Lawton G, Bhakta B B, Chamberlain M A, Tennant A
Academic Unit of Musculoskeletal and Rehabilitation Medicine, University of Leeds, Leeds, UK.
Rheumatology (Oxford). 2004 Jan;43(1):73-8. doi: 10.1093/rheumatology/keg453. Epub 2003 Jul 30.
To identify a subset of clinical features of Behçet's disease (BD) that can be summated to form an overall index of disease activity appropriate for clinical and research use internationally.
Completed Behçet's Disease Current Activity Forms were collected from a total of 524 patients with BD from five countries. The data from 14 questions on the form were subjected to Rasch analysis to establish whether these items form a hierarchical and unidimensional scale of disease activity, both within and between countries.
The data showed a good fit to the Rasch model within three countries using a dichotomous scoring function. However, when the data from these three countries were pooled, the fit to the model was poor. Cross-cultural differential item functioning (DIF) was found in seven items in the pooled data. When the items with DIF by country were separated and two items were removed, the resulting 26-item scale showed a good fit to the Rasch model.
Within Turkey, Korea and the UK, the 14 items can be summated to give an index of disease activity. Analysis of the pooled data confirmed that the index is not suitable for comparison between countries or for pooling of data in the raw form, but after fitting the data to the Rasch model such comparisons can be made. This gives a scaling tool that is quick and easy to use in the clinical situation.
确定白塞病（BD）的一组临床特征，这些特征可汇总形成一个适用于国际临床和研究的疾病活动总体指数。
从五个国家的524例BD患者中收集完整的白塞病当前活动表。对表格中14个问题的数据进行拉施分析，以确定这些项目在国家内部和国家之间是否形成疾病活动的层次化单维量表。
使用二分计分函数，三个国家的数据与拉施模型拟合良好。然而，当将这三个国家的数据合并时，与模型的拟合较差。在合并数据的七个项目中发现了跨文化差异项目功能（DIF）。当按国家将有DIF的项目分开并去除两个项目时，得到的26项量表与拉施模型拟合良好。
在土耳其、韩国和英国，这14个项目可汇总得出疾病活动指数。对合并数据的分析证实，该指数不适用于国家间比较或原始形式的数据合并，但在将数据拟合到拉施模型后可以进行此类比较。这提供了一种在临床情况下快速且易于使用的量表工具。
