Publications
Continuation of prescribed compared with over-the-counter oral contraceptives
Joseph E. Potter, Sarah McKinnon, Kristine Hopkins, Jon Amastae, Michele G. Shedlin, Daniel A. Powers, and Daniel Grossman.
Obstetrics & Gynecology 2001; 17(3): 551-557
Abstract
Objective: To estimate differences in continuation of oral contraceptive pills (OCPs) between U.S. resident women obtaining pills in U.S. family planning clinics compared with over-the-counter in Mexican pharmacies.
Methods: In El Paso, Texas, we recruited 514 OCP users who obtained pills over the counter from a Mexican pharmacy and 532 who obtained OCPs by prescription from a family planning clinic in El Paso. A baseline interview was followed by three consecutive surveys over 9 months. We asked about date of last supply, number of pill packs obtained, how long they planned to continue use, and experience of side effects. Retention was 90%, with only 105 women lost to follow-up.
Results: In a multivariable Cox proportional hazards model, discontinuation was higher for women who obtained pills in El Paso clinics compared with those who obtained their pills without a prescription in Mexico (hazard ratio 1.6, 95% confidence interval [CI] 1.1–2.3).
Contraindications to combined oral contraceptives among over-the-counter and clinic pill users
Daniel Grossman, Kari White, Kristine Hopkins, Jon Amastae, Michele G. Shedlin, and Joseph E. Potter.
Obstetrics & Gynecology 2011; 17(3): 558-565.
Abstract
Objective: To compare the estimated proportion of contraindications to combined oral contraceptives (COCs) between women living in El Paso, Texas, obtaining COCs in US public clinics versus over the counter (OTC) in Mexican pharmacies.
Methods: We recruited a cohort of 501 El Paso resident women who obtained COCs over the counter (OTC) in Mexico and 514 women who obtained COCs from family planning clinics in El Paso. Based on self-report of WHO category 3 and 4 contraindications and interviewer-measured blood pressure, we estimated the proportion of contraindications and, using multivariable-adjusted logistic regression, identified possible predictors of contraindications.
Results: The estimated proportion of any category 3 or 4 contraindication was 18%. Relative contraindications (category 3) were more common among OTC users (13% vs 9% among clinic users, p=0.006). Absolute contraindications (category 4) were not different between the groups (5% for clinic users vs 7% for OTC users, p=0.162). Hypertension was the most prevalent contraindication (8%). After multivariable adjustment, OTC users had higher odds of being contraindicated compared to clinic users (OR 1.59, 95% CI: 1.11-2.29). Women age 35 years or older (OR 5.30, 95% CI: 3.59-7.81) and those with body mass index ≥ 30.0 kg/m2 (OR 2.24, 95% CI: 1.40-3.56) also had higher odds of being contraindicated.
Conclusions: Relative COC contraindications are more common among OTC users in this setting. Research is needed to determine whether checklists can be used to accurately identify contraindications when women obtain COCs OTC. Progestin-only pills might be a better candidate for the first OTC product given their fewer contraindications.
Clinic versus over-the-counter access to oral contraception: Choices women make along the US-Mexico border
Joseph E. Potter, Kari White, Kristine Hopkins, Jon Amastae, and Daniel Grossman.
American Journal of Public Health 2010; 100:1130-1136.
Abstract
Objectives. As part of the Border Contraceptive Access Study, we interviewed oral contraceptive (OC) users living in El Paso, Texas, to assess motivations for patronizing a US clinic or a Mexican pharmacy with over-the-counter (OTC) pills and to determine which women were likely to use the OTC option.
Methods. We surveyed 532 clinic users and 514 pharmacy users about background characteristics, motivations for choosing their OC source, and satisfaction with this source.
Results. Older women and women born and educated in Mexico were more likely to patronize pharmacies. Cost of pills was the main motivation for choosing their source for 40% of pharmacy users and 23% of clinic users. The main advantage cited by 49% of clinic users was availability of other health services. Bypassing the requirement to obtain a doctor’s prescription was most important for 27% of pharmacy users. Both groups were very satisfied with their pill source.
Conclusions. Women of different ages, parities, and educational levels would likely take advantage of an OTC option were OCs available at low cost. Improving clinic provision of OCs should be considered.
Perceptions of the Safety of Oral Contraceptives among a predominantly Latina population in Texas
Daniel Grossman, Leticia Fernandez, Kristine Hopkins, Jon Amastae, and Joseph E. Potter.
Contraception; 2010 81: 254–260.
Abstract
Background: Fear of side effects and previous negative experiences are common reasons for contraceptive nonuse.
Study Design: We collected information about perceptions of oral contraceptive (OC) safety from 1271 women 18-49 years old in El Paso, TX, and compared their responses to a medical evaluation by a nurse practitioner. We also asked participants about their interest in obtaining OCs over the counter (OTC).
Results: Among 794 women potentially at risk of unintended pregnancy, 56.0% said that OCs were medically safe for them. Reasons given for OCs being unsafe were related to fears of side effects and prior negative experiences rather than true contraindications. Older women and participants recruited at the less affluent recruitment site were significantly more likely to report that OCs were medically unsafe for them (pb.05). Nonusers who thought OCs were medically unsafe for them were as likely to be medically eligible for use as current hormonal users. Among nonusers or nonhormonal users and potential OC candidates (n=601), 60.2% said they would be more likely to use OCs if they were available OTC.
Conclusions: Women's perception of OC safety does not correlate well with medical eligibility for use. More education about the safety and health benefits of hormonal contraception is needed. OTC availability might contribute to more positive safety perceptions of OCs compared to a prescription environment.
Accuracy of self-screening for contraindication to combined oral contraceptive use
Daniel Grossman, Leticia Fernandez, Kristine Hopkins, Jon Amastae, Sandra G. Garcia, and Joseph E. Potter.
Obstetrics & Gynecology 2008; 112 (3): 572-578. NIH Public Access Version.
Abstract
Objective: To estimate how well a convenience sample of women from the general population could self-screen for contraindications to combined oral contraceptives using a medical checklist.
Methods: Women 18–49 years old (N=1,271) were recruited at two shopping malls and a flea market in El Paso, Texas, and asked first whether they thought birth control pills were medically safe for them. They then used a checklist to determine the presence of level 3 or 4 contraindications to combined oral contraceptives according to the World Health Organization Medical Eligibility Criteria. The women then were interviewed by a blinded nurse practitioner, who also measured blood pressure.
Results: The sensitivity of the unaided self-screen to detect true contraindications was 56.2% (95% confidence interval [CI] 51.7– 60.6%), and specificity was 57.6% (95% CI 54.0–61.1%). The sensitivity of the checklist to detect true contraindications was 83.2% (95% CI 79.5– 86.3%), and specificity was 88.8% (95% CI 86.3–90.9%). Using the checklist, 6.6% (95% CI 5.2–8.0%) of women incorrectly thought they were eligible for use when, in fact, they were contraindicated, largely because of unrecognized hypertension. Seven percent (95% CI 5.4–8.2%) of women incorrectly thought they were contraindicated when they truly were not, primarily because of misclassification of migraine headaches. In regression analysis, younger women, more educated women, and Spanish speakers were significantly more likely to correctly selfscreen (P<.05).
Conclusion: Self-screening for contraindications to oral contraceptives using a medical checklist is relatively accurate. Unaided screening is inaccurate and reflects common misperceptions about the safety of oral contraceptives. Over-the-counter provision of this method likely would be safe, especially for younger women and if independent blood pressure screening were encouraged.