Health Services Research Unit, IMIM-Hospital del Mar, Barcelona, Spain.
Health Qual Life Outcomes. 2010 May 19;8:51. doi: 10.1186/1477-7525-8-51.
The WHODAS-2 is a disability assessment instrument based on the conceptual framework of the International Classification of Functioning, Disability, and Health (ICF). It provides a global measure of disability and 7 domain-specific scores. The aim of this study was to assess WHODAS-2 conceptual model and metric properties in a set of chronic and prevalent clinical conditions accounting for a wide scope of disability in Europe.
1,119 patients with one of 13 chronic conditions were recruited in 7 European centres. Participants were clinically evaluated and administered the WHODAS-2 and the SF-36 at baseline, 6 weeks and 3 months of follow-up. The latent structure was explored and confirmed by factor analysis (FA). Reliability was assessed in terms of internal consistency (Cronbach's alpha) and reproducibility (intra-class correlation coefficients, ICC). Construct validity was evaluated by correlating the WHODAS-2 and SF-36 domains, and comparing known groups based on the clinical-severity and work status. Effect size (ES) coefficient was used to assess responsiveness. To assess reproducibility and responsiveness, subsamples of stable (at 6 weeks) and improved (after 3 moths) patients were defined, respectively, according to changes in their clinical-severity.
The satisfactory FA goodness of fit indexes confirmed a second order factor structure with 7 dimensions, and a global score for the WHODAS-2. Cronbach's alpha ranged from 0.77 (self care) to 0.98 (life activities: work or school), and the ICC was lower, but achieved the recommended standard of 0.7 for four domains. Correlations between global WHODAS-2 score and the different domains of the SF-36 ranged from -0.29 to -0.65. Most of the WHODAS-2 scores showed statistically significant differences among clinical-severity groups for all pathologies, and between working patients and those not working due to ill health (p < 0.001). Among the subsample of patients who had improved, responsiveness coefficients were small to moderate (ES = 0.3-0.7), but higher than those of the SF-36.
The latent structure originally designed by WHODAS-2 developers has been confirmed for the first time, and it has shown good metric properties in clinic and rehabilitation samples. Therefore, considerable support is provided to the WHODAS-2 utilization as an international instrument to measure disability based on the ICF model.
WHODAS-2 是一种基于国际功能、残疾和健康分类（ICF）概念框架的残疾评估工具。它提供了残疾的全球衡量标准和 7 个领域特定分数。本研究的目的是评估 WHODAS-2 概念模型和计量特性，涵盖欧洲广泛残疾范围的 13 种慢性和常见临床疾病。
在欧洲 7 个中心招募了 1119 名患有 13 种慢性疾病之一的患者。参与者在基线、6 周和 3 个月的随访时进行临床评估，并接受 WHODAS-2 和 SF-36 评估。通过因子分析（FA）探索和确认潜在结构。信度通过内部一致性（克朗巴赫 alpha）和可重复性（组内相关系数，ICC）来评估。通过与 WHODAS-2 和 SF-36 领域相关联，以及根据临床严重程度和工作状态比较已知组来评估构念效度。效应大小（ES）系数用于评估反应性。为了评估可重复性和反应性，根据临床严重程度的变化，分别为稳定（6 周）和改善（3 个月后）患者定义了亚组。
满意的 FA 拟合优度指数证实了一个二阶因子结构，包含 7 个维度和 WHODAS-2 的一个全球评分。克朗巴赫 alpha 范围从 0.77（自我护理）到 0.98（生活活动：工作或学校），ICC 较低，但对于四个领域达到了建议的 0.7 标准。WHODAS-2 全球评分与 SF-36 的不同领域之间的相关性范围从-0.29 到-0.65。所有病变的临床严重程度组之间以及因病工作和因病不工作的患者之间，大多数 WHODAS-2 评分均存在统计学显著差异（p < 0.001）。在改善的患者亚组中，反应性系数较小至中等（ES = 0.3-0.7），但高于 SF-36。
WHODAS-2 开发人员最初设计的潜在结构首次得到证实，并且在临床和康复样本中表现出良好的计量特性。因此，为 WHODAS-2 作为基于 ICF 模型的残疾国际测量工具的使用提供了相当大的支持。
