Epidemiological evaluation of the Patient Health Questionnaire-2 in a pregnant population.

INTRODUCTION: The Patient Health Questionnaire-2 (PHQ-2) is a commonly used 2-item screening tool for depressive symptoms among pregnant women in primary care settings. However, its validity has not been assessed for large-scale epidemiological studies. Therefore, the aim of this study was to provide an epidemiological evaluation of the PHQ-2 among pregnant women.

METHOD: A total of 3033 pregnant women participating in the PRegnancy and Infant DEvelopment Study completed the PHQ-2 as well as the Hospital Anxiety Depression Scale-Depression (HADS-D) or the Edinburgh Depression Scale (EDS) three times throughout pregnancy. The validity of the PHQ-2 was assessed with the HADS-D/EDS as reference standard.

RESULTS: Sensitivity and specificity of the PHQ-2 were 69-84% and 79-84%, respectively. The positive predictive values (range 19-26%) were substantially lower than the negative predictive values (96-99%).

CONCLUSION: Despite the relatively high number of false-positive screens, initial screening for depression by two questions only may enhance routine evaluation of depressive symptoms among pregnant women.