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

Abstract

OBJECTIVES: To compare the Edinburgh Postnatal Depression Scale (EPDS) and Patient Health Questionnaire (PHQ-9) as screening tools for postpartum depression. METHODS: This study population included the first 500 women to enroll and return their packets during an ongoing study of postpartum depression. RESULTS: 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. CONCLUSIONS: 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.