TITLE:
The Patient Health Questionnaire-9 among First-Trimester Pregnant Women in Japan: Factor Structure and Measurement and Structural Invariance between Nulliparas and Multiparas and across Perinatal Measurement Time Points
AUTHORS:
Mikiyo Wakamatsu, Mariko Minatani, Ayako Hada, Toshinori Kitamura
KEYWORDS:
Patient Health Questionnaire-9, Factor Structure, Pregnancy, Measurement and Structural Invariance, Parity
JOURNAL NAME:
Open Journal of Depression,
Vol.10 No.3,
August
10,
2021
ABSTRACT: Background:Depression is frequently seen among pregnant women.ThePHQ-9 is a diagnostic criteria-based screening instrument.Objective:The objective is toidentify the factor structureof the Patient Health Questionnaire-9 (PHQ-9) and to confirm its measurement and structural invariance regarding parity and observation time, as well as to examine reliability by calculating omega indicesin a population of pregnant Japanese women.Methods:The PHQ-9 was distributed to 382 pregnant women with a gestational age of 10 to 13 weeks who were attending antenatal clinics. Of these women,129were tested again with the PHQ-9 one week later.Results:Exploratory factor analyses (EFAs) of the PHQ-9 items were conducted using a halved sample. Confirmatory factor analyses (CFAs) among the other halved sample compared the single-, two-factor models derived from the EFAs, literature model and bifactor model. The bifactor model was significantly better in terms of goodness-of-fit indices:χ2/df= 1.030 (18), CFI =0.999, RMSEA = 0.012. ECV suggested multidimensionality. Internal consistency was excellent:ω= 0.868,ω.Somatic factor = 0.756,ω.Non-somatic factor = 0.817.ωH= 0.795,ωHS.Somatic factor = 0.330,ωHS.Non-somatic factor = 0.032. The bifactor structure model showed configural, measurement, and structural invariances between primiparas and multiparas as well as at two observation occasions.Conclusion:The findings suggested that the PHQ-9 used among pregnant women was robust in its factor structure.