Swiss Paraplegic Research, Nottwil, Switzerland.
Department of Health Sciences and Health Policy, University of Lucerne, Lucerne, Switzerland.
BMC Med Res Methodol. 2019 Jul 8;19(1):141. doi: 10.1186/s12874-019-0768-y.
In most cases, the total scores from different instruments assessing the same construct are not directly comparable, but must be equated. In this study we aimed to illustrate a novel test equating methodology applied to sleep functions, a domain in which few score comparability studies exist.
Eight scales from two cross-sectional self-report studies were considered, and one scale was common to both studies. The International Classification of Functioning, Disability and Health (ICF) was used to establish content comparability. Direct (common persons) and indirect (common item) equating was assessed by means of Leunbach's model, which equates the scores of two scales depending on the same person parameter, taking into account several tests of fit and the Standard Error of Equating (SEE).
All items were linked to the body functions category b134 of the ICF, which corresponds to 'Sleep functions'. The scales were classified into three sleep aspects: four scales were assessing mainly sleep disturbance, one quality of sleep, and three impact of sleep on daily life. Of 16 direct equated pairs, 15 could be equated according to Leunbach's model, and of 12 indirect equated pairs, 8 could be equated. Raw score conversion tables between each of these 23 equated pairs are provided. The SEE was higher for indirect than for direct equating. Pairs measuring the same sleep aspect did not show better fit indices than pairs from different aspects. The instruments mapped to a higher order concept of sleep functions.
Leunbach's equating model has been successfully applied to a functioning domain little explored in test equating. This novel methodology, together with the ICF, enables comparison of clinical outcomes and research results, and facilitates communication among clinicians.
在大多数情况下，评估同一结构的不同工具的总分不能直接比较，而必须进行等化。本研究旨在举例说明一种新的测试等化方法，应用于睡眠功能领域，该领域的评分可比性研究较少。
考虑了两项横断面自我报告研究中的 8 个量表，其中一个量表在两项研究中都有。国际功能、残疾和健康分类（ICF）用于建立内容可比性。直接（共同的人）和间接（共同的项目）等化通过 Leunbach 模型进行评估，该模型根据同一人的参数来等化两个量表的分数，考虑到几个拟合测试和标准等化误差（SEE）。
所有项目都与 ICF 的身体功能类别 b134 相关，对应“睡眠功能”。量表被分为三个睡眠方面：四个量表主要评估睡眠障碍，一个评估睡眠质量，三个评估睡眠对日常生活的影响。在 16 个直接等化对中，有 15 对可以根据 Leunbach 模型等化，在 12 个间接等化对中，有 8 对可以等化。提供了这些 23 个等化对之间的每个原始分数转换表。间接等化的 SEE 高于直接等化。测量相同睡眠方面的对与来自不同方面的对相比，拟合指数并不更好。这些工具映射到更高阶的睡眠功能概念。
Leunbach 的等化模型已成功应用于测试等化中探索较少的功能领域。这种新的方法学，与 ICF 一起，使临床结果和研究结果的比较成为可能，并促进了临床医生之间的沟通。
