Editorial Commentary: An Anchor-Based Approach Is the Superior, Direct Method for Determining Achievement of Minimal Clinically Important Difference, Substantial Clinical Benefit, and Patient Acceptable Symptom State

Abstract

Over the past 20 years, the use of patient-reported outcome measures (PROMs) has drastically increased in the field of orthopaedic surgery, and these tools can assist with clinical decision-making, clinical research, health policy, and/or reimbursement decisions. However, one of the challenges with PROMs is determining if the differences in scores, which may be statistically significant, also constitute a clinically meaningful difference. To help provide clinical context, the minimal clinically important difference, substantial clinical benefit, and patient acceptable symptom state thresholds were established. For patients undergoing hip arthroscopy surgery, several common PROMs, such as the Hip Outcome Score–Sport-Specific Subscale, Hip Outcome Score–Activities of Daily Living, Modified Harris Hip Score, and/or 12-item International Hip Outcome Tool, are routinely used; however, recent studies have demonstrated variability within the literature for both the values reported and the methodology used to calculate the minimal clinically important difference, substantial clinical benefit, and patient acceptable symptom state for these respective hip arthroscopy PROMs. These differences are most likely attributed to the variability in patient populations and calculation methods. While distribution-based methods or previously published threshold values have been validated in the literature, they ultimately do not directly address the question of clinical importance. Conversely, anchor-based approaches provide a more direct evaluation of psychometric threshold achievement by specifically querying each individual patient on their clinical outcome. Ultimately, both methods of determining achievement of psychometric thresholds are appropriate; however, anchor-based approaches are easy to use and provide a direct, patient-specific approach to determining clinically meaningful improvements.