Strategies to improve adherence and continuation of shorter-term hormonal methods of contraception

Worldwide, hormonal contraceptives are among the most popular reversible contraceptives. Despite high perfect-use effectiveness rates, typical-use effectiveness rates for shorter-term methods such as oral and injectable contraceptives are much lower. In large part, this disparity reflects difficulties in ongoing adherence to the contraceptive regimen and low continuation rates. Correct use of contraceptives to ensure effectiveness is vital to reducing unintended pregnancy.

To determine the effectiveness of strategies aiming to improve adherence to, and continuation of, shorter-term hormonal methods of contraception compared with usual family planning care.

We searched to July 2018 in the following databases (without language restrictions): The Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 7), PubMed via MEDLINE, POPLINE, Web of Science, ClinicalTrials.gov, and the International Clinical Trials Registry Platform (ICTRP).

We included randomized controlled trials (RCTs) comparing strategies aimed to facilitate adherence and continuation of shorter-term hormonal methods of contraception (such as oral contraceptives (OCs), injectable depot medroxyprogesterone acetate (DMPA or Depo-Provera), intravaginal ring, or transdermal patch) with usual family planning care in reproductive age women seeking to avoid pregnancy.

We used standard methodological procedures recommended by Cochrane. Primary outcomes were continuation or discontinuation of contraceptive method, rates of discontinuation due to adverse events (menstrual disturbances and all other adverse events), and adherence to method use as indicated by missed pills and on-time/late injections. Pregnancy was a secondary outcome.

We included 10 RCTs involving 6242 women. Six trials provided direct in-person counseling using either multiple counseling contacts or multiple components during one visit. Four trials provided intensive reminders of appointments or next dosing, of which two provided additional educational health information as well as reminders. All trials stated 'usual care' as the comparison.The certainty of the evidence ranged from very low to moderate. Main limitations were risk of bias (associated with poor reporting of methodological detail, lack of blinding, and incomplete outcome data), inconsistency, indirectness, and imprecision.Continuation of hormonal contraceptive methodsIt is uncertain whether intensive counseling improves continuation of hormonal contraceptive methods compared with usual care (OR 1.28, 95% CI 1.07 to 1.54; 2624 participants; 6 studies; I² = 79%; very low certainty evidence). The evidence suggested: if the chance of continuation with usual care is 39%, the chance of continuation with intensive counseling would be between 41% and 50%. The overall pooled OR suggested continuation of improvement, however, when stratified by contraceptive method type, the positive results were restricted to DMPA.It is uncertain whether reminders (+/- educational information) improve continuation of hormonal contraceptive methods compared with usual care (OR 1.33, 95% CI 1.03 to 1.73; 933 participants; 2 studies; I² = 69%; very low certainty evidence).The evidence suggested: if the chance of continuation with usual care is 52%, the chance of continuation with reminders would be between 52% and 65%.Discontinuation due to adverse eventsThe evidence suggested that counseling may be associated with a decreased rate of discontinuation due to adverse events compared with usual care, with a lower rate of discontinuation due to menstrual disturbances (OR 0.20, 95% CI 0.11 to 0.37; 350 participants; 1 study; low certainty evidence), but may make little or no difference to all other adverse events (OR 0.73, 95% CI 0.36 to 1.47; 350 participants; 1 study; low certainty evidence). The evidence suggested: if the chance of discontinuation with usual care due to menstrual disturbances is 32%, the chance of discontinuation with intensive counseling would be between 5% and 15%; and that if the chance of discontinuation with usual care due to other adverse events is 55%, the chance of discontinuation with intensive counseling would be between 30% and 64%.Discontinuation was not reported among trials that investigated the use of reminders (+/- educational information).Adherence Adherence was not reported among trials that investigated the use of intensive counseling.Among trials that investigated reminders (+/- educational information), there was no conclusive evidence of a difference in adherence as indicated by missed pills (MD 0.80, 95% CI -1.22 to 2.82; 73 participants; 1 study; moderate certainty evidence) or by on-time injections (OR 0.84, 95% CI 0.54 to 1.29; 350 participants; 2 studies; I² = 0%; low certainty evidence). The evidence suggested: if the chance of adherence to method use as indicated by on-time injections with usual care is 50%, the chance of adherence with method use as indicated by on-time injections with reminders would be between 35% and 56%.PregnancyThere was no conclusive evidence of a difference in rates of pregnancy between intensive counseling and usual care (OR 1.24, 95% CI 0.98 to 1.57; 1985 participants; 3 studies; I² = 0%, very low certainty evidence). The evidence suggested: if the chance of pregnancy with usual care is 18%, the chance of pregnancy with counseling would be between 18% and 25%.Pregnancy was not reported among trials that investigated the use of reminders (+/- educational information).

Despite the importance of this topic, studies have not been published since the last review in 2013 (nine studies) with only one study added in 2019 that neither changed the results nor improved the certainty of evidence.Overall, the certainty of evidence for strategies to improve adherence and continuation of contraceptives is low. Intensive counseling and reminders (with or without educational information) may be associated with improved continuation of shorter-term hormonal contraceptive methods when compared with usual family planning care. However, this should be interpreted with caution due to the low certainty of the evidence. Included trials used a variety of shorter-term hormonal contraceptive methods which may account for the high heterogeneity. It is possible that the effectiveness of strategies for improving adherence and continuation are contingent on the contraceptive method targeted. There was limited reporting of objectively measurable outcomes (e.g. electronic monitoring device) among included studies. Future trials would benefit from standardized definitions and measurements of adherence, and consistent terminology for describing interventions and comparisons. Further research requires larger studies, follow-up of at least one year, and improved reporting of trial methodology.