The meaning of activities of daily living in a Thai elderly population: development of a new index.

Activities of daily living (ADL) of 703 Thai elderly people (aged 60+ years) living in a Bangkok slum community were studied with the aims of describing the prevalence of disability, considering the appropriateness of Western ADL scales and developing a new ADL index for Asian populations. The levels of disability found were higher than in industrial populations and the important areas of disability were in instrumental ADLs. The mean (SD) Barthel ADL Index (BAI) for the group was 19.5 (1.2) with a range of 10-20. The mean (SD) Office of Populations Censuses and Surveys (OPCS) disability score was 4.8 (1.9) with a range of 0-10 but was unsuitable for use in Thailand because of misinterpretation of behavioural and intellectual disability leading to 99% of subjects being scored as disabled. An analysis of the underlying dimensions making up ADL was conducted using factor analysis. Four dimensions of ADL were found: basic self-care ADLs, extended ADLs, mobility ADLs and continence. An extended ADL index suitable for use in developing countries was developed (the Chula ADL Index) which had strong hierarchical properties and high correlations with both the OPCS disability score and the Barthel ADL Index. Analysis of data derived from ADL instruments should consider each ADL dimension separately. The BAI is useful as an index of self-care ADL but the behaviour and intellectual disability sub-scales of the OPCS scale require further development for cross-cultural applications.