Table 2

Absolute risk and relative risk of mild/moderate PPD

PH and FH	Absolute risk			Relative risk
PH and FH	PPD cases	n	Absolute risk (%) (95% CI)	Crude RR (95% CI)	Adjusted* RR (95% CI)
PH_no, FH_no	1628	33 218	4.9% (4.8%; 5.0%)	Reference	Reference
PH_no, FH_yes	3921	67 382	5.8% (5.7%; 5.9%)	1.19 (1.12; 1.26)	1.18 (1.12; 1.25)
Less severe FH	3592	61 724	5.8% (5.7%; 5.9%)	1.19 (1.12; 1.26)	1.18 (1.12; 1.26)
Severe FH	329	5658	5.8% (5.7%; 5.9%)	1.19 (1.06; 1.33)	1.18 (1.05; 1.32)
PH_yes, FH_no	840	8535	9.8% (9.7%; 10.0%)	2.01 (1.85; 2.18)	1.99 (1.84; 2.16)
Less severe PH	794	8145	9.8% (9.6%; 9.9%)	1.99 (1.83; 2.16)	1.98 (1.82; 2.15)
Severe PH	46	390	11.8% (11.6%; 12.0%)	2.41 (1.82; 3.18)	2.30 (1.73; 3.04)
PH_yes, FH_yes	3843	32 929	11.7% (11.5%; 11.8%)	2.38 (2.25; 2.52)	2.35 (2.22; 2.49)
Less severe PH, less severe FH	3158	27 408	11.5% (11.4%; 11.7%)	2.35 (2.22; 2.49)	2.33 (2.20; 2.48)
Severe PH, less severe FH	208	1554	13.4% (13.2%; 13.6%)	2.73 (2.38; 3.14)	2.59 (2.24; 2.98)
Less severe PH, severe FH	427	3600	11.9% (11.7%; 12.0%)	2.42 (2.18; 2.68)	2.38 (2.14; 2.64)
Severe PH, severe FH	50	367	13.6% (13.5%; 13.8%)	2.78 (2.15; 3.60)	2.62 (2.02; 3.40)

*Adjusted for maternal age, parity, educational attainment and calendar year of delivery.
FH, family history of psychiatric disorders; PH, personal history of psychiatric disorders; PPD, postpartum depression; RR, relative risk.