Prevalence of ischemic resting and stress electrocardiographic abnormalities and angina among 40- to 59-year-old men in selected U.S. and U.S.S.R. populations.

The prevalence of electrocardiographic (ECG) abnormalities and angina was investigated in 40- to 59-year-old men from two samples, one from a U.S.S.

Determination of free digoxin concentrations in serum for monitoring Fab treatment of digoxin overdose.

A rapid method for assessing the free digoxin concentration in the serum of digoxin-overdosed patients receiving treatment with digoxin-specific Fab fragments has been developed. For this method, a protein-free ultrafiltrate is prepared from the patient's serum, and the digoxin in the ultrafiltrate (free digoxin) is measured by fluorescence polarization immunoassay. Both the inaccuracies associated with measurements of total digoxin by immunoassay in the presence of Fab and the long turnaround time associated with measurements of free digoxin by equilibrium dialysis were avoided.

Effect of positive end-expiratory pressure on right and left ventricular function in patients with the adult respiratory distress syndrome.

The predominant mechanism of the cardiac output reduction associated with positive end-expiratory pressure (PEEP) is unclear. Reported possibilities include decreased systemic venous return, increased pulmonary vascular resistance, or change in ventricular contractility. We investigated this question by studying 9 patients with the adult respiratory distress syndrome (ARDS) during PEEP application.

Specificity, sensitivity, and prevalence in the design of randomized trials: a univariate analysis.

The number of cases needed to conduct a randomized trial is related to the sensitivity and specificity of a measurement indicative of a condition, to the prevalence of the condition, to the expected benefit of therapy (or other basis for change), and to the statistical precision desired. Sample size calculations frequently ignore sensitivity and specificity (at least qualitatively) probably because no simple formula is provided in the literature. Such a formula is included here.