Reliability, Validity, and Responsiveness of the WHODAS 2.0 12-Item Scale in persons with Non-Specific Neck Pain

This study aimed to evaluate the reliability, validity, and responsiveness of the 12-item version of WHODAS 2.0 in persons with mechanical neck pain.

Ninety-eight patients with mechanical neck pain, aged over 18 years, participated in the evaluation of the 12-item version of WHODAS 2.0. Twenty-nine subjects completed the questionnaire on two occasions, 48 hours apart, to assess test-retest reliability. In addition to WHODAS 2.0, the Short-form McGill Pain Questionnaire (SFMPQ), SF-12, the Fear Avoidance Belief Questionnaire Neck (FABQN), the Neck Disability Index (NDI), and the Global Perceived Effect (GPE) were used to collect data at baseline and post-treatment follow-up. Test-retest reliability was assessed using the intraclass correlation coefficient (ICC). Internal consistency was measured with Cronbach’s alpha. Construct validity was examined using Pearson’s correlations between the 12-item version of WHODAS 2.0 and other measures. Responsiveness was assessed using Effect Size (ES) and Standardized Response Mean (SRM), calculated separately within each group - improved and not improved - using the Global Perceived Effect (GPE) as an anchor. Minimal Detectable Change (MDC_95%) score also calculated.

The 12-item version of WHODAS 2.0 demonstrated excellent test-retest reliability (ICC = 0.87, 95% CI 0.71 to 0.94) and high internal consistency (Cronbach’s alpha = 0.88). Strong construct validity was observed, with significant correlations between WHODAS 2.0 and NDI (r = 0.66), SFMPQ_{usual pain} (r = 0.52), SF-12 (r = -0.50), and FABQN (r = 0.38). The 12-item WHODAS 2.0 also showed moderate to excellent responsiveness (ES = 0.67; SRM = 0.85) in improved participants, and the MDC_95% was 9.40.

The 12-item version of WHODAS 2.0 is a reliable, valid, and responsive tool for assessing disability in individuals with neck pain.

The findings of this study suggest that the 12-item version of WHODAS 2.0 is a reliable and valid tool for assessing disability in individuals with mechanical neck pain, with good test-retest reliability, internal consistency, and construct validity. Its moderate responsiveness indicates that it can detect meaningful changes in disability over time, particularly in individuals who report improvement. Given these psychometric properties, the 12-item WHODAS 2.0 can be confidently used in both clinical and research settings to tract patient outcomes, evaluate the effectiveness of interventions, and monitor functional improvements in patients with neck pain.