Blake J J, Munyombwe T, Fischer F, Quinn T J, Van der Feltz-Cornelis C M, De Man-van Ginkel J M, Santos I S, Jeon Hong Jin, Köhler S, Schram M T, Wang J L, Levin-Aspenson H F, Whooley M A, Hobfoll S E, Patten S B, Simning A, Gracey F, Broomfield N M
Department of Clinical Psychology and Psychological Therapies, University of East Anglia, Norwich NR4 7TJ, UK.
School of Medicine, Worsley Building, University of Leeds, Woodhouse, Leeds LS2 9JT, UK.
J Psychosom Res. 2025 Jan;188:111983. doi: 10.1016/j.jpsychores.2024.111983. Epub 2024 Nov 16.
It is unclear if certain post-stroke somatic symptoms load onto items of the Patient Health Questionnaire-9 (PHQ-9), a self-report depression questionnaire. We investigated these concerns in a stroke sample using factor analysis, benchmarked against a non-stroke comparison group.
The secondary dataset constituted 787 stroke and 12,016 non-stroke participants. A subsample of 1574 comparison participants was selected via propensity score matching. Dimensionality was assessed by comparing fit statistics of one-factor, two-factor, and bi-factor models. Between-group differences in factor structure were explored using measurement invariance.
A two-factor model, consisting of somatic and cognitive-affective factors, showed better fit than the unidimensional model (CFI = 0.984 versus CFI = 0.974, p < .001), but the high correlation between the factors indicated unidimensionality (r = 0.866). Configural invariance between stroke and non-stroke was supported (CFI = 0.983, RMSEA = 0.080), as were invariant thresholds (p = .092) and loadings (p = .103). Strong invariance was violated (p < .001, ΔCFI = -0.003), stemming from differences in the tiredness and appetite intercepts. These differences resulted in a moderate overestimation of depression in stroke when using a summed score approach, relative to the comparison sample (Cohen's d = 0.434).
The findings suggest that the PHQ-9 measures a single factor in stroke. Because stroke patients may report higher tiredness on item 4, caution is advisable when classifying patients as depressed if they are near the cut-off and have significant post-stroke fatigue. Caution is also advised when comparing total scores between stroke and other populations.
尚不清楚某些中风后的躯体症状是否加载到患者健康问卷-9（PHQ-9）的项目上，PHQ-9是一份自我报告的抑郁问卷。我们在中风样本中使用因子分析对这些问题进行了研究，并与非中风对照组进行了对比。
二次数据集包括787名中风参与者和12016名非中风参与者。通过倾向得分匹配选择了1574名对照参与者的子样本。通过比较单因素、双因素和双因子模型的拟合统计量来评估维度。使用测量不变性探索组间因子结构的差异。
由躯体和认知-情感因子组成的双因素模型显示出比单维模型更好的拟合度（CFI = 0.984对CFI = 0.974，p <.001），但因子之间的高相关性表明为单维性（r = 0.866）。中风组和非中风组之间的构型不变性得到支持（CFI = 0.983，RMSEA = 0.080），阈值（p =.092）和负荷（p =.103）的不变性也得到支持。强不变性被违反（p <.001，ΔCFI = -0.003），这源于疲劳和食欲截距的差异。与对照样本相比，这些差异导致在使用总分法时中风患者的抑郁程度被适度高估（科恩d = 0.434）。
研究结果表明，PHQ-9在中风中测量的是单一因子。由于中风患者在第4项上可能报告更高的疲劳感，因此当患者接近临界值且有明显的中风后疲劳时，在将其分类为抑郁时应谨慎。在比较中风组和其他人群的总分时也建议谨慎。
