Unexpected discrepancies in hospital administrative databases can impact the accuracy of monitoring thyroid surgery outcomes in France

OBJECTIVE: To determine the validity of hospital administrative databases compared to prospective collection of medical data assessing thyroid surgery complications. BACKGROUND: Administrative data are increasingly used to track surgical outcomes. METHODS: All patients undergoing thyroid surgery at three French university hospitals between April 2008 and April 2009 were prospectively included. Using diagnosis and procedural codes from hospital administrative database, we designed three indicators for measuring complications of thyroid surgery: recurrent laryngeal nerve palsy, postoperative hypoparathyroidism, and postoperative hemorrhage. Gold standard was obtained from a prospective collection of medical data after systematically screening each patient for the above-mentioned complications. Their ability to monitor surgical outcomes over time within individual hospitals was estimated using control charts. Spatial comparison between hospitals was performed by funnel plots. RESULTS: A total of 1909 patients were included. Complication rates extracted from administrative data were significantly lower compared to medical data (nerve palsy 2.4% vs. 6.7%, hypoparathyroidism 10.6% vs. 22.3%, p<0.0001). Indicator sensitivity was 30.4% for nerve palsy, 45.4% for hypoparathyroidism and 71.4% for postoperative hemorrhage. Corresponding positive predictive values were 84.4%, 95.1% and 68.2%. In two of the three hospitals, administrative data were not able to track temporal variations in complications rates. Regarding inter-hospital comparisons, 2 out of 3 hospitals were considered outliers according to administrative data despite having an average performance based on medical data. CONCLUSIONS: The ability of indicators extracted from administrative databases to measure thyroid surgery outcomes depends on the quality of underlying data coding. Validation in every center should be a prerequisite before implementing such metrics for tracking performance