Explaining variation in ventral and inguinal hernia repair outcomes: A population-based analysis

Background. No study has evaluated the relative importance of patient, surgeon, and hospital-level factors on surgeon and hospital variation in hernia reoperation rates. This population-based retrospective cohort study evaluated factors associated with variation in reoperation rates for recurrence after initial ventral hernia repair and inguinal hernia repair. Methods. The Statewide Planning and Research Cooperative System identified initial ventral hernia repairs and inguinal hernia repairs in New York state from 2003-2009. Mixed-effects Cox proportional hazards analyses were performed assessing factors associated with surgeon/hospital variation in 5-year reoperation rates for hernia recurrence. Results. Among 78,267 ventral hernia repairs and 124,416 inguinal hernia repairs, the proportion of total variation in reoperation rates attributable to individual surgeons compared with hospitals was 87% for ventral hernia repairs and 92% for inguinal hernia repairs. In explaining variation in ventral hernia repair reoperation between surgeons, 19% was attributable to patient-level factors, 4% attributable to mesh placement, and 10% attributable to surgeon volume and type of board certification. In explaining variation in inguinal hernia repair reoperation between surgeons, 1.1 % was attributable to mesh placement and 10% was attributable to surgeon volume and years of experience. However, 67% of the variation between surgeons for ventral hernia repair and 89% of the variation between surgeons for inguinal hernia repair remained unexplained by factors in the models. Conclusion. The majority of variation in hernia reoperation rates is attributable to surgeon-level variation. This suggests that hernia recurrence may be an appropriate surgeon quality metric. While modifiable factors such as mesh placement and surgeon characteristics play roles in surgeon variation, future research should focus on identifying additional surgeon attributes responsible for this variation.