Comparing the factor structures and reliabilities of the EPDS and the PHQ‑9 for screening antepartum and postpartum depression: a multigroup confrmatory factor analysis Comparing the factor structures and reliabilities of the EPDS and the PHQ‑9 for screening antepartum and postpartum depression: a multigroup confrmatory factor analysis Alberto Stefana, Joshua A. Langfus, Gabriella Palumbo, · Loredana Cena, · Alice Trainini, Antonella Gigantesco, · Fiorino Mirabella

Abstract
To evaluate and compare the factor structure and reliability of EPDS and PHQ in antepartum and postpartum samples. Paral lel analysis and exploratory factor analysis were conducted to determine the structure of both scales in the entire sample as
well as in the antepartum and postpartum groups. McDonald’s omega statistics examined the utility of treating items as a
single scale versus multiple factors. Multigroup confrmatory factor analysis (MCFA) was utilized to test the measurement
invariance between the antepartum and postpartum groups. Two-factor models ft best for the EPDS in both the antepar tum and postpartum groups; however, the most reliable score variance was attributable to a general factor for each scale.
MCFA provided evidence of weak invariance across groups regarding factor loadings and partial invariance regarding item
thresholds. PHQ-9 showed a two-factor model in the antepartum group; however, the same model did not ft well in the
postpartum group. EPDS should be preferred to PHQ-9 for measuring depressive symptoms in peripartum populations. Both
scales should be used as a single-factor scale. Caution is required when comparing the antepartum and postpartum scores.