School of Health and Related Research, University of Sheffield, Sheffield, UK.
Centre for Health Economics Research and Evaluation, University of Technology Sydney, Sydney, NSW, Australia.
Med Care. 2020 Jun;58(6):557-565. doi: 10.1097/MLR.0000000000001325.
The objective of this study was to develop the classification system for version of the SF-6D (SF-6Dv2) from the SF-36v2. SF-6Dv2 is an improved version of SF-6D, one of the most widely used generic measures of health for the calculation of quality-adjusted life years.
A 3-step process was undertaken to generate a new classification system: (1) factor analysis to establish dimensionality; (2) Rasch analysis to understand item performance; and (3) tests of differential item function. To evaluate robustness, Rasch analyses were performed in multiple subsets of 2 large cross-sectional datasets from recently discharged hospital patients and online patient samples.
On the basis of factor analysis, other psychometric evidence, cross-cultural considerations, and amenability to valuation, the 6-dimension classification used in SF-6D was maintained. SF-6Dv2 resulted in the following modifications to SF-6D: a simpler classification of physical function with clearer separation between levels; a more detailed 5-level description of role limitations; using negative wording to describe vitality; and using pain severity rather than pain interference.
The SF-6Dv2 classification system describes more distinct levels of health than SF-6D, changes the descriptions used for a number of dimensions and provides clearer wording for health state valuation. The second stage of the study has developed a utility value set using discrete choice methods so that the measure can be used in health technology assessment. Further work should investigate the psychometric characteristics of the new instrument.
本研究旨在开发 SF-6D（SF-6Dv2）的版本分类系统，SF-6Dv2 是 SF-6D 的一个改进版本，SF-6D 是最常用于计算质量调整生命年的通用健康衡量标准之一。
采用三步法生成新的分类系统：（1）因子分析以确定维度；（2）Rasch 分析以了解项目表现；（3）差异项目功能测试。为了评估稳健性，在最近出院的医院患者和在线患者样本的 2 个大型横断面数据集的多个子集中进行了 Rasch 分析。
基于因子分析、其他心理测量证据、跨文化考虑因素以及估值的适应性，SF-6D 中使用的 6 维度分类得以保留。SF-6Dv2 对 SF-6D 进行了以下修改：物理功能的分类更简单，水平之间的分离更清晰；角色限制的 5 级描述更详细；使用负面措辞描述活力；以及使用疼痛严重程度而不是疼痛干扰。
SF-6Dv2 分类系统比 SF-6D 更能描述健康的不同水平，改变了许多维度使用的描述，并为健康状况估值提供了更清晰的措辞。研究的第二阶段使用离散选择方法开发了效用值集，以便该测量方法可用于卫生技术评估。进一步的工作应研究新工具的心理测量特征。
