PROCESS AND OUTCOME OF CARE FOR ACUTE MYOCARDIAL-INFARCTION AMONG MEDICARE BENEFICIARIES IN CONNECTICUT - A QUALITY IMPROVEMENT DEMONSTRATION PROJECT

Objective: To evaluate the feasibility of linking claims-based pattern analysis with medical record review in the assessment of quality of h ospital care among Medicare beneficiaries with acute myocardial infarc tion. Design: An analysis of risk-adjusted mortality after hospital ad mission for acute myocardial infarction using the regression model fro m the Health Care Financing Administration for predicting mortality ra tes. Hospital records for 300 patients admitted for myocardial infarct ion were abstracted to evaluate the accuracy of diagnostic coding and the adequacy of claims data-based risk adjustment and to assess proces s measures of quality care. Setting: Six Connecticut hospitals in the pilot study of the Medicare Hospital information Project. Patients: Me dicare beneficiaries 65 years of age or older who were hospitalized wi th a primary diagnosis of acute myocardial infarction from 1989 to 199 1. Main Outcome Measures: Principal diagnosis code verification rates for acute myocardial infarction; observed mortality rates at 30 and 36 5 days; 30-day standardized mortality ratios; and utilization rates fo r thrombolytic agents, aspirin, and beta-blockers. Results: The coding of acute myocardial infarction diagnosis had an overall accuracy of 9 6%. Little change was noted in relative mortality ratio hospital rank order after the exclusion of 13 patients who did not fulfill criteria for acute myocardial infarction and after additional risk adjustment w ith Killip class data. Utilization rates for therapies among eligible patients were as follows: aspirin, 73%; beta-blockers, 41%; and thromb olytic agents, 43%. The use of thrombolytic agents was associated with a lower 30-day mortality; the use of thrombolytic agents, aspirin, an d beta-blockers was related to lower mortality rates at 1 year after d ischarge; and the use of these three therapies was lower in the two ho spitals with the highest risk-adjusted mortality. Conclusions: Medicar e principal diagnosis codes for acute myocardial infarction were accur ate in the six study hospitals. Therapies that have been endorsed by c linicians in Connecticut were underused in elderly patients. Pattern a nalysis of Medicare claims data can be useful as a quality-of-care scr eening tool; however, additional clinical information is required to s timulate quality improvement efforts within hospitals.