Measuring antenatal depressive symptoms across the world: A validation and cross-country invariance analysis of the Patient Health Questionnaire – 9 (PHQ-9) in eight diverse low resource settings

Measures that produce valid and reliable antenatal depressive symptom scores in low resource country contexts are important for research efforts to better understand risk factors, outcomes, and effective interventions in these contexts. Establishing the psychometric comparability of scores across countries also facilitates cross-country analysis of similarities and differences across contexts. To date, however, very few studies have evaluated the psychometric properties and comparability of widely used antenatal depressive symptom measures across diverse cultural, political and social contexts. To address this gap, we used data from the Evidence for Better Lives Study – Foundational Research (EBLS-FR) to examine the reliability, validity, and cross-country invariance of the 9-item version of the Patient Health Questionnaire (PHQ-9) in antenatal samples across eight low- and middle-income countries (LMICs). We found that the PHQ-9 scores had good internal consistency and construct validity across all eight countries. However, in measurement invariance analyses, only partial metric invariance held and only across four of the countries. Further, there were some notable between-site contrasts in the nomological networks of PHQ-9 scores. Our results suggest that the PHQ-9 yields reliable scores when administered in antenatal populations; however, the meaning of the scores varies by country. Thus, interpretation of PHQ scores should consider local meanings of depression to ensure that local conceptualisations and manifestations of antenatal depressive symptoms are adequately reflected.