Table 4.

Multivariable logistic regression model of risk factors for blood transfusion with an interaction between OH and hemoglobin. Odds ratios with 95% confidence intervals (CI) are shown, and the p value for association of each variable with transfusion is shown in the left-hand column.

Parameter		OR	95% CI
Hospital (0.0064)	CHB	1.00	.	.
	GSH	1.84	1.24	2.72
	KEH	1.50	1.03	2.17
	MMH	1.03	0.73	1.45
Age [Years] (0.8026)	<=19	1.00	.	.
	20–24	0.74	0.49	1.12
	25–29	0.79	0.52	1.20
	30–34	0.88	0.56	1.37
	35–39	0.79	0.47	1.33
	40+	0.80	0.37	1.75
Gestational Age [Weeks] (<0.0001)	<=34	2.90	1.98	4.25
	35–36	1.07	0.64	1.79
	37	1.53	0.95	2.45
	38	1.36	0.89	2.08
	39	0.75	0.44	1.27
	40	1.00	.	.
	41	1.19	0.67	2.12
	42+	1.30	0.52	3.26
HIV Status (0.0046)	Negative	1.00	.	.
	Positive	1.52	1.14	2.03
Prenatal Care (<0.0001)	Booked	1.00	.	.
	Unbooked	2.77	1.68	4.56
Hemoglobin [g/dL] (p<0.0001) by Hemorrhage (p<0.0001) Interaction (p=0.0198)
With OH: Hemoglobin (g/dL)	<=9.2	467.0	200.1	>999.9
	9.3–10.0	928.2	317.1	>999.9
	10.1–10.5	217.6	79.8	593.1
	10.6–11.0	264.7	95.2	736.1
	11.1–11.4	163.3	54.0	493.8
	11.5–11.8	150.8	53.7	423.6
	11.9–12.2	287.4	106.3	777.1
	12.3–12.6	160.9	53.9	480.1
	12.7–13.3	94.1	34.6	256.0
	13.4+	158.9	50.0	505.1
Without OH: Hemoglobin (g/dL)	<=9.2	9.3	4.6	18.8
	9.3–10.0	2.9	1.3	6.3
	10.1–10.5	2.4	1.0	5.6
	10.6–11.0 (ref. cell)	1.0
	11.1–11.4	1.6	0.6	4.0
	11.5–11.8	2.5	1.1	5.7
	11.9–12.2	1.6	0.7	3.8
	12.3–12.6	1.4	0.5	3.7
	12.7–13.3	1.8	0.8	4.4
	13.4+	1.9	0.8	4.7