RECALMIN: The association between management of Spanish National Health Service Internal Medical Units and health outcomes.

OBJECTIVE: To investigate the association between management of Internal Medical Units (IMUs) with outcomes (mortality and length of stay) within the Spanish National Health Service. DESIGN: Data on management were obtained from a descriptive transversal study performed among IMUs of the acute hospitals. Outcome indicators were taken from an administrative database of all hospital discharges from the IMUs. SETTING: Spanish National Health Service. PARTICIPANTS: One hundred and twenty-four acute general hospitals with available data of management and outcomes (401 424 discharges). MAIN OUTCOME MEASURES: IMU risk standardized mortality rates were calculated using a multilevel model adjusted by Charlson Index. Risk standardized myocardial infarction and heart failure mortality rates were calculated using specific multilevel models. Length of stay was adjusted by complexity. RESULTS: Greater hospital complexity was associated with longer average length of stays (r: 0.42; P < 0.001). Crude in-hospital mortality rates were higher at larger hospitals, but no significant differences were found when mortality was risk adjusted. There was an association between nurse workload with mortality rate for selected conditions (r: 0.25; P = 0.009). Safety committee and multidisciplinary ward rounds were also associated with outcomes. CONCLUSIONS: We have not found any association between complexity and intra-hospital mortality. There is an association between some management indicators with intra-hospital mortality and the length of stay. Better disease-specific outcomes adjustments and a larger number of IMUs in the sample may provide more insights about the association between management of IMUs with healthcare outcomes.