Clinical practice guidelines are an important innovation to improve the quality of care by defining appropriate clinical practice.1 A growing number of organizations are using evidence-based methods to develop practice guidelines.2 This approach emphasizes the critical evaluation of evidence, rather than expert opinion, to define proper care. Evidence-based methods have been used for over a decade to develop guidelines on clinical preventive services, beginning with the work of the Canadian Task Force on the Periodic Health Examination in the late 1970s.3Clinical preventive services include screening tests (eg, mammography), counseling interventions (eg, smoking cessation), and immunizations.
See also p 2664.
The need for evidence of effectiveness is never higher than when clinicians advise healthy people about preventive services rather than treating existing disease. Therefore, it is important to ensure that the benefits of preventive services (eg, a longer, healthier life) exceed their potential harms (eg, mislabeling, complications