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

Background: Psychological 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. Methods: We 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). Results: A 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. Limitations: The 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. Conclusions: The K-10 had good psychometric properties in this population and may be useful for measuring broad psychological distress in general medical settings.