Study protocol on criterion validation of Edinburgh Postnatal Depression Scale (EPDS), Patient Health Questionnaire (PHQ-9) and Centre for Epidemiological Studies-Depression (CES-D) screening tools among rural postnatal women; a cross-sectional study

BACKGROUND: Screening women for postnatal depression (PND) provides an opportunity to reach undetected cases and enhance pregnancy outcomes. In Zimbabwe, no validation of depression screening tools has been done on postnatal women in rural settings. OBJECTIVES: This study aims to determine criterion validity of the Edinburgh Postnatal Depression Scale (EPDS), the Patient Health Questionnaire (PHQ-9) and the Center for Epidemiological Studies-Depression (CES-D) scale using the Diagnostic and Statistical Manual for Mental Disorders (DSM-5) criteria as the reference standard. METHODS: Women (n=462) attending postnatal care at 7 or 42 days at two rural district hospitals in Zimbabwe will be assessed for depressive symptoms using the EPDS, PHQ-9 and CES-D. The women will be interviewed by a clinical psychologist using DSM-5 criteria. Sensitivities, specificities, positive predictive values, negative predictive values and test efficiencies will be calculated for each of the three tools. The area under the receiver operating curve will quantify the overall ability of the three tests to discriminate between those mothers with PND and those without. DISCUSSION: Findings from this study will add to the body of knowledge on PND among women in resource-limited settings. Identifying women with PND will enable healthcare providers to link them with care, which will ultimately improve maternal and child health outcomes. Furthermore, this study will provide evidence on which screening tool would be best for screening PND in rural settings of Zimbabwe.