Bayesian Inference for Hospital Quality in a Selection Model

FRB of San Francisco Working Paper No. 2002-18

63 Pages Posted: 3 May 2005

See all articles by John Geweke

John Geweke

University of Technology Sydney - Economics Discipline Group

Gautam Gowrisankaran

Columbia University; HEC Montreal; Centre for Economic Policy Research (CEPR); National Bureau of Economic Research (NBER)

Robert J. Town

National Bureau of Economic Research (NBER)

Multiple version iconThere are 2 versions of this paper

Date Written: July 2002

Abstract

This paper develops new econometric methods to infer hospital quality in a model with discrete dependent variables and non-random selection. Mortality rates in patient discharge records are widely used to infer hospital quality. However, hospital admission is not random and some hospitals may attract patients with greater unobserved severity of illness than others. In this situation the assumption of random admission leads to spurious inference about hospital quality. This study controls for hospital selection using a model in which distance between the patient's residence and alternative hospitals are key exogenous variables. Bayesian inference in this model is feasible using a Markov chain Monte Carlo posterior simulator, and attaches posterior probabilities to quality comparisons between individual hospitals and groups of hospitals. The study uses data on 74,848 Medicare patients admitted to 114 hospitals in Los Angeles County from 1989 through 1992 with a diagnosis of pneumonia. It finds the smallest and largest hospitals to be of the highest quality. There is strong evidence of dependence between the unobserved severity of illness and the assignment of patients to hospitals, whereby patients with a high unobserved severity of illness are disproportionately admitted to high quality hospitals. Consequently a conventional probit model leads to inferences about quality markedly different than those in this study's selection model.

Keywords: Medical care

Suggested Citation

Geweke, John and Gowrisankaran, Gautam and Town, Robert J., Bayesian Inference for Hospital Quality in a Selection Model (July 2002). FRB of San Francisco Working Paper No. 2002-18, Available at SSRN: https://ssrn.com/abstract=709364 or http://dx.doi.org/10.2139/ssrn.709364

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Robert J. Town

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