Evaluating the reliability and validity of the 12-item WHODAS 2.0 among people with mental health conditions in seven low- and middle-income countries: analysis of secondary data.

Background: The World Health Organization Disability Assessment Schedule (WHODAS 2.0) has been validated across various settings and health conditions. However, few studies have evaluated the 12-item WHODAS 2.0 within low- and middle-income countries (LMICs) among individuals with mental health conditions.

Aims: This study aimed to evaluate the psychometric properties of the 12-item WHODAS 2.0 in populations with depression, anxiety and psychosis from seven LMICs.

Method: Secondary analyses were carried out using existing longitudinal data-sets in adult populations with depression, anxiety and psychosis across Brazil, Ethiopia, Ghana, India, Nigeria, Peru and South Africa. Reliability, validity and responsiveness to change of the 12-item WHODAS 2.0 were examined.

Results: The 12-item WHODAS-2.0 was acceptably one-dimensional for all data-sets at baseline, with model-fit indices ranging from moderate to excellent. Internal consistency of the measure was found to be high across settings (Cronbach's α = 0.83-0.97). Weak to moderate correlations with measures of symptom severity were found across all countries, except India. Moderate to strong correlations were observed with measures of functioning/quality of life across all countries, except Nigeria and Ghana.Internal responsiveness to change was large in five out of seven studies, except both Ethiopian studies. However, external responsiveness to change exhibited variability, with weak to moderate correlations between change in WHODAS 2.0 and symptom scores across all countries.

Conclusion: The 12-item WHODAS 2.0 generally showed acceptable psychometric properties across different settings and mental health conditions. However, high variability was observed in convergent validity and external responsiveness to change, which warrants further investigation.