Division of Gastroenterology-Hepatology, Department of Internal Medicine, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ, Maastricht, The Netherlands.
Department of Clinical Epidemiology and Medical Technology Assessment, CAPHRI Care and Public Health Research Institute, Maastricht University Medical Center, Maastricht, The Netherlands.
Qual Life Res. 2022 Apr;31(4):1209-1221. doi: 10.1007/s11136-021-02995-y. Epub 2021 Sep 21.
The Irritable Bowel Syndrome Quality of Life (IBS-QoL) questionnaire is a commonly used and validated IBS-specific QoL instrument. However, this questionnaire is in contrast to the EQ-5D-5L, not preference-based and as such does not allow calculation of QALYs. The objective of this study was to describe the convergent- and known-group validity of both questionnaires and to develop a mapping algorithm from EQ-5D-5L which enable IBS-QoL scores to be transformed into utility scores for use in economic evaluations.
We used data from two multicenter randomized clinical trials, which represented the estimation and external validation dataset. The convergent validity was investigated by examining correlations between the EQ-5D-5L and IBS-QoL and the known-group validity by calculating effect sizes. Ordinary least squares (OLS), censored least absolute deviations (CLAD), and mixture models were used in this mapping approach.
283 IBS patients were included (n = 189 vs. n = 84). Mean IBS-QoL score was 71.13 (SD 15.66) and mean EQ-5D-5L utility score was 0.73 (SD 0.19). The overall sensitivity of the IBS-QoL and EQ-5D-5L to discriminate between patient and disease characteristics was similar. CLAD model 4, containing the total IBS-QoL score and squared IBS-SSS (IBS severity scoring system), was chosen as the most appropriate model to transform IBS-QoL scores into EQ-5D-5L utility scores.
This study reports the development of an algorithm where the condition-specific questionnaire IBS-QoL can be used to calculate utility values for use in economic evaluations. Including a clinical measure, IBS-SSS, in the model improved the performance of the algorithm.
肠易激综合征生活质量问卷（IBS-QoL）是一种常用的、经过验证的肠易激综合征特异性生活质量工具。然而，与 EQ-5D-5L 不同，该问卷不是基于偏好的，因此不能计算 QALY。本研究的目的是描述这两个问卷的收敛有效性和已知组有效性，并开发一个从 EQ-5D-5L 映射算法，使 IBS-QoL 分数能够转换为效用分数，用于经济评估。
我们使用了来自两项多中心随机临床试验的数据，这些数据代表了估计和外部验证数据集。通过检查 EQ-5D-5L 和 IBS-QoL 之间的相关性，以及通过计算效应大小来研究收敛有效性。在这种映射方法中，我们使用了普通最小二乘法（OLS）、有截尾最小绝对偏差（CLAD）和混合模型。
共纳入 283 例 IBS 患者（n=189 例 vs. n=84 例）。IBS-QoL 评分的平均值为 71.13（标准差 15.66），EQ-5D-5L 效用评分的平均值为 0.73（标准差 0.19）。IBS-QoL 和 EQ-5D-5L 总体上对区分患者和疾病特征的敏感性相似。包含总 IBS-QoL 评分和平方 IBS-SSS（IBS 严重程度评分系统）的 CLAD 模型 4 被选为将 IBS-QoL 评分转换为 EQ-5D-5L 效用评分的最合适模型。
本研究报告了一种算法的开发，该算法可以使用特定于疾病的问卷 IBS-QoL 来计算效用值，用于经济评估。在模型中纳入临床指标 IBS-SSS 可提高算法的性能。
