Intra-hospital correlations among 30-day mortality rates in 18 different clinical and surgical settings

OBJECTIVE: To examine whether a correlation exists in hospitals among 30-day mortality rates for different types of hospitalizations. DESIGN: Cross-sectional study of hospital care based on publically available Italian data from the National Outcome Evaluation Program Edition 2015 of the Italian Agency for Regional Health Services. SETTING AND PARTICIPANTS: Patients hospitalized with a diagnosis of congestive heart failure, acute myocardial infarction, chronic renal failure, chronic obstructive pulmonary disease exacerbation, femoral neck fracture, ischemic stroke and non-variceal upper gastrointestinal bleeding, or those who underwent isolated cardiac valve procedure, isolated coronary artery bypass graft surgery, non-ruptured abdominal aortic aneurysm repair and interventions for the following tumors: colon, kidney, brain, lung, stomach, rectal, liver or pancreatic cancer. MAIN OUTCOME MEASURES: Condition-specific 30-day crude and risk-adjusted mortality rates. RESULTS: A total of 808 280 admissions were reported from 844 institutions (median of 4 conditions evaluated per hospital; interquartile range 2-8). Volumes and outcome varied by clinical and surgical conditions across hospitals. Out of 153 pairs of different conditions, 41 were statistically significant in terms of concordance with crude mortality rates and 44 for their adjusted values. The hospital mean percentile rank for 30-day mortality, a composite measure that summarized the multiple indicators, increased significantly alongside number of conditions per hospital with a significant reduction of mortality when most of the studied conditions were treated in the same hospital. CONCLUSIONS: The variability in 30-day mortality rates at hospital level and the correlation between risk mortality rates suggest that there may be common hospital-wide factors influencing short-term mortality.