Part I. A look at population-based medical care

Part I. A Look at Population-Based Medical Care

Abstract.-Recent trends toward managed health care have generated interest in developing strategies to manage the health care of a population as a whole. Population-based medicine places the individual patient within the context of the larger community, which is composed of both sick and well individuals; when viewed in these terms, only a small proportion of the people who consult a primary care physician are at risk for substantial morbidity. However, the physician serves as the central figure for delivering populationbased health care to the entire community. Many strategies for population-based care contain the following 4 basic elements: 1. Identifying the health and disease states that are likely to be responsive to population-based care, 2. Applying principles of epidemiology to define the population-of-interest, 3. Assembling a multidisciplinary team, and 4. Building information systems to support ongoing suveillance of population-based care. To date, most of the published examples of population-based management have been conducted in managed care environments, but population-based management may also be used by a single physician practice or a small group practice. Programs aimed at health promotion or disease prevention are among the easiest to implement. By examining the results of an entire population with a given condition, physicians and their teams may begin to identify ways to improve the overall delivery of care, either by establishing new procedures or improving old ones. DM.

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In Brief The majority of primary care physicians provide medical care based on the unique histories of their patients and their individual encounters with those patients. However, recent trends toward managed care have generated new interest in treating patients with similar conditions as a group. As illustrated by the Kerr White model, population-based medicine places primary, secondary, and tertiary medical care within the context of the community as a whole. While only a small proportion of individuals in the community are at risk for hospitalization or specialized care, the primary care physician is in a critical position between the community at large and the health care delivery system. Because this is true, the primary care physician has an excellent opportunity to practice population-based care. Most population-based care strategies are made up of 4 basic steps: 1. Identifying the health and disease states that are likely to be responsive to population-based care. These conditions are usually treated according to a set of commonly accepted practice guidelines, and they respond to clearly defined, effective interventions that may be targeted at small subpopulations. 2. Applying principles of epidemiology to define the populationof-interest. Such populations may include patients in a certain practice panel or those who have had office visits in the past 2 years. The patient populations may then be further stratified according to risk factors of the selected condition (eg, age, gender, family history, diagnosis). Health care utilization records, such as hospitalizations, pharmacy records, and laboratory records may be helpful in defining the population. 3. Assembling a multidisciplinary team. Input from multiple clinical providers (eg, specialists, nurses, allied health professionals), as well as from the administrative staff, is an essential element of population-based care. 4. Building information systems to support ongoing surveillance of population-based care. Population-based care needs its own set of information systems to store, track, and monitor patient outcomes. The literature provides several examples of successful populationbased care programs in primary care settings: Example 1: Population-based health promotion screening activities. In this example, the effectiveness of telephone call or postcard reminder systems for increasing 354

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influenza vaccination or mammography rates is shown. Example 2: Population-based care for people with diabetes. This example presents a brief review of the Group Health Cooperative of Puget Sound’s organization-wide diabetes program. which is patterned after the British model of mini-clinics. Example 3: Population-based care for children with asthma. Here a brief review of the Harvard Pilgrim Health Care Central Pediatric Asthma Program, a multitiered disease management strategy, is given. Example 4: Managing high-risk elderly populations. This example gives a brief review of the high-risk elderly initiatives sponsored by the Robert Wood Johnson Foundation. The majority of published population-based care initiatives to date have been conducted in large managed care environments that have the resources to support academic research studies. However, populationbased medicine may be conducted on a much smaller scale, in the individual or group practice setting. To conduct a small study, the physician(s) and the team would first characterize the patient population and divide it into groups according to the conditions or illnesses being targeted for intervention. This may be accomplished on a rolling basis at the time of the patient’s office visit via a quick audit of medical records, or by a more sophisticated query of the electronic billing system. Once the subpopulation of patients has been identified and a separate registry of names and addresses established, this smaller registry may be used to send reminder cards for health maintenance (eg. mammography. diabetic eye care referrals). Patient responses may also be tracked on the same registry. On both large and small scales, population-based care is beginning to emerge as an important strategy for effective health care delivery.

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Kevin Weiss is associate professor of internal medicine at

the RushPrimary Care Institute, Rush-Presbyterian-St. Luke’s Medical Center, Chicago, III. Dr. Weiss conducts collaborative health services research projects involving primary care oriented information systems development, outcomes measurement, and quality improvement. He is currently the principal investigator for a large, multisite, randomized, and controlled cost-effectiveness study of national guidelines for the treatment of asthma in pediatric populations.

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Part I. A Look at Population-Based Medical Care

In clinical practice, most primary care physicians focus on providing clinical care that is responsive to the individual patient’s needs, based on experiences gained from individual encounters with that patient. However, recent trends toward managed health care in the US have generated new interest in developing strategies to optimally manage not only individual patients but large populations of health care consumers as well.’ The purpose of the following section is to explore the issues that define population-based medical care. The discussion will begin with the Kerr White concepts that define individual medical care within the context of a larger community practice. This is followed by a description of the essential elements that are beginning to define population-based strategies. This article will then explore some successful applications of population-based medical care in the US and conclude with some suggestions for primary care providers about how to begin to implement populationbased care in their own practices.

The Kerr White

Model

of Population-Based

Medicine

The core concepts of population-based medicine can be traced to the early practices of public health and the beginnings of the field of epidemiology. However, much of the contemporary view of population-based medicine in the US came to light in the 1960s through the observations of Kerr White et al. White examined the ecology of a medical practice and, though a series of manuscripts, built a model for understanding the role of the primary care physician in relation to the health care needs of the surrounding community. The model places primary, secondary, and tertiary care within the context of the community.” At the core of White’s observations lie the basic concepts of population-based care. As seen in Figure 1, the patients treated by the primary care physician are viewed as a subset of a larger population-at-risk within the communiDM,

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l,OOOtAdull

populatiia1ris.k

Aduns reputing one or more illnesws per month

,A

ar injuries

Adults consuntng a ‘physician one or more times per month

Adunpatients

10B

admltted g,~hospitalpWOtMh Adult pstlmts referred IO 5 snolhec physician per month Adun petlenl referred to a 1 univefsii mediil center perFIG.

1. Monthly

and medical

prevelance

centers

estimates

in the provision

of illness of medical

in the community

and the roles

of physicians,

hospitals,

care.

ty. Similarly, only a small proportion of the patients who consult the primary care physician are at risk for substantial morbidity, as measured by the need for hospitalization or a referral to a specialized care physician. In simplest terms, the Kerr White model demonstrates that the physician is a central figure for the delivery of population-based care within the community.

Population-Based Management

Care Versus Disease State

No agreement has been reached about what to call the type of care described by the Kerr White model. In the literature, the terms community-oriented primary care3 and population-based care are most often used.4 More recently, disease state management has become a fashionable way to describe this approach to care.5T6 Throughout this article, the term population-based medicine will refer to the broadest aspects of community medical care, from primary prevention through tertiary care; the term disease state management (DSM) will be used to describe population-based care for specific diagnoses. DSM could be considered the subset of population-based care that focus358

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es on disease control strategies and interventions of secondary prevention, as it usually excludes interventions aimed at primary prevention.

Elements of Population-Based

Care Strategies

There are 4 basic elements of population-based care strategies: 1. Identifying the health and disease states that are likely to be responsive to population-based care, 2. Applying principles of epidemiology to define the populationof-interest, 3. Assembling a multidisciplinary team, and 4. Building information systems to support ongoing surveillance of population-based care. The next sections of this article will further describe each of these 4 elements. Identifying

he

Health

and

Disease

Responsive

to Population-Based

States That Are Likely to Be

Care

It is important to consider which health and disease states might best be managed by a population-based approach. While there are no comprehensive reviews or clear references for identifying conditions that might benefit from a population-based approach rather than an individualized care approach, the field of preventive medicine provides the foundation for such thought as a result of widely used practice guidelines. Practice guidelines for health promotion and disease prevention and treatment are promoted by a number of organizations, such as the US Preventive Services Task Force,7 the American College of Physicians.x the US Agency for Health Care Policy and Research,9 and the Canadian Task Force on the Periodic Health Examination. lo Through these agencies. there are guidelines available for a plethora of diseases and conditions. Some of the important aspects that define whether a chronic disease might be amenable to population-based management include: A set of commonly accepted practice guidelines. As mentioned above, one of the starting points for any population-based intervention strategy is a clear body of evidence-based literature that has been codified and standardized. Practice guidelines for a particular disease or condition may be developed anew by each physician by conducting a search of the literature for a given topic, synthesizing the information that is found into meaningful pieces. and then giving it a rating based on the evidence of scientific and clinical merit. However. this process is extremely l

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time-consuming. Adopting a predefined set of guidelines allows more time for intervention and outcomes analysis. Effective intervention strategies to implement for subpopulations. Another important aspect to consider when choosing a topic for population-based care is the presence or absence of clearly defined intervention strategies. Often the most effective strategies target small subpopulations of patients with a given health condition or disease. Based on the aforementioned criteria, diseases and conditions that are good candidates for treatment by population-based medicine, DSM, or both include diabetes,11,12 chronic heart failure,12-14 asthma,15 hypertension,5,6 and possibly arthritis.5,6 l

Applying

Principles

of Epidemiology

to Define

the fopulation-of

Interest Once a condition that may be responsive to population-based care has been identified, the next step in the population-based care strategy is to define the population-of-interest, which is made up of people that are both at risk for morbidity and amenable to intervention. For many primary care physicians, this is perhaps the most difficult issue in population-based care. Most physicians can accurately recount their productivity according to the number of patients they saw per day, week, or year. However, of the few physicians who can provide an accurate count of the number of patients in their practice, even fewer can provide an accurate demographic description of their patient populations (eg, number of patients with diabetes, number of female patients over age 50). An accurate characterization of the patient population is at the core of any population-based management activity. For example, populationbased management of childhood vaccinations requires knowledge of how many children in the practice are in the age range to receive those vaccinations. Cancer screening requires identifying patients of a certain age or gender or whose family history puts them at a higher risk for particular cancers. A population-based approach to medical care only seems logical if it can be directed toward a defined subpopulation for targeted intervention. Rational methods for subpopulation identification and stratification must be employed. Examples of categories of patient subpopulations include “patients who have visited a primary care office within a 2 year period” and “all patients currently active under a single capitation contract.” 360

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Salaried physicians in staff model HMOs might view their population as a “panel” of active, capitated enrollees. Depending on what the means of the planned intervention are, the subpopulations may then be differentiated according to various risk factors. For example, it would be appropriate to target patients of a specific age and gender when scheduling cancer screenings. Patient populations may also be divided into groups in other ways. Patients can be grouped together if they have been diagnosed with a chronic disease such as diabetes or asthma; if they have known risk factors such as history of smoking; or if they are of a functional status that qualities them for interventions involving home health services. There are a number of methods that may be used to identify and further stratify subpopulations of patients. For example, patients with diabetes might be identified by pulling the records of all patients with a certain diagnostic coding. Hospitalizations, pharmacotherapy, and laboratory records are also helpful, both individually and in combination, for defining a population-at-risk. For example, a diabetes disease management pro gram might target a subpopulation of patients with diagnoses of diabetes that show evidence of an elevated glycated hemoglobin. Similarly, a population-based asthma care program might focus on people with asthma who have had a recent hospitalization.‘” Assembling

a Multidisciplinary

Team

The third element of population-based care is the establishment of an appropriate multidisciplinary team. 11.t3 Input from a team of several different types of clinical providers (primary care physicians, specialty physicians, nurses, and other allied health professionals) is important-if not essential-to achieve optimal outcomes. Disease management programs for chronic illnesses often benefit from the input of physicians practicing the relevant subspecialties. Nurses may often conduct the patient education for the population-at-risk. through either individual contacts or group sessions. In addition, most teams require administrative support, especially to assist in identifying the correct population. In a small practice, this administrative support might consist of a clerical assistant to conduct chart reviews or a receptionist to help obtain survey information from patients. In larger group practices or health care organizations, the administrative support may come from the claims department or the office of medical records. DM,

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RNIPCP consultation, then central c ase management team

Patient visit to Central review, case analysis Health Ce based RN and PCP csiwltati Pt education,

treatment plan and referral to local allergist if indicated

FIG. 2. A tiered Health

approach

to population-based

asthma

core at the Central

Division

of Harvard

Pilgrim

Care.

Building

Information

of Population-Based

Systems

to Support

Ongoing

Surveillance

Care

The fourth essential element of population-based care is an adequate information system to support population management. For the same reasons that individual patient care cannot be achieved in a physician’s office without an effective medical records system, a population-based approach to care requires its own information system. This system is used to identify and stratify subpopulations and track and monitor outcomes. Methods for storing and tracking patient information can vary dramatically, ranging from simple paper and pen registries l&l7 to state-of-the-art electronic medical record tracking systems. *8,‘9

Successful Examples

Disease State Management

Strategies:

The following section provides several examples of successful published efforts in the area of population-based management/DSM programs in primary care. The first example describes efforts in the area of health promotion screening. The second example describes successful strategies used by Group Health Cooperative of Puget Sound in the population-based management of diabetes. Example 3 describes population-based management of asthma at Harvard Pilgrim Health Care in Boston. Example 4 illustrates population-based management of the high-risk elderly, a special population identified not by a single disease state, but rather by the multidimensional health risks and needs that may be involved when caring for these patients. 362

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Example

7, Population-Based

Health

Promotion

Screening

Perhaps the most familiar clinical application of population-based health care is found in health promotion and disease prevention activities. Justification for these types of efforts is commonly known and accepted, but it is also readily apparent that physicians often do not successfully conduct health prevention or health promotion activities for their patients.?“-? Population-based approaches to care are being used to improve the rates of successful health promotion.‘3 For example, office-based reminder systems (eg, post cards, telephone calls) have been been shown to significantly increase influenza vaccination rates for high-risk outpatients.‘4 and mailed reminders to patients listed in a compute1 database have been used to improve rates of compliance to fecal occult blood testing or mammography.” Example

2. Population-Based

Care for People

With Diabetes

Diabetes affects millions of people, and its cost exceeds billions in US health care expenditures each year.‘” With demonstrated efticacy of tight metabolic control on positive clinical outcomesZ7 and methods for easily identifying populations with this condition. diabetes mellitus represents an important chronic condition that should be of high interest to those physicians looking to implement successful population-based management strategies. The first reports of experiments in population-based diabetes care appeared in the UK in the ~%OS.‘~~‘~In the US, the Group Health Cooperative of Puget Sound has been conducting one of the most notable efforts in population-based diabetes care. ” Group Health’s diabetes program is part of a larger organization-wide initiative in clinical quality improvement. Elements of the diabetes program include adopting changes in the patterns of routine clinic visits for diabetes to reflect the British model of the diabetes mini-clinics; developing and distributing practice-specific diabetes registries either on paper or computer disk; establishing professional education programs for physicians and nurses; and establishing multidisciplinary teams of local experts to support the primary care physicians who are treating diabetes. While the outcome evaluation of this diabetes program is not yet complete, the program is reported to be well received by both the clinical providers and the patient community. Example

3. Population-Based

Care for Children

With Asthma

Asthma is one of the most common chronic health conditions in the US. affecting over I2 million people and costing over $6 billion to treat annuDM,

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ally.30,31 Since 1991, asthma care in the US has benefited from a set of well accepted national practice guidelines developed by the National Asthma Education and Prevention Program of the National Heart, Lung, and Blood Institute of the National Institutes of Health.32,33 In addition to these guidelines, there are a number of published reports that explore acceptable methods for defining asthma subpopulations at risk. Most of these methods stratify asthma populations based on either utilization of health care facilities (eg, hospitalizations, emergency visits),34 utilization of pharmacotherapy (eg, prescriptions for inhaled corticosteroids or beta2-agonists), 35 or some combination of the two.36 While lately there appears to be much interest in developing DSM programs for asthma care, there is little published information describing successful programs in this area. One apparently successful populationbased asthma management program was conducted at Harvard Pilgrim Health Care in Boston.36337 Harvard Pilgrim initiated their asthma disease management program within the staff model portion of their managed health plan (the Health Center’s Division). This population-based program evolved over time. It began as an Asthma Outreach Program to identify and target services for children with severe asthma. Later, the outreach effort evolved into a multitiered disease management strategy called the Central Pediatric Asthma Program (CPAP). Patients enrolled in CPAP receive coordinated asthma care from primary care physicians, asthma specialists, and asthma nurses. As seen in Figure 2, the outer tier of care is delivered by an office-based registered nurse and includes primary care physician consultation, patient education, and referral to local allergists as needed. The middle tier of patients receives more intensive intervention from a central case management team. For each patient in this tier, the team makes an evaluation and provides recommendations to the primary care provider. For children with severe asthma, tier 3 care involves an in-depth case review and a treatment plan conducted by a central team of asthma physicians and asthma nurse specialists. Example

4. Managing

Case of Population-Based

High-Risk

Elderly

Populations:

A Special

Management

The previous examples focus on population-based care strategies that target specific health conditions or disease states. However, there is also an opportunity to use population-based management for people whose risk is defined by age rather than by a single disease. It is well known that older adults are at a higher risk for poor health than are younger populations. Also, older adults who are ill often have 364

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FIG. 3. The “inverted

pyramid”

of case finding

and assessment.

several chronic health problems. In the US, people over 65 years account for a disproportionate share of the total health care expenditures. As a result of both the burden of illness and the high costs of care associated with this population, the Health Care Financing Administration has begun to explore the value of high-risk screening and interventions for Medicare populations enrolled in capitate health plans. This new initiative is an example of one of the most current uses of population-based management. The Robert Wood Johnson Foundation has been very supportive of developing population-based care of the high-risk elderly.“* One of the Robert Wood Johnson Foundation sponsored programs in populationbased care is schematically represented in Figure 3. The pyramid in this figure represents the total elderly population for a physician or a health plan, The first step in population-based care for this population is to screen for high risk. For many managed health care plans, screening has become commonplace, in part facilitated by using one of the available validated survey instruments- 39,4” The screening is used to identify the subpopulations of elderly who might best benefit from targeted health care interventions. For the subpopulation of the elderly that is determined to be at risk, a second “case finding” interview is conducted. Case finding assessments identify risk across 8 health care domains: cognitive function, diagnoses or medical conditions, medications, health care access, functional status, social situation, nutrition, and emotional function. This full population assessment (screening and case finding interviews) narrows the subpopulation-at-risk to approximately 5% to 15% of the total elderly population and focuses case management interventions to very specific health care domains. DM,

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The targeted interventions for elderly populations at risk may be related to disease prevention and health promotion (eg, vaccinations or cancer screening) or DSM (eg, diabetes or arthritis care). Often, the screening and case findings identify multiple social environmental and health care needs. When the social environment (eg, the availability of family member caregivers) is a factor, the geriatric literature has described comprehensive follow-up strategies that involve multidisciplinary health care teams.41-43

Building Population-Based Care Setting

Medical

Care in the Primary

Most of the published examples of population-based management describe large population studies in managed care environments. This is primarily due to the resource-intensive efforts required to conduct such scholarly research studies. However, smaller and more modest efforts of population-based management can be implemented even in the context of a single physician practice or small group practice. The population-based approach to care requires that the physician or group practice adequately characterize the essential demographics of its patient population and then develop registries of patients with conditions or chronic illnesses for which the practice would like to initiate DSM or population-based management programs. Among the easiest programs are those aimed at health promotion or disease prevention. The first step would be to record the names and addresses of all persons in the practice who meet certain age and gender criteria. This registry of individuals could be developed by recording the names of eligible patients at the time of their office visit, or patients could be identified by means of a quick audit of the practice’s medical records. Alternatively, many electronic billing systems will include simple demographics and can be queried for a list of names according to certain age and gender criteria. Once the registry is developed, it is easy to send reminder cards for routine health maintenance. Tracking patient responses is quite simple and well proven as a population-based care strategy. 16,24 A little more ambitious strategy for chronic illness management might include registering diabetic patients on a rolling basis at the time of their next office visit. Patients would complete a short questionnaire of 3 to 5 items related to essential diabetes care practices, such as the date of their last diabetic retinal exam or foot exam, or a self-reported confidence their knowledge of the American Diabetes Association diet. Based on these findings, physicians can then work with the staff of their clinics to 366

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improve patient referrals for diabetes eye and foot care and perhaps identify a small number of patients that might benefit from a group education session on diabetes nutrition. These simple strategies can also be applied to other chronic conditions, such as asthma or congestive heart failure.

Conclusion Increases in capitate managed care within US health systems is resulting in an increased awareness of the need for and possible benefits of population-based approaches to health care. The essential elements that define successful population-based management strategies are beginning to emerge. Also, there is an increasing body of literature that reflects successful efforts in population-based management for both health promotion and disease prevention, as well as management of chronic illnesses like diabetes and asthma and the comprehensive management of high-risk populations like the elderly. As a result, it seems very likely that primary care practices in the next decade will increasingly require physicians to have skills in population-based health care management. REFERENCES I. Wagner EH, Austin DT, Von Korff M. Organizing care for patients with chronic illness. Milbank Q 1996;74:5 I I-33. 2. White KL, Williams TF. Greenberg BG. The ecology of medical care. N Engl J Med I961 ;265:885-92. 3. Nutting PA. Community oriented primary care: from principles to practice. Rockville. MD: Health Resource and Services Administration: 1987. Office of Primary Care Studies Publication HRS-S-PE-86. I 4. Greenlick MR. Educating physicians for population-based clinical practice. JAMA 1992:276: 1645-8. 5_ Harris JM. Disease management: new wine in new bottles? Ann Intern Med 1996;124:838-42. 6. Epstein RS, Sherwood LM. From outcomes research to disease management: a guide for the perplexed. Ann Intern Med 1996; 124:832-7. I. USPSTF (US Preventive Services Task Force). Guide to clinical preventive services: an assessment of the eifectiveness of 169 interventions. Baltimore: Williams & Wilkins, 1989. 8. Medical Practice Committee. American College of Physicians: periodic health examination: a guide for designing individual preventive health care in the asymptomatic patient. Ann Intern Med I98 I ;95:729-32. 9. The Agency for Health Care Policy and Research. Guidelines and medical outcomes. Available at: http://www.ahcpr.gov:%Yguide/ IO. Woolf SH, Battista RN, Anderson GM, Logan AC. Wang E. Assessing the effectiveness of preventive maneuvers: analytic principles and systematic methods in reviewing evidence and developing clinical practice recommendations. A report by the Canadian Task Force on the Periodic Health Examination. J Clin Epidemiol 1990:43:89 I -YO5. DM, August 1998

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11. Wagner EH. Population-based management of diabetes care. Patient Educ Coun 1995;26:225-30. 12. Gibbins RL, Saunders J. Develop diabetic care in general practice. BMJ 1988;297: 187-9. 13. Rich MW, Beckham RN, Wittenberg RN, Leven CH, Freedland KE, Camey RM. A multidisciplinary intervention to prevent the readmission of elderly patients with congestive heart failure. N Engl J Med 1995;333: 1190-5. 14. BrasslMynderse NJ. Disease management for chronic congestive heart failure. J Car diovasc Nurs 1996; 1154-62. 1.5. 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. 16. Turner RB, Waivers LE, O’Brien K. The effect of patient-carried reminder cards on the performance of health maintenance measures. Arch Intern Med 1990;150:645-7. 17. Dickey LL, Petitti D. A patient-held minirecord to promote adult preventive care. J Fam Pratt 1992;34:457-63. 18. Weingarten MA, Bazel D, Shannon HS. Computerized protocol for preventive medicine, a controlled self audit in family practice. Fam Pratt 1989;6: 120-4. 19. 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. 20. Williams WW, Hickson MA, Kane MA, Kendal MP, Spika JS, Hinman AR. Immunization policies and vaccine coverage among adults: the risk for missed opportunities. Ann Intern Med 1988;108:616-25. 21. Woo B, Woo B, Cook EF, Weisberg M, Goldman L. Screening procedures in the asymptomatic adult: comparison of physicians’ recommendations, patients’ desires, published guidelines, and actual practices. JAMA 1985;254: 1480-4. 22. Use of a data-based approach by a health maintenance organization to identify and address physician barriers to pediatric vaccination-California 1995. MMWR 1996;45: 188-93. 23. Schoenbaum SC. Implementation of preventive services in an HMO practice. J Gen Intern Med 1990;5(suppl): 123-7. 24. Merkel PA, Caputo CG. Evaluation of a simple office-based strategy for increasing influenza vaccine administration and the effect of differing reimbursement plans on the patient acceptance rate. J Gen Intern Med 1994;9:679-83. 25. Litzelman DK, Dittus RS, Miller ME, Tiemey WM. Requiring physicians to respond to computerized reminders improves their compliance with preventive care protocols. J Gen Intern Med 1993;8:31 l-7. 26. National Diabetes Data Group. Diabetes in America. 2nd ed. National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases; 1995. Publication 95-1468. 27. The Diabetes Control and Complications Trial Research Group. The effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin-dependent diabetes mellitus. N Engl J Med 1993;329:977-86. 28. Thorn PA, Watkins PJ. Organization of diabetic care. BMJ 1982;285:787-9. 29. Farmer A, Coulter A. Organization of care for diabetic patients in general practice: influence on hospital admissions. Br J Gen Pratt 1990;40:56-8. 368

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30. Collins JG. Prevalence of selected chronic conditions: United States. 199% 1992. Vital Health Stat IO 1997;Jan: l-89. 3 I. Weiss KB, Gergen PJ, Hodgson TA. An economic evaluation of asthma in the United States. N Engl J Med 1992;326%62-6. 32. National Asthma Education and Prevention Forum. Expert panel report: guidelines fat the diagnosis and management of asthma. Bethesda (MD): National Institutes 01 Health; 199 I. Publication 9 I-3042. 33. National Asthma Education and Prevention Forum. Expert pane1 report 2: guidelines for the diagnosis and management of asthma. National Institutes of Health; 1997. Publication 97-405 I. 34. Vollmer WM. Osborne ML. Buist AS. Temporal trends in hospital-based episodes of asthma care in a health maintenance organization. Am Rev Respir Dis 1993:147: 347-53. 35. Stemple DA, Hedblom ED, Durcanin-Robbins JF. Sturm LL. Use of a pharmacy and medical claims database to document cost centers for 1993 annual asthma expenditures. Arch Fam Med 1996;5:36-40. 36. Greineder DK, Loane KB, Parks P. Reduction in resource utilization by an asthma outreach program. Arch Pediatr Adolesc Med 1995;149:415-20. 37. Greineder DK. The adaptation of asthma practice guidelines into clinical care: the Harvard Pilgrim Health Care experience. J Outcomes Management 1996;3:4-9. 38. RWJ Foundation. Planning care for high-risk Medicare HMO members. chronic care initiatives in HMOs. Washington (DC): The Foundation; 1997. 39. Boult C, Pacala JT, Boult LB. Targeting elders for geriatric evaluation and management: reliability, validity, and practicality of a questionnaire. Aging (Milano) 1995;7:159-64.

Pacala JT, Boult C, Reed RL, Aliberti E. Predictive validity of the Pm instrument among older recipients of managed care. J Am Geriatr Sot 1997;45:6 14-7. 41. Cefalu CA, Kaslow LD, Mims B, Simpson S. Follow-up of comprehensive geriatric assessment in a family medicine residency clinic. J Am Board Fam Pratt 1995;8:263-9. 42. Shah PN, Maly RC, Frank JC, Hirsch SH, Reuben DB. Managing geriatric syndromes: what geriatric assessment teams recommend, what primary care physicians implement, what patients adhere to. J Am Geriatr Sot 1997;45:413-9. 43. Engelhardt JB, Toseland RW, O’Donnell JC, Richie JT, Jue D. Banks S. The etiectivenexs and efficiency of outpatient geriatric evaluation and management. J Am Get-inn Sot 1996;44:847-56. 40.

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