Department of Public Health and Amsterdam Public Health (APH) research institute, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
Department of Public Health, Academic Medical Center, PO 22660, 1100, DD, Amsterdam, The Netherlands.
BMC Psychiatry. 2017 Oct 24;17(1):349. doi: 10.1186/s12888-017-1506-9.
In Western European countries, the prevalence of depressive symptoms is higher among ethnic minority groups, compared to the host population. We explored whether these inequalities reflect variance in the way depressive symptoms are measured, by investigating whether items of the PHQ-9 measure the same underlying construct in six ethnic groups in the Netherlands.
A total of 23,182 men and women aged 18-70 of Dutch, South-Asian Surinamese, African Surinamese, Ghanaian, Turkish or Moroccan origin were included in the HELIUS study and had answered to at least one of the PHQ-9 items. We conducted multiple group confirmatory factor analyses (MGCFA), with increasingly stringent model constraints (i.e. assessing Configural, Metric, Strong and Strict measurement invariance (MI)), and regression analysis, to confirm comparability of PHQ-9 items across ethnic groups.
A one-factor model, where all nine items reflect a single underlying construct, showed acceptable model fit and was used for MI testing. In each subsequent step, change in goodness-of-fit measures did not exceed 0.015 (RMSEA) or 0.01 (CFI). Moreover, strict invariance models showed good or acceptable model fit (Men: RMSEA = 0.050; CFI = 0.985; Women: RMSEA = 0.058; CFI = 0.979), indicating between-group equality of item clusters, factor loadings, item thresholds and residual variances. Finally, regression analysis did not indicate potential ethnicity-related differential item functioning (DIF) of the PHQ-9.
This study provides evidence of measurement invariance of the PHQ-9 regarding ethnicity, implying that the observed inequalities in depressive symptoms cannot be attributed to DIF.
在西欧国家，与宿主人群相比，少数民族群体的抑郁症状更为普遍。我们通过调查 PHQ-9 量表的项目是否在荷兰的六个族裔群体中测量相同的潜在结构，来探讨这些不平等是否反映了抑郁症状测量方式的差异。
共有 23182 名年龄在 18-70 岁的荷兰、南亚苏里南、非洲苏里南、加纳、土耳其或摩洛哥裔的男性和女性参与了 HELIUS 研究，并且至少回答了 PHQ-9 量表的一个项目。我们进行了多次分组验证性因素分析（MGCFA），采用越来越严格的模型约束（即评估结构、度量、强和严格的测量不变性（MI））和回归分析，以确认 PHQ-9 量表在不同族裔群体中的可比性。
一个包含所有九个项目的单一因素模型反映了一个单一的潜在结构，具有可接受的模型拟合度，并用于 MI 测试。在随后的每个步骤中，拟合优度指标的变化均不超过 0.015（RMSEA）或 0.01（CFI）。此外，严格不变性模型显示出良好或可接受的模型拟合度（男性：RMSEA=0.050；CFI=0.985；女性：RMSEA=0.058；CFI=0.979），表明组间项目聚类、因子负荷、项目阈值和残差方差的相等性。最后，回归分析并未表明 PHQ-9 存在潜在的与种族相关的项目功能差异（DIF）。
本研究提供了 PHQ-9 量表在种族方面具有测量不变性的证据，这意味着观察到的抑郁症状的不平等不能归因于 DIF。
