Background The Warwick Edinburgh Mental Wellbeing Scale (WEMWBS) is validated for measuring mental wellbeing in UK populations aged 11+ and has been translated into 30+ languages. The primary aim of this study was to translate and validate WEMWBS for use in Swahili-speaking populations. This will facilitate measurement and understanding of wellbeing in these populations, evaluation of policy and practice, and enable international comparisons. The secondary aim was to describe mental wellbeing in the participants of the Girls’ Education Challenge (GEC) project in Tanzania, run by CAMFED and funded through the UK’s Foreign, Commonwealth and Development Office. Specifically, to examine sociodemographic characteristics associated with higher and lower wellbeing in this population.

Methods We created a short questionnaire including WEMWBS and similar scales for comparison, socio-demographic information and self-reported health. This was translated into Swahili using gold standard methodology. We aimed to use this tool to collect data from secondary school students (girls and boys), learner guides, teacher mentors and teachers taking part in the GEC programme in Tanzania. Quantitative data analysis examined internal consistency of WEMWBS, correlation with comparator scales and confirmatory factor analysis. Qualitative work to assess acceptability and comprehensibility of WEMWBS and conceptual understanding of mental wellbeing was carried out through focus groups with GEC participants. These were audio-taped, transcribed and analysed thematically. Finally, we used multivariable logistic regression to explore associations between individual characteristics and ‘low’ and ‘high’ mental wellbeing, defined as the lowest and highest quartile of WEMWBS scores.

Results 3052 students were recruited into the study and 574 adults. Both WEMWBS and its short form met quantitative test of reliability and validity. They were correlated with comparator scales and met the criteria to determine that they were measuring one factor. Overall, WEMWBS seemed applicable, understood and relevant to the focus groups of students, learner guides and teachers. For students in the Girls Education Challenge supported government schools: being male, being urban, the absence of markers of marginality and better self-reported health were all significantly associated with better mental wellbeing. Mental wellbeing is higher in students in the final two ‘forms’ of school compared with the first two. For adults: being urban and better self-reported health were associated with better mental wellbeing.

Conclusion The Swahili translation of WEMWBS is available for use in Swahili speaking populations. Further work to explore how to intervene to increase mental wellbeing in vulnerable GEC participants is needed.