Sinhala version of the Cornell Musculoskeletal Discomfort Questionnaire: Cross-cultural adaptation and validation

BACKGROUND: Work-related musculoskeletal disorders (WMSDs) are highly prevalent among people who work in sedentary jobs. The Cornell Musculoskeletal Discomfort Questionnaire (CMDQ) is a valid tool to assess WMSDs, but is not available in the local language of Sri Lanka (Sinhala). OBJECTIVE: To cross-culturally adapt the original CMDQ from English to Sinhala and evaluate its psychometric properties. METHODS: The linguistic and cultural adaptation of the CMDQ to the Sinhala (Si-CMDQ) language followed international guidelines. The adapted pre-version was tested for comprehensibility among 32 subjects from different educational and occupational backgrounds. The Content Validity Index (CVI) was computed with ratings from five experts. The questionnaire was validated further by 111 security guards employed at the university. The tool was validated with reference to the Numeric Rating Scale. Test-retest reliability was assessed at two time points one week apart and internal consistency was tested. RESULTS: The Si-CMDQ showed adequate cross-cultural, content and construct validity, internal consistency, and test-retest reliability. The Kappa coefficient showed excellent agreement between NRS and Si-CMDQ frequency scale. Spearman’s correlation coefficients showed a moderate to a strong significant positive correlation between NRS and the severity scale of Si-CMDQ. The Kappa values for test-retest reliability were moderate to excellent for the three scales of CMDQ. The internal consistency was high. CONCLUSION: The Si-CMDQ fulfilled the psychometric requirement for questionnaires. This tool will be beneficial to assess WMSDs among sedentary workers in different occupations in Sri Lanka.