Table 3.

Risk of glioma by duration of hormonal contraceptive use by women aged 15–49 years

Hormonal contraceptive use (HC)	Cases	Controls	Adjusted odds ratioa (95% CI)	P for trend
Non-use	131	1061	1 (reference)
Ever use
One or more types of HCb, years
Any type of HC
<1	27	143	1.4 (0.8, 2.3)
≥1, <5	96	563	1.5 (1.1, 2.2)
≥5	63	359	1.9 (1.2, 2.9)	0.6
Oestrogen and progestagen
<1	19	118	1.1 (0.6, 2.1)
≥1, <5	86	525	1.4 (1.0, 2.1)
≥5	60	346	1.8 (1.2, 2.9)	0.7
Progestagen only
<1	8	28	2.5 (1.0, 6.2)
≥1, <5	18	87	1.8 (0.9, 3.4)
≥5	15	55	2.4 (1.1, 5.1)	0.2
Single type of HCc, years
Oestrogen and progestagen
<1	19	115	1.2 (0.6, 2.2)
≥1, <5	78	476	1.5 (1.0, 2.1)
≥5	48	304	1.7 (1.1, 2.8)	0.7
Progestagen only
<1	8	25	2.7 (1.1, 6.8)
≥1, <5	10	38	2.9 (1.2, 6.9)
≥5	3	13	4.1 (0.8, 20.8)	1.0

^aAdjusted for age and calendar year by design; additionally adjusted for years of schooling and hospital contacts for allergy and asthma.

^bWomen with dispensed prescriptions for one or more types of contraceptives in 1995 to index date.

^cWomen with dispensed prescriptions for only a single type of contraceptive in 1995 to index date.