Concordance of Edinburgh Postnatal Depression Scale (EPDS) and Patient Health Questionnaire (PHQ-9) to Assess Increased Risk of Depression among Postpartum Women

Abstract

To compare the Edinburgh Postnatal Depression Scale (EPDS) and Patient Health Questionnaire (PHQ-9) as screening tools for postpartum depression. This study population included the first 500 women to enroll and return their packets during an ongoing study of postpartum depression. The primary outcome of this study was to find rates of concordance and discordance in the EPDS and PHQ-9 categories of "normal" and "increased risk for major depressive disorder." Overall, 97% of eligible women enrolled and 70% returned the packets that included the EPDS and PHQ-9. Four hundred eighty-one of the first 500 packets had complete data, with elevated EPDS or PHQ-9 scores in 138 and 132 women, respectively. Concordance of the EPDS and PHQ-9 were present in 399 women (83%): 326 (67.8%) had "normal" score on both, and 73 (15.2%) had elevated scores for both. Discordant scores in 82 women included 17 with elevated PHQ-9 scores but normal EPDS scores and 65 with elevated EPDS scores and PHQ-9 scores <10. In multivariate logistic regression modeling, only age >30 and low education level were predictive of discordant scores, using EPDS and PHQ-9 scores of > or =10 as elevated (odds ratio, 1.9 and P = .02; and odds ratio, 2.3 and P = .01, respectively). PHQ-9 scores of 5 to 9 have been referred to as consistent with "mild depressive symptoms" and appropriate for "watchful waiting" and repeat PHQ-9 at follow-up. Using this follow-up approach would require re-evaluation of 120 (25%) of the women screened. Postpartum depression screening is feasible in primary care practices, and for most women the EPDS and PHQ-9 scores were concordant. Further work is required to identify reasons for the 17% discordant scores as well as to provide definitive recommendations for PHQ-9 scores of 5 to 9.