Multi-ethnic validation of 15-item Geriatric Depression Scale in Chile

BACKGROUND: There has been scant research published regarding the assessment of depression in ethnic groups, and few studies have addressed the validation of scales for standardized assessment of depressive symptoms among indigenous minorities. OBJECTIVE: The aim of this study was to analyze the psychometric properties of the 15-item Geriatric Depression Scale (GDS-15) for a multi-ethnic sample of older Chilean adults. METHODS: Cross-sectional study with a sample of 800 older people, 71% of whom were self-declared indigenous (Aymara/Mapuche). RESULTS: The non-indigenous group had a higher total GDS-15 score and lower quality of life and wellbeing scores than the indigenous groups (p < 0.001). The GDS-15 had a KR-20 coefficient of 0.90 for the non-indigenous group, 0.80 for Aymara, and 0.85 for Mapuche. The homogeneity index was 0.38 for non-indigenous, 0.24 for Aymara, and 0.29 for Mapuche. DISCUSSION: The GDS-15 showed satisfactory psychometric characteristics for the samples studied. However, the better results observed for the non-indigenous group suggest that some characteristics and content of the rating scale are not fully appropriate for the indigenous older population. CONCLUSIONS: There is a need to develop the transcultural validation of scales such as GDS-15, which are applied in a standardized manner in geriatric evaluations as part of primary healthcare.