This commentary reviews the argument that clinical trials with data monitoring committees that use statistical stopping guidelines should generally not be stopped early for large observed efficacy differences because efficacy estimates may be exaggerated and there is minimal information on treatment harms. Overall, the average of estimates from trials that use these boundaries differs minimally from the true value. Estimates from a given trial that seem implausibly high can be moderated by using Bayesian methods. Data monitoring committees are not ethically required to precisely estimate a large efficacy difference if that difference differs convincingly from zero, and the requirement to detect harms and balance efficacy against harm depends on whether the nature of the harm is known or unknown before the trial.

Stopping randomized trials early because of an apparent benefit is becoming more common. To protect and promote the interests of trial participants, investigators may feel obligated to stop a trial early because of the apparent benefit of a study treatment (compared with placebo or other treatment). There are, however, serious ethical problems with doing so. Truncated trials systematically overestimate treatment effects; in cases where the number of accrued outcome events is small, the overestimation may be very large. Generating seriously inflated estimates of treatment effect violates the ethical research requirement of scientific validity. Subsequent use of inflated estimates to inform clinical decision making and practice guidelines violates the ethical requirements of social value and a favorable risk-benefit ratio. Researchers should ensure that a large number of outcome events accrues before stopping a trial and then continue recruitment to assess whether positive trends continue. This can balance the need to protect research participants with the ethical requirements of scientific validity, social value, and a favorable risk-benefit ratio.

Knee osteoarthritis is a major cause of pain and functional limitation.

The U.S. Preventive Services Task Force (USPSTF), an independent panel that has provided the gold standard for evidence-based guidelines in prevention for the past 2 decades, continuously refines its methodology. To keep up with the evolving field of evidence- based medicine and to update recommendations in a timely, efficient, and transparent manner, the USPSTF has developed new methods for evidence reviews and recommendation development. This article summarizes the most recent changes in the recommendation development process, including how the USPSTF solicits and prioritizes topics for review, updates evidence reviews and recommendations, and communicates with its audience.

Since 2001, the U.S. Preventive Services Task Force (USPSTF) has worked to refine its methods of evidence review and assessment and to create more usable documents in response to clinicians' needs. These changes have resulted in a revised grading system, as well as a new format and new language for the recommendation statement. This paper focuses on the changes to and the new look of the USPSTF recommendation statement. The new recommendation statement comprises 9 sections. Important changes include standardization of the format of the summary statement to specify what service is being recommended in what population; standardization of the headings in the rationale section; a change in the wording of the grade C recommendation and the I statement; and a new section, called "Other Considerations," in which salient issues related to cost-effectiveness, mandates, and other implementation issues are described.

Update of 2001 U.S. Preventive Services Task Force (USPSTF) recommendations about screening sexually active adolescents and adults for chlamydial infection.

Chlamydial infection is the most common sexually transmitted bacterial infection in the United States, with an estimated 3 million new cases annually. In 2001, the U.S. Preventive Services Task Force (USPSTF) recommended that clinicians screen all sexually active women at increased risk for infection for Chlamydia trachomatis.

Whether mortality rates among diabetic adults or excess mortality associated with diabetes in the United States has declined in recent decades is not known.

In 2002, the Accreditation Council on Graduate Medical Education enacted regulations, effective 1 July 2003, that limited work hours for all residency programs in the United States.

Limits on resident work hours are intended to reduce fatigue-related errors, but may raise risk by increasing transfers of responsibility for patients.