Development and initial validation of the Kiswahili version of the Migraine Disability Assessment (MIDAS-K) questionnaire

Background: The Migraine Disability Assessment Scale (MIDAS) is one of the tools for measuring and understanding disability caused by migraine. The purpose of this study was to validate a Kiswahili translation of the MIDAS (MIDAS-K) among patients suffering from migraines in Dar es Salaam, Tanzania. Methods: A psychometric validation study of MIDAS was conducted after translation to Kiswahili. A total of 70 people with migraine were recruited by systematic random sampling and they completed the MIDAS-K questionnaire twice, 10–14 days apart. Internal consistency, split-half reliability, and test-retest reliability, convergent and divergent validity were examined. Results: 70 patients (F:M; 59:11) with median (25th, 75th) headache days of 4.0 (2.0, 7.0) were recruited. Twenty-eight out of 70 (40%) of the population had severe disability on MIDAS-K. The overall test-retest reliability of MIDAS-K was high (ICC = 0.86; 95% CI = 0.78–0.92 p < 0.001). Factor analysis showed a two-factor structure; the number of days missed and reduced efficiency. MIDAS-K had a good internal consistency of 0.78, good split-half reliability of 0.80 and acceptable test-retest reliability for all items as well as total MIDAS-K scores. Conclusion: The Kiswahili version of the MIDAS questionnaire (MIDAS-K) is a valid, responsive, and reliable tool to measure migraine-related disability among Tanzanians and other Swahili-speaking populations. Quantification of migraine disability in the region will guide policies directed at care allotment, improvement in the provision of interventions for migraine, as well as enhancement of health-related quality of life for patients with migraine in our region.