van Hartingsveld Frank, Lucas Cees, Kwakkel Gert, Lindeboom Robert
Amsterdam School of Allied Health, Amsterdam, The Netherlands.
Stroke. 2006 Jan;37(1):162-6. doi: 10.1161/01.STR.0000195176.50830.b6. Epub 2005 Nov 23.
Attempts have been made to provide guidelines for interpreting Barthel scores. We used a Rasch analysis to improve the measurement properties and clinical interpretability of the Barthel index score.
A specific extension of Rasch model was used to identify items that preclude the summation of items and to improve the item rating scale by examining the scores on the Barthel of 559 stroke patients scored 3 weeks (n=89) and 6 months (n=470) after stroke. The clinical interpretation of the revised Rasch modeled Barthel was illustrated by re-examining the results of a previously published trial on the effectiveness of leg and arm training after stroke.
Most rating scales could be improved by collapsing nondiscriminating rating categories. Two items showed misfit: Bladder and Bowel. The remaining Barthel showed an excellent fit to the extended Rasch model (R1c Goodness-of-Fit P=0.35). Both items and patients could be placed on a common logit unit scale, allowing a clearer interpretation of the trial effect. Using the modeled activities of daily living difficulty/ability scale, we could express the differences between treatment arms in modeled probabilities of a positive score to each Barthel item for the treatment arms not conveyed by the original ordinal Barthel sum scores.
We improved the psychometric properties and clinical interpretation of the Barthel index.
人们已尝试为解读巴氏评分提供指导原则。我们运用拉施分析来改善巴氏指数评分的测量特性及临床可解释性。
采用拉施模型的一种特定扩展形式，通过检查559例脑卒中患者在卒中后3周（n = 89）和6个月（n = 470）时的巴氏评分，来识别妨碍项目求和的条目，并改进项目评分量表。通过重新审视先前发表的一项关于卒中后腿部和手臂训练效果的试验结果，来说明经拉施模型修正后的巴氏评分的临床解释。
通过合并无区分度的评分类别，多数评分量表得以改进。有两个条目表现出不拟合：膀胱和肠道。其余的巴氏评分对扩展的拉施模型表现出极佳的拟合度（R1c拟合优度P = 0.35）。条目和患者均可置于一个通用的对数单位量表上，从而能更清晰地解释试验效果。使用所构建的日常生活困难/能力量表模型，我们能够表达各治疗组之间在每个巴氏条目获得阳性评分的模型概率上的差异，而这是原始的顺序巴氏总分所无法传达的。
我们改进了巴氏指数的心理测量特性及临床解释。
