Validation of an Inguinal Pain Questionnaire for assessment of chronic pain after groin hernia repair

Background: Long-term pain is an important outcome after inguinal hernia repair. The aim of this study was to test the validity and reliability of a specific Inguinal Pain Questionnaire (IPQ). Methods: The study recruited patients aged between 15 and 85 years who had undergone primary inguinal or femoral hernia repair. To test the validity of the questionnaire, 100 patients received the IPQ and the Brief Pain Inventory (BPI) 1 and 4 weeks after surgery (group 1). To test reliability and internal consistency, 100 patients received the IPQ on two occasions 1 month apart, 3 years after surgery (group 2). Non-surgery-related pain was analysed in group 3 (2853 patients). Results: A significant decrease in IPQ-rated pain intensity was observed in the first 4 weeks after surgery (P < 0.001). Significant correlations with corresponding BPI pain intensity items corroborated the criterion validity (P < 0.050). Logical incoherence did not exceed 5.5 per cent for any item. Values for kappa in the test-retest in group 2 were higher than 0.5 for all but three items. Cronbach's alpha was 0.83 for questions on pain intensity and 0.74 for interference with daily activities. Conclusion: This study found good validity and reliability for the IPQ, making it a useful instrument for assessing pain following groin hernia repair.