Health Reports
Oral contraceptive use in Canada

Abstract

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.

Keywords

contraception, estrogen, pregnancy prevention, progestin, reproductive health

Author

Michelle Rotermann is with the Health Analysis and Modelling Division at Statistics Canada.

 

What is already known on this subject?

• Oral contraceptives (OCs) are used primarily for pregnancy prevention but offer many non-contraceptive benefits, including menstrual cycle regulation; reduced menstrual flow and cramps; improved perimenopausal, vasomotor, moliminal, and endometriosis symptoms; decreased acne, body, and facial hair growth; and reduced risks of endometrial and ovarian cancers.
• Contraception remains important for women, their partners, and society. The best contraceptive methods are those that are effective, safe, and used correctly and consistently.
• OCs are the most used method of reversible contraception in Canada and are particularly popular among females younger than 30.

What does this study add?

• It provides updated current OC use (past 30 days) prevalence by various sociodemographic and other characteristics for women aged 15 to 49.
• For the first time, information about former OC use and duration of use is available for women who are currently using OCs or who had taken them at some other time.
• Given the enactment of the first phase of the national universal pharmacare program in October 2024, which provides insurance coverage for contraceptives, these estimates will provide important benchmarking information on OC use in Canada, allowing for future evaluations of the impact of this national medication coverage policy change.

Introduction

Oral contraceptives (OCs) have been legally available in Canada since 1969.^Note 1, ^Note 2 They are the most common method of reversible contraception^Note 3, ^Note 4, ^Note 5 and are among the most frequently used medications by reproductive-aged women in Canada.^Note 6, ^Note 7 OCs include combined oral contraceptive (COC) pills, which contain both estrogen and progestin, and progestin-only pills.^Note 8, ^Note 9

Canadian women spend a significant portion of their lives at risk of an unintended pregnancy.^Note 10 OCs are a type of effective and reversible contraception that helps women manage their fertility,^Note 9 and this in turn can improve educational attainment and employment and decrease reliance on social assistance.^Note 11, ^Note 12

While OCs are used primarily for pregnancy prevention, they have non-contraceptive benefits, including better cycle regulation; reduced menstrual cramping; improved perimenopausal and endometriosis symptoms; and decreased menstrual flow, acne, and body and facial hair growth.^Note 8, ^Note 9 Use of OCs is also associated with a reduction in the risks of some cancers (e.g., endometrial and ovarian).^Note 13, ^Note 14

OCs have evolved, with decreasing estrogen doses, new progestins, and different dosing regimens. Information about the types of OCs used can be of interest to clinicians because of potential differences in the risk–benefit profiles of various formulations.^Note 15, ^Note 16, ^Note 17, ^Note 18, ^Note 19

The introduction (and subsequent royal assent) of the first phase of national universal pharmacare in Canada, which provides insurance coverage for many prescription contraceptives as of October 2024,^Note 20, ^Note 21 has broadened interest in information on contraception use in Canada. The estimates presented in this study of OC use and the characteristics of users during a 12-year period collected prior to this policy change will be important benchmarks for future evaluation of the impact of this national medication coverage policy change.

Despite the widespread use of OCs in Canada, there is a lack of detailed, national information about their use. For example, only some provinces (e.g., British Columbia and Quebec) have administrative dispensary or billing data with basic sociodemographic information.^Note 22, ^Note 23, ^Note 24 The Canadian Institute for Health Information publishes some information about hormonal contraceptive use, but only for recipients of publicly funded programs, such as social assistance.^Note 7 A portrait of age, sex and provincial patterns of prescription drug use and costs of OCs and other commonly used medications is available but dated.^Note 23 Older cycles of the Canadian Community Health Survey (CCHS) have occasionally included questions about birth control among those aged 15 to 24.^Note 25 More recently, some CCHS cycles have collected expanded information from sexually active people aged 25 or older, but only for those who reported sexual activity.^Note 26 In 2006 and 2016, the Canadian Contraception Survey was another source of population-level contraception information.^Note 3, ^Note 27

The main objective of this study—using pooled data from multiple cycles of the Canadian Health Measures Survey (CHMS) from the 2007-to-2009 cycle to the 2018-to-2019 cycle—was to examine the prevalence of, and factors associated with, OC use among non-pregnant, reproductive-aged (15 to 49) women in Canada by sociodemographic characteristics and other factors. This study also sought to identify the OCs used, by estrogen dose and progestin type, and, for the first time, to examine lifetime OC use, as well as duration of use, for both current and former OC users.

Methods

Data source

Data are from the CHMS , a repeated cross-sectional, nationally representative survey conducted by Statistics Canada, in partnership with the Public Health Agency of Canada and Health Canada, that collects self-reported and directly measured health information from the Canadian population aged 3 to 79 years (aged 6 to 79 in Cycle 1) living in private dwellings in the 10 provinces^Note 28 (Appendix Table A). People living in the three territories or on reserves and Indigenous settlements in the provinces, the institutionalized population, residents of certain remote regions, and full-time members of the Canadian Forces are excluded (about 4% of the Canadian population). Data were collected from March 2007 to February 2009 (Cycle 1), August 2009 to November 2011 (Cycle 2), January 2016 to December 2017 (Cycle 5), and January 2018 to December 2019 (Cycle 6). A questionnaire on sociodemographic characteristics, health behaviours, and medication use was administered at the respondent’s home. This was followed by a mobile examination centre appointment, where additional questions were asked and physical measurements (e.g., height, weight, and blood pressure) were taken. More information about the CHMS , including sampling and quality assurance, is available elsewhere.^Note 28

Cycle 1 collected information from Canadian residents aged 6 to 79 and had an overall response rate of 51.7%, corresponding to a total of 5,604 respondents. Cycles 2, 5 and 6 collected information from those aged 3 to 79, and the overall response rates ranged from 45.9% to 55.5%, with sample sizes ranging from 5,786 to 6,395. Participants from one cycle were not eligible to participate in another cycle.

Study samples

Main analytical sample

The main analytical sample of current OC use (past 30 days, according to medication histories) includes combined data from women aged 15 to 49 years (age at household interview) from cycles 1, 2, 5, and 6, totaling 5,110 respondents. There were 143 female respondents who were excluded because of self-reported pregnancy or missing or unknown pregnancy status, yielding a final sample of 4,967. These four CHMS cycles with information about parity and sexual activity were selected for study inclusion because of the importance of these variables to contraceptive use. Four cycles were combined to form the main analytical sample because preliminary analyses suggested that the statistical power was insufficient using two-cycle pooling, particularly for cycles 5 and 6.

Secondary sample 2 (type of oral contraceptive)

The sample consisted of the 869 respondents from the main analytical sample who used OCs (according to medication histories reported using drug identification numbers [DINs]) in the 30-day period preceding data collection. 

Secondary sample 3 (current users of oral contraceptives, former users, and those who never used them)

The sample included 2,253 of 2,262 respondents from the main analytical sample who participated in cycle 5 or 6 (the only cycles that asked about lifetime birth control pill use). Nine records were excluded because the lifetime birth control pill question was not answered.

Secondary sample 4 (duration of use among current and former oral contraceptive users)

The sample included 1,592 of 1,605 respondents from the main analytical sample who participated in cycle 5 or 6 and were identified as current or former OC users based on past-30-day OC use, according to medication use, and valid responses to the questions about lifetime birth control pill use and duration of use.

Definitions

Outcomes

Current oral contraceptive use (past 30 days)

DINs were collected from the packaging of medications during the household and mobile examination centre visits. Only medications that respondents reported taking in the month before either interview were used for classifying the women as current OC users or non-users. The OCs used by study participants correspond to 13 level-7 Anatomical Therapeutic Chemical (ATC) codes (Appendix Table B). A computer-assisted reference tool facilitated medication capture when required. Each DIN was associated with ATC classification codes assigned by Health Canada.^Note 29 In accordance with Statistics Canada’s Directive on the Security of Sensitive Statistical Information, which includes the protection of brands, the specific medications identified based on the DINs are presented as aggregate ATC codes.^Note 30

Type of oral contraceptive taken within the past 30 days (current use)

OCs used were categorized by the dose of ethinylestradiol (EE) (less than 30 micrograms [mcg], or 30 mcg or more) and by progestin type (levonorgestrel, norgestimate, desogestrel, drospirenone, or other). Information about active ingredients, EE dosages, and type of progestin was taken from Health Canada’s Drug Product Database.^Note 31

Lifetime oral contraceptive use and duration 

Lifetime OC use was based on the following question: “Have you ever used birth control pills?” Responses were combined with current OC user information (past 30 days, from medication history) to create the lifetime OC user variable, which enabled women to be categorized as current OC users, former OC users, and those who never used OCs. Duration of OC use was based on the following question: “In total, over your lifetime, how many years did you use birth control pills?” Three response categories were provided: less than two years, two to less than four years, and four years or more. 

Covariates

Age groups were established according to the respondent’s age at the time of the household interview. For current OC use (past 30 days) prevalence and modelled current use, six age groups were used (15 to 19, 20 to 24, 25 to 29, 30 to 34, 35 to 39, and 40 to 49). Owing to more limited sample sizes associated with the other study outcomes, fewer age groups were used. For the type of OC taken and OC use duration, age was dichotomized: 15 to 34 compared with 35 to 49. For the analysis of current OC users, former OC users, and those who never used OCs, four age groups were used (15 to 19, 20 to 29, 35 to 39, and 40 to 49).

The population group variable was based on “To which ethnic or cultural groups did your ancestors belong?” and “Are you an Aboriginal person, that is, North American Indian, Métis or Inuit?” (cycles 1 and 2), or “You may belong to one or more racial or cultural groups on the following list” and “Are you an Aboriginal person, that is, First Nations, Métis or Inuk/Inuit?” (cycles 5 and 6). Respondents were grouped into three categories (non-racialized and non-Indigenous, racialized, and Indigenous).

Marital status was categorized as married, common-law, previously married (including separated, divorced, and widowed), and single (never married). Parity (number of live births) was categorized as nulliparous (none), primiparous (one), or multiparous (more than one).

Respondents were classified as being sexually active if they answered “yes” to the following question: “In the past 12 months, have you had sexual intercourse?” Immigrant status was coded as immigrant or Canadian-born person, based on country of birth and citizenship.

Household income was classified into two categories: less than $50,000 and $50,000 or more.

Respondents were asked whether they had “a regular medical doctor.”

Analytical techniques

Weighted cross-tabulations were used to present current OC use (past 30 days) by age group, population or Indigenous group, marital status, parity, sexual activity, immigrant status, household income, and having a regular doctor. Multivariable logistic regression was used to model relationships between these variables and current OC use. Cross-tabulations were also used to examine current OC use, former OC use, and no OC use among non-pregnant women aged 15 to 49. Duration of OC use, stratified by age, was also examined for both current and former OC users, combining information about OC use in the past 30 days according to medications identified via DINs and self-reported use of birth control pills. 

The selection of covariates was guided by the literature, data availability, and consistency of content across CHMS cycles.

To account for survey design effects, coefficients of variation and 95% confidence intervals were estimated using the bootstrap technique.^Note 32 Differences between prevalence estimates were calculated with t-tests, and results at the p < 0.05 level were considered statistically significant. All analyses were conducted in SAS 9.4 and SUDAAN v.11, using weighted data and specifying in the procedure statements the number of degrees of freedom (DDF) of either 22 or 46, depending on whether two or four cycles were combined. The original sampling weights were rescaled by dividing by the number of survey cycles combined.

Results

Sociodemographic and other characteristics of current oral contraceptive users

According to combined medication history data from the 2007-to-2009 cycle of the CHMS to the 2018-to-2019 cycle, 15.9% of non-pregnant women aged 15 to 49 had used OCs in the previous 30 days (i.e., current use) (Table 1). OC use decreased from 29.1% among those aged 15 to 19 to 4.5% among those aged 40 to 49. Rates of OC use were comparable among women who were single or who reported their marital status as common-law (23.1% compared to 21.5%) but significantly higher than among married or previously married women. For women who had not had children (nulliparous) and for women born in Canada, the use of OCs was more prevalent (25.4% and 18.8%, respectively) than for women who had had children (primiparous or multiparous women) and for immigrants (10.2%, 6.2%, and 8.4%, respectively). About one in five non-racialized and non-Indigenous women (19.8%) reported taking an OC, nearly three times the percentage for racialized women (7.1%). The use of OCs was also more common among women who were currently sexually active (17.1%), compared with their non-sexually active peers (11.0%). 

Because sociodemographic and behaviour characteristics are not independent of each other, multivariable logistic regression analysis was performed to account for the simultaneous effects of these factors. The adjusted odds of OC use remained significantly higher for women aged 15 to 39 than for those aged 40 to 49 (Table 1). Also, the adjusted odds were higher in women who were nulliparous, non-racialized and non-Indigenous, and currently sexually active. Marital status and immigrant status were no longer significantly associated with OC use when other characteristics were taken into account. Use of OCs was not associated with whether women had a regular medical doctor or with household income, in both the descriptive frequency analysis (percentages) and the adjusted multivariable model.



Oral contraceptive formulation

Nearly all (98.6%) current OC users (past 30 days) took COCs, that is, OCs containing a combination of EE and progestin (Table 2). Six in 10 COC users (60.7%) used formulations with levonorgestrel or norgestimate. Use of other formulations, containing different progestins, was less common. During the study’s reference period (the 2007-to-2009 cycle to the 2018-to-2019 cycle), the COCs available in Canada contained 10 mcg to 50 mcg of EE. Less than half (48.7%) of COC users who reported use in the previous 30 days took lower-dose formulations with 10 mcg to 25 mcg of EE.



Lifetime oral contraceptive use and duration

In cycles 5 and 6, information about lifetime OC use and duration of use was collected for the first time. According to these combined data, more than two-thirds (68.9%) of non-pregnant women aged 15 to 49 had taken an OC at some point in their lives (Table 3). Over half (53.9%) of these women reported non-current (former) use, while 15.0% were current users (according to medication history), and about 3 in 10 (31.1%) had never used them. There were some differences depending on sociodemographic characteristics. For example, one-third of those aged 40 to 49 reported never having used an OC, about half the estimate for those aged 15 to 19 (33.4% compared with 58.9%). Rates of former OC use also tended to be higher for older rather than younger women. For example, among those aged 40 to 49, 60.5% reported having used OCs, four times the percentage (15.0%) for those aged 15 to 19. Lifetime OC use (includes current and former users) was comparable between non-racialized and non-Indigenous women (84.5%) and Indigenous women (91.9%). By contrast, the percentage of racialized women (40.5%) reporting lifetime OC use was less than half the estimate of non-racialized and non-Indigenous women (84.5%). Additionally, the rate of never having used OCs was lower among Canadian-born women (21.0%) than immigrant women (53.2%).



Duration of use also tended to differ by age and whether use was current or occurred in the past (Table 4). For example, among current users aged 15 to 34, about one-fifth (18.0%) reported OC use of less than two years, one-quarter (23.8%) had used OCs for two to less than four years, and the remaining 6 in 10 (58.2%) reported four years or more of use. Among current users aged 35 to 49, most (95.2%) reported OC use of at least four years. For former users aged 15 to 34, 4 in 10 (40.7%) had taken OCs for four years or more, while among those aged 35 to 49, the corresponding figure was higher, at 62.1%.   



Discussion

This study provides updated, nationally representative prevalence estimates of current OC use (past 30 days) in Canada by sociodemographic characteristics and other risk factors, and information about OC formulations. For the first time using CHMS data, information about former use of OCs and duration of use is also available and presented.

According to this study, use of OCs by reproductive-aged women in Canada is common, with nearly one in six reporting current use and more than one in two reporting having used them in the past.

Estimates of OC use by women aged 15 to 49 in Canada (15.9%; 95% confidence interval: 13.7% to 18.5%) were comparable to survey-based estimates from the United States (16.0% of women aged 15 to 44 from 2011 to 2013 and 14.0% of women aged 15 to 49 from 2017 to 2019).^Note 33, ^Note 34 While several other countries, including the United Kingdom,^Note 35 Australia,^Note 36 and Denmark,^Note 37 publish OC use prevalence, comparisons of overall rates tend not to be very informative because of differences in methodology and population exclusions. By contrast, comparisons of use patterns by sociodemographic characteristics of OC users across countries tend to be more meaningful. 

For example, in this study, past-month OC use decreased with age, and nulliparous women were more likely than primiparous and multiparous women to use OCs. These differences are well established and have been found before in Canada^Note 4, ^Note 5, ^Note 38 and elsewhere.^Note 33, ^Note 34, ^Note 36, ^Note 37 Use of OCs is highest before age 30 and then declines, with at least some of the drop being related to a shift to trying to become or becoming pregnant. Vital statistics also substantiate this, as mothers in Canada during this period were aged 29.7 to 31.2 years, on average.^Note 39 At older ages, women tend to prefer more permanent methods (e.g., tubal ligation) or long-acting reversible contraceptive (LARC) methods (e.g., intrauterine devices or systems).^Note 34

Health care providers may also be more hesitant to prescribe OCs to older women because the risk of experiencing OC-related adverse events and some medical conditions contraindicated with OC use increases with age.^Note 40 However, not all women older than 35 are at risk, and restricting access based on age alone is no longer as widely endorsed, owing to other risks (i.e., unintended pregnancy).^Note 41

According to these CHMS  results, non-racialized and non-Indigenous women were more likely than racialized women to be current users of OCs (past 30 days). Other studies have also found lower use of hormonal contraceptives among immigrant or minority women.^Note 33, ^Note 34, ^Note 36, ^Note 42, ^Note 43 Acceptability of contraception and method preference also vary by country or region of birth,^Note 44 as do cultural attitudes and religious beliefs.^Note 42, ^Note 44, ^Note 45 Some populations may also have culture-specific fears of adverse events associated with OC use, causing some to opt for non-hormonal, and sometimes less effective, contraceptive methods.^Note 44, ^Note 46 Unmet contraceptive needs may also have contributed to lower OC rates in some populations because of language barriers, unfamiliarity with the Canadian health care system, health care provider attitudes, or difficulties accessing health care.^Note 41, ^Note 42, ^Note 44, ^Note 45

OCs are a safe and effective method of birth control with a long history of women using them to prevent pregnancy.^Note 8, ^Note 9 Like many medications, OCs have some side effects and risks, depending on the quantity of estrogen and the type of progestin.^Note 16, ^Note 17, ^Note 18, ^Note 19, ^Note 40 Newer formulations of COCs typically contain lower dosages of estrogen.^Note 47 Over this study period from the 2007-to-2009 cycle to the 2018-to-2019 cycle, 48.7% of COCs were using lower dose formulations. An estimate of 33.9% pertaining to the period from 2007 to 2011 suggests that the use of lower-dose formulations has become more common in Canada.^Note 4 

Other studies have found not only that ever using OCs has health impacts, compared with never using them, but also that the length of time women were using them matters.^Note 16, ^Note 18, ^Note 40 CHMS cycles 5 and 6 made it possible to examine OC use by duration; these new data suggest that the majority of both current and former users have taken the medication for at least four years.      

Strengths and limitations

Combining data from CHMS cycles allows for a more in-depth analysis than would be possible if only a single cycle was used. This includes the use of more refined variables, such as one pertaining to parity with greater precision and another for the population group of Indigenous people. 

However, the challenge of small samples was not entirely eliminated, occasionally requiring the use of more general covariate categories than desirable. Additionally, the CHMS does not collect data on some variables of interest, including pregnancy intention, use of other forms of contraception, sexual health knowledge, medication insurance, and length of gap since stopping OC use. The OC duration variable had response categories that did not include the established length of risk exposure intervals of 5 and 10 years.^Note 18, ^Note 48 Available data were also limited to household respondents living in the provinces and not on reserves or Indigenous settlements, so not all reproductive-aged women in Canada are represented in this study. Nevertheless, having more information about Canadian women’s exposure to OCs is an improvement over an earlier CHMS -based OC study.^Note 4     

Although quality assurance measures were applied at each stage of data collection and processing, and interviewers had extensive training, data from the CHMS have several limitations. Some data are self-reported and are, therefore, susceptible to social desirability and recall bias. That said, because CHMS cycles 5 and 6 asked directly about the use of birth control pills, in addition to collecting DINs, this provided an opportunity to compare self-reported birth control use with DIN-derived OC-use variables. Among current OC users (past 30 days) based on medication labels and corresponding DINs, 97.9% also reported birth control use, suggesting that self-reported birth control use is another source of high-quality data on contraception (Table 4).

The main approach of this study derived OC use from medications identified via DINs. This is not ideal for capturing the use of other hormonal contraceptives, such as LARCs, because insertion (or administration) might have occurred several months or even years prior, thereby affecting recall.

Conclusion

This study spans 12 years and presents nationally representative estimates of OC use for women in the decade or so before many forms of prescription contraception will be made free in Canada.^Note 20, ^Note 21 A detailed understanding of OC use by sociodemographic and other characteristics before this policy change will be important baseline information to facilitate future surveillance. Understanding which women use OCs is also essential for identifying women who are at risk of unplanned pregnancy and more generally for informing and supporting health promotion, including family planning support.