Psychometric validation and optimal cut-point determination of the Hausa WHO-5 well-being index for depression...

Depression remains underrecognized among internally displaced persons (IDPs) in Nigeria, where access to mental health and psychosocial support is limited. This study assessed the reliability, validity, and cutoff performance of the Hausa WHO-5 Well-Being Index for identifying probable moderate-to-severe depressive symptoms among IDPs in Abuja, Nigeria. A total of 264 IDPs completed the Hausa WHO-5 and PHQ-9. Internal consistency was evaluated using ordinal Cronbach's alpha and McDonald's omega, factorial validity using one-factor confirmatory factor analysis with the weighted least squares mean and variance adjusted estimator, and construct validity with Spearman's correlation between Hausa WHO-5 and PHQ-9 scores. Receiver operating characteristic analysis assessed sensitivity and specificity for cutoffs of ≤28 and <50, using PHQ-9 scores ≥10 as the reference standard. The Hausa WHO-5 demonstrated excellent internal consistency and a unidimensional structure with strong loadings and excellent model fit. Scores were inversely associated with PHQ-9 scores across age and sex subgroups. Discrimination was moderate at both thresholds, and the <50 cutoff provided the best balance of sensitivity and specificity for screening, triage, and referral.