.18

While many applications of population-based medicine have focused on primary care, Emergency Medicine has also been identified to be an area for which applications of population-based medicine have great potential.  Emergency departments and emergency physicians provide a number of functions (i.e. care for life-threatening conditions and for those who do not have access to primary care) that provide opportunities for this approach of identifying unmet community needs and designing potential ways to address them, both within the emergency department itself and the overall health system.19  

Another facet to consider in the application of population-based medicine is how to incorporate it into physician education.  Attention has been paid to expanding the traditional physician-patient role obligations to include a set of physician-population duties.6  An argument was made for adding three additional components to medical education: (1) economic or resource allocation of medical care, (2) the epidemiologic nature of the new clinical practice, and (3) a focus on members of the population who do not regularly visit physicians or who have needs that the normal context of care does not address.6  Consequently, medical schools do seem to be responding (at least somewhat) to the need to provide training in population-based medicine.  Assessing the extent of population-based medical education, a study of all the US allopathic medical schools reported that while an unexpectedly large number of schools placed students in public health agencies to receive training, overall, schools are not taking full advantage of the potential of public health agencies as teaching sites.20   

Debates

Discussion has been paid to the differences between population-based medicine and community-oriented primary care.21  Population-based medicine (and its implementation by professionals without the use of community involvement) has been compared to its counter approach of community-oriented primary care, which focuses on active community participation.21  A proposed merging of the two approaches may be beneficial because it would combine epidemiological and community development strategies, thereby allowing community members to be collectively involved in health care decisions as well as the health care system itself.21 

Another issue of debate concerns the ethical dilemmas that exist in the provision of population-based care.  Research has proposed that physicians, in providing care, must struggle with the issue of whether to incorporate population-based medicine in making clinical decisions for the individual patient and, therefore, encounter an ethical dilemma.22

Issues of implementing population-based strategies have not escaped debate either.  On the positive side, the premise behind population-based medicine—that properly designed programs would be more efficient than similar efforts that might depend on individual steps taken during numerous physician-patient interactions—has been shown to have merit (i.e. population-based immunization programs have repeatedly demonstrated their ability to save costs).2  However, on the negative side, it may be easy to overestimate the potential benefit of particular programs.  As a result, large amounts of funding may be put into programs where the benefits may not outweigh the set-up costs.2  This point stresses the importance of properly assessing the impact of a particular disease on a population before implementing efforts to address it from a population-based approach, as well as properly evaluating outcomes of programs once they have been implemented.

CONCLUSION

                With the ever-increasing focus on health care cost containment, population-based medicine represents an alternative option to the traditional physician-patient-centered approach in providing the best health services possible for not only the individual patient, but also the community at-large.  The population-based approach has great potential for improving physician care while also focusing on necessary preventive services that can reduce morbidity and mortality within specific populations and potentially reduce health care utilization.  Additionally, with a team approach to health care, it offers the opportunity for increased continuity of care between physicians and other health care professionals.

Overall, while applying population-based medicine is inherently more complicated than utilizing the traditional physician-patient model of care, in order for the implementation to be effective, a core set of steps needs to be followed: identification of health and disease states for which population-based care may be effective; defining the target population; using a team approach; and creating information systems to support continued surveillance of care and outcomes.  With this framework, a population-based approach to medicine can potentially allow for more complete health care, while still containing costs.

REFERENCES

1.      Weiss K. Part I. A look at population-based medical care. Dis Mon. 1998 Aug;44(8):353-69.

2.      Harris JM Jr. Disease management: new wine in new bottles? Ann Intern Med. 1996 May 1;124(9):838-42.

3.      Dalzell, MD. Just what the devil is population-based care? Managed Care. 1998 Sep; http://www.managedcaremag.com/archiveMC/9809/9809.population.shtml

4.      Association of American Medical Colleges. AAMC contemporary issues in medicine: medical informatics and population health; medical school objectives project report II. Washington, DC: Association of American Medical Colleges, 1998; June.

5.      Flexner A. Medical Education in the United States and Canada. New York, NY:Carnegie Foundation for the Advancement of Teaching; 1910. Bulletin No. 4.

6.      Greenlick MR. Educating physicians for population-based clinical practice. JAMA. 1992;267(12):1645-1648.

7.      Rust G. Population-based medicine for the primary care physician. Hospital Practice (Off Ed). 1997 June 15;32(6):64, 70.

8.      Nutting PA. Population-based family practice: the next challenge of primary care. Journal of Family Practice. 1987;24(1):83-88.

9.      Glasgow RE, Wagner EH, Kaplan RM, Vinicor F, Smith L, Norman J. If diabetes is a public health problem, why not treat it as one?  A population-based approach to chronic illness. Ann Behav Med. 1999 Spring;21(2):159-70.

10.  Hanchak NA, Murray JF, Arkans H, McHugh E, McDermott P, Schlackman N. Improved outcomes of an outpatient pediatric asthma patient management program in an IPA HMO. Am J Managed Care. 1996;2:387-92.

11.  Barton MB, Schoenbaum SC. Improving influenza vaccination performance in an HMO setting: the use of computer-generated reminders and peer comparison feedback. Am J Public Health. 1990;80:534-6.

12.  Mullooly JP, Bennett MD, Hornbrook MC, Barker WH, Williams WW, Patriarca PA, et al. Influenza vaccination programs for elderly persons: cost-effectiveness in a health maintenance organization. Ann Intern Med. 1994;121:947-52.

13.  Ward JE, Young JM, Jelfs P. Population-based cancer control: where is the greatest benefit from proven strategies to ‘regain’ years of life lost prematurely. Aust N Z J Public Health. 1999 Oct;23(5):538-40.

14.  Mason JM, Moayyedi P, Young PJ, Duffett S, Crocombe W, Drummond MF, Axon AT. Population-based and opportunistic screening and eradication of Helicobacter pylori. An analysis using trial baseline data. Leeds H. pylori study group. Int J Technol Assess Health Care. 1999 Fall;15(4):649-60.

15.  Rivo ML. It’s time to start practicing population-based health care. Fam Pract Manag. 1998 Jun;5(6):37-46.

16.  Akukwe C, Nowell AH. Essential strategies for achieving durable population-based maternal and child health services. J R Soc Health. 1999 Mar;119(1):42-9.

17.  Roos NP, Black CD, Roos LL, Tate RB, Carriere KC. A population-based approach to monitoring adverse outcomes of medical care. Med Care. 1995 Feb;33(2):127-38.

18.  Roos NP, Black C, Frohlich N, DeCoster C, Cohen M, Tataryn DJ, et al. Population health and health care use: an information system for policy makers. Milbank Q. 1996;74(1):3-31.

19.  Clancy CM, Eisenberg JM. Emergency medicine in population-based systems of care. Ann Emerg Med. 1997 Dec;30(6):800-3.

20.  Melville SK, Coghlin J, Chen DW, Sampson N. Population-based medical education: linkages between schools of medicine and public health agencies. Acad Med. 1996 Dec;71(12):1350-2.

21.  Henley E, Williams, RL. Is population-based medicine the same as community-oriented primary care? Fam Med. 1999;31(7):501-2.

22.  Kirsner RS, Federman DG. The ethical dilemma of population-based medical decision making. Am J Manag Care. 1998 Nov;4(11):1571-6.