We examined the following determinants of primary and secondary outcomes: period of measurement, risk status of the sample (eg, infant problems, medically assisted fertilization), and case identification method (interview vs rating scale). Study location was also coded because previous work has identified geographic variations in postpartum depression.33 Because the timing of paternal depression vis-à-vis childbirth is of great interest in this study, period of measurement was coded into blocks that included (1) first trimester to 6 months' gestation, (2) greater than 6 months' gestation to birth, (3) immediately postbirth to 3 months postpartum, (4) greater than 3 months postpartum to 6 months postpartum, and (5) greater than 6 months postpartum to 12 months postpartum.