Comparison of preference-based health-related quality of life measures for chronic neck pain: a pooled analysis of data from three RCTs

Objectives This study aimed to identify a preference-based health-related quality of life (HRQOL) measure that best reflects disease-specific features in patients with neck pain by comparing the characteristics of the instruments. Design Pooled data from three multicentre randomised controlled clinical trials (RCTs) on neck pain were included for analysis in this study. Setting All three RCTs were conducted between 2017 and 2020 in Korea, and patients were recruited from four hospitals and one university teaching hospital. Participants In total, 313 patients with neck pain were included in the three RCTs. Primary and secondary outcome measures A correlation analysis was conducted using Spearman's correlation coefficients between preference-based HRQOL scores (EuroQol-5 Dimension 5 Levels (EQ-5D-5L) and Short-Form 6-Dimension version 1 (SF-6Dv1)) and the disease-specific measures for pain and function (Numerical Rating Scale (NRS), Visual Analogue Scale (VAS), Neck Disability Index (NDI) and Northwick Park Questionnaire). Results Spearman's correlation analyses (p value <0.01 for all) showed that EQ-5D-5L exhibited slightly stronger negative correlations with pain-related measures (VAS: -0.277, NRS: -0.262) compared with SF-6Dv1 (VAS: -0.207, NRS: -0.182). For functional outcomes, EQ-5D-5L demonstrated stronger negative correlations with function-related measures such as NDI (-0.636 to -0.711) compared with SF-6Dv1 (-0.506 to -0.579). In patients with moderate-to-severe neck pain (VAS>5), EQ-5D-5L appeared to better capture functional and pain aspects. Despite these differences, both instruments consistently reflected treatment-related improvements in pain and function. Distribution analysis further indicated that EQ-5D-5L and SF-6Dv1 were not fully interchangeable due to variations in domain-level scoring patterns and ceiling effects observed in EQ-5D-5L. Conclusions EQ-5D-5L showed stronger negative correlations with both pain and functional outcomes compared with SF-6Dv1, suggesting that it may better capture the functional aspects of chronic neck pain, particularly in moderate-to-severe conditions. However, the ceiling effect observed in EQ-5D-5L warrants caution when interpreting results in patients with mild neck pain. These findings provide practical guidance for selecting preference-based HRQOL measures in economic evaluations of musculoskeletal conditions, supporting more informed healthcare decision-making. Trial registration number NCT03294785, Post-results; NCT03558178, Results; NCT04035018, Post-results.