Young Tracey, Yang Yaling, Brazier John E, Tsuchiya Aki, Coyne Karin
School of Health and Related Research, HEDS University of Sheffield, Regent Court 30 Regent Street, Sheffield, S1 4DA, UK.
Qual Life Res. 2009 Mar;18(2):253-65. doi: 10.1007/s11136-008-9428-0. Epub 2008 Dec 11.
To set out the methodological process for using Rasch analysis alongside classical psychometric methods in the development of a health-state classification that is amenable to valuation.
The overactive bladder questionnaire is used to illustrate a five step process for deriving a reduced health-state classification from an existing non-preference-based health-related quality-of-life instrument. Step I uses factor analysis to establish instrument dimensions, step II excludes items that do not meet the initial validation process and step III uses criteria based on Rasch analysis and other psychometric testing to select the final items for the health-state classification. In step IV, item levels are examined and Rasch analysis is used to explore the possibility of reducing the number of item levels. Step V repeats steps I-IV on alternative data sets in order to validate the selection of items for the health-state classification.
The techniques described enable the construction of a five-dimension health-state classification, the OAB-5D, amenable to valuation tasks that will allow the derivation of preference weights.
The health-related quality of life of patients with conditions like overactive bladder can be valued and quality adjustment weights estimated for calculation of quality-adjusted life years.
阐述在开发适用于估值的健康状态分类时，将拉施分析与经典心理测量方法结合使用的方法学过程。
以膀胱过度活动症问卷为例，说明从现有的基于非偏好的健康相关生活质量工具中得出简化的健康状态分类的五步过程。第一步使用因子分析来确定工具维度，第二步排除不符合初始验证过程的项目，第三步使用基于拉施分析和其他心理测量测试的标准来选择健康状态分类的最终项目。在第四步中，检查项目水平，并使用拉施分析来探索减少项目水平数量的可能性。第五步在替代数据集上重复第一步至第四步，以验证健康状态分类项目的选择。
所描述的技术能够构建一个五维度的健康状态分类，即OAB-5D，适用于能够得出偏好权重的估值任务。
膀胱过度活动症等疾病患者的健康相关生活质量可以进行估值，并估计质量调整权重以计算质量调整生命年。
