Translation, cross-cultural adaptation, and psychometric properties of the Hausa version of the Insomnia Severity Index among internally displaced persons in Africa

Background: Although sleep disturbances and insomnia are common among Internally Displaced Persons (IDPs), these disorders remain largely understudied among victims fleeing ethnoreligious genocide. The Insomnia Severity Index (ISI), though a widely used measure of insomnia, has not been translated, cross-culturally adapted, nor validated in common African languages. This paper aimed to translate, adapt and validate the ISI scale into Hausa, the most widely spoken non-Indo-European language in African continent. Methods: A six-stage validation model was used for the translation and adaptation of the ISI into Hausa [(ISI-Hausa), Item-Content Validity Index (I-CVI)=0.9 to 1.0]. The tool was administered among IDPs residing in Maiduguri, North-Eastern Nigeria, from October to November 2019. A total of 281 participants from six camps were recruited via convenience sampling. The psychometric properties of the scale were assessed using an Exploratory Factor Analysis (EFA), Cronbach's alpha (α) and Intraclass Correlation Coefficients (ICC) for determining factor structure, internal consistency and test-retest reliability, respectively. Results: Exploratory factor reduction resulted in a two-factor solution, with “ severity of insomnia ” identified as the construct for Factor 1 and “ impact of insomnia ” as the construct for Factor 2. Factor 1 consisted of four scale items and Factor 2 consisted of three items. Factor loadings for each item ranged from 0.535-0.812. The scale demonstrated acceptable internal consistency (α=0.72) and good test-retest reliability (ICC=0.72) (p<0.001). Conclusion: The ISI-Hausa scale is a psychometrically sound and culturally relevant tool for assessing the severity and impact of insomnia among Hausa speaking IDPs in Africa.