Factor Structure and Differential Item Functioning of the Edinburgh Postnatal Depression Scale: A Comparison of Zulu and English Versions Among Ante- and Postnatal Women Living with HIV in South Africa

Purpose Measuring perinatal depression in women with HIV poses a challenge to accurate assessment. South Africa has particularly high rates of perinatal depression, with antenatal depression rates ranging from 21 to 47% and postnatal depression rates ranging from 17 to 50%. With the goal of providing an examination of the psychometric properties of the Edinburgh Postnatal Depression Scale (EPDS) in a population at greater risk for depression, the current manuscript examined the factor structures and reliability of the English and Zulu versions of the EPDS among pre- and postnatal women with HIV in South Africa. Methods This study included n = 1179 women who completed the EPDS in Zulu (n = 709) and English (n = 470) antenatally, and n = 866 women were analyzed at 12-months after birth (n = 494 in Zulu and n = 372 in English). Results Using factor analytic and item response theory approaches, the English and Zulu versions of the EPDS were compared. Although a few items performed poorly, particularly item 4, the construct validity of the English and Zulu versions of the pre- and postnatally administered EPDS was supported; the reliability of the scale was also supported, with adequate reliability in Zulu and English ante-natally (alpha = .78), and postnatally (alpha = .82 and alpha = .77 respectively). Discussion This study contributes to improved measurement of depressive symptoms among vulnerable women in a resource constrained setting. The early and accurate detection of depressive symptoms ante- and postnatally among perinatal women living with HIV can facilitate increased treatment which may in turn help prevent the negative maternal and neonatal outcomes associated with depression.