Health care payors and providers are increasingly monitoring hospital discharge data bases for adverse events as markers for quality of care. The principal criticisms of these analyses have focused on the impediments to risk adjustment posed by the incompleteness and inaccuracy of the data bases. However, efforts to address the inadequacies of the data bases will not correct deficiencies of the analytic process. These deficiencies arise from the application of one adverse outcome to all disease states. Instead, analysis should be restricted to comparisons of subgroups of patients in which a close fit exists between the quality of care for the disease state and the expected outcome. Furthermore, these disease-outcome pairs should be minimally subject to measurement error. The authors present a conceptual framework for developing such meaningful disease-outcome pairs, and using the hospital discharge data base of the Department of Veterans Affairs, show how the framework can be used to devise a monitoring strategy for re-admission.