Developing and validating a perinatal depression screening tool in Kenya blending Western criteria with local idioms: A mixed methods study.

BACKGROUND: Routine screening for perinatal depression is not common in most primary health care settings. The U.S. Preventive Services Task Force only recently updated their recommendation on depression screening to specifically recommend screening during the pre- and postpartum periods. While practitioners in high-income countries can respond to this new recommendation by implementing one of several existing depression screening tools developed in Western contexts, such as the Edinburgh Postnatal Depression Scale (EPDS) or the Patient Health Questionnaire-9 (PHQ-9), these tools lack strong evidence of cross-cultural equivalence, validity for case finding, and precision in measuring response to treatment in developing countries. Thus, there is a critical need to develop and validate new screening tools for perinatal depression that can be used by lay health workers, primary health care personnel, and patients. METHODS: Working in rural Kenya, we used free listing, card sorting, and item analysis methods to develop a locally-relevant screening tool that blended Western psychiatric concepts with local idioms of distress. We conducted a validation study with a random sample of 193 pregnant women and new mothers to test the diagnostic accuracy of this scale along with the EPDS and PHQ-9. RESULTS: The sensitivity/specificity of the EPDS and PHQ-9 was estimated to be 0.70/0.72 and 0.70/0.73, respectively. This compared to sensitivity/specificity of 0.90/0.90 for a new 9-item locally-developed tool called the Perinatal Depression Screening (PDEPS). Across these three tools, internal consistency reliability ranged from 0.77 to 0.81 and test-retest reliability ranged from 0.57 to 0.67. The prevalence of depression ranges from 5.2% to 6.2% depending on the clinical reference standard. CONCLUSION: The EPDS and PHQ-9 are valid and reliable screening tools for perinatal depression in rural Western Kenya, the PDEPS may be a more useful alternative. At less than 10%, the prevalence of depression in this region appears to be lower than other published estimates for African and other low-income countries.