Table 2.

Relative risk of ovarian cancer in users of hormonal contraception according to time since last current use and duration of current use

Use category	No of person years	No of ovarian cancer events	Age standardised incidence per 100 000 person years	Adjusted relative risk (95% CI)*
Never use	8 150 250	771	7.5	1.00
Ever use (any hormonal contraception)	13 344 531	478	4.3	0.66 (0.58 to 0.76)
Former use (any hormonal)	4 505 157	244	5.0	0.77 (0.66 to 0.91)
Current or recent use (any hormonal)	8 839 374	234	4.0	0.58 (0.49 to 0.68)
Current or recent use (combined oral)	7 751 904	175	3.8	0.53 (0.45 to 0.64)
Current or recent use (progestogen only)	1 087 470	59	4.2	0.72 (0.55 to 0.95)
Duration of current or recent use of any hormonal contraception†
≤1 year	1 265 020	42	5.9	0.82 (0.59 to 1.12)
>1-≤5 years	4 063 111	103	4.6	0.62 (0.50 to 0.77)
>5-≤10 years	2 580 300	71	4.4	0.57 (0.44 to 0.74)
>10 years	930 943	18	1.7	0.26 (0.16 to 0.43)
Time since last current use of any hormonal contraception‡
>1-≤5 years	2 442 620	110	5.0	0.76 (0.61 to 0.93)
>5-≤10 years	1 397 257	83	4.3	0.78 (0.61 to 0.99)
>10 years	665 281	51	3.8	0.80 (0.59 to 1.08)

^*Adjusted for calendar year, parity, age, education, tubal sterilisation, hysterectomy, endometriosis, polycystic ovary syndrome, and family history of breast or ovarian cancer.

^†P_trend<0.001.

^‡P_trend=0.03.