The performance of the Edinburgh Postnatal Depression Scale in English speaking and non-English speaking populations in Australia.

BACKGROUND

The Edinburgh Postnatal Depression Scale (EPDS) has been widely used to assess maternal depression following childbirth in a range of English speaking countries, and increasingly also in translation in non-English speaking ones. It has performed satisfactorily in most validation studies, has proved easy to administer, is acceptable to women, and rates of depression in the range of 10-20% have been consistently found.

METHODS

The performance of the EPDS was compared across different population samples in Australia: (i) Women born in Australia or in another English speaking country who completed the EPDS in English as part of the 1994 postal Survey of Recent Mothers (SRM) 6-7 months after birth (n = 1166); (ii) Women born in non-English speaking countries who also completed the EPDS in English in the same survey (n = 142); and (iii) Women born in Vietnam (n = 103), Turkey (n = 104) and the Philippines (n = 106) who completed the EPDS 6-9 months after birth in translation in the Mothers in a New Country Study (MINC) study (total n = 313). The pattern of item responses on the EPDS was assessed in various ways across the samples and internal reliability coefficients were calculated. Exploratory factor analyses were also conducted to assess the similarity in the factor solutions across the samples.

RESULTS

The EPDS had good construct validity and item endorsement by women was similar across the samples. Internal reliability of the scale was also very satisfactory with Cronbach's alpha for each sample being > or = 8. Between 39 and 46% of the variance in each of the three main samples was accounted for by one principal factor 'depression' (6-7 items loading), with two supplementary factors 'loss of enjoyment' (2 items loading) and 'despair/self-harm' (2-3 items loading) accounting for a further 20-25% of the variance. Alternative one and two factor solutions also showed a great deal of consistency between the samples.

CONCLUSIONS

The good item consistency of the EPDS and the relative stability of the factor patterns across the samples are indicative that the scale is understood and completed in similar ways by women in these different English speaking and non-English speaking population groups. With the proviso that careful translation processes and extensive piloting of translations are always needed, these findings lend further support to the use of the EPDS in cross-cultural research on depression following childbirth.