Table 3. Multivariable analysis of risk factors for anemia in pregnant women in Nagpur, India, 2011–2013: multivariable, multinomial logistic regression model.

		Mild anemia		Moderate-to-severe anemia
Risk factor	Category	RRR	95% CI	RRR	95% CI
Fuel type	Clean fuel	1.00*		1.00*
	Biomass fuel	1.38	1.19–1.61 ‡	1.79	1.53–2.09 ‡
Age (years)	—	0.95	0.93–0.98 ‡	0.94	0.91–0.96 ‡
BMI (kg/m2)	—	0.92	0.90–0.94 ‡	0.83	0.81–0.86 ‡
Education	No formal schooling	1.00*		1.00*
	Primary	0.81	0.47–1.41	0.55	0.32–0.95 ‡
	Secondary	0.78	0.46–1.32	0.50	0.29–0.85 ‡
	University/ college	0.60	0.35–1.02	0.30	0.17–0.51 ‡
Exposure to household tobacco smoke	Never	1.00*		1.00*
	Less than monthly	1.21	1.01–1.46 ‡	1.51	1.25–1.83 ‡
	Monthly	1.11	0.86–1.44	1.06	0.81–1.39
	Weekly	1.23	0.89–1.72	1.17	0.83–1.65
	Daily	1.01	0.80–1.29	0.99	0.77–1.28
Parity (n)	0	1.00*		1.00*
	1	1.30	1.12–1.51 ‡	1.49	1.28–1.74 ‡
	2	1.68	1.29–2.21 ‡	2.30	1.75–3.04 ‡
	3+	2.10	1.18–3.75 ‡	4.49	2.52–7.98 ‡
Trimester	1st	1.00*		1.00*
	2nd	0.85	0.73–0.99 ‡	0.82	0.70–0.96 ‡
	3rd	1.00	0.84–1.20	0.69	0.57–0.84 ‡
Prenatal iron and folate supplements	Yes	1.00*		1.00*
	No	1.06	0.66–1.70	1.06	0.65–1.71

RRRs for a given risk factor are adjusted for all other tabulated risk factors. Mild anemia and moderate-to-severe anemia are defined as 10 g/dl ≤ hemoglobin (Hb) < 11 g/dl and Hb < 10 g/dl, respectively.

* Baseline category.

^‡ Differs significantly from 1 at the 95% confidence level.

Abbreviations: RRR = relative risk ratio, 95% CI = 95% confidence interval, BMI = body mass index.