Construct validity and factor structure of the K-10 among Ugandan adults

Abstract

BackgroundPsychological distress is often used as a proxy measure for the mental health of a population. The Kessler Psychological Distress Scale (K-10) is a widely used brief screening tool for psychological distress, yet few studies have evaluated its utility in sub-Saharan Africa. We evaluated its construct validity and factor structure in Uganda. MethodsWe used data from an ongoing case-control study. Participants in the present study were patients seeking general medical outpatient services and caretakers of mentally ill persons. Demographic data were collected using a structured questionnaire, and psychological distress was assessed using the K-10. K-10 construct validity and factorial structure were assessed through exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). ResultsA total of 2104 participants were included in this analysis, these were controls from a general medical setting. The mean K-10 score was 2.34 with an internal consistency of 0.86. EFA resulted in a two-factor solution that accounted for 78.37% of the variance. CFA revealed that a unidimensional model of psychological distress with correlated errors between some of K-10 items was superior, with a comparative fit index of 0.95, Tucker-Lewis index of 0.93, and a root mean square error of approximation of 0.08. LimitationsThe study was limited to evaluating internal consistency and construct validity. Future studies are warranted to examine criterion validity and establish cut-offs for psychological distress. ConclusionsThe K-10 had good psychometric properties in this population and may be useful for measuring broad psychological distress in general medical settings.