Table 1.

Characteristics of Participants at Mid-Point of the Study in 2010^*

		Oral contraceptive use§
		Never N = 1,812	Past N = 816	Current N = 572
Age (yrs), mean (std)		37.5 (8.8)	30.1 (7.8)	27.1 (7.7)
Age at diagnosis (yrs), %
16–20		4.4	9.2	23.1
21–30		17.8	47.3	44.9
31–40		35.2	30.9	24.8
41–51		42.6	12.6	7.2
Medications (ever use), %
5-Aminosalicylic acid (oral/topical)		89.8	92.0	94.9
Steroids		66.4	72.1	70.1
Immunomodulators¶		28.4	33.5	34.6
Anti-TNF†		5.5	6.3	7.2
Health care region of residence, %
Northern Sweden		9.6	6.9	6.5
Stockholm-Gotland		22.4	20.1	17.0
Southeastern Sweden		9.9	14.1	12.4
Southern Sweden		19.2	19.4	21.7
Uppsala-Örebro		18.9	19.5	25.4
Western Sweden		20.0	20.1	17.1
Education** (yrs), %
≤ 9		7.8	4.2	4.7
10–12		43.3	37.9	40.0
≥ 13		48.5	57.8	55.1
Number of encounters, median (range)		8 (2–96)	9 (2–112)	9 (2–55)

^*Abbreviations: standard deviation (std) and years (yrs).

^§6,104 participants contributed person-years to this study with nearly 54% of women using OC through follow up.

^¶Consists of methotrexate, azathioprine, and 6-mercaptopurine (6-MP).

^†refers to use of infliximab and adalimumab in Stockholm county only.

^**Percentages do not add up to 100 as there is <1% missing in each group of OC use.