Mr. Chairman, I appreciate this opportunity to discuss the work of the U. S. Preventive Services Task Force (Task Force) and the role of the Department of Health and Human Services's (HHS) Agency for Healthcare Research and Quality (AHRQ), which provides the Task Force with scientific and administrative support.  Because the Task Force chair and vice chair were unable to attend today's hearing, I have been asked to provide an overview of AHRQ's role in  developing scientific evidence of the effectiveness of preventive health care services and how the Task Force, an independent group of prevention experts, uses that scientific evidence. 

Role of the Agency for Healthcare Research and Quality (AHRQ)

The primary focus of the Agency for Healthcare Research and Quality (AHRQ) is on clinical services B the care patients receive from health care providers B and the health care systems through which those services are provided.   AHRQ research provides the scientific evidence to improve the outcomes, quality, and safety of health care, reduce its cost, broaden access to effective services, and improve the efficiency and effectiveness of the ways we organize, deliver, and finance those services. 

Clinical preventive services B which include common screening tests, immunizations, preventive medications like aspirin to prevent heart attacks, and counseling about lifestyle that are delivered by clinicians B are an important focus of AHRQ research.   Our research develops new scientific evidence regarding their effectiveness and cost-effectiveness, synthesizes existing scientific knowledge, and assesses strategies for facilitating their delivery and appropriate use.   AHRQ's focus on the effectiveness of clinical preventive services B what works best in daily practice B complements the research at the National Institutes of Health (NIH) and Centers for Disease Control and Prevention (CDC).

In addition, in 1999, the Congress directed the agency to provide scientific and administrative support to the U.S. Preventive Services Task Force, and legislation enacted in 2000 requires AHRQ to produce an annual report to Congress on what preventive services are effective for older Americans.  A copy of our first report is attached to my testimony. (1150 kb) (requires Adobe Acrobat)

The strengths and limitations of existing scientific evidence 

To ensure that Americans benefit from our existing knowledge, AHRQ supports Evidence-based Practice Centers (EPCs) that undertake comprehensive reviews of the scientific evidence regarding the effectiveness, risks, and benefits of specific health care services.  The evidence reports they produce provide unbiased summaries of existing knowledge without recommendations, so that those who need to make decisions about health care and health systems, such as patients, providers, health plans, insurers and policy makers, can make more informed decisions.  In response to requests from the Task Force, AHRQ relies primarily upon two of these EPCs to assess the scientific evidence regarding clinical preventive services.

How do they do that?  Before the EPCs can begin to synthesize the findings of  available studies, they undertake a rigorous methodological review of each study, asking questions such as: Did the investigators use an appropriate research design for the question being asked?  Did they control for other factors that might affect the outcome (what researchers call "threats to validity")?  Did they use the right statistical tests and calculate them properly?  Did they examine health outcomes that are most important to patients?  Not surprisingly, there are many studies that do not survive scrutiny; they were poorly designed, poorly executed, or both.  Unfortunately, the number of solid, well-designed, well-executed research studies is often smaller than policy makers would prefer.

Because a determination of effectiveness often has significant implications in controversies over coverage or reimbursement, it is critical that policy makers understand one important distinction.  A conclusion that there is not evidence of the effectiveness of a service is different from a conclusion that the service is ineffective.  "No evidence of effectiveness" can simply mean there are no studies on the subject, the studies that exist are flawed and cannot be trusted, or an existing good study involved so few patients that it is not generalizable.  No judgment is implied regarding the effectiveness or ineffectiveness of the service; it simply means there are too few good scientific studies on the subject to guide your decision-making.

In its obligation to provide scientific support for the Task Force, AHRQ follows this same approach and identifies the strengths and limitations of the existing knowledge base but makes no recommendations.   

The U.S. Preventive Services Task Force

The U.S. Preventive Services Task Force is in its third incarnation. The HHS first convened a Task Force of independent prevention experts in 1984; their report was released in 1989, and then completely updated by the second Task Force in 1996.  In 1999, Congress established the Task Force as an ongoing body so that it could regularly review and update its recommendations based upon new scientific findings. A list of the current membership of the Task Force is attached.

For each topic that the Task Force addresses, it requests an updated evidence report, which AHRQ then commissions from one of its EPCs.  After reviewing the evidence report, the Task Force develops recommendations based upon the strength of the scientific evidence and their collective expert judgment regarding the balance of benefits and harms of a specific service. These recommendations are then circulated widely for comment from Federal agencies and private organizations, but the final recommendations reflect the conclusions of the independent Task Force, rather than policy decisions of  HHS or any organization.  Task Force recommendations are not binding on public or private sector providers or funders of care.  

The Task Force requires evidence that a given intervention will actually improve important health outcomes, such as lowering morbidity or mortality, not simply detecting more disease or improving some laboratory test result.  As a result, Task Force recommendations are sometimes more conservative than those of specialty groups.  The principle that clinical recommendations should be based on careful and objective assessments of the evidence, rather than simply the opinions of experts, is at the heart of the movement known as "evidence-based medicine".  These principles are especially important in prevention, because an intervention, such as testing for colon cancer, will be offered  to large populations of healthy people. 

The Task Force experience has demonstrated we still have substantial room for progress in providing preventive services that are supported by good evidence.  Often the Task Force concludes that the existing evidence is not sufficient to prove or disprove whether a service is effective, indicating that more good scientific studies are needed and that clinicians must use their own judgment with individual patients until more definitive research is completed.

Since its first report, the Task Force has been recognized for producing rigorous and unbiased assessments of what works in clinical prevention.   As a result, the influence of its recommendations goes far beyond its primary mission, which is to make recommendations for doctors and nurses to guide clinical practice.  In fact, its recommendations have formed the basis of prevention guidelines of the American Academy of Family Physicians and other professional societies, are used by health plans and insurers in developing their prevention policies, and have figured prominently in the development of health care quality measures and national health objectives.  Finally, the Task Force's Guide to Clinical Preventive Services is used widely in undergraduate and post-graduate medical and nursing education as the definitive reference for teaching preventive care. 

Clinical Preventive Services and the Elderly

Primary care clinicians play a central role in prevention for older Americans. The average Medicare recipient makes 13 medical visits per year, providing opportunities for doctors and nurses to deliver a range of clinical preventive services, including screening tests, counseling, immunizations, and advice about preventive medications such as aspirin or hormone therapy. 

Contrary to common misperceptions, one is never too old to benefit from effective preventive interventions. Prevention is especially important for older Americans, since preventive measures even at this age can help delay the onset of disease. The challenge in prevention is identifying which services are most effective for which patients and finding ways to ensure they are delivered to all eligible patients.

In its comprehensive 1996 report, and in updates released over the past 2 years, the Task Force has documented the scientific evidence that preventive services can significantly improve health. For older patients, it found compelling evidence to recommend that clinicians regularly provide the following services: screening for high blood pressure and high cholesterol; screening for cancers of the breast, colon, and cervix; screening for vision and hearing problems; immunization against influenza, pneumococcal disease and tetanus; and discussions with patients about aspirin to prevent heart attacks.  In addition, the Task Force has noted the importance of counseling to reduce tobacco and alcohol use, to promote healthy diets and physical activity, and to prevent injuries.  The general conclusions of the Task Force urge clinicians to be more selective in their use of some screening tests, pay more attention to behavioral health issues, and find opportunities to deliver preventive services outside of the traditional "annual check-up."

Medicare Coverage

Thanks to the combined efforts of the Task Force and many other agencies and organizations committed to prevention, the landscape for prevention in 2002 is dramatically different from the one facing the first Task Force in 1984.   At that time, delivery of preventive care was uneven, insurance coverage was rare, and attitudes of patients and providers were often skeptical.  

As AHRQ notes in its report to Congress on preventive services, Medicare now covers nearly all of the screening services recommended by the Task Force.  The one exception, cholesterol screening, is often covered as a part of follow-up care or treatment of other problems.  Similar progress has been documented in the private sector -- among employer-based health plans, over 90% cover mammograms and Pap tests, and over 85% cover routine physicals and gynecological exams.  

Ensuring that Americans Benefit from Preventive Services

Mr. Chairman, deciding what works is only the first step toward quality preventive care.   A report on clinical priorities in prevention from the Partnership for Prevention, developed with support from CDC and AHRQ, documented that a number of high priority services relevant to older Americans are delivered to less than half of the population nationally. These include smoking cessation counseling, colorectal cancer screening, and pneumococcal vaccination. 

Addressing this problem B facilitating the use of effective and cost-effective health care services B is another aspect of AHRQ's mission, which we term "Translating Research into Practice."  We do this in two ways.  First, we develop a variety of materials and tools that help providers ensure that patients receive the right preventive service at the right time.  An example is AHRQ's "Put Prevention Into Practice" effort that provides materials to help primary care clinicians effectively deliver preventive services to patients, educates patients about the services they should receive, and asks patients to remind their physician if a useful service is not provided.

The second approach is through research designed to identify ways to overcome barriers that may lead to under-use of effective preventive services.  For example, a recent research solicitation, co-funded by AHRQ and the NIH's National Cancer Institute, solicits research to identify the most effective ways to improve the delivery of preventive colorectal cancer screening services in the clinical setting.