Table 3.

Associations between smoking cessation during pregnancy and socio-demographic characteristics of women (N = 12,871)

Variable	Crude ORa	95 % CI	P-value	Adjusted ORa,b	95 % CI	P-value
Maternal age (years)						0.083c
≤ 19	0.61	0.51–0.74	<0.001	0.97	0.75–1.24
20–24	0.88	0.81–0.96	0.005	0.98	0.86–1.11
25–29	1.00			1.00
30–34	0.97	0.86–1.10	0.646	1.09	0.99–1.20
≥ 35	0.88	0.72–1.06	0.172	1.16	0.94–1.43
Residence
Urban	1.00			1.00
Rural	0.64	0.47–0.87	0.005	0.76	0.57–1.02	0.068
Ethnicity
Russian	1.00			1.00
Other	0.93	0.67–1.29	0.667	0.90	0.66–1.23	0.512
Education			<0.001d			<0.001d
Incomplete secondary	0.13	0.10–0.18		0.19	0.15–0.24
Secondary	0.31	0.21–0.47		0.39	0.27–0.55
Vocational	0.50	0.35–0.71		0.57	0.41–0.78
University	1.00			1.00
Unknown	0.09	0.04–0.19		0.12	0.06–0.25
Marital status
Married	1.00			1.00
Cohabitation	0.46	0.33–0.64	<0.001	0.53	0.39–0.72	<0.001
Single	0.43	0.34–0.54	<0.001	0.49	0.41–0.58	<0.001
Parity			<0.001c			<0.001c
0	2.37	1.96–2.85		2.21	1.78–2.75
1	2.05	1.71–2.45		1.69	1.46–1.95
≥ 2	1.00			1.00

^a Calculated using logistic regression with robust clustered standard errors by delivery department

^b OR adjusted for the variables listed in this table, alcohol abuse and delivery year

^c Test for linear trend

^d Test for linear trend (unknown category excluded)