Since the late 19th century, state legislatures and professional medical organizations have developed mechanisms to license physicians and other conventional nonphysician providers, establish standards of practice, and protect health care consumers by establishing standardized credentials as markers of competence. The popularity of complementary and alternative medical (CAM) therapies presents new challenges. This article describes the current status of, and central issues in, efforts to create models for health care credentialing of chiropractors, acupuncturists, naturopaths, massage therapists, and other CAM practitioners. It also suggests a strategy of CAM provider credentialing for use by physicians, health care administrators, insurance companies, and national professional organizations. The credentialing debate reflects fundamental questions about who determines which providers and therapies will be accepted as safe, effective, appropriate, and reimbursable. More nationally uniform credentialing mechanisms are necessary to ensure high standards of care and more generalizable clinical research. However, the result of more uniform licensure and credentialing may be excessive standardization and a decrease in individualization of services. Thus, increased standardization of credentialing for CAM practitioners may alter CAM practice substantially. Furthermore, even credentialed providers can deliver ineffective therapy. The suggested framework balances the desire to protect the public from dangerous practices against the wish to grant patients access to reasonably safe and effective therapies.

In U.S. men, prostate cancer is the most common noncutaneous cancer and the second leading cause of cancer death. Screening for prostate cancer is controversial.

Mounting evidence indicates that subclinical thyroid dysfunction has important clinical effects and prognostic implications, supporting the view that it is not a compensated biochemical change sensu strictu.

Many patients with cancer use complementary and alternative medical (CAM) therapies. Physicians need authoritative information on CAM therapies to responsibly advise patients who seek these interventions. This article summarizes current evidence on the efficacy and safety of selected CAM therapies that are commonly used by patients with cancer. The following major categories of interventions are covered: dietary modification and supplementation, herbal products and other biological agents, acupuncture, massage, exercise, and psychological and mind-body therapies. Two categories of evidence on efficacy are considered: possible effects on disease progression and survival and possible palliative effects. In evaluating evidence on safety, two types of risk are considered: the risk for direct adverse effects and the risk for interactions with conventional treatments. For each therapy, the current balance of evidence on efficacy and safety points to whether the therapy may be reasonably recommended, accepted (for example, dietary fat reduction in well-nourished patients with breast or prostate cancer), or discouraged (for example, high-dose vitamin A supplementation). This strategy allows the development of an approach for providing responsible, evidence-based, patient-centered advice to persons with cancer who seek CAM therapies.

This statement summarizes the U.S. Preventive Services Task Force (USPSTF) recommendations for use of hormone replacement therapy for the primary prevention of chronic conditions in postmenopausal women and updates the 1996 USPSTF recommendations on this topic. The complete information on which this statement is based, including evidence tables and references, is available through the USPSTF Web site (http://www.preventiveservices.ahrq.gov) and through the National Guideline Clearinghouse (http://www.guideline.gov) The USPSTF reviewed the evidence on the use of postmenopausal hormone replacement therapy and the following outcomes: cardiovascular disease, including CHD and stroke; osteoporosis and fractures; thromboembolism; dementia and cognitive function; breast, colon, ovarian, and endometrial cancer; and cholecystitis. The USPSTF also reviewed evidence of the effects of hormone replacement therapy on phytoestrogens and osteoporosis and cardiovascular disease. The use of hormone replacement therapy for relieving active symptoms of menopause, such as hot flashes, urogenital symptoms, and mood and sleep disturbances, among others, is outside the scope of these USPSTF recommendations, and literature on this topic was not reviewed. Sources for estimates of benefits and harms cited in this Recommendation statement are described in the summary of the evidence available from the Agency for Healthcare Research and Quality.

Acute coronary syndromes--unstable angina, myocardial infarction, and sudden cardiac death--are caused by acute disruption of an unstable coronary atheroma. Unstable plaques have three histologic characteristics: a large lipid core, many inflammatory cells, and a thin fibrous cap. Because the unstable plaque is not necessarily obstructive, it may cause no symptoms before rupture. The cellular processes that lead to the characteristic histologic features of unstable plaque have recently been identified. This new understanding of the cell biology of plaque instability suggests new therapeutic strategies: passivation of the endothelium, reduction of low-density lipoprotein (LDL) in the vessel wall by decreasing serum LDL levels or accelerating reverse cholesterol transport, inhibition of LDL oxidation, inhibition of inflammatory cytokine expression, and inhibition of thrombus formation. Although the morbidity and mortality resulting from acute coronary disease have been reduced by more than 50% over the past 30 years, it is reasonable to anticipate further reductions of similar magnitude in the decade ahead.

Women commonly use soy products, herbs, and other complementary and alternative medicine (CAM) therapies for menopausal symptoms. Randomized, controlled trials have evaluated the efficacy and short-term safety of these therapies.

The term dysautonomia refers to a change in autonomic nervous system function that adversely affects health. The changes range from transient, occasional episodes of neurally mediated hypotension to progressive neurodegenerative diseases; from disorders in which altered autonomic function plays a primary pathophysiologic role to disorders in which it worsens an independent pathologic state; and from mechanistically straightforward to mysterious and controversial entities. In chronic autonomic failure (pure autonomic failure, multiple system atrophy, or autonomic failure in Parkinson disease), orthostatic hypotension reflects sympathetic neurocirculatory failure from sympathetic denervation or deranged reflexive regulation of sympathetic outflows. Chronic orthostatic intolerance associated with postural tachycardia can arise from cardiac sympathetic activation after "patchy" autonomic impairment or blood volume depletion or, as highlighted in this discussion, from a primary abnormality that augments delivery of the sympathetic neurotransmitter norepinephrine to its receptors in the heart. Increased sympathetic nerve traffic to the heart and kidneys seems to occur as essential hypertension develops. Acute panic can evoke coronary spasm that is associated with sympathoneural and adrenomedullary excitation. In congestive heart failure, compensatory cardiac sympathetic activation may chronically worsen myocardial function, which rationalizes treatment with beta-adrenoceptor blockers. A high frequency of positive results on tilt-table testing has confirmed an association between the chronic fatigue syndrome and orthostatic intolerance; however, treatment with the salt-retaining steroid fludrocortisone, which is usually beneficial in primary chronic autonomic failure, does not seem to be beneficial in the chronic fatigue syndrome. Dysautonomias are an important subject in clinical neurocardiology.

Acute tubular necrosis (ATN) is common in hospitalized patients, particularly in the intensive care unit. Over the past four decades, the mortality rate from ATN has remained at 50% to 80%.

To assess the effect of cardioselective beta-blockers on respiratory function of patients with reactive airway disease.

Breast cancer in men is uncommon; 1500 new cases are diagnosed in the United States yearly. Optimal management of breast cancer in men is unknown because the rarity of the disease precludes large randomized trials. A review of the literature was undertaken with emphasis on articles published over a 10-year period.

Colon cancer is a common disease that can be sporadic, familial, or inherited. Recent advances have contributed to the understanding of the molecular basis of these various patterns of colon cancer. Germline genetic mutations are the basis of inherited colon cancer syndromes; an accumulation of somatic mutations in a cell is the basis of sporadic colon cancer; and, in Ashkenazi Jewish persons, a mutation that was previously thought to be a polymorphism may cause familial colon cancer. Mutations of three different classes of genes have been described in colon cancer etiology: oncogenes, suppressor genes, and mismatch repair genes. Knowledge of many of the specific mutations responsible for colon carcinogenesis allows an understanding of the phenotypic manifestations observed and forms the basis of genetic testing for inherited disease. Although genetic testing is possible and available, it is only an adjunct to the clinical management of persons at risk for colon cancer and patients with colon cancer. As a result of advances in the understanding of the molecular causes of colon cancer and the availability of colon cancer screening methods such as colonoscopy, it should be possible to prevent the vast majority of colon cancer in our society. Practicing clinicians should recognize the patterns of clinical colon cancer, understand its causes, and be able to use genetic testing and endoscopic screening for prevention.

To review evidence on the diagnostic accuracy of clinical information and imaging for patients with low back pain in primary care settings.

To systematically review the methodologic rigor of the research on volume and outcomes and to summarize the magnitude and significance of the association between them.