RT International, Research Triangle Park, NC, USA.
Int J Methods Psychiatr Res. 2010 Jun;19 Suppl 1(Suppl 1):49-60. doi: 10.1002/mpr.313.
A psychometric analysis was conducted to reduce the number of items needed to assess the disability associated with mental disorders using the World Health Organization Disability Assessment Schedule (WHODAS). The WHODAS was to be used in the Substance Abuse and Mental Health Services Administration National Survey on Drug Use and Health (NSDUH), beginning in 2008, as part of a screening algorithm to produce estimates of the prevalence of serious mental illness (SMI) in the US adult population. The goal of the work presented in this paper was to create a parsimonious screening scale from the full 16-item WHODAS that was administered to 24,156 respondents (aged 18+) in the 2002 NSDUH. Exploratory factor analysis showed that WHODAS responses were unidimensional. A two-parameter polytomous Item Response Theory model showed that all 16 WHODAS items had good item discrimination (slopes greater than 1.0) for each response option. Analysis of item difficulties and differential item function across socio-demographic categories was then used to select a subset of eight items to create a short version of the WHODAS. The Pearson correlation between scores in the original 16-item and reduced eight-item WHODAS scales was 0.97, documenting that the vast majority of variation in total scale scores was retained in the reduced scale.
采用世界卫生组织残疾评定量表（WHODAS）对与精神障碍相关的残疾进行评估，需要对项目进行删减以减少所需项目的数量。自 2008 年起，该量表将被用于药物滥用和心理健康服务管理局国家药物使用和健康调查（NSDUH），作为产生美国成年人群体严重精神疾病（SMI）流行率估计值的筛选算法的一部分。本文介绍的工作旨在从对 24156 名（年龄在 18 岁及以上）受访者进行的 2002 年 NSDUH 中使用的完整的 16 项 WHODAS 中创建一个简约的筛选量表。探索性因素分析表明，WHODAS 的反应是单维的。双参数多项逻辑斯蒂克项目反应理论模型表明，WHODAS 的所有 16 个项目对于每个反应选项都具有良好的项目区分度（斜率大于 1.0）。然后，对社会人口统计学类别中的项目难度和差异项目功能进行分析，以选择 8 个项目子集来创建 WHODAS 的简短版本。原始的 16 项和简化的 8 项 WHODAS 量表的得分之间的 Pearson 相关系数为 0.97，证明在简化量表中保留了总量表得分的绝大多数变化。
