Cross-cultural adaptation and psychometric properties of the AUDIT and CAGE questionnaires in Tanzanian Swahili for a traumatic brain injury population

Aims: To develop Swahili versions of the Alcohol Use Disorders Identification Test (AUDIT) and CAGE questionnaires and evaluate their psychometric properties in a traumatic brain injury (TBI) population in Tanzania. Methods: Swahili versions of the AUDIT and CAGE were developed through translation and backtranslation by a panel of native speakers of both English and Swahili. The translated instruments were administered to a sample of Tanzanian adults from a TBI registry. The validity and reliability were analyzed using standard statistical methods. Results: The translated versions of both the AUDIT and CAGE questionnaires were found to have excellent language clarity and domain coherence. Reliability was acceptable ( > 0.85) for all tested versions. Confirmatory factor analysis of one, two and three factor solution for the AUDIT and one factor solution for the CAGE showed adequate results. AUDIT and CAGE scores were strongly correlated to each other (R > 0.80), and AUDIT scores were significantly lower in non-drinkers compared to drinkers. Conclusions: This article presents the first Swahili and Tanzanian adaptations of the AUDIT and CAGE instruments as well as the first validation of these questionnaires with TBI patients. Both instruments were found to have acceptable psychometric properties, resulting in two new useful tools for medical and social research in this setting.