How Should We Define Clinically Significant Outcome Improvement on the iHOT-12?

Abstract

Background: There is increased emphasis on efficiently administering patient-reported outcome measures (PROMs). The International Hip Outcome Tool-12 (iHOT-12) is a short-form version of the iHOT-33, and relatively little is known about clinically significant outcomes using the iHOT-12. Questions/Purposes: The purpose of this study was to define minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) for the iHOT-12 and to identify predictors for achieving these psychometric end points in patients undergoing arthroscopic treatment of femoroacetabular impingement (FAI). Methods: Data was prospectively collected and retrospectively analyzed as part of an institutional hip preservation repository. One hundred and twenty patients were included; mean age and body mass index (BMI) were 38.7 years and 25.9, respectively. A majority of patients were female (67.5%) and white (81.7%) and participated in recreational sports (79.2%). The iHOT-12 was administered preoperatively and at 1-year follow-up to patients undergoing primary hip arthroscopy for FAI. The following anchor question was also asked at 1-year follow-up: BTaking into account all the activities you have during your daily life, your level of pain, and also your functional impairment, do you consider that your current state is satisfactory?^MCID was calculated using a distribution-based method. Receiveroperating characteristic analysis with area under the curve was used to confirm the significance of the PASS threshold. Results: Mean iHOT-12 scores improved from 35.6 at preoperative assessment to 70.7 at 1-year follow-up. Patients indicating satisfaction with their outcome improved from 37.5 pre-operatively to 79.0 at 1-year follow-up. MCID value for the iHOT-12 was 13.0. The PASS threshold was 63.0, indicating an excellent predictive value that patients scoring above this threshold were likely to have met an acceptable symptom state. Worker's compensation patients and those with increased BMI were less likely to achieve PASS; lower pre-operative iHOT-12 score was predictive for achieving MCID, and achieving MCID was predictive for achieving PASS. Conclusion: This is the first study to define PASS and MCID for the iHOT-12, which measures clinically significant outcome improvement comparably to that of other commonly used hip PROMs. As its use becomes more widespread, the iHOT-12 data-points presented in this study can be used to determine clinically significant improvement of patient-reported outcomes. Keywords hip. femoroacetabular impingement. MCID. PASS. patient-reported outcome measures (PROMs)

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

“…We used distributional methodology to calculate the MCID for the iHOT-12 and found this to be 13 points. This is very similar to the estimates of other studies that have reported the MCID for the iHOT-12 score [21,22] and although this was not the primary analysis of our study it lends credibility to the representativeness of our underlying dataset.…”

“…A further study has also calculated the PASS threshold for the iHOT-12 and found it to be 63 [21]. However, in their study the authors used the external anchor question "Taking into account all the activities you have during your daily life, your level of pain, and also your functional impairment, do you consider that your current state is satisfactory?"…”

“…The benefit of this is that a predetermined PASS score may be compared with PROMs at any given time point. Two recent studies have published contrasting PASS thresholds for postoperative iHOT-12 scores [21,22] which may attributed to differences in the methodology of the psychometric analysis.…”

Preoperative Predictors of Achieving Clinically Significant Athletic Functional Status After Hip Arthroscopy for Femoroacetabular Impingement at Minimum 2-Year Follow-Up

“…The 2year PASS value was then identified by using an receiver operating characteristic (ROC) curve analysis as previously done in prior studies (analysis provided in Appendix 1). 3,23,24,[27][28][29] A sensitivity and specificity of 0.80 was used as the cut-off for determining an acceptable HOS-SS PASS score. Patients were classified as achieving PASS if PASS was achieved on any of the included outcome measures.…”

Editorial Commentary: PASSing the Test Versus Acing It: Understanding Clinically Significant Outcome Improvement in Arthroscopic Hip Surgery

“…In this regard, it should be noted that a similar study used an anchorbased method to calculate PASS and reported a threshold score of 63.0 (compared with 75.2 in the study under commentary). 11 Overall, Kivlan et al 9 have provided another data point in the evolving literature on clinically significant outcome. As the authors note, their study findings may help shape how patient outcome on the iHOT-12 is interpreted going forward.…”