The feasibility and validity of the EQ-5D-Y and CHU9D in a challenging context: adolescent mental health in India

BACKGROUND: Outcome measurement and economic evaluation in mental health are increasingly conducted in challenging contexts, including for young people, in low- and middle-income countries, and outside of the healthcare system. This study aimed to assess the feasibility, acceptability, and content validity of two key preference-based measures (the EQ-5D-Y-3L and CHU9D) in such a context in India. METHODOLOGY: Ten cognitive interviews with semi-structured follow-up discussions and 164 surveys were conducted with adolescents in Indian schools. Coding of the cognitive interviews and semi-structured follow-up discussions was conducted to identify completion challenges. The surveys contained both instruments and open-ended follow-up questions, and were analysed to further explore the feasibility, acceptability, and content validity of the instruments. RESULTS: Error rates were higher for the EQ-5D-Y-3L than for the CHU9D in the cognitive interviews, principally due to the ‘Having pain or discomfort’ item, and difficulty in reporting what occurred ‘today’. A lower proportion of adolescents completed the full EQ-5D-Y-3L instrument in the surveys. The CHU9D was the more preferred instrument by participants for reasons including having more relevant content, particularly regarding mental and psychological health, and more response options. However, some participants indicated neither instrument covered all important aspects of their quality-of-life, including social interactions, education, and material circumstances. CONCLUSIONS: Researchers might prioritise the CHU9D as an instrument for measuring quality-of-life in school-going Indian adolescents. However, the measure was not without limitations, and careful attention should be paid to understanding age- and country-specific factors that pose challenges to its usage in economic evaluations.