Reliability and validity of the English (Singapore) and Chinese (Singapore) versions of the Short-Form 36 version 2 in a multi-ethnic urban Asian population in Singapore
Thumboo, J.; Wu, Y.; Tai, E.-S.; Gandek, B.; Lee, J.; Ma, S.; Heng, D.; Wee, H.-L.
Quality of Life Research An International Journal of Quality of Life Aspects of Treatment Care and Rehabilitation 22(9): 2501-2508
2013
ISSN/ISBN: 1573-2649 PMID: 23475690 DOI: 10.1007/s11136-013-0381-1Document Number: 646808
We aimed to evaluate the measurement properties of the Singapore English and Chinese versions of the Short-Form 36 version 2 (SF-36v2) Questionnaire, an improved version of the widely used SF-36, for assessing health-related quality of life (HRQoL) in a multi-ethnic urban Asian population in Singapore. SF-36v2 scores and data on medical history, demographic and lifestyle factors from the Singapore Prospective Study Programme were analyzed. Convergent and divergent validity, internal consistency, floor and ceiling effects, known group validity and factor structure of the SF-36v2 were assessed for the English and Chinese versions, respectively. Complete data for 4,917 participants (45.8 %) out of 10,747 eligible individuals were analyzed (survey language: 4,115 English and 802 Chinese). Item-scale correlations exceeded 0.4 for all items of the English SF-36v2 and for all except one item of the Chinese SF-36v2 (bathe and dress: item-scale correlation: 0.36). In the English SF-36v2, Cronbach's alpha exceeded 0.70 for all scales. In the Chinese SF-36v2, Cronbach's alpha exceeded 0.7 on all scales except social functioning (Cronbach's alpha: 0.68). For known groups validity, respondents with chronic medical conditions expectedly reported lower SF-36v2 score on most English and Chinese SF-36v2 scales. In confirmatory factor analysis, the Singapore three-component model was favored over the United States two-component and Japan three-component models. The English and Chinese SF-36v2 are valid and reliable for assessing HRQoL among English and Chinese-speaking Singaporeans. Test-retest reliability and responsiveness of the English and Chinese SF-36v2 in Singapore remain to be evaluated.