Editorials

The third report of the US Preventive Services Task Force

New guidelines are timely, accessible, and useful in primary care

Papers BMJ USA p 187

This article originally appeared in BMJ USA

This month the first four installments in the third US Preventive Services Task Force (USPSTF) report are being published. Unlike the first two reports, published in 1989 and 1996 in single volumes, the third report will appear sequentially and in a variety of formats. Each of the topics reviewed by the Task Force will be available as: 1) a detailed, systematic evidence report published on the Agency for Healthcare Research and Quality's (AHRQ's) web site (www.ahrq.gov/clinic/ uspstfix. htm), 2) a shorter synthesis of the evidence published in a variety of general medicine and family practice journals, and 3) a recommendation and rationale statement (R&R) containing the clinical conclusions derived by the Task Force.

The first four topics reviewed by the Task Force are screening for lipid disorders in adults, chlamydial infection, bacterial vaginosis during pregnancy, and skin cancer. The results are being published in a supplement to the American Journal of Preventive Medicine.¹ A clinical review of these four areas appears in this issue of BMJ USA (BMJ USA p 187).²

The primary mission of the USPSTF from its inception in 1984 has been to promote effective clinical prevention. Using evidence-based methodology, the Task Force reports have become the single best reference on the effectiveness of screening procedures. Still, studies have shown that primary care physicians have generally low awareness of and compliance with the USPSTF guidelines.^3-5 Barriers to guideline adoption are complex and involve both patient and clinician factors. Availability of the third Task Force report in a variety of formats, combined with changes in how it is disseminated, will address these deficiencies, in part, by improving accessibility. Publication of individual reports in specialty journals ensures that a wider audience will be reached. Web availability of technical reports and R&R statements is essential, given that provision of medical care increasingly relies on access to electronic information.

Timely dissemination of information has become a priority of the third Task Force and its new sponsor, the AHRQ (the first two reports were sponsored by the Office of Disease Prevention and Health Promotion). To that end, expedited evaluations may be performed on topics in which advances are being made. Publication of individual topic reviews as they are completed, rather than all at once in a single volume, will improve physician confidence that the information represents the current state of knowledge.

The R&R statements are concise and clearly written, making them practical to refer to in the middle of a busy clinic. The statements summarize the Task Force recommendations using terminology similar to that in the second report: A = strong recommendation for, B = recommendation for, C = no recommendation for or against, D = recommendation against, and I = insufficient evidence for recommendation for or against. Also included are the recommendations from other groups, which provide a useful counterpoint to the USPSTF guidelines.

Of the four recently published guidelines, the most surprising recommendation to many clinicians will be the "I" given to skin cancer screening, even in high-risk groups. The Task Force makes the point that when screening is done by nondermatologists, its sensitivity for detecting carcinomas or melanomas is probably lower than it is when done by dermatologists; also, such screening could lead to unnecessary biopsies and expense. Most importantly, the skin exam has not been shown to lower mortality, mainly because other than melanomas, most skin cancers are not fatal.

Guidelines for chlamydia screening are based on age, risk, pregnancy status, and symptoms, with the strongest "A" recommendation for sexually active women age 25 and under and other asymptomatic but high-risk women. Pregnant women under age 25, even though asymptomatic, get a "B" recommendation for screening, as do high-risk pregnant women at any age. Asymptomatic, low-risk pregnant women age 26 and older and asymptomatic low-risk women in the general population get a "C" recommendation (neither for nor against routine chlamydial infection screening). Primary care physicians who care for women will find these very specific guidelines useful in decision making.

Obstetricians and primary care physicians who do obstetric care may be a little puzzled by the recommendations on screening for bacterial vaginosis in pregnancy. The USPSTF concludes that the evidence is insufficient to recommend for or against routinely screening high-risk pregnant women for bacterial vaginosis ("I" recommendation), although they admit that some studies have found that screening and treatment of asymptomatic bacterial vaginosis in high-risk pregnant women reduces the incidence of preterm delivery (see the paper by Atkins on page 187 for a description of the studies). The "I" recommendation indicating "insufficient evidence" in this case really translates into "conflicting evidence," leaving the decision up to the discretion of the physician. The USPSTF recommends against routinely screening average-risk asymptomatic pregnant women for bacterial vaginosis because it does not improve outcomes, such as the incidence of preterm labor or preterm birth.

The statements also include sections on clinical considerations that go beyond just screening evidence. For example, the statement on screening for lipid disorders in adults includes discussions of whether to measure fasting or nonfasting samples, what is the optimal interval for screening, and what is the age at which screening can be stopped. Such practical considerations increase the usefulness of the statements and also aid the clinician in explaining to patients why it is not necessary to keep checking lipid levels yearly or why it is prudent to stop screening at age 65 (because it is unlikely that lipid levels change greatly after that).

The third Task Force decided that 55 of the 70 preventive care topics (over 100 actual services) from the second Guide to Clinical Preventive Services required updating due to availability of new evidence or continued controversy. In addition, 15 new topics were identified. New topics currently being reviewed by the third Task Force include chemoprevention of breast cancer, vitamin supplementation to prevent cancer and cardiovascular disease, counseling to promote breastfeeding, and screening for child developmental delay. In the spirit of responsiveness to its audience, the Task Force will take suggestions for new topics to review. The third USPSTF has made significant changes since the previous report was issued, and we look forward to reading the recommendations that follow.

Mary Ann Gilligan, assistant professor of medicine. 
Rebekah Wang-Cheng, professor of medicine. 

Department of Medicine, Division of General Internal Medicine, Medical College of Wisconsin, Froedtert East Office Building, Suite 4200, 9200 West Wisconsin Avenue, Milwaukee, Wisconsin 53226, USA (gilligan{at}mcw.edu)