Misajon RoseAnne, Pallant Julie, Bliuc Ana-Maria
Monash University, Melbourne, Australia.
Griffith University, Nathan, QLD, Australia.
Qual Life Res. 2016 Oct;25(10):2565-2569. doi: 10.1007/s11136-016-1302-x. Epub 2016 Apr 27.
The Personal Wellbeing Index (PWI) is used internationally to measure subjective well-being. While numerous studies have reported on the psychometric properties of the PWI using classic test theory, the current paper provides additional psychometric evaluation using the Rasch measurement model.
The responses to the PWI items of 593 healthy adults living in Australia or Canada were analysed using Rasch analysis. Assessed were overall model fit was assessed, individual person fit and item fit, reliability, differential item functioning (DIF), unidimensionality, targeting, and response format.
Results indicate excellent psychometric properties of the PWI, provided the religion/spirituality item is excluded. The seven-item PWI showed good model fit (overall item-trait interaction χ (2) = 70.59, df = 63, p = 0.24), excellent person separation (PSI = .89), no item or person misfit, and no DIF for country or gender, and unidimensionality was supported. In addition, only very mild disordered thresholds were observed for the 'safety' item, indicating that overall, the 11-point response format was suitable for this population.
It is recommended that the religion/spirituality item not be included in the aggregated or averaged total score in Western context and that caution should be used in comparison across different groups where the eight-item version has been used.
个人幸福指数（PWI）在国际上用于衡量主观幸福感。虽然已有大量研究使用经典测试理论报告了PWI的心理测量特性，但本文使用拉施测量模型提供了额外的心理测量评估。
对居住在澳大利亚或加拿大的593名健康成年人对PWI项目的回答进行拉施分析。评估了整体模型拟合度、个体拟合度和项目拟合度、信度、项目功能差异（DIF）、单维度性、目标定位和回答格式。
结果表明，排除宗教/精神性项目后，PWI具有优异的心理测量特性。七项PWI显示出良好的模型拟合度（整体项目-特质交互χ(2)=70.59，自由度=63，p=0.24），出色的个体区分度（PSI=.89），无项目或个体不拟合，国家或性别方面无DIF，且支持单维度性。此外，仅观察到“安全”项目存在非常轻微的无序阈值，表明总体而言，11点回答格式适用于该人群。
建议在西方背景下，宗教/精神性项目不应包含在汇总或平均总分中，并且在使用八项版本进行不同组之间的比较时应谨慎。
