Postpartum Depression Screening Scale: development and psychometric testing

BACKGROUND: Approximately 400,000 mothers in the United States experience postpartum depression each year. However, only a small proportion of these women are identified as depressed by health care professionals. OBJECTIVES: To improve detection of this postpartum mood disorder, the purpose of this study was to assess the psychometric properties of a newly devised instrument, the Postpartum Depression Screening Scale (PDSS), a 35-item Likert-type self-report instrument. METHODS: Content validity was supported through the literature and the judgments rendered by a panel of five content experts and a focus group. The PDSS was administered to 525 new mothers. RESULTS: Confirmatory factor analysis provided empirical support for the existence of the hypothesized seven dimensions. A Tucker-Lewis goodness-of-fit index of 0.87 and a root mean square residual of 0.05 were judged supportive of model fit. Item response theory techniques provided further construct validity support for finer interpretations of the respective seven dimensions. Analysis of the Likert 5-point response categories further supported meaningful score interpretations. Alpha internal consistency reliabilities ranged from 0.83 (sleeping/eating disturbances) to 0.94 (loss of self). CONCLUSIONS: Empirically, all of the reliability and validity analyses supported the score interpretations posited for the PDSS. Currently, the sensitivity, specificity, and positive predictive value of the PDSS are being determined.