How does one measure hospital quality? Quality occurs along multiple dimensions. Thus, to summarize overall quality, one must create a weighting scheme to compete the distinct quality measures in a single measure. In most cases, quality measures should also account for differences in patient case mix. Hospitals should not be punished with lower quality scores for treating sicker patients. Various risk adjustment methodologies can be applied to account for variation in patient case mix across hospitals.
Step 1: Calculate Risk Adjusted Rates for Each Measure
Yi = Oi/Ei,
Oi = ni-1Σjyij
Ei = ni-1Σjpij
where pij is the predicted probability based on a logit function [i.e., pij=P(yij=1|Xij)] and Xij are patient covariates such as age, gender, race, and health status. Yi is a Kx1 vector of risk-adjusted mortality rate for hospital i.