The purpose of the proposed study is to determine whether hospital staffing is related to clinical outcomes, and if so, to determine the intermediate or operant mechanisms by which staffing and hospital organization influence outcomes. The design will enable advancement of knowledge about how nursing affects clinical outcomes in hospital inpatient settings something that has been missing in multivariate studies of correlates of differential hospital outcomes. Based on their previous research, the investigators hypothesize that organizational attributes mediate the effects of nurse staffing on outcomes. Thus, they approach this study with an analytic model and data that facilitates testing the interaction between staffing and organization. A detailed data set is available on staffing patterns including all categories of hospital staff, not just nursing personnel. The investigators also will be able to explore whether changes in hospital staffing patterns over time appear to have an effect on clinical outcomes above and beyond that of current staffing levels. Finally, they will move beyond hospital-specific mortality rates to complication rates and failure to rescue. They argue that if nurse staffing ratios are sufficient to detect early signs of complications in an increasingly sick inpatient population and/or there are organizational impediments to timely clinical intervention, patients with complications are more likely to die, hence the connection between hospital organization, nurse staffing, and mortality. The research proposal has the following specific aims: (1) to determine the relative effects of hospital staffing variables and organizational attributes on severity-adjusted inpatient mortality rates, controlling for other likely explanatory variables; (2) to determine the relative effects of hospital staffing variables and organizational attributes on deaths following complications (failure to rescue), and to determine the extent to which our measures of failure to rescue explain nurse-related staffing and organization effects on inpatient mortality; and, (3) to determine the relative effects of hospital staffing variables and organizational attributes on nurse burnout and nurse injuries from blood-contaminated needles/sharps (a measure of safety).