Temporal variation in surgical mortality within French hospitals

Surgical mortality varies widely across hospitals, but the degree of temporal variation within individual hospitals remains unexplored and may reflect unsafe care.

To add a longitudinal dimension to large-scale profiling efforts for interpreting surgical mortality variations over time within individual hospitals.

Longitudinal analysis of the French nationwide hospital database using statistical process control methodology.

A total of 9,474,879 inpatient stays linked with open surgery from 2006 through 2010 in 699 hospitals.

For each hospital, a control chart was designed to monitor inpatient mortality within 30 days of admission and mortality trend was determined. Aggregated funnel plots were also used for comparisons across hospitals.

Over 20 successive quarters, 52 hospitals (7.4%) experienced the detection of at least 1 potential safety issue reflected by a substantial increase in mortality momentarily. Mortality variation was higher among these institutions compared with other hospitals (7.4 vs. 5.0 small variation signals, P<0.001). Also, over the 5-year period, 119 (17.0%) hospitals reduced and 36 (5.2%) increased their mortality rate. Hospitals with improved outcomes had better control of mortality variation over time than those with deteriorating trends (5.2 vs. 6.3 signals, P=0.04). Funnel plots did not match with hospitals experiencing mortality variations over time.

Dynamic monitoring of outcomes within every hospital may detect safety issues earlier than traditional benchmarking and guide efforts to improve the value of surgical care nationwide.