Screening for postpartum depression with the Edinburgh Postnatal Depression Scale in an indigent population: does a directed interview improve detection rates compared with the standard self-completed questionnaire?

BACKGROUND

The Edinburgh Postnatal Depression Scale (EPDS) is a well-validated screening tool for the detection of patients at risk for postpartum depression. It was postulated that screening utilizing the EPDS in a directed interview would increase the detection rate compared with a self-completed EPDS in an indigent population.

OBJECTIVE

To compare the results of a self-completed EPDS with those of a directed interview utilizing the EPDS in the identification of patients at increased risk for postpartum depression.

METHODS

All patients undergoing a 6-week postpartum evaluation in the obstetric clinic at a community teaching hospital between November 1, 2003 and March 31, 2004 were screened for postpartum depression using the self-completed EPDS. This was followed by a directed interview, which consisted of a verbally administered EPDS by a social worker blinded to the results of the self-completed EPDS. A positive screen was defined as an EPDS score of > or =12 by either method. The number of patients with a positive screen to either the self-completed EPDS, the directed interview EPDS, or both were recorded. The two techniques were compared by the McNemar Chi-square test. The self-completed and directed interview EPDS scores were compared by Pearson's correlation coefficient to examine differences in screening techniques. Demographic data and characteristics in each group were examined.

RESULTS

Among the 134 patients evaluated, 24 (17.9%) screened positively for being at an increased risk of having postpartum depression. The self-completed EPDS and the directed interview EPDS screening detection rates were not different, identifying 23 (17.2%) and 22 (16.4%) patients, respectively (p = 1.0). The use of the self-completed EPDS and the directed interview EPDS in parallel detected one additional subject (0.7%; p = 0.99). The self-completed EPDS and directed interview EPDS scores correlated significantly (r = 0.94; p = 0.01). The demographics and characteristics of patients with a positive screen were not different from those with a negative screen.

CONCLUSIONS

The self-completed EPDS and directed interview EPDS are equivalent screening techniques for postpartum depression. There is no evidence to suggest that parallel screening improves detection. Either technique should be incorporated into the postpartum visit to screen for postpartum depression.