Studies that evaluated a screening instrument (or combination of instruments) for classifying pregnant women in any care setting as being at risk or not at risk of postnatal depression were eligible for the review. No inclusion criteria for study design were stated. Outcomes of interest were measures of diagnostic accuracy; the proportion of those screened defined as being at risk; and the proportion of women diagnosed with postnatal depression after birth that had been screened during pregnancy as not at risk.
The included studies varied widely in population, setting and the timing and method of antenatal assessment. The majority included a study-specific screening instrument but only one of these used an instrument developed for an earlier study. Postnatal depression was most commonly assessed using the Edinburgh Postnatal Depression Scale; the score taken to indicate depression ranged from >9 to >14.
The authors did not state how the papers were selected for the review, or how many reviewers performed the selection.