Estimating the out-of-hospital mortality rate using patient discharge data

This paper explores the hospital quality measures based on routine administrative data such as patient discharge records. Most of the measures used in the literature are based on in-hospital mortality risks rather than post-discharge events. The in-hospital outcomes are sensitive to the hospital's discharge policy, thus could bias the quality estimates. This study aims at identifying out-of-hospital mortality risks and disentangling discharge and re-hospitalization rates from mortality rates using patient discharge data. It is shown that these objectives can be achieved without post-discharge death records. This is an example of the use of public use administrative data for estimating empirical relations when key dependent variables are not available. Using data on the lengths of hospitalizations and out-of-hospital spells, the mortality rates before and after discharge are estimated for a sample of heart-attack patients hospitalized in California between 1992 and 1998. The results suggest that the quality assessments that ignore the variation of discharge rates among hospitals could be misleading.