CONFIDENCE-INTERVAL ESTIMATES OF AN INDEX OF QUALITY PERFORMANCE-BASED ON LOGISTIC-REGRESSION MODELS

This paper considers an index of hospital quality performance defined as the ratio of the observed number deaths to the number predicted by a fitted logistic regression model. We study tests and confidence inte rvals under two different scenarios depending on the availability of a n estimate of the covariance matrix of the coefficients from the fitte d logistic regression model. We propose parametric as well as bootstra p-based confidence intervals. We apply the methods to an analysis of t he performance of 27 intensive care units.