W85. evaluation of the psychometric properties of the ubacc questionnaire in assessing capacity to consent in diverse african populations

Voluntary informed consent in research participation is essential in ethical research practice and is challenging to assess in vulnerable populations, such as psychiatric patients. The University of California, San Diego Brief Assessment of Capacity to Consent (UBACC) is a tool used to assess the capacity of participants to consent in psychiatric research globally, but very little is known about its use in low and middle-income countries especially in the context of genetics studies. This study aimed to examine the psychometric properties of the UBACC in a sample of 16,467 individuals with psychosis and 15,741 controls across four countries in Africa. We examined the reliability, latent factor structure, and item difficulty of the UBACC items in the full sample and stratified by country, diagnostic status, sex, and language group. Across all groups, the internal consistency of the UBACC was low, indicating poor reliability, even after the removal of non-salient items. Multi-group exploratory factor analysis suggested a 2-factor model for the overall sample. However, a 3-factor model was more appropriate when examining the latent structure across country, language, and sex. Confirmatory factor analyses revealed an adequately fitting 3-factor model for the full sample and across country, sex, and most languages. A two-factor model, however, was more appropriate for English and Amharic languages. Examination of item discrimination and difficulties using a multidimensional item-response theory framework for the full sample, revealed that UBACC item 8, measuring understanding of the benefits of study participation, was the most discriminating item. Many of the other items had below-threshold discriminating characteristics. The present study is the first to provide preliminary evidence that the internal consistency item functioning of the UBACC is low and dissimilar across different settings and populations in Africa; however, exploratory, and confirmatory factor analysis converged towards a two and three-dimensional structure, in line with the developers of the original scale. Future studies are warranted to investigate the cultural and linguistic nuances that may account for the differences we have observed between populations and language groups. Understanding the psychometric properties and utility of consent tools such as the UBACC in underrepresented populations will ensure that research participants are adequately protected in genetics research.