Objective: To evaluate the performance of a routine incident reporting system in identifying patient safety incidents.
Design: Two stage retrospective review of patients' case notes and analysis of data submitted to the routine incident reporting system on the same patients.
Setting: A large NHS hospital in England.
Population: 1006 hospital admissions between January and May 2004: surgery (n=311), general medicine (n=251), elderly care (n=184), orthopaedics (n=131), urology (n=61), and three other specialties (n=68).
Main outcome measures: Proportion of admissions with at least one patient safety incident; proportion and type of patient safety incidents missed by routine incident reporting and case note review methods.
Results: 324 patient safety incidents were identified in 230/1006 admissions (22.9%; 95% confidence interval 20.3% to 25.5%). 270 (83%) patient safety incidents were identified by case note review only, 21 (7%) by the routine reporting system only, and 33 (10%) by both methods. 110 admissions (10.9%; 9.0% to 12.8%) had at least one patient safety incident resulting in patient harm, all of which were detected by the case note review and six (5%) by the reporting system.
Conclusion: The routine incident reporting system may be poor at identifying patient safety incidents, particularly those resulting in harm. Structured case note review may have a useful role in surveillance of routine incident reporting and associated quality improvement programmes.