Cognitive testing of the PHQ-9 for depression screening among pregnant and postpartum women in Kenya

African women face high rates of depression, particularly during pregnancy or postpartum or after a recent HIV diagnosis. The Patient Health Questionnaire-9 (PHQ-9) depression screening tool has been quantitatively validated and extensively used to identify depression and link individuals to care. However, qualitative work is necessary to identify important opportunities to improve PHQ-9 question comprehension and performance among Kenyan women.

We administered the Kiswahili or English PHQ-9 (based on preference) to 29 pregnant and postpartum women in Thika, Kenya. Following administration, we conducted cognitive interviews with a purposive sample of 20 women. We used analytic memos and data matrices to identify themes around scale acceptability, comprehension, and decision and response processes.

Most participants preferred to answer the PHQ-9 in Kiswahili (N = 15; 52%). Among the 20 interview participants, 12 (60%) had scores ≥5, indicating depressive symptoms. Overall, participants found the scale acceptable as an interviewer-administered tool. Participants reported few problems related to comprehension but had difficulty answering items not relevant to their lives (e.g., "watching television") and double-barreled items (e.g., "poor appetite or overeating"). They were hesitant to endorse items related to "duties as a wife and mother" and suicidal ideation. Most participants had difficulty distinguishing between response options of "several days" and "more than half the days".

We detected several problems related to PHQ-9 comprehension, decision processes, and response processes. We provide recommended changes to instructions and item wording to improve PHQ-9 validity among Kenyan women.