Because of the pressure for timely, informed decisions in public health and clinical practice and the explosion of information in the scientific literature, research results must be synthesized. Meta-analyses are increasingly used to address this problem, and they often evaluate observational studies. A workshop was held in Atlanta, Ga, in April 1997, to examine the reporting of meta-analyses of observational studies and to make recommendations to aid authors, reviewers, editors, and readers.

Access to medical information via the Internet has the potential to speed the transformation of the patient-physician relationship from that of physician authority ministering advice and treatment to that of shared decision making between patient and physician. However, barriers impeding this transformation include wide variations in quality of content on the Web, potential for commercial interests to influence online content, and uncertain preservation of personal privacy. To address these issues, the American Medical Association (AMA) has developed principles to guide development and posting of Web site content, govern acquisition and posting of online advertising and sponsorship, ensure site visitors' and patients' rights to privacy and confidentiality, and provide effective and secure means of e-commerce. While these guidelines were developed for the AMA Web sites and visitors to these sites, they also may be useful to other providers and users of medical information on the Web. These principles have been developed with the understanding that they will require frequent revision to keep pace with evolving technology and practices on the Internet. The AMA encourages review and feedback from readers, Web site visitors, policymakers, and all others interested in providing reliable quality information via the Web.

Glucosamine and chondroitin preparations are widely touted in the lay press as remedies for osteoarthritis (OA), but uncertainty about their efficacy exists among the medical community.

Sedation has become an integral part of critical care practice in minimizing patient discomfort; however, sedatives have adverse effects and the potential to prolong mechanical ventilation, which may increase health care costs.

To update recommendations for antiretroviral therapy for adult human immunodeficiency virus type 1 (HIV-1) infection, based on new information and drugs that are available.

Controversy exists over the fact that physicians have regular contact with the pharmaceutical industry and its sales representatives, who spend a large sum of money each year promoting to them by way of gifts, free meals, travel subsidies, sponsored teachings, and symposia.

Lowering low-density lipoprotein cholesterol (LDL-C) is known to reduce risk of recurrent coronary heart disease in middle-aged men. However, this effect has been uncertain in elderly people and women.

Despite years of use in coronary artery disease (CAD) and several studies of its effectiveness, the role of oral anticoagulants (OAs) remains controversial.

The Second Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel II) was issued without the benefit of multiple recently published large clinical trials.

Nonsteroidal anti-inflammatory drug (NSAID)-induced gastrointestinal (GI) toxic effects, such as upper GI tract perforations, symptomatic gastroduodenal ulcers, and upper GI tract bleeding (PUBs), are thought to be attributable to cyclooxygenase 1 (COX-1) inhibition. Rofecoxib specifically inhibits COX-2 and has demonstrated a low potential for causing upper GI injury.

Despite wide promulgation, clinical practice guidelines have had limited effect on changing physician behavior. Little is known about the process and factors involved in changing physician practices in response to guidelines.

Patients with advanced dementia frequently develop eating difficulties and weight loss. Enteral feeding tubes are often used in this situation, yet benefits and risks of this therapy are unclear. We searched MEDLINE, 1966 through March 1999, to identify data about whether tube feeding in patients with advanced dementia can prevent aspiration pneumonia, prolong survival, reduce the risk of pressure sores or infections, improve function, or provide palliation. We found no published randomized trials that compare tube feeding with oral feeding. We found no data to suggest that tube feeding improves any of these clinically important outcomes and some data to suggest that it does not. Further, risks are substantial. The widespread practice of tube feeding should be carefully reconsidered, and we believe that for severely demented patients the practice should be discouraged on clinical grounds.

To estimate the risk and prevalence of Mycobacterium tuberculosis (MTB) infection and tuberculosis (TB) incidence, prevalence, and mortality, including disease attributable to human immunodeficiency virus (HIV), for 212 countries in 1997.

A recent meta-analysis found calcium supplementation to be highly effective in preventing preeclampsia but a large National Institutes of Health trial (Calcium for Preeclampsia Prevention [CPEP]) found no risk reduction due to calcium in healthy nulliparous women.

The clinical breast examination (CBE) is widely recommended and practiced as a tool for breast cancer screening; however, its effectiveness is dependent on its precision and accuracy.

Despite the frequency of depression in women of childbearing age, information to guide patients and physicians through a consideration of treatment during pregnancy is limited.

Transplantation therapies have revolutionized care for patients with endstage organ (kidney, liver, heart, lung, and pancreatic beta-cell) failure, yet significant problems persist with treatments designed to prevent graft rejection. Antirejection therapies are not always effective, must be taken daily, and are both expensive and associated with well-known toxic effects. Recent advances have suggested that the immune system has more self-regulatory capability than previously appreciated. In this review, we discuss immune system function and new therapeutic agents that modify so-called costimulatory receptor signaling to support transplant function without generally suppressing the immune system.