Is the EPDS a magic wand?:: 1.: A comparison of the Edinburgh Postnatal Depression Scale and health visitor report as predictors of diagnosis on the Present State Examination

The Edinburgh Postnatal Depression Scale (EPDS) was developed because most episodes of postnatal depression were undetected and untreated. The systematic introduction of the EPDS has been followed by reports of increased detection of postnatal depression. It has been assumed that the EPDS is a more sensitive measure of new mothers' depression than a health visitor. A study of the prediction and prevention of postnatal depression included data on the EPDS plus a health visitor report at 6 weeks postnatal for 134 women and EPDS plus psychiatric interview (Present State Examination (PSE)) on 199 women at 3 months postnatal. The relationships between these three measures of postnatal well-being are presented. At 3 months a cut-off score of 12/13 produced a sensitivity of 70%, specificity of 93% and positive predictive value of 33% compared with the PSE. A cut-off of 9/10 gave sensitivity of 90%, specificity of 84% and positive predictive value of 23%. The health visitors' description of the women as fed up or depressed at 6 weeks was a better predictor of depression diagnosed by the PSE in the first 2 months (positive predictive value 62%) than the EPDS (positive predictive value 47%). The strengths and limitations of these results and the implications for research and practice are discussed.