Validation of the Edinburgh postnatal depression scale (EPDS) in Chilean postpartum women

A validity study of the Edinburgh Postnatal Depression Scale (EPDS) against the Research Diagnostic Criteria (RDC) was carried out on a sample of women attending a health care center in Santiago. One hundred and eight middle-class mothers filled in the EPDS and were later interviewed by the main author using the Psychiatric Assessment Schedule (PAS). The internal consistency of the EPDS was reasonably good (Cronbach's alpha 0.77). Validity coefficients for the scale were calculated to determine the best case/non-case threshold which was found to be 9/10. Sensitivity specificity and positive predictive value for this threshold were 100%, 80% and 37% correspondingly. The same best cut-off point (9/10) was found by other Chilean investigators in a sample of working-class women. The EPDS was shown to be a useful screening instrument for postnatal depression in these settings.