A critical review of research on hospital mortality among medical–surgical and acute myocardial infarction patients

Research results reporting the relationships of hospital structural characteristics to inpatient mortality for medical–surgical and Acute Myocardial Infarction patients are inconclusive. Hospital characteristics thought to be significantly associated with mortality are: percentage of board‐certified physicians, the hospital's teaching status, and technological resource availability. Yet studies of these characteristics have yielded mixed results. Only Registered Nurse ratios (measures of Registered Nurse hours per patient days or per patient) have been shown to be consistently (and inversely) associated with mortality. However, far fewer studies have examined the impact of this variable and design weaknesses, including the absence of a conceptual framework to guide the selection of a given study's explanatory variables, have hindered those that have. Further, inconsistencies, indeed clear contradictions, in these studies’ findings (with the exception of nurse ratios) necessitate further analysis of both research methods and interpretation of results. Such analyses must occur to promote advances in research design and methodology in studies of inpatient mortality.