Table 3. Odds ratios of prenatal screening for chlamydial and gonococcal infections in relation to maternal sociodemographic characteristics (n=2,688).

Maternal characteristics	Odds ratio	95% CI	p value	Adjusted odds ratioa	95% CI	p value
Age (continuous)	0.97	(0.96–0.99)	0.006	0.99	(0.97–1.01)	0.17
Smoking	1.18	(0.84–1.67)	0.30	N/A	N/A	N/A
Alcohol	1.04	(0.52–2.07)	0.90	N/A	N/A	N/A
Drugs	2.54	(1.01–6.37)	0.04	2.35	(0.93–5.94)	0.09
≥1 habit	1.23	(0.89–1.69)	0.20	N/A	N/A	N/A
Prenatal visit in first trimester	0.92	(0.71–1.18)	0.50	N/A	N/A	N/A
OBGYN follow-upb	1.07	(0.87–1.32)	0.50	N/A	N/A	N/A
Gravidity (per additional pregnancy)	0.92	(0.87–0.98)	0.01	N/A	N/A	N/A
Parity (per additional delivery)	0.83	(0.75–0.90)	<0.001	0.89	(0.80–0.97)	0.01

Abbreviations: CI, confidence interval; OBGYN, obstetrician–gynecologist; N/A, not applicable

^a Each variable associated with screening with a p value ≤0.20 in the univariable analysis was considered for the multivariable model. This multivariable model was constructed using a forward design, retaining only age and variables that increased the model fit

^b In comparison to general practitioner follow-up