Graduation Year


Document Type




Degree Name

Doctor of Philosophy (Ph.D.)

Degree Granting Department

Public Health

Major Professor

Ellen Daley, Ph.D.

Committee Member

Stephanie Marhefka, Ph.D.

Committee Member

Cheryl Vamos, Ph.D.

Committee Member

Joseph Puccio, M.D.


LARC, IUD, implant, adolescent, young adult


Background: The United States has the highest rate of unintended pregnancy compared to any other developed country. Unintended pregnancy is associated with negative health outcomes for both parents and children. It is estimated that government expenditures for unintended pregnancy total $21 billion each year. Women ages 18-25 years old have the highest rate of unintended pregnancy. This age group is categorized as emerging adulthood, and this is a unique developmental period in a person’s life. Given the high rate of unintended pregnancies and the associated negative outcomes, increasing the use of more reliable methods of birth control is a public health priority. Long-acting reversible contraception (LARC) are the most effective reversible forms of contraception available. However, the use of LARC among young women is low, with only 5% of those ages 15-24 using this method. Additionally, among women who use LARC, 89% use the IUD and only 11% use the implant. By understanding factors that influence LARC initiation, use of these highly effective methods can be increased and subsequently the rate of unintended pregnancy could be decreased.

Purpose: The purpose of this study was to advance our understanding of key factors in LARC initiation and why women chose one LARC method over another. The objectives were as follows: 1) Determine if interpersonal and intrapersonal differences exist between IUD users and implant users; and 2) Explore how participants chose either the IUD or the implant.

Methods: A mixed method study was conducted among 18-25 year old, nulliparous women who were currently using LARC. Phase I consisted of a quantitative survey administered online to 226 participants. Phase II involved conducting in-depth, semi-structured interviews with a subset of participants (N=30) from Phase I to further explore important factors in LARC initiation. This study was guided by Social Cognitive Theory. Phase I data were analyzed using MANOVA or chi-square tests, and Phase II interviews were analyzed using the Applied Thematic Analysis approach.

Results: Quantitative results indicated that Hispanic women and participants who were younger were more likely to use the implant compared to the IUD. Women using the IUD more often reported that their friends were influential in their choice compared to implant users. The most common and trusted sources of information for participants was their health care provider or the internet. In the qualitative phase, the majority of women reported that using a previous method of contraception inconsistently (outcome expectations) was an important motivator in considering LARC. They then sought out health information (knowledge) on LARC from their provider and the internet. They also sought — either through their social network and/or social media — to hear the experiences of other women who had used these methods (observational learning). Upon making the decision to use LARC, women then intentionally set a goal of using LARC and used behavioral skills and self-efficacy to overcome barriers and achieve LARC initiation. Most women experienced barriers to LARC insertion, e.g. health insurance issues, health care providers engaging in non-evidence based practice behaviors, and an unusually long delay between the consultation appointment and the insertion appointment. Participants discussed choosing one LARC method over the other due to an aversion to the location of placement, insertion procedure, and/or some other characteristic specific to the implant or IUD.

Conclusion: This study found that key factors in LARC initiation were outcome expectations, reinforcement, knowledge, observational learning, behavioral skills, intentions, self-efficacy, and opportunities and barriers. Targeting these key factors in future interventions can lead to an increase in LARC use among young women, thereby leading to a decrease in unintended pregnancy. Furthermore, addressing policy and practice barriers to LARC initiation will allow women easier access to these highly effective methods, which will also ultimately lead to a decrease in the rate of unintended pregnancy.

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Public Health Commons