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 numberNCT03294785, Post-results; NCT03558178, Results; NCT04035018, Post-results.