PURPOSE 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. METHODS 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. RESULTS 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. CONCLUSIONS 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.

中文翻译：

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一致性很重要：血液恶性肿瘤患者EORTC QLQ-C30问卷的测量不变性。

目的确保观察到的欧洲癌症研究和治疗组织生活质量问卷核心30分（EORTC QLQ-C30）的差异反映与健康相关的生活质量（HRQoL）的实际差异，而不是测量偏倚，测量需要确定不变性。我们调查了年龄，性别，合并症，疾病类型和时间的血液系统恶性肿瘤患者EORTC QLQ-C30测量不变性的假设。方法我们使用了一个大型血液恶性肿瘤患者数据库，其中包括用EORTC QLQ-C30收集的HRQoL数据。我们使用结构方程建模方法测试了各组（年龄，性别，合并症，疾病）和时间（基线，1个月和2个月的随访）之间的测量（度量和标量）不变性。在诊断为骨髓增生异常综合症的患者亚组中检查了纵向不变性。结果验证性因素分析表明，年龄，合并症以及随着时间的推移，测量的完全不变性，而性别和疾病得到了部分标量不变性的支持。在身体功能量表和情绪功能量表的项目中观察到性别不变性，而在疾病类型中，在身体功能量表，情绪功能量表和认知功能量表项目中观察到不变性。结论我们的发现支持大量血液恶性肿瘤患者EORTC QLQ-C30的测量不变性。结果表明，不变项的数量可以忽略不计，