Detecting depression in pregnancy: validation of EPDS in British Pakistani mothers

Recent reports suggest that antenatal depression is as prevalent as postnatal depression. The Edinburgh Postnatal Depression Scale (EPDS) is the most widely used tool to detect postnatal depression, which can also detect depression during the antenatal period. Mothers of Pakistani origin have the highest birth rate in the UK. The validity of EPDS has not been assessed in this group. A prospective cohort of 714 women in their third trimester of pregnancy completed the EPDS while waiting for their antenatal visit. Women scoring 12 or more on the EPDS, and a random sample of low scores were assessed with the Schedule for Clinical Assessment in Neuropsychiatry to establish psychiatric diagnosis. A cut-off point of 8 showed the best discrimination with sensitivity = 89.6% and specificity 54.7%. Positive predictive value was 29.4 and negative predictive value was 96.2. The area under the curve (AUC) was 0.72 (0.66-0.78). When language is taken into account the area under the ROC curve for subjects who preferred the Urdu or Punjabi language is slightly higher at 0.79 than those who preferred English (0.61). We have not been able to find a single clear cut-off is a result of the AUCs not being particularly large, and confirms that the EPDS should only be used as a screen and not for diagnostic purposes. The larger AUC for the Urdu/Punjabi speakers than for the English speakers suggests that the EPDS is as good a screen for this group as for the indigenous English population.