Department of Quantitative Health Sciences, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01665-002, USA.
Qual Life Res. 2011 Jun;20(5):745-58. doi: 10.1007/s11136-010-9807-1. Epub 2010 Dec 12.
Role functioning (RF) is an important part of health-related quality of life, but is hard to measure due to the wide definition of roles and fluctuations in role participation. This study aims to explore the dimensionality of a newly developed item bank assessing the impact of health on RF.
A battery of measures with skip patterns including the new RF bank was completed by 2,500 participants answering only questions on social roles relevant to them. Confirmatory factor analyses were conducted for the participants answering items from all conceptual domains (N = 1193). Conceptually based dimensionality and method effects reflecting positively and negatively worded items were explored in a series of models.
A bi-factor model (CFI = .93, RMSEA = .08) with one general and four conceptual factors (social, family, occupation, generic) was retained. Positively worded items were excluded from the final solution due to misfit. While a single factor model with methods factors had a poor fit (CFI = .88, RMSEA = .13), high loadings on the general factor in the bi-factor model suggest that the RF bank is sufficiently unidimensional for IRT analysis.
The bank demonstrated sufficient unidimensionality for IRT-based calibration of all the items on a common metric and development of a computerized adaptive test.
角色功能（RF）是健康相关生活质量的重要组成部分，但由于角色定义广泛且角色参与度波动，因此难以衡量。本研究旨在探讨新开发的用于评估健康对 RF 影响的项目库的维度。
2500 名参与者完成了一整套带有跳题模式的测量工具，包括新的 RF 银行，他们只回答与他们相关的社会角色问题。对回答所有概念领域项目的参与者（N=1193）进行验证性因子分析。在一系列模型中探索了基于概念的维度和反映正、负向措辞项目的方法效应。
保留了一个双因素模型（CFI=0.93，RMSEA=0.08），其中包括一个通用因素和四个概念因素（社会、家庭、职业、通用）。由于拟合不良，正向措辞项目被排除在最终解决方案之外。虽然具有方法因素的单因素模型拟合不佳（CFI=0.88，RMSEA=0.13），但双因素模型中通用因素的高负荷表明 RF 银行具有足够的单维性，可用于 IRT 分析。
该银行在共同度量标准上对所有项目进行 IRT 校准和开发计算机自适应测试方面表现出足够的单维性。
