Psychometric evaluation of the affiliate stigma scale for caregivers of people with mental illness in Uganda

Background Affiliate stigma is common among caregivers of people with mental illness and impacts negatively on the caregivers' quality of life and their ability to care for the patients. Although there is evidence of affiliate stigma in sub-Saharan Africa, the psychometric properties of commonly used tools are not available in the African context. The aim of this analysis was to evaluate the factor structure of the affiliate stigma scale among caregivers of people with mental illness in southwestern Uganda. Having a validated method to assess affiliate stigma in the Ugandan setting helps to appropriately evaluate affiliate stigma among caregivers of people with mental illnesses, which could inform the development of interventions to support such caregivers. Method A total of 385 caregivers of people with mental illness attending outpatient psychiatry clinics in selected tertiary hospitals in southwestern Uganda were enrolled in the study. The affiliate stigma and depression were assessed using the affiliate stigma scale and the patient health questionnaire (PHQ-9) respectively. We conducted exploratory and confirmatory factor analysis to determine the factor structure, reliability and validity of the affiliate stigma scale. We also evaluated the convergent validity of the affiliate stigma scale by determining the correlation between affiliate stigma scale scores and the PHQ-9. Result More than half of participants were male (55.06%) and majority of caregivers were living in rural areas (80.26%). The sample size was adequate, as evidenced by the KMO of 0.91 and the inter-correlation was sufficient to conduct the factor analysis, according to the Bartlett test. Confirmatory factor analysis revealed four factors and all 22 items were retained as all of them had a factor loading > 0.4. The internal consistency of the total scale was excellent (alpha = 0.92). The affiliate stigma score correlated with depression which has been hypothesized to be associated with the stigma of mental illness. Conclusion The study findings show the affiliate stigma scale as a valid measure of affiliate stigma among the caregivers of patients with mental illness in southwestern Uganda. Therefore, this scale provides an opportunity to mental health care providers to assess affiliate stigma and develop interventions aimed at prevention stigma among caregivers and improve outcomes among people with mental illness.