Huang I-Chan, Wu Albert W, Frangakis Constantine
Department of Health Policy and Management, Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, MD 21205-1901, USA.
Qual Life Res. 2006 Feb;15(1):15-24. doi: 10.1007/s11136-005-8486-9.
The SF-36 and WHOQOL-BREF are available for international use, but it is not clear if they measure the same constructs. We compared the psychometric properties and factor structures of these two instruments.
Data were collected from a national representative sample (n=11,440) in the 2001 Taiwan National Health Interview Survey, which included Taiwan versions of the SF-36 and WHOQOL-BREF. We used Cronbach's alpha coefficient to estimate scale reliability. We conducted exploratory factor analysis to determine factor structure of the scales, and applied multi trait analysis to evaluate convergent and discriminant validity. We used standardized effect size to compare known-groups validity for health-related variables (including chronic conditions and health care utilization) and self-reported overall quality of life. Structural equation modeling was used to analyze relationships among the two SF-36 component scales (PCS and MCS) and the four WHOQOL subscales (physical, psychological, social relations, and environmental).
Cronbach's alpha coefficients were acceptable ([Symbol: see text]0.7) for all subscales of both instruments. The factor analysis yielded two unique factors: one for the 8 SF-36 subscales and a second for the 4 WHOQOL subscales. Pearson correlations were weak (<0.3) among subscales of both instruments. Correlations for subscales hypothesized to measure similar constructs differed little from those measuring heterogeneous subscales. Effect sizes suggested greater discrimination by the SF-36 for health status and services utilization known groups, but greater discrimination by the WHOQOL for QOL-defined groups. Structural equation modeling suggested that the SF-36 PCS and MCS were weakly associated with WHOQOL.
In this Taiwan population sample, the SF-36 and WHOQOL-BREF appear to measure different constructs: the SF-36 measures health-related QOL, while the WHOQOL-BREF measures global QOL. Clinicians and researchers should carefully define their research questions related to patient-reported outcomes before selecting which instrument to use.
SF-36和世界卫生组织生活质量简表（WHOQOL-BREF）可在国际上使用，但尚不清楚它们是否测量相同的结构。我们比较了这两种工具的心理测量特性和因子结构。
数据收集自2001年台湾国民健康访问调查中的一个全国代表性样本（n = 11440），该调查包括台湾版的SF-36和WHOQOL-BREF。我们使用克朗巴哈α系数来估计量表的信度。我们进行探索性因子分析以确定量表的因子结构，并应用多特质分析来评估收敛效度和区分效度。我们使用标准化效应量来比较健康相关变量（包括慢性病和医疗保健利用情况）和自我报告的总体生活质量的已知组效度。使用结构方程模型分析两个SF-36分量表（生理健康分量表和心理健康分量表）与四个WHOQOL子量表（生理、心理、社会关系和环境）之间的关系。
两种工具的所有子量表的克朗巴哈α系数均可接受（[符号：见原文]0.7）。因子分析产生了两个独特的因子：一个用于8个SF-36子量表，另一个用于4个WHOQOL子量表。两种工具的子量表之间的皮尔逊相关性较弱（<0.3）。假设测量相似结构的子量表之间的相关性与测量异质子量表的相关性差异不大。效应量表明，SF-36对已知健康状况和服务利用组的区分度更大，但WHOQOL对生活质量定义组的区分度更大。结构方程模型表明，SF-36的生理健康分量表和心理健康分量表与WHOQOL的相关性较弱。
在这个台湾人群样本中，SF-36和WHOQOL-BREF似乎测量不同的结构：SF-36测量与健康相关的生活质量，而WHOQOL-BREF测量总体生活质量。临床医生和研究人员在选择使用哪种工具之前，应仔细定义与患者报告结果相关的研究问题。
