RESEARCH ARTICLE


The Edinburgh Postnatal Depression Scale: Model Comparison of Factor Structure and its Psychosocial Correlates Among Mothers at One Month After Childbirth in Japan



Ayako Hada1, 2, 3, *, Chika Kubota4, 8, Masumi Imura3, Fumie Takauma5, Katsuhiko Tada6, Toshinori Kitamura1, 2, 7, 8
1 Kitamura Institute of Mental Health Tokyo, Tokyo, Japan
2 Kitamura KOKORO Clinic Mental Health, Tokyo, Japan
3 Japanese Red Cross College of Nursing, Tokyo, Japan
4 Department of Psychiatry, National Centre of Neurology and Psychiatry, Tokyo, Japan
5 Okayama University Hospital, Okayama, Japan
6 Department of Obstetrics and Gynaecology, National Hospital Organization, Okayama Medical Centre, Okayama, Japan
7 T. and F. Kitamura Foundation of Mental Health Studies and Skill Advancement, Tokyo, Japan
8 Department of Psychiatry, Graduate School of Medicine, Nagoya University, Nagoya, Japan


© 2019 Hada et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Kitamura Institute of Mental Health Tokyo, Flat A, 2-26-3, Tomigaya, Shibuya, Tokyo, Japan;
Tel: +81-03-5738-8371; E-mail: ayako-ha.fbm@jcom.zaq.ne.jp


Abstract

Background:

The Edinburgh Postnatal Depression Scale (EPDS; Cox, Holden & Sagovsky, 1987) has been widely used as a screening instrument. It is also used as a measure of Postnatal Depression (PND) severity. Various EPDS factor structure models have been proposed in many studies without an unequivocal conclusion. We compared first-order, higher-order factor, and bifactor models of the EPDS, and examined possible predictors of subscales by Structural Equation Modelling (SEM).

Methods:

Data came from a follow-up study of 758 women after childbirth on two occasions (five days and one month postnatal). We used the EPDS together with items tapping Negative Life Events (NLEs) and coping styles and behaviours.

Results:

The bifactor model showed the best fit with data compared with all other models: CFI = 0.999, RMSEA = 0.14, and AIC = 79.637. A single general dimension alongside three distinct subfactors (anhedonia, anxiety, and dysphoria) was predicted differentially by various predictor variables.

Conclusion:

Our study expanded on a previous factor structural study of the EPDS and developed the hierarchical (bifactor) model. The model’s construct validity was confirmed by its meaningful associations with NLEs and coping styles and behaviours.

Keyword: Edinburgh Postnatal Depression Scale, Factor structure, Bifactor model, Negative life events, Coping styles, Screening instrument.