The New England journal of medicine
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Randomized Controlled Trial Clinical Trial
Bias in treatment assignment in controlled clinical trials.
Controlled clinical trials of the treatment of acute myocardial infarction offer a unique opportunity for the study of the potential influence on outcome of bias in treatment assignment. A group of 145 papers was divided into those in which the randomization process was blinded (57 papers), those in which it may have been unblinded (45 papers), and those in which the controls were selected by a nonrandom process (43 papers). ⋯ Differences in case-fatality rates between treatment and control groups (P less than 0.05) were found in 8.8 per cent of the blinded-randomization studies, 24.4 per cent of the unblinded-randomization studies, and 58.1 per cent of the nonrandomized studies. These data emphasize the importance of keeping those who recruit patients for clinical trials from suspecting which treatment will be assigned to the patient under consideration.
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We studied insulin-like growth factors (IGF) I and II, prolactin, and the insulin response to arginine in 19 children with craniopharyngioma and documented growth hormone deficiency. Patients were divided into three groups according to their growth rate during the first postoperative year. Seven patients with excessive growth (Group A) had hyperinsulinism, normal IGF values, elevated basal prolactin levels, and a delayed thyrotropin response to thyrotropin-releasing hormone, which was compatible with hypothalamic lesions. ⋯ Patients in all groups had low or undetectable basal levels of growth hormone. We conclude that in Group B, normal IGF permitted normal growth, and prolactin hypersecretion may have been responsible for normal IGF I values. Excessive growth in Group A may have been caused by hyperinsulinism associated with hyperphagia and obesity of hypothalamic origin.
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To determine how physicians ration limited critical resources, we studied the allocation of intensive-care-unit (ICU) beds during a shortage caused by a lack of nurses. As the bed capacity of the medical ICU decreased from 18 to 8, the percentage of days on which one or more beds were available decreased from 95 to 55 per cent, and monthly admissions decreased from 122 to 95. Physicians responded by restricting ICU admissions to acutely ill patients and reducing the proportion of patients admitted primarily for monitoring. ⋯ In addition, physicians transferred patients out of the ICU sooner. There was no apparent withdrawal of care from dying patients. Our results suggest that physicians can respond to moderate resource limitations by more efficient use of intensive-care resources.