Evaluation of the patient acceptable symptom state following hip arthroscopy using the 12 item international hip outcome tool.

Background: The International Hip Outcome Tool 12 (iHOT-12) is a shorter version of the iHOT-33 which measures health related quality of life following treatment of hip disorders in young, active patients. The purpose of this study was identify a PASS threshold for a UK population undergoing hip arthroscopy for intra-articular hip pathology.
Methods: Data was identified retrospectively from a prospective database of patients undergoing hip arthroscopy under the care of a single surgeon within the date range January 2013 to March 2017. All patients with a diagnosis of femoroacetabular impingment (FAI) undergoing arthroscopic treatment were included. iHOT-12, EuroQol 5D-5 L (EQ-5D-5 L) and a satisfaction questionnaire were available pre and post-operatively. PASS was calculated using an anchor-based approach and receiver operator characteristic (ROC) analysis.
Results: 171 patients underwent hip arthroscopy in the study period. Linked longitudinal follow-up data was available for 122 patients (71.3%) at a median of 24.3 months (740 days, interquartile range 576-1047). The PASS threshold for the iHOT-12 was 59.5 (sensitivity 81.1%, specificity 83.9%; area under the curve (AUC) 0.92, 95% CI 0.87-0.97). 64% of patients achieved this score. The median postoperative iHOT-12 score was 72.5 (IQR 44) and the mean change in score was 35 (SD 25, p < 0.001). The EQ-5D Index improved by 0.18 (SD 0.25, p < 0.001) and there was a mean change of 7.67 (SD 24.82) on the EQ-5D VAS (p = 0.001).
Conclusions: We report a PASS threshold of the iHOT-12 following hip arthroscopy for FAI as a measurable benchmark for clinicians using this outcome measure.