Interpreting the Health Care Financing Administration's mortality statistics

In this article, the methodology used by the Health Care Financing Administration in the 1992 release of 1990 mortality statistics is described, and the performance of one outlier hospital is evaluated as a case study. The study hospital is compared to all other hospitals, and to a smaller cohort of 200-to-299-bed minor teaching hospitals, in terms of predicted and observed mortality rates and mortality model determinants. Proportionately more patients treated in the study hospital were women and had cerebrovascular degeneration or chronic renal disease; fewer patients had cardiovascular disease. Substantially more patients from this hospital were transfers from a skilled nursing facility. Fewer patients were admitted through the emergency department. Although patients tended to be more seriously ill overall compared with other hospitals in the country, observed mortality rates were still higher than predicted. Possible explanations for the discrepancy were coding inconsistencies, inability to control adequately for the severity of illness of transfers from skilled nursing facilities, or quality of care problems.