Variation in practice and outcomes after inguinal hernia repair: a nationwide observational study

Inguinal hernia repair has often been used as a showcase to illustrate practice variation in surgery. This study determined the degree of hospital variation in proportion of patients with an inguinal hernia undergoing operative repair and the effect of this variation on clinical outcomes.

A nationwide, longitudinal, database study was performed in all hospitals in the Netherlands between 2013 and 2015. Patients with inguinal hernias were collected from the Diagnosis-Related-Group (DRG) database. The case-mix adjusted operation rate in patients with a new DRG determines the observed variation. Hospital variation in case-mix adjusted inguinal hernia repair-rates was calculated per year. Clinical outcomes after surgery were compared between hospitals with high and low adjusted operation-rates.

In total, 95,637 patients were included. The overall operation rate was 71.6%. In 2013-2015, the case-mix adjusted performance of inguinal hernia repairs in hospitals with high rates was 1.6-1.9 times higher than in hospitals with low rates. Moreover, in hospitals with high adjusted rates of inguinal hernia repair the time to surgery was shorter, more laparoscopic procedures were performed, less emergency department visits were recorded post-operatively, while more emergency department visits were recorded when patients were treated conservatively compared to hospitals with low adjusted operation rates.

Hospital variation in inguinal hernia repair in the Netherlands is modest, operation-rates vary by less than two-fold, and variation is stable over time. Hernia repair in hospitals with high adjusted rates of inguinal hernia repair are associated with improved outcomes.