Oral contraceptive use in Canada.

BACKGROUND

Oral contraceptives (OCs) have been legally available in Canada since 1969. OCs remain the most common method of reversible contraception in Canada and are among the most commonly used medications by reproductive-aged women in Canada. The use of OCs offers protection against unplanned pregnancy, in addition to other non-contraceptive benefits. Detailed data about current and lifetime OC use in Canada are rarely available.

METHODS

Data from four cycles (from the 2007-to-2009 cycle to the 2018-to-2019 cycle) of Statistics Canada's Canadian Health Measures Survey were combined to estimate current OC use (past 30 days) by sociodemographic characteristics and other factors and formulations by estrogen dose and progestin type. Logistic regression was used to examine the association between current OC use and sociodemographic characteristics and other factors. Combined data from 2016-to-2017 and 2018-to-2019 were used to estimate lifetime OC use and use duration.

RESULTS

According to combined data from the 2007-to-2009 period to the 2018-to-2019 period, an average of 15.9% of non-pregnant women aged 15 to 49 had used OCs in the previous 30 days. Most (98.6%) used OCs containing estrogen and progestin, and 48.7% of them took lower-dose formulations with 10 to 25 micrograms of ethinylestradiol. Younger women aged 15 to 39 were more likely to have used OCs in the previous 30 days than those aged 40 to 49. Additionally, the adjusted odds of being an OC user were higher for women who had not had children, were non-racialized and non-Indigenous, and were currently sexually active. Another 53.9% of women aged 15 to 49 reported former use. A majority of both current (67.5%) and former (52.8%) OC users reported having used them for at least four years.

INTERPRETATION

Substantial proportions of reproductive-aged women in Canada are current or former OC users.