Affiliations: [a] Research Division, Institute of Mental Health, Singapore, Singapore
| [b] Early Psychosis Intervention Programme, Institute of Mental Health, Singapore, Singapore
| [c]
Department of Psychological Medicine, Changi General Hospital, Singapore, Singapore
| [d]
Health Service and Population Research Department, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, United Kingdom
Correspondence:
[*]
Correspondence to: Chao Xu Peh, Research Division, Institute of Mental Health, 10 Buangkok View, 539747 Singapore, Singapore. Tel.: +65 6389 3698; E-mail: Chao_Xu_PEH@imh.com.sg.
Abstract: Background: The latent variable δ has been proposed as a proxy for dementia. Previous validation studies have been conducted using convenience samples. It is currently unknown how δ performs in population-wide data. Objective: To validate δ in Singapore using population-wide epidemiological study data on persons aged 60 and above. Methods: δ was constructed using items from the Community Screening Instrument for Dementia (CSI’D) and World Health Organization Disability Assessment Schedule (WHODAS II). Confirmatory factor analysis (CFA) was conducted to examine δ model fit. Convergent validity was examined with the Clinical Dementia Rating scale (CDR) and GMS-AGECAT dementia. Divergent validity was examined with GMS-AGECAT depression. Results: The δ model demonstrated fit to the data, χ2(df) = 249.71(55), p < 0.001, CFI = 0.990, TLI = 0.997, RMSEA = 0.037. Latent variable δ was significantly associated with CDR and GMS-AGECAT dementia (range: β= 0.32 to 0.63), and was not associated with GMS-AGECAT depression. Compared to unadjusted models, δ model fit was poor when adjusted for age, gender, ethnicity, and education. Conclusion: The study found some support for δ as a proxy for dementia in Singapore based on population data. Both convergent and divergent validity were established. In addition, the δ model structure appeared to be influenced by age, gender, ethnicity, and education covariates.
