The factor structure of the Patient Health Questionnaire-9 in stroke: A comparison with a non-stroke population

• Published in: Journal of psychosomatic research 2025-01, Vol.188, p.111983, Article 111983
• Main Authors: 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.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Confirmatory factor analysis; Depression; Depression - diagnosis; Depression - psychology; Dimensionality; Factor Analysis, Statistical; Female; Humans; Male; Middle Aged; Patient Health Questionnaire; PHQ-9; Psychometrics; Self Report; Stroke; Stroke - complications; Stroke - psychology; Surveys and Questionnaires
• ISSN: 0022-3999; 1879-1360; 1879-1360
• DOI: 10.1016/j.jpsychores.2024.111983

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