By Steven H. Woolf, M.D., M.P.H.a and David Atkins, M.D., M.P.H.b
Address correspondence to: Steven H. Woolf, M.D., M.P.H., Virginia Commonwealth University, Medical College of Virginia, 3712 Charles Stewart Drive, Fairfax, VA 22033. E-mail: shwoolf@aol.com.
This article originally appeared in the American Journal of Preventive Medicine. Select for copyright and source information.
Introduction
Historical background: The journey of the U.S. Preventive Services Task Force
The changing climate of prevention
Continuing evolution of guidelines and evidence-based health care
The current USPSTF
Implementation: The final frontier of preventive medicine
Future challenges
References and Notes
Many of the leading causes of death and disability in the United States can be prevented (1). Primary prevention can prevent or arrest the disease process in its earliest stages by promoting healthier lifestyles or immunizing against infectious disease. Secondary prevention, by detecting and treating asymptomatic risk factors or early asymptomatic disease, can substantially reduce subsequent morbidity or mortality. The clinician plays a pivotal role in both primary and secondary prevention. Health professionals deliver vaccinations, screen for modifiable risk factors such as high blood pressure and high cholesterol, counsel patients about smoking and other behavioral risk factors, provide screening tests for early detection of cancer and other chronic conditions, and advise patients about the benefits and risks of preventive therapies such as postmenopausal hormone replacement therapy.
The health care landscape has changed dramatically in the 17 years since the U.S. Preventive Services Task Force (USPSTF/Task Force) was first established in 1984 to provide advice about prevention for health professionals. Prevention has become an integral component of primary health care (2). Delivery of clinical preventive services such as immunizations, mammograms, and cholesterol screening has risen steadily over the past two decades (3). Roughly 90% of employers now include well-child visits, childhood immunizations, screening tests, and adult physical examinations among covered health benefits, compared to less than half that did so in 1988 (4). Interest in prevention has grown significantly among the public, clinicians, educators, employers, and policymakers (5). Furthermore, health plans and individual clinicians are increasingly being held accountable for the quality of the preventive care they provide to their patients (6).
Substantial gaps in the delivery of effective preventive care in the United States remain, however, because clinicians continue to face many of the same barriers that originally spurred the formation of the first USPSTF (7). Identifying effective interventions can be difficult in prevention, where prospective controlled trials are often difficult to conduct. Conflicting recommendations from different organizations, further exacerbated by the advocacy positions of some groups, leave many clinicians uncertain about what to do. Clinicians facing increasing time pressures in practice may question the value of some routine preventive interventions, as may employers and other payers struggling with accelerating health care costs. Although more prevention information is reaching the public, the messages conveyed are often inconsistent and increasingly colored by commercial self-interest. Clinicians may feel compelled to provide unproven or ineffective services because patients demand them or they fear being sued, but patients may find that insurance coverage for individual preventive services, especially new technologies, is inconsistent (4,7).
The importance of clarifying what we know and do not know about the effectiveness of specific preventive services is as important in 2001 as it was in 1984. But the experience of the USPSTF illustrates that understanding effectiveness is only one step on a path to improving preventive health care. In this article, we briefly review the history of the USPSTF from its inception in 1984, reflect on the impact of the Task Force on both preventive care policy and practice and its influence on the contemporary movement of practice guidelines and evidence-based health care in general, and comment on future challenges to the work of the USPSTF and other efforts to promote the implementation of effective preventive health care.
Although major groups had advocated annual physical examinations for decades (8) and promoted routine screening tests such as blood and urine chemistry panels, chest radiographs, and electrocardiograms, a comprehensive review of the scientific evidence to support specific preventive services was lacking in the early 1980s. Doubts grew as critical review articles focused attention on the absence of data for many commonly delivered services (9). In 1979, the Canadian Task Force on the Periodic Health Examination published its first report (10), a seminal work using systematic rules of evidence to support the strength of recommendations for a wide variety of preventive services.
In 1984, the Public Health Service, part of the U.S. Department of Health and Human Services, established the USPSTF to extend the approach of the Canadian Task Force to address a comprehensive set of clinical preventive services. The USPSTF was charged with systematically reviewing the scientific evidence for individual clinical preventive services and making recommendations for practitioners about what services should be routinely offered. The 20-member panel of nonfederal experts included 14 physicians and a dentist, nurse, health services researcher, health educator, economist, and sociologist. In contrast to many other disease-specific guideline panels (11), the Task Force consisted of generalists with expertise in research methodology and prevention, allowing it to address a wide range of topics. Broad expertise also lessened the potential for conflict of interest on a given issue. Following publication of a series of journal articles on individual services, the USPSTF released the Guide to Clinical Preventive Services (12) in 1989. The Guide reviewed the evidence for 169 screening tests, counseling interventions, immunizations, and chemopreventive regimens, grading the recommendations on a 5-level (A to E) scale to reflect the quality of the supporting evidence, for age groups ranging from infancy to old age.
The release of the Guide had effects both on preventive medicine and on the nascent discipline of evidence-based medicine. The Guide represented the first attempt to assess a broad set of services using a consistent approach and with an emphasis on the perspective of the primary care clinician. It provided a single reference to which clinicians and policymakers could turn for the evidence for specific preventive services. The conclusions that the available evidence did not support some services ardently advocated by other medical groups drew heated criticism, but helped establish the credibility of the USPSTF among more skeptical audiences. Casting a spotlight on deficiencies in the evidence also focused attention on the gaps in knowledge and helped guide an agenda for future research needed to establish effectiveness.
The services for which the USPSTF did find compelling evidence—and which typically had wide support from other groups—formed the nucleus of a core set of preventive services advocated by skeptics and enthusiasts alike. This enabled the boundaries of "mainstream" preventive medicine to take form, something that had not occurred before, which in turn became a strategic tool in leveraging policymakers, insurers, and employers to provide a package of well-supported preventive services to large population groups.
The release of the Guide accelerated a growing movement to replace traditional "expert consensus" methods for developing clinical recommendations with a systematic and explicit process for reviewing evidence and of linking clinical practice recommendations directly to the quality of the science (13). Early contributors to this movement included David Eddy (14) and the Evidence-based Medicine Working Group (15). The strict approach taken by the Task Force drew praise and criticism for eschewing expert opinion as a basis for making recommendations and for taking a neutral position when evidence was lacking. The systems for rating evidence and grading recommendations popularized by the Canadian and U.S. Task Forces were joined by similar schemes used by other groups (16). The USPSTF formed close collaborations with other groups committed to evidence-based policy, such as the American College of Physicians (17) and American Academy of Family Physicians, staking out similar positions in polarized debates with advocacy organizations using the older opinion-based methods.
Although the USPSTF was disbanded in 1989 with the release of the Guide, the need to keep pace with the rapid growth in scientific evidence led to convening a second panel in 1990. The second USPSTF was smaller, with only ten members, eight of whom were primary care physicians. It refined the previous group's methods for reviewing evidence and making recommendations, and expanded the scope of topics. It adopted policies for disclosure of conflicts arising from financial interests, funding sources, or other affiliations. The work of the second USPSTF was marked by strengthened ties with both federal and nongovernmental partners, including primary care subspecialty societies. The work of the second USPSTF culminated in the publication of the second edition of the Guide (18) in 1996, which covered over 200 interventions in 70 areas.
By the time the second edition of the Guide appeared, the environment for preventive medicine and evidence-based medicine had changed dramatically. Managed care organizations, which had emerged as a dominant paradigm for delivering and paying for health care, included preventive care among basic covered services more commonly than had traditional fee-for-service insurance (4,19,20). At the same time, the heightened competition spurred by managed care brought increased attention to costs and value. Although clinicians were the primary intended audience for the Guide, it soon became clear that the recommendations had an even greater impact on practice by reaching a wider audience of purchasers, health plans, and policymakers, who valued the objective approach to the evidence. The Guide was frequently cited by health plans and systems of care in defending their health maintenance programs and benefits packages, and its recommendations informed many of the Health Plan Employer Data and Information Set (HEDIS) (6) quality measures developed by the National Committee on Quality Assurance for evaluating health plan performance.
These developments occurred against a backdrop of greater interest in health promotion and healthy lifestyles on the part of the American public. Public education campaigns and commercial advertising had spurred interest in low-fat diets, exercise, and weight management. The emergence of new screening technologies and the promotion of specific tests by celebrities and national organizations made patient requests for screening a common occurrence in clinicians' offices. With the advent of the Internet and other information technologies, many patients grew more knowledgeable about options for preventive care and newly released guidelines. Access to information was accompanied by a greater sense of empowerment among patients, including a desire to be more informed consumers and to take a more active role in making health care choices. Health plans, in turn, recognized that including comprehensive health promotion and disease prevention was a valuable marketing tool for attracting patients.
The attention the Guide brought to clinical preventive services also highlighted the importance of health promotion and disease prevention efforts outside of the clinician's office. For some health problems (e.g., teenage smoking), the potential impact of the individual clinician was much smaller than that of other community-based interventions. In 1996, the U.S. Centers for Disease Control and Prevention impaneled the Task Force on Community Preventive Services, modeled on the USPSTF, to create the Guide to Community Preventive Services, to address a broad range of interventions targeting communities and health care systems rather than individual patients. Recommendations in the Community Guide are targeted at persons involved in planning, funding, and implementing population-based services at the state and local levels. The first products of the Community Guide effort, including a systematic review of interventions to increase vaccination coverage in children and adults, were published in a January 2000 supplement to the American Journal of Preventive Medicine (21).
By 1996, the enthusiasm for clinical practice guidelines and for evidence-based medicine had been tempered by a realization of their attendant practical and political challenges (22). At its inception, the U.S. Congress authorized the Agency for Health Care Policy and Research (AHCPR; renamed the Agency for Healthcare Research and Quality [AHRQ] in 1999) to develop practice guidelines as part of its twin goals of improving quality and reducing unnecessary costs. By 1995, however, controversies sparked by several guidelines led to a re-examination of the appropriate role of AHCPR in developing clinical practice policies. At the same time, specialty societies and professional organizations that had reorganized and invested in the early 1990s to establish their own practice guideline programs soon found their efforts eclipsed by guidelines developed by commercial vendors and sold to health plans and hospital systems with the promise of lower health care costs and lengths of stay. Moreover, as experience with evidence-based guidelines grew, observers gained a more mature appreciation of their limitations: a recognition that the critical appraisal of evidence involved more than assigning letter codes; that evidence was lacking for much of medicine; that waiting for better data from controlled trials was often unrealistic or unethical; and that evidence-based guidelines and policies, however well-intentioned, could cause unintended harm to patients, health professionals, and the health care system at large (23).
Notwithstanding these difficulties, the evidence-based perspective gained its footing in health care. Entire journals, and sections of other major journals, are now devoted to the critical appraisal of individual studies, and articles and Web sites detail the methods for conducting such reviews. Systematic reviews following an explicit methodology (24) and meta-analyses of multiple studies, popularized by the Cochrane Collaboration's Cochrane Library (25,26), appear regularly in most medical journals and offer a more rigorous alternative to the traditional review paper reflecting the opinions of a single expert. Evidence-based guidelines, founded on systematic reviews, are produced throughout the world (23), and the AHRQ National Guideline Clearinghouse™ (http://www.guideline.gov), established in 1998, provides access to a steadily growing number of guidelines (over 500 as of October 2000). Software tools to facilitate evidence-based decision making at the bedside are increasingly popular (27). Policymakers, payers, and legislators are becoming increasingly aware that evidence-based health policy is a tool for quality improvement and for confronting the unrelenting rise in the costs of health care.
It is in this context that a third USPSTF was convened in 1998 to update the recommendations of the second Task Force. Following the release of the second edition of the Guide, responsibility for the work of the USPSTF and the related Put Prevention Into Practice (28) initiative (www.ahrq.gov/clinic/prevenix.htm) were transferred to AHRQ as part of its commitment to supporting evidence-based practice. Thirteen Task Force members (including four returning members) were selected from a pool of over 70 individuals nominated by national organizations and experts (see Table 1). Recognizing the need for a broader interdisciplinary approach, the new USPSTF added two nurses, an expert in behavioral medicine, and several experts in cost effectiveness.
U.S. Preventive Services Task Force
Alfred O. Berg, M.D., M.P.H. (chair)
Department of Family Medicine
Univ. of Washington School of Medicine
Seattle, Washington
Janet D. Allan, Ph.D., R.N. (vice-chair)
School of Nursing
Univ. of Texas Health Science Center at San Antonio
San Antonio, Texas
Paul S. Frame, M.D.
Tri-County Family Medicine
Cohocton, New York
Charles J. Homer, M.D., M.P.H.
National Initiative for Children's Healthcare Quality
Institute for Healthcare Improvement
Boston, Massachusetts
Tracy A. Lieu, M.D., M.P.H.
Dept. of Ambulatory Care and Prevention
Harvard Pilgrim Health Care and Harvard Medical School
Boston, Massachusetts
Cynthia D. Mulrow, M.D., M.Sc.
Dept. of Medicine
University of Texas, San Antonio
Audie L. Murphy Memorial Veterans Hospital
San Antonio, Texas
Carole Tracy Orleans, Ph.D.
Robert Wood Johnson Foundation
Princeton New Jersey
Jeffrey F. Peipert, M.D., M.P.H.
Department of Obstetrics and Gynecology
Women & Infants Hospital of Rhode Island
Providence, Rhode Island
Nola J. Pender, Ph.D., R.N., F.A.A.N.
School of Nursing
University of Michigan
Ann Arbor, Michigan
Harold C. Sox, Jr, M.D.
Department of Medicine
Dartmouth-Hitchcock Medical Center
Lebanon, New Hampshire
Steven M. Teutsch, M.D., M.P.H.
Merck & Co., Inc.
West Point, Pennsylvania
Carolyn Westhoff, M.D., M.Sc.
Department of Obstetrics and Gynecology
Columbia University
New York, New York
Steven H. Woolf, M.D., M.P.H.
Department of Family Practice
Medical College of Virginia
Virginia Commonwealth University
Fairfax, Virginia
Agency for Healthcare Research and Quality
David Atkins, M.D., M.P.H.
Scientific and Technical Editor, USPSTF
Dana Best, M.D., M.P.H.
Assistant Scientific and Technical Editor, USPSTF
Randie A. Siegel, M.S.
Director, Division of Print and Electronic Publishing
Eve N. Shapiro
Managing Editor, USPSTF (under contract to AHRQ)
Barbara Gordon
Program Analyst, USPSTF
Oregon Health & Science University Evidence-based Practice Center
Mark Helfand, M.D., M.S.
Director, OHSU Clinical Prevention Center
Director, OHSU Evidence-based Practice Center
Kathryn Pyle Krages, A.M.L.S., M.A.
Project Manager, OHSU Clinical Prevention Center
Benjamin KS Chan, M.S.
Petronella Davies, M.S.
Karen B. Eden, Ph.D.
Jeanne-Marie Guise, M.D., M.P.H.
Linda L. Humphrey, M.D., M.P.H.
Susan Mahon, M.P.H.
Gary Miranda, M.A.
Heidi D. Nelson, M.D., M.P.H.
Margaret M. Nygren, M.A.
Evelyn P. Whitlock, M.D., M.P.H.
Susan Wingenfeld
Research Triangle Institute (RTI)/University of North Carolina at Chapel Hill (UNC) Evidence-based Practice Center
RTI:
Kathleen N. Lohr, Ph.D.
Co-Director, Evidence-based Practice Center
Co-Director, RTI-UNC Clinical Prevention Center
Sonya Sutton, B.S.P.H.
Project Manager, RTI-UNC Clinical Prevention Center
Linda Lux, M.P.A.
Sheila White
UNC:
Russell P. Harris, M.D., M.P.H.
Co-Director, RTI-UNC Clinical Prevention Center
Timothy S. Carey, M.D., M.P.H.
Co-Director, RTI-UNC Evidence-based Practice Center
Mark Dowell, B.A.
Anne Jackman, M.S.W
Carol Krasnov
Michael P. Pignone, M.D., M.P.H.
Lynn Whitener, Dr.P.H., M.S.L.S.
Changes are also apparent in the organization of the scientific support to the USPSTF process. Congressional reauthorization of AHRQ in 1999 made federal support for the USPSTF explicit. It also redirected AHRQ from sponsoring guideline development to supporting the production of evidence syntheses for use by outside partners such as professional societies, who could in turn develop guidelines and policies more appropriate for their settings and populations. To this end, AHRQ established a network of 12 Evidence-based Practice Centers (EPCs) in universities and private research organizations with expertise in research synthesis and systematic review. Two of these centers (Oregon Health Sciences University and a collaboration between the Research Triangle Institute and the University of North Carolina at Chapel Hill) provide ongoing support for the USPSTF. Research staff members consult with the USPSTF, conduct systematic reviews, and produce detailed technical reports summarizing the evidence of effectiveness of specific interventions. These reports, which undergo outside review and revision, serve as the foundation for briefer summaries of evidence and for the USPSTF to formulate its recommendations. The centers and their sponsor focus on the science, leaving the formulation of policy and practice recommendations to the independent USPSTF.
Accordingly, the USPSTF process produces three types of documents: a detailed systematic evidence review, written largely by EPC staff with input from the USPSTF; a shorter summary of the evidence, suitable for publication in journals and on the Internet; and a "recommendation and rationale" statement authored by the USPSTF, containing the clinical conclusions derived by the Task Force. These recommendations represent the independent positions of the USPSTF and do not reflect the policies of its sponsor (AHRQ) or the U.S. Public Health Service. Included on this Web site are the first products resulting from this program. An EPC-authored summary of the evidence and a USPSTF-authored recommendation statement appear for each of the four preventive services (screening for lipid disorders, bacterial vaginosis in pregnancy, chlamydial infection, and skin cancer). The full details of the technical reports are available online.
This new model of collaboration among the USPSTF, AHRQ, and the academic EPCs offers new opportunities and challenges. The resources provided by the independent, AHRQ-supported centers allow for more detailed reviews than were possible with a small internal staff. Similarly, separating the processes of reviewing evidence and developing recommendations helps ensure that the assessment of the evidence is insulated from policy or political considerations. Clarifying the independence of the USPSTF, and explaining situations in which the conclusions of the USPSTF diverge from that of other federal agencies, will remain ongoing challenges.
Despite its independence, the USPSTF continues to benefit from close relationships with federal health agencies and primary care professional organizations, which regularly attend Task Force meetings and provide peer review of draft documents (see Table 2). These collaborations help to ensure that the evidence that serves as the basis of USPSTF recommendations is complete and accurate, that USPSTF recommendations are clear and credible to practitioners and policymakers, and that consensus is achieved when the position is supported by evidence. In addition, representatives of the USPSTF, Canadian Task Force on Preventive Health Care, and the Community Guide Task Force routinely attend each other's meetings and contribute to methods and manuscripts.
Private organizations
American Academy of Family Physicians
American Academy of Pediatrics
American Academy of Physicians Assistants
American College of Obstetricians and Gynecologists
American College of Physicians/American Society of Internal Medicine
American College of Preventive Medicine
Canadian Task Force on Preventive Health Care
Federal organizations
Centers for Disease Control and Prevention
National Institutes of Health
Veterans Administration
Health Care Financing Administration
Indian Health Service
Health Resources Services Administration
United States Navy, Bureau of Medicine and Surgery
United States Air Force, Medical Operations Agency
United States Army, Center for Health Promotion and Preventive Medicine