Psychometric testing of the SF-36 Taiwan version on older stroke patients.

AIM AND OBJECTIVE: To assess the psychometric properties of the SF-36 Taiwan version on a sample of older stroke patients in Taiwan.

BACKGROUND: The Medical Outcomes Study Short Form-36 (SF-36) has proven to be a valid and reliable instrument in evaluating outcomes among stroke patients in western countries; however, less is known regarding its value for Asian stroke patients.

DESIGN: A descriptive correlational study design was used to explore the reliability and validity of the SF-36 Taiwan version.

METHOD: Older stroke patients (n = 87) from a medical centre in northern Taiwan were interviewed at the end of the first and sixth months after hospital discharge.

RESULTS: Items on each subscale of the SF-36 Taiwan version had similar standard deviations, supporting the scaling assumption of equal-item variance in measuring the same concept. Correlations between items and their subscale were generally >or=0.70 with a few being 0.50 or 0.60. Cronbach's alpha coefficients were >0.70 for almost all subscales, supporting internal consistency. At both the first and sixth months after discharge, participants had lower scores, especially on the physical- and social function-related scales, than the norm for older people. At both times, patients with physical dependence had lower scores across subscales than those without physical dependence, supporting construct validity.

CONCLUSIONS: The SF-36 Taiwan version demonstrated good reliability and validity when applied to stroke patients at either a transitional or stable time point after hospital discharge. However, the SF-36 Taiwan version has a potential to underestimate changes in certain domains due to floor or ceiling effects.

RELEVANCE TO CLINICAL PRACTICE: Health care providers who deal with Taiwanese/Chinese stroke patients can use the SF-36 Taiwan version to assess health outcomes at either a transitional or a stable time point after hospital discharge.