Data Center and Health Outcomes Research Unit, Italian Group for Adult Hematologic Diseases (GIMEMA), Rome, Italy.
Division of Psychosocial Research and Epidemiology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
Qual Life Res. 2020 Mar;29(3):815-823. doi: 10.1007/s11136-019-02369-5. Epub 2019 Nov 28.
To ensure that observed differences in the scores of the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) reflect actual differences in health-related quality of life (HRQoL) rather than measurement bias, measurement invariance needs to be established. We investigated the assumption of measurement invariance of the EORTC QLQ-C30 in patients with hematological malignancies across age, sex, comorbidity, disease type, and time.
We used a large database of patients with hematological malignancies, which included HRQoL data collected with the EORTC QLQ-C30. We used the structural equation modeling approach to test for measurement (metric and scalar) invariance across groups (age, sex, comorbidity, disease) and time (baseline, 1 month and 2 month follow-up). Longitudinal invariance was examined in a subgroup of patients diagnosed with myelodysplastic syndromes.
Confirmatory factor analyses demonstrated full measurement invariance for age and comorbidity and over time, while support for partial scalar invariance was obtained for sex and disease. Violations of invariance for sex were observed for items of the physical functioning scale and the emotional functioning scale, while for disease type, violations of invariance were observed for items of the physical functioning scale, emotional functioning scale, and the cognitive functioning scale.
Our findings support measurement invariance of the EORTC QLQ-C30 in a large sample of patients with hematological malignancies. The results showed that the number of non-invariant items was negligible, suggesting that this questionnaire is a valid and robust measurement tool in patients with hematological malignancies, also for comparisons across groups and time.
为了确保欧洲癌症研究与治疗组织生活质量问卷核心 30 项（EORTC QLQ-C30）评分的差异反映的是健康相关生活质量（HRQoL）的实际差异，而不是测量偏差，因此需要建立测量不变性。我们调查了 EORTC QLQ-C30 在血液恶性肿瘤患者中在年龄、性别、合并症、疾病类型和时间上的测量不变性假设。
我们使用了一个大型血液恶性肿瘤患者数据库，其中包括使用 EORTC QLQ-C30 收集的 HRQoL 数据。我们使用结构方程模型方法来测试组间（年龄、性别、合并症、疾病）和时间（基线、1 个月和 2 个月随访）的测量（度量和标度）不变性。在诊断为骨髓增生异常综合征的患者亚组中检查了纵向不变性。
验证性因子分析表明，年龄和合并症以及随时间的变化具有完全的测量不变性，而性别和疾病的部分标度不变性得到了支持。对于身体功能量表和情绪功能量表的项目，性别不变性受到了违反，而对于身体功能量表、情绪功能量表和认知功能量表的项目，疾病类型不变性受到了违反。
我们的研究结果支持 EORTC QLQ-C30 在大量血液恶性肿瘤患者中的测量不变性。结果表明，不变性项目的数量可以忽略不计，这表明该问卷在血液恶性肿瘤患者中是一种有效和可靠的测量工具，也可以用于组间和时间的比较。
