We propose that an investigation of the serum digitalis concentration as a test for digitalis toxicity should (1) study patients with similar toxic manifestations, (2) obtain control concentrations from nontoxic patients with symptoms suggesting toxicity, (3) define criteria for toxicity and nontoxicity, (4) select representative patients, (5) describe the study population and (6) analyze how much diagnostic information the serum digitalis concentration provides that cannot be inferred from other observations. To determine if available evidence validates the digitalis concentration as a test for toxicity 27 reports were reviewed. No investigation employed symptomatic controls. Of five studies most consistent with points 1-5 only three demonstrated higher mean serum digitalis concentrations in toxic patients. Whether knowledge of the digitalis concentrations was diagnostically more useful than knowledge of the digitalis dosage, renal function, serum potassium concentration and cardiac status was not determined in any study. The usefulness of the serum digitalis concentration as a test for digitalis toxicity is therefore not established.

No abstract

The frequency of electrocardiographic evidence of coronary heart disease (CHD) and the rate of autopsy-proved myocardial infarction were determined in the Pima, a tribe of American Indians with a high prevalence of diabetes mellitus. The electrocardiograms of 701 Pimas, aged 40 years and over (85 per cent of the adult reservation population, 45 per cent of whom had diabetes) were read according to the Minnesota Code, and 120 postmortem examinations were reviewed for evidence of myocardial infarction. The frequency of CHD as evidenced by major Q-wave changes in the Pima (1.6/100) was about one-half that found in Tecumseh, Michigan (p less than 0.10). The relatively low rate of myocardial infarction at autopsy (15 per cent of males and 8 per cent of females aged 40 years and over) was consistent with the low prevalence of Q-wave changes. The subjects with diabetes had a higher rate of CHD than nondiabetics, both electrocardiographically and at postmortem examination, although the differences were not statistically significant. The low prevalence of CHD in the living Pima and the low rate of infarction at autopsy indicate that this tribe has a low frequency of CHD despite the extraordinarily high prevalence of diabetes mellitus.

No abstract

We reviewed 103 controlled clinical trials that compared the antiarthritic efficacy and tolerance of previously and currently marketed nonsteroidal antiinflammatory drugs (NSAIDs) and aspirin. Of 52 studies, 35 had data sufficient to calculate an NSAID efficacy index (the ratio of mean improvement in NSAID-treated patients to that in aspirin-treated patients) based on subjective and/or objective criteria. The mean indexes (obtained from all studies from which an index could be calculated) indicated no statistically significant difference in efficacy between aspirin and the NSAIDs as a group; the indexes tended to become less variable as the number of study subjects increased. Tolerance, assessed from the percentage of patients who discontinued the drug because of side effects, was significantly greater for NSAIDs than for aspirin. The NSAIDs had greater efficacy but not greater toxicity at increased doses. Efficacy differences described among NSAIDs in some studies were attributable either to comparisons at nonequivalent doses or to chance.