Hematology/Oncology Program, Hamilton Health Sciences, Hamilton, ON. ; School of Rehabilitation Sciences, McMaster University, Hamilton, ON.
School of Rehabilitation Sciences, McMaster University, Hamilton, ON.
Curr Oncol. 2014 Apr;21(2):e186-94. doi: 10.3747/co.21.1735.
Reliable and valid assessment of the disease burden across all forms of cancer is critical to the evaluation of treatment effectiveness and patient progress. The Edmonton Symptom Assessment System (esas) is used for routine evaluation of people attending for cancer care. In the present study, we used Rasch analysis to explore the measurement properties of the esas and to determine the effect of using Rasch-proposed interval-level esas scoring compared with traditional scoring when evaluating the effects of an exercise program for cancer survivors.
Polytomous Rasch analysis (Andrich's rating-scale model) was applied to data from 26,645 esas questionnaires completed at the Juravinski Cancer Centre. The fit of the esas to the polytomous Rasch model was investigated, including evaluations of differential item functioning for sex, age, and disease group. The research implication was investigated by comparing the results of an observational research study previously analysed using a traditional approach with the results obtained by Rasch-proposed interval-level esas scoring.
The Rasch reliability index was 0.73, falling short of the desired 0.80-0.90 level. However, the esas was found to fit the Rasch model, including the criteria for uni-dimensional data. The analysis suggests that the current esas scoring system of 0-10 could be collapsed to a 6-point scale. Use of the Rasch-proposed interval-level scoring yielded results that were different from those calculated using summarized ordinal-level esas scores. Differential item functioning was not found for sex, age, or diagnosis groups.
The esas is a moderately reliable uni-dimensional measure of cancer disease burden and can provide interval-level scaling with Rasch-based scoring. Further, our study indicates that, compared with the traditional scoring metric, Rasch-based scoring could result in substantive changes to conclusions.
可靠和有效的评估所有形式癌症的疾病负担对于评估治疗效果和患者进展至关重要。埃德蒙顿症状评估系统（esas）用于常规评估接受癌症治疗的人群。在本研究中，我们使用 Rasch 分析探讨了 esas 的测量特性，并确定了当评估癌症幸存者的锻炼计划的效果时，使用 Rasch 提出的区间级 esas 评分与传统评分相比的效果。
多项 Rasch 分析（Andrich 的评分量表模型）应用于 Juravinski 癌症中心完成的 26,645 份 esas 问卷的数据。研究了 esas 对多项 Rasch 模型的拟合情况，包括对性别、年龄和疾病组的差异项目功能的评估。通过比较以前使用传统方法分析的观察性研究结果与 Rasch 提出的区间级 esas 评分获得的结果，研究了研究结果的意义。
Rasch 可靠性指数为 0.73，低于理想的 0.80-0.90 水平。然而，发现 esas 符合 Rasch 模型，包括一维数据的标准。分析表明，当前的 esas 评分系统 0-10 可以简化为 6 点量表。使用 Rasch 提出的区间级评分得出的结果与使用汇总有序级 esas 得分计算得出的结果不同。未发现性别、年龄或诊断组的差异项目功能。
esas 是一种中度可靠的癌症疾病负担一维测量工具，可提供基于 Rasch 的评分的区间级量表。此外，我们的研究表明，与传统评分指标相比，基于 Rasch 的评分可能会导致结论发生实质性变化。
