COMPARING MORTALITY AND MORBIDITY IN HOSPITALS - THEORY AND PRACTICE OF QUALITY ASSESSMENT IN PEER-REVIEW

The incidence of mortality in a specific hosPital depends on many risk factors. These risk factors may be divided roughly into two categorie s. The intake category, consists of those risk factors for which the h ospital has hardly any influence upon their incidence; and the care ca tegory being those for which the incidence depends partly or completel y on the treatment policy of the hospital. A hospital with a high inci dence of risk factors in the intake category will have a higher mortal ity rate than a hospital with a low incidence, even if their care is e xactly the same (i. e., if they treat their infants equally well). The refore, a fair comparison between one hospital and a reference cohort, or among several hospitals (using a national registry) should adjust e. g. correct for those risk factors belonging to the intake category. A practical method is proposed, based on logistic regression, to effe ctuate such a ''fair'' judgment. The regression technique enables to c ompare ''observed'' and 'expected'' rates in a specific hospital and t o test whether a difference between these rates is statistically signi ficant. Both clinical and statistical aspects of the method are discus sed, as well as the actual implementation of an automated annual repor ting system. The method has been implemented in the Netherlands as an annual peer review and quality assessment system in obstetric care.