Examining the hierarchical factor structure of the SF‐36 Taiwan version by exploratory and confirmatory factor analysis

Abstract

The purpose of this study was to examine the factor structure of the Medical Outcome Study Short Form-36 Taiwan version (SF-36 Taiwan version) using data from the 2001 National Health Interview Survey in Taiwan. The 2001 National Health Interview Survey was conducted by stratified multistage systematic sampling, resulting in 19,777 valid responses for the SF-36 Taiwan version. In this study, the 19,777 participants were randomly divided into two independent samples. One sample (n = 9856) was used for exploratory factor analysis (EFA), and the other (n = 9921) was used for confirmatory factor analysis (CFA). The EFA suggested a seven-first-order-factor structure for the SF-36 Taiwan version. In addition, hierarchical EFA revealed that there was only one second-order factor underlying the seven first-order factors. Further, CFA was conducted on the other sample to compare the performances of the original model with eight first-order factors and two second-order factors, and the revised model with seven first-order factors and one second-order factor. The CFA results revealed that the original model was better than the revised model. According to the EFA and CFA, it can be concluded that the original structure is still acceptable for the SF-36 Taiwan version.