Defining minimal clinically important difference, patient acceptable symptomatic state and substantial clinical benefit for the visual analog scale pain score after arthroscopic rotator cuff repair

Introduction

Patient satisfaction after arthroscopic rotator cuff repair (RCR) is commonly assessed with patient-reported outcome measures (PROMs), and there is an increased need to establish clinical relevance within these measures. The purpose of this study was to (1) define minimal clinically important difference (MCID), patient acceptable symptomatic state (PASS), and substantial clinical benefit (SCB) for the visual analog scale (VAS) pain score in patients undergoing arthroscopic RCR, and (2) identify preoperative predictors of achieving each of these threshold values.

Methods

Data from consecutive patients who underwent primary arthroscopic rotator cuff repair study between 2010 and 2016 were prospectively collected. Baseline data and VAS pain scores were collected preoperatively and at 1 year and 2 years postoperatively. MCID, PASS and SCB were determined using an anchor-based approach, with anchor questions assessing postoperative satisfaction and expectation fulfillment. Multivariate logistic regression analysis was also used to identify preoperative predictors for achieving MCID, PASS, and SCB.

Results

A total of 286 patients were included in the final analysis, with an average age of 60.2 ​± ​10.4 and the majority being female (61.2%). The values for the VAS pain score identified to represent MCID, PASS, and SCB, respectively, at 1-year postoperatively were: 5, 2, and 1. The rates of achieving clinically significant improvement based on VAS were 60.5%, 63.3%, and 57.2%, respectively. A higher preoperative VAS was predictive for achieving MCID (odds ratio [OR], 1.84; P ​< ​0.01).

Conclusion

This study identified threshold VAS pain scores of 5, 2, and 1 for achieving MCID, PASS, and SCB, respectively, at 1-year follow-up after arthroscopic rotator cuff repair. A higher preoperative VAS pain score was also identified as a statistically significant predictor of attaining MCID after arthroscopic rotator cuff repair.

Level of Evidence

II.