39. Extended Use of the Etonogestrel Implant in AYA

Background

Although the etonogestrel implant is FDA approved for 3 years, recent data demonstrate efficacy up to 5 years. Evidence supporting extended use is limited in adolescents and young adults (AYA), especially those with higher BMI. We report on the AYA experience of extended implant use.

Methods

This secondary data analysis used prospectively collected QI data of all implant insertions with ≥1 follow-up visit from September 2012 to December 2023 across 4 U.S. adolescent medicine practices. Baseline demographic and clinical characteristics were assessed. We used Chi-Square and Fisher's Exact tests to compare clinical characteristics between participants with device removal before 3 y, 3-4 y, and >4 y. Univariable logistic regression was utilized to assess for factors associated with extended use. Kaplan Meier curves estimated continuation rates and Cox proportional-hazards modeling examined the risk of implant discontinuation accounting for site using a robust sandwich estimator

Results

We included 1317 AYA (mean age 18.6 y (SD 2.5)) in our analysis. Patients primarily identified as Hispanic/Latinx (36.4%), Black/African American (21.3%), or White (21.1%). Based on age-appropriate classifications, most participants were normal weighted (44%) at time of insertion; 15.4% were overweight, 27.9% obese. Of the 807 implant removals, unsatisfactory bleeding (45.4%) and weight concerns (11.9%) were the most frequent reasons for removal. One-fifth (20%) of removals (n=200) occurred 3-4 y after insertion, and 8% (n=67) >4 y. Factors reported at removal that were significantly associated with shorter use of implant (≤3 y vs >3 y) included perceived unsatisfactory uterine bleeding (OR 3.94, 95% CI 2.77 - 5.59, p<.05), weight concerns (OR 14.17, 95% CI 4.44 - 45.21 p< .05), and mental health change (OR 3.94, 95% CI 1.78 – 8.73 p<.05). There were no pregnancies noted with extended implant use. The 1-year continuation rate was 78%, dropping to 56%, 36%, 12% and 2% at years 2, 3, 4, and 5. Our survival analysis (Fig) demonstrated a significant difference between BMI categories and time to discontinuation. Obese patients had the lowest discontinuation rates for the study period compared to normal weighted patients (hazard ratio adjusted for site 0.945, 95% CI 0.921-0.970, P<.0001)

Conclusions

Over a quarter of participants kept their implant >3 years. AYA are more likely to undergo early device removal for concerns related to mental health change, unsatisfactory bleeding, and weight. AYA with obesity at time of insertion may keep their device longer. No pregnancies were observed. Clinicians should engage in shared decision making with patients regarding extended use of the implant.