Performance of the 3-item screener, the Edinburgh Postnatal Depression Scale, the Hopkins Symptoms Checklist-15 and the Self-Reporting Questionnaire and Pregnancy Risk Questionnaire, in screening of depression in antenatal clinics in the Blantyre district of Malawi

Background
Screening instruments for antenatal depression vary in performance. This study aimed at assessing the performance of a range of screening instruments in detecting depressive symptoms in antenatal clinics in Blantyre district, Malawi.
Methods
A cross-sectional study was conducted to screen for depression among women attending 8 selected antenatal clinics in Blantyre district using 3-item screener, Edinburgh Postnatal Depression Scale (EPDS), Hopkins Symptoms Checklist-15 (HSCL-15), Self-Reporting Questionnaire (SRQ) and Pregnancy Risk Questionnaire (PRQ). The instruments were administered to a random sample of 480 pregnant women. Data were analysed using SPSS 22.0 testing for performance differences in proportions of screen positives and how screen positive results might differ by particular variables.
Results
The prevalence estimates yielded by screening instruments ranged from 12.9% (SRQ) to 42.1% (3-item screener). There were no significant differences in prevalence estimates for EPDS, HSCL-15, PRQ and SRQ. There were performance differences in the proportions of screen positives with significant systematic differences between proportions of screen positives of PRQ and SRQ (p<.001), EPDS and HSCL-15 (p=.001), HSCL and PRQ (p<.001), and EPDS and SRQ (p<.001). Screen positive results on HSCL-15, PRQ, 3-item screener and EPDS were found to differ by variables such as “not being supported by partner” which resulted in respondents having ≥3 times chances to screen positive on these four instruments. The screen positive results on SRQ were found not to differ by age, education, employment status, marital status, setting, gestation and number of pregnancies.
Conclusions
There were minimal variations in the performance of the EPDS, SRQ and HSCL-15 as standard public health screening instruments. However, systematic differences between proportions of screen positives exist and screen positive results from these instruments differed by demographics. It is important to validate screening instruments against a gold standard to ensure relevant clinical outcomes for pregnant women with depression.

Keywords
antenatal; antenatal screening; depression; depressive symptoms; instruments