Correlation Between Changes in Visual Analog Scale and Patient-Reported Outcome Scores and Patient Satisfaction After Hip Arthroscopic Surgery
Background: Improvements in pain, function, and patient satisfaction are used to evaluate the outcomes of hip arthroscopic surgery.
Purpose: To identify correlations between the visual analog scale (VAS) score for pain and patient satisfaction with 4 commonly used patient-reported outcome (PRO) scores to determine to what extent changes in these 2 parameters are reflected in each of the PRO scores.
Study design: Cohort study (diagnosis); Level of evidence, 3.
Methods: Patients undergoing hip arthroscopic surgery between February 2008 and February 2013 were assessed prospectively before surgery, at 3 months, and annually thereafter with the modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), Hip Outcome Score-sports-specific subscale (HOS-SSS), and Hip Outcome Score-activities of daily living (HOS-ADL). Patients were also assessed using a 10-point VAS for pain and queried for satisfaction at the same time points ("0" indicated no pain, and "10" indicated complete satisfaction with surgery). The VAS score and patient satisfaction were correlated with changes in the 4 PRO scores.
Results: During the study period, 1417 patients underwent hip arthroscopic surgery, of whom 1137 patients had 2-year postoperative PRO scores after primary surgery. There was a significant improvement in all PRO scores at 2-year follow-up. The mean improvements in mHHS, NAHS, HOS-ADL, and HOS-SSS scores were 16.7, 21.6, 19.7, and 22.7 points, respectively. The mean improvement in the VAS score was 2.9 points. Mean patient satisfaction at 2-year follow-up was 7.74 (of 10). There was a statistically significant correlation between the VAS and patient satisfaction scores and changes in each of the 4 PRO scores. The strength of the correlation was moderate.
Conclusion: This study demonstrated a moderate correlation between the VAS and patient satisfaction outcomes and changes in 4 commonly used PRO scores in hip arthroscopic surgery (mHHS, HOS-ADL, HOS-SSS, and NAHS). In addition to several PRO instruments, a VAS for pain and patient satisfaction may add to the overall assessment of the efficacy of hip arthroscopic surgery.