INTRODUCTION i.Overview This report is intended for primary care clinicians: physicians, nurses, nurse practitioners, physician assistants, other allied health professionals, and students. It provides recommendations for clinical practice on preventive interventions-screening tests, counseling interventions, immunizations, and chemoprophylactic regimens-for the prevention of more than 80 target conditions. The patients for whom these services are recommended include asymptomatic individuals of all age groups and risk categories. Thus, the subject matter is relevant to all of the major primary care specialties: family practice, internal medicine, obstetrics-gynecology, and pediatrics. The recommendations in each chapter reflect a standardized review of current scientific evidence and include a summary of published clinical research regarding the clinical effectiveness of each preventive service. Value of Prevention Clinicians have always intuitively understood the value of prevention. Faced daily with the difficult and often unsuccessful task of treating advanced stages of disease, primary care providers have long sought the opportunity to intervene early in the course of disease or even before disease develops. The benefits of incorporating prevention into medical practice have become increasingly apparent over the past 30-40 years, as previously common and debilitating conditions have declined in incidence following the introduction of effective clinical preventive services. Infectious diseases such as poliomyelitis, which once occurred in regular epidemic waves (over 18,300 cases in 1954), have become rare in the U.S. as a result of childhood immunization.<1> Only three cases of paralytic poliomyelitis were reported in the U.S. in 1993, and none was due to endemic wild virus. Before rubella vaccine became available, rubella epidemics occurred regularly in the U.S. every 6-9 years; a 1964 pandemic resulted in over 12 million rubella infections, 11,000 fetal losses and about 20,000 infants born with congenital rubella syndrome.<2,3> The incidence of rubella has decreased 99% since 1969, when the vaccine first became available.<4> Similar trends have occurred with diphtheria, pertussis, and other once-common childhood infectious diseases.<1> Preventive services for the early detection of disease have also been associated with substantial reductions in morbidity and mortality. Age- adjusted mortality from stroke has decreased by more than 50% since 1972, a trend attributed in part to earlier detection and treatment of hypertension.<5-7> Dramatic reductions in the incidence of invasive cervical cancer and in cervical cancer mortality have occurred following the implementation of screening programs using Papanicolaou testing to detect cervical dysplasia.<8> Children with metabolic disorders such as phenylketonuria and congenital hypothyroidism, who once suffered severe irreversible mental retardation, now usually retain normal cognitive function as a result of routine newborn screening and treatment.<9-16> Although immunizations and screening tests remain important preventive services, the most promising role for prevention in current medical practice may lie in changing the personal health behaviors of patients long before clinical disease develops. The importance of this aspect of clinical practice is evident from a growing literature linking some of the leading causes of death in the U.S., such as heart disease, cancer, cerebrovascular disease, chronic obstructive pulmonary disease, unintentional and intentional injuries, and human immunodeficiency virus infection,<17> to a handful of personal health behaviors. Smoking alone contributes to one out of every five deaths in the U.S., including 150,000 deaths annually from cancer, 100,000 from coronary artery disease, 23,000 from cerebrovascular disease, and 85,000 from pulmonary diseases such as chronic obstructive pulmonary disease and pneumonia.<18> Failing to use safety belts and driving while intoxicated are major contributors to motor vehicle injuries, which accounted for 41,000 deaths in 1992.<17> Physical inactivity and dietary factors contribute to coronary atherosclerosis, cancer, diabetes, osteoporosis, and other common diseases.<19-22> High-risk sexual practices increase the risk of unintended pregnancy, sexually transmitted diseases (STDs), and acquired immunodeficiency syndrome.<23,24> Approximately half of all deaths occurring in the U.S. in 1990 may be attributed to external factors such as tobacco, alcohol, and illicit drug use, diet and activity patterns, motor vehicles, and sexual behavior, and are therefore potentially preventable by changes in personal health practices.<25> Barriers to Preventive Care Delivery Although sound clinical reasons exist for emphasizing prevention in medicine, studies have shown that clinicians often fail to provide recommended clinical preventive services.<26-32> This is due to a variety of factors, including inadequate reimbursement for preventive services, fragmentation of health care delivery, and insufficient time with patients to deliver the range of preventive services that are recommended.<33-35> Even when these barriers to implementation are accounted for, however, clinicians fail to perform preventive services as recommended,<28> suggesting that uncertainty among clinicians as to which services should be offered is a factor as well. Part of the uncertainty among clinicians derives from the fact that recommendations come from multiple sources, and these recommendations often differ. Recommendationsa relating to clinical preventive services are issued regularly by government health agencies and expert panels that they sponsor,<5,36-42> medical specialty organizations,<43-50> voluntary associations,<51-53> other professional and scientific organizations,<54,55> and individual experts.<56-59> A second major reason clinicians might be reluctant to perform preventive services is skepticism about their effectiveness. Whether performance of certain preventive interventions can significantly reduce morbidity or mortality from the target condition is often unclear. The relative effectiveness of different preventive services is also unclear, making it difficult for busy clinicians to decide which interventions are most important during a brief patient visit. A broader concern is that some maneuvers can ultimately result in more harm than good. While this concern applies to all clinical practices, it is especially important in relation to preventive services because the individuals who receive these interventions are often healthy. Minor complications or rare adverse effects that would be tolerated in the treatment of a severe illness take on greater importance in the asymptomatic population and require careful evaluation to determine whether benefits exceed risks. This is particularly relevant for screening tests, which benefit only the few individuals who have the disorder but expose all the individuals screened to the risk of adverse effects from the test. Moreover, because recommendations for preventive services such as routine screening often include a large proportion of the population, there are potentially important economic implications. Historical Perspective Uncertainties about the effectiveness of clinical preventive services raise questions about the value of the routine health examination of asymptomatic persons, in which a predetermined battery of tests and physical examination procedures are performed as part of a routine checkup. The annual physical examination of healthy persons was first proposed by the American Medical Association in 1922.<60> For many years after, it was common practice among health professionals to recommend routine physicals and comprehensive laboratory testing as effective preventive medicine. While routine visits with the primary care clinician are important, performing the same interventions on all patients and performing them annually are not the most clinically effective approaches to disease prevention. Rather, both the frequency and the content of the periodic health examination should reflect the unique health risks of the individual patient and the quality of the evidence that specific preventive services are clinically effective. This new approach to the periodic visit was endorsed by the American Medical Association in 1983 in a policy statement that withdrew support for a standard annual physical examination.<61> The individualized periodic health visit should emphasize evidence of clinical effectiveness, and thus increased attention has turned to the collection of reliable data on the effectiveness of specific preventive services. One of the first comprehensive efforts to examine these issues was undertaken by the Canadian government, which in 1976 convened the Canadian Task Force on the Periodic Health Examination (CTFPHE). This expert panel developed explicit criteria to judge the quality of evidence from published clinical research on clinical preventive services, and the panel used uniform decision rules to link the strength of recommendations for or against a given preventive service to the quality of the underlying evidence (see Appendix A). These ratings were intended to provide the clinician with a means of selecting those preventive services supported by the strongest evidence of effectiveness. Using this approach, the CTFPHE examined preventive services for 78 target conditions, releasing its recommendations in a monograph published in 1979.<62> In 1982, the CTFPHE reconvened and applied its methodology to new evidence as it became available, periodically publishing revised recommendations and evaluations of new topics. These were updated and compiled in 1994 in The Canadian Guide to Clinical Preventive Health Care.<63> A similar effort began in the U.S. in 1984 when the Public Health Service commissioned the U.S. Preventive Services Task Force (USPSTF). Like the Canadian panel, this 20-member non-Federal panel was charged with developing recommendations for clinicians on the appropriate use of preventive interventions, based on a systematic review of evidence of clinical effectiveness.<64> A methodology similar to that of the CTFPHE was adopted at the outset of the project. This enabled the U.S. and Canadian panels to collaborate in a binational effort to review evidence and develop recommendations on preventive services. The first USPSTF met regularly between 1984 and 1988 to develop comprehensive recommendations addressing preventive services. The panel members and their scientific support staff reviewed evidence and developed recommendations on preventive services for 60 topic areas affecting patients from infancy to old age, published in 1989 as the Guide to Clinical Preventive Services. The Second U.S. Preventive Services Task Force The USPSTF was reconstituted in 1990 to continue and update these scientific assessments.<65> Its charge has been to evaluate the effectiveness of clinical preventive services that were not previously examined; to reevaluate those that were examined and for which there is new scientific evidence, new technologies that merit consideration, or other reasons to revisit the published recommendations; and to produce this new edition of the Guide, with updated recommendations for the periodic health examination. In addition, a continuing mission of the USPSTF has been to define a research agenda by identifying significant gaps in the literature. The USPSTF has 10 members, comprising two family physicians, two internists, two pediatricians, two obstetrician-gynecologists, and two methodologists. Content experts from academic institutions and Federal agencies also joined the deliberations of the panel on an ad hoc basis. The USPSTF met quarterly between September 1990 and April 1994, with scientific support staff from the Office of Disease Prevention and Health Promotion, Public Health Service, U.S. Department of Health and Human Services, to analyze systematically scientific evidence pertaining to clinical preventive services that had been published since the first edition of the Guide. The USPSTF greatly expanded its collaboration with medical specialty organizations and Federal agencies, and it has continued its close cooperation with the CTFPHE. Designated liaisons from primary care medical specialty societies (American Academy of Family Physicians, American Academy of Pediatrics, American College of Obstetricians and Gynecologists, and American College of Physicians), the agencies of the Public Health Service, and the CTFPHE attended all of the USPSTF meetings, and their respective organizations reviewed all draft recommendations. The USPSTF and the CTFPHE, which has also recently updated its analyses of the scientific evidence and recommendations,<63> shared background papers and draft chapters throughout their updating processes to avoid unnecessary duplication of effort. Seventeen chapters in The Canadian Guide to Clinical Preventive Health Care<63> were based in part on background papers prepared for the USPSTF, and 21 chapters in this edition of the Guide are based in part on papers prepared for the CTFPHE. The USPSTF also collaborated with the American College of Physicians’ Clinical Efficacy Assessment Program (CEAP), which uses a similar evidence- based methodology. A liaison from the USPSTF regularly attended CEAP meetings, and several chapter updates were based on reviews prepared for CEAP. Principal Findings of the U.S. Preventive Services Task Force The review of evidence for the second edition of the Guide to Clinical Preventive Services has produced several important findings. These can be summarized as follows: 1. Interventions that address patients’ personal health practices are vitally important. Effective interventions that address personal health practices are likely to lead to substantial reductions in the incidence and severity of the leading causes of disease and disability in the U.S. Primary prevention as it relates to such risk factors as smoking, physical inactivity, poor nutrition, alcohol and other drug abuse, and inadequate attention to safety precautions holds greater promise for improving overall health than many secondary preventive measures such as routine screening for early disease.<25> Therefore, clinician counseling that leads to improved personal health practices may be more valuable to patients than conventional clinical activities such as diagnostic testing. In the past, the responsibility of the clinician was primarily to treat illnesses; the asymptomatic healthy individual did not need to see the doctor. In addition, personal health behaviors were often not viewed as a legitimate clinical issue. A patient’s use of safety belts would receive less attention from the clinician than the results of a complete blood count (CBC) or a routine chest radiograph. A careful review of the data, however, suggests that different priorities are in order. Motor vehicle injuries affect nearly 3.5 million persons each year in the U.S.;<66> they account for over 40,000 deaths each year.<67> Proper use of safety belts can prevent 40-60% of motor vehicle injuries and deaths.<68-70> In contrast, there is little evidence that performing routine CBCs or chest radiographs improves clinical outcome,<71,72> and these procedures are associated with increased health care expenditures. An important corollary of this finding is that clinicians must assist patients to assume greater responsibility for their own health. In the traditional doctor-patient relationship, the patient adopts a passive role and expects the doctor to assume control of the treatment plan. Whereas the clinician is often the key figure in the treatment of acute illnesses and injuries, the patient is the principal agent in primary prevention that addresses personal health practices. Therefore, one of the initial tasks of the clinician practicing primary prevention is shifting control to the patient. To achieve competence in the task of helping to empower patients and in counseling them to change health-related behaviors, many clinicians will need to develop new skills (see Chapter iv). 2. The clinician and patient should share decision-making. Many preventive services involve important risks or costs that must be balanced against their possible benefits. Because not all patients weigh risks and benefits the same way, clinicians must fully inform patients about the potential consequences of proposed interventions, including the possibility of invasive follow-up procedures, tests, and treatments. Incorporating patient preferences is especially important when the balance of risks and benefits, and therefore the best decision for each patient, depends greatly on the values placed on possible outcomes (e.g., prolonged life vs. substantial morbidity from treatment). Where evidence suggested that patient values were critical to the balance of risks and benefits (e.g., screening for Down syndrome or neural tube defects, hormone prophylaxis in postmenopausal women), the USPSTF specifically recommended patient education and consideration of patient preferences in decision- making rather than a uniform policy for all patients. Shared decision- making also requires explicitly acknowledging areas of uncertainty. Patients must understand not only what is known, but also what is not yet known about the risks and benefits from an intervention, in order to make an informed decision. 3. Clinicians should be selective in ordering tests and providing preventive services. Although certain screening tests, such as blood pressure measurement,<73-75> Papanicolaou smears,<8> and mammography,<76> can be highly effective in reducing morbidity and mortality, the USPSTF found that many others are of unproven effectiveness. Screening tests with inadequate specificity often produce large numbers of false-positive results, especially when performed routinely without regard to risk factors; these results might lead to unnecessary and potentially harmful diagnostic testing and treatment. Recognizing the cardinal importance of avoiding harm to asymptomatic patients (“primum non nocere”), the USPSTF recommended against a number of screening tests (e.g., serum tumor markers for the early detection of pancreatic or ovarian cancer) that had unproven benefit but likely downstream harms. Many tests that lack evidence that they improve clinical outcome, such as home uterine activity monitoring, have the additional disadvantage of being expensive, especially when performed on large numbers of persons in the population. In a few instances, the USPSTF found evidence that certain screening tests that have been widely used in the past (e.g., routine chest x-ray to screen for lung cancer, dipstick urinalysis for asymptomatic bacteriuria) are ineffective. Although the USPSTF did not base its recommendations on evidence of cost-effectiveness (see Chapter v), judging health benefit based on scientific evidence provides a rational basis for directing resources toward effective services and away from ineffective services and from interventions for which the balance of benefits and risks is uncertain.<65> In addition to weighing evidence for effectiveness, selecting appropriate screening tests requires considering age, gender, and other individual risk factors of the patient in order to minimize adverse effects and unnecessary expenditures (see Chapters ii and iii). An appreciation of the risk profile of the patient is also necessary to set priorities for preventive interventions. The need for assessing individual risk underscores a time-honored principle of medical practice: the importance of a complete medical history and detailed discussion with patients regarding their personal health practices, focused on identifying risk factors for developing disease. 4. Clinicians must take every opportunity to deliver preventive services, especially to persons with limited access to care. Those individuals at highest risk for many preventable causes of premature disease and disability, such as cervical cancer, tuberculosis, human immunodeficiency virus infection, and poor nutrition, are the same individuals least likely to receive adequate preventive services. Devising strategies to increase access to preventive services for such individuals is more likely to reduce morbidity and mortality from these conditions than performing preventive services more frequently on those who are already regular recipients of preventive care and who are often in better health. One important solution is to deliver preventive services at every visit, rather than exclusively during visits devoted entirely to prevention. While preventive checkups often provide more time for counseling and other preventive services, and although healthy individuals might be more receptive to such interventions than those who are sick, any visit provides an opportunity to practice prevention. In fact, some individuals may see clinicians only when they are ill or injured. The illness visit provides the only opportunity to reach individuals who, due to limited access to care, would be otherwise unlikely to receive preventive services. 5. For some health problems, community-level interventions may be more effective than clinical preventive services. Important health problems that are likely to require broader-based interventions than can be offered in the clinical setting alone include youth and family violence, initiation of tobacco use, unintended pregnancy in adolescents, and certain unintentional injuries. Other types of interventions, such as school-based curricula,<77-81> community programs,<82-84> and regulatory and legislative initiatives,<85-87> might prove more effective for preventing morbidity and mortality from these conditions than will preventive services delivered in the clinical setting. There may, nevertheless, be an important role for clinicians as participants in community systems that address these types of health problems. Such a role might include becoming aware of existing community programs and encouraging patient participation and involvement; acting as a consultant for communities implementing programs or introducing legislation; and serving as an advocate to initiate and maintain effective community interventions. A Research Agenda in Preventive Medicine By reviewing comprehensively and critically the scientific evidence regarding clinical preventive services, the USPSTF identified important gaps in the literature and helped define targets for future clinical prevention research. Among the most important of these targets is more and better quality research evaluating the effectiveness of brief, directed counseling that can be delivered in the busy primary care practice setting. Given the importance of personal health practices, the scarcity of adequate evidence evaluating the effectiveness of brief counseling in the primary care setting is striking. The effectiveness of such counseling in reducing smoking and problem drinking is clear.<88-90> For many other behaviors, however, counseling has been tested and proven effective only in highly specialized settings (e.g., STD clinics<91-94>) or when delivered through multiple, lengthy visits with specially trained counselors (e.g., certain cholesterol-lowering interventions<95,96>). Whether the effects of these interventions can be reproduced by brief advice during the typical clinical encounter with a primary care provider is uncertain. Counseling to change some personal health practices (e.g., unsafe pedestrian behavior, drinking and driving) has received insufficient attention by researchers. Some personal health practices may not respond to brief clinician counseling in the context of routine health care. Therefore, research should also evaluate the effectiveness (and cost-effectiveness) of referring patients to allied health professionals with special counseling skills in their areas of expertise (e.g., dietitians, substance abuse counselors) and of using other modalities to educate patients in the primary care setting (e.g., videos, interactive software). For screening interventions, randomized controlled trials are powerful in resolving controversy about the benefits and risks. Many important questions will be answered by major ongoing screening trials such as the Prostate, Lung, Colorectal, Ovarian Cancer (PLCO) Screening Trial of the National Cancer Institute,<97> and by ongoing trials evaluating the clinical efficacy of treating common asymptomatic conditions detectable by screening, such as high cholesterol levels in the elderly and moderately elevated blood lead levels in children. For unproven screening interventions, finding ways to streamline randomized controlled trials so that they can be performed efficiently and cost-effectively is essential. Improving the Delivery of Clinical Preventive Services This report will help resolve some of the uncertainties among primary care clinicians about the effectiveness of preventive services, thus removing one barrier to the appropriate delivery of preventive care. The USPSTF did not, however, address other barriers to implementing clinical preventive services, such as insufficient reimbursement for counseling or other preventive interventions, provider uncertainty about how to deliver recommended services, lack of patient or provider interest in preventive services, and lack of organizational/system support to facilitate the delivery of clinical preventive services. Many of these barriers are addressed by “Put Prevention into Practice,” the Public Health Service prevention implementation program.<98> Programs such as “Put Prevention into Practice” can help ensure that prevention is delivered at every opportunity that patients are seen. Other publications also provide useful information on the effective delivery of clinical preventive services.<99> The increasing formation of integrated health care systems (e.g., managed care organizations) may also create new opportunities for crafting better preventive practices. The USPSTF explored issues of prevention for a wide range of disease categories and for patients of all ages. The comprehensive and systematic approach to the review of evidence for each topic should provide clinicians with the means to compare the relative effectiveness of different preventive services and to determine, on the basis of scientific evidence, what is most likely to benefit their patients. Organizations using evidence-based methodologies to develop guidelines on clinical preventive services are finding broad agreement on a core set of preventive services of proven effectiveness that can be recommended to primary care providers and their patients.<63,100> Basing preventive health care decisions on the evidence of their effectiveness is an important step in the progress of disease prevention and health promotion in the U.S. The draft update of this chapter was prepared for the U.S. Preventive Services Task Force by Carolyn DiGuiseppi, MD, MPH. REFERENCES 1. Centers for Disease Control and Prevention. Summary of notifiable diseases, United States, 1993. MMWR 1994;42: 1-74. 2. Witte JJ, Karchmer AW, Case G, et al. Epidemiology of rubella. Am J Dis Child 1969;118:107-111. 3. Orenstein WA, Bart KJ, Hinman AR, et al. The opportunity and obligation to eliminate rubella from the United States. JAMA 1984;251:1988-1994. 4. Centers for Disease Control and Prevention. Rubella and congenital rubella syndrome-United States, January 1, 1991-May 7, 1994. MMWR 1994;43:391, 397-401. 5. Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure. The fifth report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure. Bethesda: National Institutes of Health, 1993. (Publication no. 93-1088.) 6. Garraway WM, Whisnant JP. The changing pattern of hypertension and the declining incidence of stroke. JAMA 1987;258:214-217. 7. Casper M, Wing S, Strogatz D, et al. Antihypertensive treatment and U.S. trends in stroke mortality, 1962 to 1980. Am J Public Health 1992;82:1600-1606. 8. IARC Working Group. Summary chapter. In: Hakama M, Miller AB, Day NE, eds. Screening for cancer of the uterine cervix. Lyon, France: International Agency for Research on Cancer, 1986:133-144. (IARC Scientific Publication no. 76.) 9. Berman PW, Waisman HA, Graham FK. Intelligence in treated phenylketonuric children: a developmental study. Child Dev 1966;37:731-747. 10. Hudson FP, Mordaunt VL, Leahy I. Evaluation of treatment begun in first three months of life in 184 cases of phenylketonuria. Arch Dis Child 1970;45:5-12. 11. Williamson ML, Koch R, Azen C, et al. Correlates of intelligence test results in treated phenylketonuric children. Pediatrics 1981;68:161-167. 12. Azen CG, Koch R, Friedman EG, et al. Intellectual development in 12-year-old children treated for phenylketonuria. Am J Dis Child 1991;145:35-39. 13. New England Congenital Hypothyroidism Collaborative. Elementary school performance of children with congenital hypothyroidism. J Pediatr 1990;116:27-32. 14. Rovet JF, Ehrlich RM, Sorbara DL. Neurodevelopment in infants and preschool children with congenital hypothyroidism: etiological and treatment factors affecting outcome. J Pediatr Psychol 1992;17:187-213. 15. Kooistra L, Laane C, Vulsma T, et al. Motor and cognitive development in children with congenital hypothyroidism: a long-term evaluation of the effects of neonatal treatment. J Pediatr 1994;124:903-909. 16. Fuggle PW, Grant DB, Smith I, et al. Intelligence, motor skills and behaviour at 5 years in early-treated congenital hypothyroidism. Eur J Pediatr 1991;150:570-574. 17. Kochanek KD, Hudson BL. Advance report of final mortality statistics, 1992. Monthly vital statistics report; vol 43 no 6 (suppl). Hyattsville, MD: National Center for Health Statistics, 1995. 18. Centers for Disease Control. Cigarette smoking-attributable mortality and years of potential life lost-United States, 1990. MMWR 1993;42:645-649. 19. Centers for Disease Control and Prevention. Public health focus: physical activity and the prevention of coronary heart disease. MMWR 1993;42:669-672. 20. Bouchard C, Shepard RJ, Stephens T, eds. Physical activity, fitness, and health. Champaign, IL: Human Kinetics, 1994. 21. Department of Health and Human Services. The Surgeon GeneralÕs report on nutrition and health. Washington, DC: Government Printing Office, 1988. (Publication no. DHHS (PHS) 88- 50210.) 22. Food and Nutrition Board, National Research Council. Diet and health: implications for reducing chronic disease. Washington, DC: National Academy Press, 1989. 23. Hatcher RA, Trussell J, Stewart F, et al. Contraceptive technology. 16th ed. New York: Irvington Publishers, 1994. 24. Institute of Medicine. AIDS and behavior: an integrated approach. Washington, DC: National Academy Press, 1994. 25. McGinnis JM, Foege WH. Actual causes of death in the United States. JAMA 1993;270:2207-2212. 26. Lewis CE. Disease prevention and health promotion practices of primary care physicians in the United States. Am J Prev Med 1988;4(suppl):9-16. 27. National Center for Health Statistics. Healthy People 2000 review, 1993. Hyattsville, MD: Public Health Service, 1994. (DHHS Publication no. (PHS) 94-1232-1.) 28. Lurie N, Manning WG, Peterson C, et al. Preventive care: do we practice what we preach? Am J Public Health 1987;77:801-804. 29. Montano DE, Phillips WR. Cancer screening by primary care physicians: a comparison of rates obtained from physician self-report, patient survey, and chart audit. Am J Public Health 1995;85:795-800. 30. Dietrich AJ, Goldberg H. Preventive content of adult primary care: do generalists and subspecialists differ? Am J Public Health 1984;74:223-227. 31. Battista RN. Adult cancer prevention in primary care: patterns of practice in Quebec. Am J Public Health 1983;73: 1036-1039. 32. Lemley KB, OÕGrady ET, Rauckhorst L, et al. Baseline data on the delivery of clinical preventive services provided by nurse practitioners. Nurs Pract 1994;19:57-63. 33. Logsdon DN, Rosen MA. The cost of preventive health services in primary medical care and implications for health insurance coverage. J Ambul Care Man 1984;46-55. 34. Battista RN, Lawrence RS, eds. Implementing preventive services. Am J Prev Med 1988;4(4 Suppl):1-194. 35. Frame PS. Health maintenance in clinical practice: strategies and barriers. Am Fam Phys 1992;45:1192-1200. 36. Centers for Disease Control. Screening for tuberculosis and tuberculous infection in high-risk populations, and the use of preventive therapy for tuberculous infection in the United States: recommendations of the Advisory Committee for Elimination of Tuberculosis. MMWR 1990;39(RR-8):1-7. 37. Centers for Disease Control and Prevention. Injury control recommendations: bicycle helmets. MMWR 1995;44(RR-1):1-17. 38. Centers for Disease Control and Prevention. General recommendations on immunization: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR 1994;43(RR- 1):1-38. 39. National Institutes of Health. Early identification of hearing impairment in infants and young children. NIH consensus statement. Bethesda: National Institutes of Health, 1993;11:1-24. 40. National Cholesterol Education Program. Second report of the Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults. (Adult Treatment Panel II). Bethesda: National Heart, Lung, Blood Institute, National Institutes of Health, 1993. 41. Green M, ed. Bright Futures: guidelines for health supervision of infants, children and adolescents. Arlington, VA: National Center for Education in Maternal and Child Health, 1994. 42. National Cholesterol Education Program. Report of the Expert Panel on Blood Cholesterol Levels in Children and Adolescents. Bethesda: National Heart, Lung, Blood Institute, National Institutes of Health, 1991. (DHHS Publication no. (PHS)91-2732.) 43. American College of Physicians Task Force on Adult Immunization and Infectious Diseases Society of America. Guide for adult immunization. 3rd ed. Philadelphia: American College of Physicians, 1994. 44. Eddy DM, ed. Common screening tests. Philadelphia: American College of Physicians, 1991. 45. American College of Obstetricians and Gynecologists. Standards for obstetric-gynecologic services. 7th ed. Washington, DC: American College of Obstetricians and Gynecologists, 1989. 46. American Medical Association. AMA guidelines for adolescent preventive services (GAPS): recommendations and rationale. Chicago: American Medical Association, 1994. 47. American Academy of Family Physicians. Age charts for periodic health examination. Kansas City, MO: American Academy of Family Physicians, 1994. (Reprint no. 510.) 48. Peter G, ed. 1994 Red Book: report of the Committee on Infectious Diseases. 23rd ed. Elk Grove Village, IL: American Academy of Pediatrics, 1994. 49. Joint Committee on Infant Hearing. 1994 position statement. Pediatrics 1995;95:152-156. 50. American Academy of Ophthalmology. Policy statement. Frequency of ocular examinations. Washington, DC: American Academy of Ophthalmology, 1990. 51. American Cancer Society. Guidelines for the cancer-related checkup, an update. Atlanta: American Cancer Society, 1993. 52. American Diabetes Association. Screening for diabetes. Diabetes Care 1993;16:7-9. 53. American Heart Association. Statement on exercise: benefits and recommendations for physical activity programs for all Americans. Dallas, TX: American Heart Association, 1992. 54. American Optometric Association. Recommendations for regular optometric care. Alexandria, VA: American Optometric Association, 1994. 55. Consensus Development Conference: Diagnosis, prophylaxis, and treatment of osteoporosis. Am J Med 1993;94: 646-650. 56. Frame PS. A critical review of adult health maintenance. Part 1. Prevention of atherosclerotic diseases. J Fam Pract 1986;22:341-346. 57. Frame PS. A critical review of adult health maintenance. Part 2. Prevention of infectious diseases. J Fam Pract 1986;22:417-422. 58. Frame PS. A critical review of adult health maintenance. Part 3. Prevention of cancer. J Fam Pract 1986;22:511-520. 59. Frame PS. A critical review of adult health maintenance. Part 4. Prevention of metabolic, behavioral, and miscellaneous conditions. J Fam Pract 1986;23:29-39. 60. American Medical Association. Periodic health examination: a manual for physicians. Chicago: American Medical Association, 1947. 61. American Medical Association. Medical evaluations of healthy persons. Council on Scientific Affairs. JAMA 1983; 249:1626-1633. 62. Canadian Task Force on the Periodic Health Examination. The periodic health examination. Can Med Assoc J 1979;121:1194-1254. 63. Canadian Task Force on the Periodic Health Examination. Canadian guide to clinical preventive health care. Ottawa: Canada Communication Group, 1994. 64. Lawrence RS, Mickalide AD. Preventive services in clinical practice: designing the periodic health examination. JAMA 1987;257:2205-2207. 65. Sox HC Jr, Woolf SH. Evidence-based practice guidelines from the U.S. Preventive Services Task Force [editorial]. JAMA 1993;269:2678. 66. National Highway Traffic Safety Administration. Traffic safety facts 1992: a compilation of motor vehicle crash data from the Fatal Accident Reporting System and the General Estimates System. Washington, DC: Department of Transportation, 1994. (Publication no. DOT HS 808 022.) 67. National Highway Traffic Safety Administration. Traffic safety facts 1993. Washington, DC: Department of Transportation, 1994. (Publication no. DOT HS 808 169.) 68. Campbell BJ. Safety belt injury reduction related to crash severity and front seated position. J Trauma 1987;27: 733-739. 69. Cooper PJ. Estimating overinvolvement of seat belt nonwearers in crashes and the effect of lap/shoulder restraint use on different crash severity consequences. Accid Anal Prev 1994;26:263-275. 70. Department of Transportation. Final regulatory impact assessment on amendments to Federal Motor Vehicle Safety Standard 208, Front Seat Occupant Protection. Washington, DC: Department of Transportation, 1984. (Publication no. DOT HS 806 572.) 71. Tape TG, Mushlin AI. The utility of routine chest radiographs. Ann Intern Med 1986;104:663-670. 72. Shapiro MF, Greenfield S. The complete blood count and leukocyte differential count. Ann Intern Med 1987;106: 65-74. 73. Collins R, Peto R, MacMahon S, et al. Blood pressure, stroke, and coronary heart disease. Part 2, short-term reductions in blood pressure: overview of randomised drug trials in their epidemiological context. Lancet 1990;335: 827-838. 74. MacMahon SW, Cutler JA, Furberg CD, et al. The effects of drug treatment for hypertension on morbidity and mortality from cardiovascular disease: a review of randomized, controlled trials. Prog Cardiovasc Dis 1986; 29(suppl):99-118. 75. Hebert PR, Moser M, Mayer J, et al. Recent evidence on drug therapy of mild to moderate hypertension and decreased risk of coronary heart disease. Arch Intern Med 1993;153:578-581. 76. Kerlikowske K, Grady D, Rubin SM, et al. Efficacy of screening mammography: a meta-analysis. JAMA 1995;273: 149-154. 77. Hansen WB, Johnson CA, Flay BR, et al. Affective and social influences approaches to the prevention of multiple substance abuse among seventh grade students: results from Project SMART. Prev Med 1988;17:135-154. 78. Abernathy TJ, Bertrand LD. Preventing cigarette smoking among children: results of a four-year evaluation of the PAL program. Can J Public Health 1992;83:226-229. 79. Elder JP, Wildey M, de Moor C, et al. The long-term prevention of tobacco use among junior high school students: classroom and telephone interventions. Am J Public Health 1993;83:1239-1244. 80. Schinke SP, Gilchrist LD, Snow WH. Skills intervention to prevent cigarette smoking among adolescents. Am J Public Health 1985;75:665-667. 81. Botvin GJ, Dusenbury L, Tortu S, et al. Preventing adolescent drug abuse through a multi-modal cognitive-behavioral approach: results of a three-year study. J Consult Clin Psychol 1990;58:437-446. 82. Rivara FP, Thompson DC, Thompson RS, et al. The Seattle childrenÕs bicycle helmet campaign: changes in helmet use and head injury admissions. Pediatrics 1994;93:567-569. 83. Schwarz DF, Grisso JA, Miles C, et al. An injury prevention program in an urban African-American community. Am J Public Health 1993;83:675-680. 84. Davidson LL, Durkin MS, Kuhn L, et al. The impact of the Safe Kids/Healthy Neighborhoods injury prevention program in Harlem, 1988 through 1991. Am J Public Health 1994;84:580-586. 85. Erdmann TC, Feldman KW, Rivara FP, et al. Tap water burn prevention: the effect of legislation. Pediatrics 1991;88: 572-577. 86. Walton WW. An evaluation of the Poison Prevention Packaging Act. Pediatrics 1982;69:363-370. 87. Cote TR, Sacks JJ, Lambert-Huber DA, et al. Bicycle helmet use among Maryland children: effect of legislation and education. Pediatrics 1992;89:1216-1220. 88. Kottke TE, Battista RN, DeFriese GH, et al. Attributes of successful smoking cessation interventions in medical practice: a meta-analysis of 39 controlled trials. JAMA 1988;259:2882-2889. 89. Bien TH, Miller WR, Tonigan JS. Brief interventions for alcohol problems: a review. Addiction 1993;88:315-336. 90. Brief interventions and alcohol use. Bulletin 7. Leeds, UK: Effective Health Care, 1993. 91. Cohen DA, Dent C, MacKinnon D, Hahn G. Condoms for men, not women. Sex Transm Dis 1992;19: 245-251. 92. Cohen DA, MacKinnon DP, Dent C, et al. Group counseling at STD clinics to promote use of condoms. Public Health Rep 1992;107:727-731. 93. Heaton CG, Messeri P. The effect of video interventions on improving knowledge and treatment compliance in the sexually transmitted disease setting. Sex Transm Dis 1993;20:70-76. 94. Rickert VI, Gottlieb AA, Jay MS. Is AIDS education related to condom acquisition? Clin Pediatr 1992; 31:205-210. 95. Caggiula AW, Christakis G, Farrand M, et al. The Multiple Risk Factor Intervention Trial (MRFIT). IV. Intervention on blood lipids. Prev Med 1981;10:443-475. 96. The Writing Group for the DISC Collaborative Research Group. Efficacy and safety of lowering dietary intake of fat and cholesterol in children with elevated low-density lipoprotein cholesterol: the Dietary Intervention Study in Children (DISC). JAMA 1995;273:1429-1435. 97. Gohagan JK, Prorok PC, Kramer BS, et al. Prostate cancer screening in the Prostate, Lung, Colorectal, Ovarian Cancer Screening Trial of the National Cancer Institute. J Urol 1994;152:1905-1909. 98. Department of Health and Human Services, Public Health Service, Office of Disease Prevention and Health Promotion. Put Prevention into Practice education and action kit. Washington, DC: Government Printing Office, 1994. 99. Woolf SH, Jonas S, Lawrence RS, eds. Health promotion and disease prevention in clinical practice. Baltimore: Williams & Wilkins, 1995. 100. Hayward RSA, Steinberg EP, Ford DE, et al. Preventive care guidelines: 1991. Ann Intern Med 1991;114:758-783.