Table 3.

Predictors of the Occurrence of Bleeding, Right From the Start, 2000–2008 (n=4539).

	n	%	Unadjusted OR	95% CI	P	Adjusted OR*	95% CI	P
Age					<0.01			<0.01
18–27 years	1792	39.5	1.0			1.0
28–34 years	2083	45.9	1.4	1.2, 1.6		1.3	1.1, 1.6
35–45 years	664	14.6	1.2	1.0, 1.5		1.1	0.9, 1.4
Education					<0.01			0.11
≤ High school	899	19.8	1.0			1.0
Some college	822	18.1	1.3	1.0, 1.6		1.2	0.9, 1.5
College or more	2817	62.1	1.4	1.2, 1.6		1.2	1.0, 1.5
Cycle length					<0.01			<0.01
<27 days	667	17.7	1.3	1.1, 1.6		1.4	1.1, 1.6
27–33 days	2793	74.1	1.0			1.0
≥ 34 days	312	8.3	1.3	1.0, 1.6		1.3	1.0, 1.6
Infection					0.11			0.06
No	3442	76.2	1.0			1.0
Yes	1076	23.8	1.1	1.0, 1.3		1.2	1.0, 1.4
Fibroids					<0.01			0.01
No	3753	88.8	1.0			1.0
Yes	472	11.2	1.4	1.2, 1.8		1.3	1.0, 1.6
Diabetes					0.15			0.07
None	4381	97.0	1.0			1.0
Pre-existing/prior	137	3.0	1.3	0.9, 1.9		1.4	1.0, 2.1
Parity					<0.01			<0.01
≥ 1 live birth	2338	52.5	1.0			1.0
Nulliparous	2113	47.5	1.2	1.1, 1.4		1.3	1.2, 1.5
Miscarriage history					0.03			0.01
None	3457	77.7	1.0			1.0
One	795	17.9	1.2	1.0, 1.4		1.2	1.0, 1.4
Multiple	199	4.5	1.4	1.0, 1.9		1.5	1.1, 2.1
Induced abortion history					<0.01			<0.01
None	3729	83.7	1.0			1.0
One	546	12.3	1.4	1.1, 1.6		1.3	1.1, 1.6
Multiple	179	4.0	1.4	1.0, 1.9		1.4	1.0, 1.9

CI Confidence interval; OR Odds ratio

^*Factors are adjusted for all other variables in the table.