A causal model of functional performance in Thai elderly

Abstract

The purposes of this study are 1) to develop a causal model for explaining the functional performance including muscle strength, vision, chronic illness, level of exercise, social support and depression, and 2) to examine the causal relationship between those variables and functional performance in Thai elderly. The hypothesized model was based on functional consequence theory developed by Miller (1995). Stratified four-stage random sampling was employed to obtain a sample of 320 elderly aged 60 years and over who resided in community from five parts of Thailand including Northern Sourthern, Central, Northeastern, and Eastern part. The interview questionnaires including the Yale Physical Activity Survey, the Personal Resource Questionnaire (PRQ 85), the Geriatric Depression Scale, the Chronic Illness Questionnaire, the Modified Barthel ADL Index, the Chula ADL Index and equipments including leg dynamometer and the Snellen Chart were employed to collect data. The SPSS for Window version 13 and LISREL version 8.72 were used for data analysis. The results showed that the model fitted well with the empirical data (chi-square = 133.59; df = 116; p = .126; GFI = .96; AGFI = .93) and explained 66% of the variance of functional performance among Thai elderly. Level of exercise was the most powerful predictor and had a positive direct effect on functional performance. Chronic illness had a negative direct effect on functional performance and an indirect effect through depression. Vision had a positive direct effect on functional performance. Social support had a positive direct effect on functional performance and an indirect effect through depresion. The study findings indicated that nursing intervention focusing on maintaining or enhancing functional performance in Thai elderly should be significantly established. The prominent components of the intervention shall consist of promoting exercise, social support, vision and preventing chronic illness and depression in Thai elderly.