Abstract
BACKGROUND: Clinical auditing is a powerful tool to evaluate and improve healthcare. Deviations from the expected quality of care are identified by benchmarking the results of individual hospitals using national averages. This study aimed to evaluate the use of quality indicators for benchmarking hepato-pancreato-biliary (HPB) surgery and when outlier hospitals could be identified. METHODS: A population-based study used data from two nationwide Dutch HPB audits (DHBA and DPCA) from 2014 to 2021. Sample size calculations determined the threshold (in percentage points) to identify centres as statistical outliers, based on current volume requirements (annual minimum of 20 resections) on a two-year period (2020-2021), covering mortality rate, failure to rescue (FTR), major morbidity rate and textbook/ideal outcome (TO) for minor liver resection (LR), major LR, pancreaticoduodenectomy (PD) and distal pancreatectomy (DP). RESULTS: In total, 10 963 and 7365 patients who underwent liver and pancreatic resection respectively were included. Benchmark and corresponding range of mortality rates were 0.6% (0 -3.2%) and 3.3% (0-16.7%) for minor and major LR, and 2.7% (0-7.0%) and 0.6% (0-4.2%) for PD and DP respectively. FTR rates were 5.4% (0-33.3%), 14.2% (0-100%), 7.5% (1.6%-28.5%) and 3.1% (0-14.9%). For major morbidity rate, corresponding rates were 9.8% (0-20.5%), 28.1% (0-47.1%), 36% (15.8%-58.3%) and 22.3% (5.2%-46.1%). For TO, corresponding rates were 73.6% (61.3%-94.4%), 54.1% (35.3-100), 46.8% (25.3%-59.4%) and 63.3% (30.7%-84.6%). Mortality rate thresholds indicating a significant outlier were 8.6% and 15.4% for minor and major LR and 14.2% and 8.6% for PD and DP. For FTR, these thresholds were 17.9%, 31.6%, 22.9% and 15.0%. For major morbidity rate, these thresholds were 26.1%, 49.7%, 57.9% and 52.9% respectively. For TO, lower thresholds were 52.5%, 32.5%, 25.8% and 41.4% respectively. Higher hospital volumes decrease thresholds to detect outliers. CONCLUSION: Current event rates and minimum volume requirements per hospital are too low to detect any meaningful between hospital differences in mortality rate and FTR. Major morbidity rate and TO are better candidates to use for benchmarking.