Depression, anxiety and psychosomatic complaints are referred to collectively as common mental disorders (CMD). CMD contribute substantially to the global burden of disease, with major social and economic consequences for those affected. The WHO Self-Reporting Questionnaire (SRQ-20) was designed as a universally applicable case-finding instrument for CMD that is widely used in community-based screening and epidemiological population surveys. The scale comprises 20 items about symptoms and problems using a yes/no response format. It has been validated in a wide range of languages and cultural settings, some of which report gender differences in scale performance. Only one study, set in Brazil, has examined the SRQ-20 with older adults. The current study examines the factor structure and gender-based measurement invariance of the SRQ-20 in a sample of community-dwelling older adults in Puerto Rico.
We conducted face-to-face interviews with a non-probability sample of 154 adults aged 60+ in 5 of Puerto Rico’s 6 regions from September 2019 to January 2020. We recruited participants in their homes, NGOs, senior centers, public spaces, and by word-of-mouth. The sample ranged in age from 60-97 (M=73.77, SD=8.67); 61.7% were female. We used the Spanish version of the WHO SRQ-20 (M=6.64, SD=5.14; α=.89). Participants self-reported gender as male or female.
We used multiple confirmatory factor analyses (CFA) to test for gender-based measurement invariance. After examining the factor structure of a unidimensional model with all 20 items, we tested for gender invariance in two steps. We first tested configural invariance to determine equivalence of the factor structure between groups by evaluating fit indices (χ2, CFI, TLI, RMSEA, SRMR). We then examined scalar invariance to determine whether factor loadings and intercepts were equal between gender groups. We tested for differences in the scalar model and the configural model with a χ2 difference test and evaluated change in model fit indices.
Using the common clinical cutoff score of 7 / 8, 42% of the sample screened positive for common mental disorder. The total sample CFA showed that a unidimensional model fit the data well. Configural invariance of gender was evidenced by satisfactory fit indices in the configural model: χ2 (334) = 372.156, p=.074, CFI=.981, TLI=.979, RMSEA=.039, SRMR=.138. Fit indices for the final scalar model were also good (χ2 (352) =391.927, p=.070, CFI=.980, TLI=.979, RMSEA=.038, SRMR=.140) and were nearly identical to the configural model. The configural and scalar models did not differ significantly (χ2 (18) =21.868, p=.238). These findings support our hypothesis of gender invariance in this sample of older adults.
Conclusions and Implications
Our findings indicate that the SRQ-20, a straightforward, easily administered measure, provides a valid and reliable means of detecting CMD among older adults, including men and women, in Puerto Rico. This study adds to the limited literature on assessing CMD among community-dwelling older adults in diverse populations and settings. Future research should use a gold-standard measure of mental health problems to determine the optimal cut-off score for older adults in Puerto Rico and to assess possible threshold differences for older men and women.