JAMA : the journal of the American Medical Association
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Randomized Controlled Trial Multicenter Study Clinical Trial
Effects of selenium supplementation for cancer prevention in patients with carcinoma of the skin. A randomized controlled trial. Nutritional Prevention of Cancer Study Group.
To determine whether a nutritional supplement of selenium will decrease the incidence of cancer. ⋯ Selenium treatment did not protect against development of basal or squamous cell carcinomas of the skin. However, results from secondary end-point analyses support the hypothesis that supplemental selenium may reduce the incidence of, and mortality from, carcinomas of several sites. These effects of selenium require confirmation in an independent trial of appropriate design before new public health recommendations regarding selenium supplementation can be made
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To examine the protective effectiveness of bicycle helmets in 4 different age groups of bicyclists, in crashes involving motor vehicles, and by helmet type and certification standards. ⋯ Bicycle helmets, regardless of type, provide substantial protection against head injuries for cyclists of all ages involved in crashes, including crashes involving motor vehicles.
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Editorial Comment Comparative Study
Swapping health care systems. Whose grass is really greener?