Long-acting reversible contraceptive acceptability and unintended pregnancy among women presenting for short-acting methods: a randomized patient preference trial.
BACKGROUND
Measures of contraceptive effectiveness combine technology and user-related factors. Observational studies show higher effectiveness of long-acting reversible contraception compared with short-acting reversible contraception. Women who choose long-acting reversible contraception may differ in key ways from women who choose short-acting reversible contraception, and it may be these differences that are responsible for the high effectiveness of long-acting reversible contraception. Wider use of long-acting reversible contraception is recommended, but scientific evidence of acceptability and successful use is lacking in a population that typically opts for short-acting methods.


OBJECTIVE
The objective of the study was to reduce bias in measuring contraceptive effectiveness and better isolate the independent role that long-acting reversible contraception has in preventing unintended pregnancy relative to short-acting reversible contraception.


METHODS
We conducted a partially randomized patient preference trial and recruited women aged 18-29 years who were seeking a short-acting method (pills or injectable). Participants who agreed to randomization were assigned to 1 of 2 categories: long-acting reversible contraception or short-acting reversible contraception. Women who declined randomization but agreed to follow-up in the observational cohort chose their preferred method. Under randomization, participants chose a specific method in the category and received it for free, whereas participants in the preference cohort paid for the contraception in their usual fashion. Participants were followed up prospectively to measure primary outcomes of method continuation and unintended pregnancy at 12 months. Kaplan-Meier techniques were used to estimate method continuation probabilities. Intent-to-treat principles were applied after method initiation for comparing incidence of unintended pregnancy. We also measured acceptability in terms of level of happiness with the products.


RESULTS
Of the 916 participants, 43% chose randomization and 57% chose the preference option. Complete loss to follow-up at 12 months was <2%. The 12-month method continuation probabilities were 63.3% (95% confidence interval, 58.9-67.3) (preference short-acting reversible contraception), 53.0% (95% confidence interval, 45.7-59.8) (randomized short-acting reversible contraception), and 77.8% (95% confidence interval, 71.0-83.2) (randomized long-acting reversible contraception) (P < .001 in the primary comparison involving randomized groups). The 12-month cumulative unintended pregnancy probabilities were 6.4% (95% confidence interval, 4.1-8.7) (preference short-acting reversible contraception), 7.7% (95% confidence interval, 3.3-12.1) (randomized short-acting reversible contraception), and 0.7% (95% confidence interval, 0.0-4.7) (randomized long-acting reversible contraception) (P = .01 when comparing randomized groups). In the secondary comparisons involving only short-acting reversible contraception users, the continuation probability was higher in the preference group compared with the randomized group (P = .04). However, the short-acting reversible contraception randomized group and short-acting reversible contraception preference group had statistically equivalent rates of unintended pregnancy (P = .77). Seventy-eight percent of randomized long-acting reversible contraception users were happy/neutral with their initial method, compared with 89% of randomized short-acting reversible contraception users (P < .05). However, among method continuers at 12 months, all groups were equally happy/neutral (>90%).


CONCLUSIONS
Even in a typical population of women who presented to initiate or continue short-acting reversible contraception, long-acting reversible contraception proved highly acceptable. One year after initiation, women randomized to long-acting reversible contraception had high continuation rates and consequently experienced superior protection from unintended pregnancy compared with women using short-acting reversible contraception; these findings are attributable to the initial technology and not underlying factors that often bias observational estimates of effectiveness. The similarly patterned experiences of the 2 short-acting reversible contraception cohorts provide a bridge of generalizability between the randomized group and usual-care preference group. Benefits of increased voluntary uptake of long-acting reversible contraception may extend to wider populations than previously thought.
FHI 360, Durham, NC. Electronic address: dhubacher@fhi360.org.
David
D
Hubacher
Planned Parenthood South Atlantic, Raleigh, NC.
Hannah
H
Spector
Planned Parenthood South Atlantic, Raleigh, NC.
Charles
C
Monteith
FHI 360, Durham, NC.
Pai-Lien
PL
Chen
FHI 360, Durham, NC.
Catherine
C
Hart
D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D011247:Pregnancy; D055815:Young Adult; D003267:Contraception / Q000379:methods; D003271:Contraceptive Agents, Female / Q000627:therapeutic use; D003278:Contraceptives, Oral, Hormonal / Q000627:therapeutic use; D003692:Delayed-Action Preparations; D017135:Desogestrel / Q000627:therapeutic use; D004343:Drug Implants; D007434:Intrauterine Devices; D007435:Intrauterine Devices, Copper; D007436:Intrauterine Devices, Medicated; D053208:Kaplan-Meier Estimate; D017258:Medroxyprogesterone Acetate / Q000627:therapeutic use; D010342:Patient Acceptance of Health Care; D057240:Patient Preference; D049168:Pregnancy, Unplanned
D003271:Contraceptive Agents, Female; D003278:Contraceptives, Oral, Hormonal; D003692:Delayed-Action Preparations; D017135:Desogestrel; D004343:Drug Implants; C044815:etonogestrel; D017258:Medroxyprogesterone Acetate
LARC; acceptability; adherence; contraceptive continuation; depot medroxyprogesterone acetate; discontinuation; intrauterine device; long-acting reversible contraception; oral contraceptives; subdermal contraceptive implant; unintended pregnancy
Contraception. 2016 Feb;93(2):139-44
26386444
Am J Public Health. 2016 Jan;106(1):18-9
26562116
Contraception. 2014 Apr;89(4):237-41
24582293
BMJ. 1999 Sep 11;319(7211):670-4
10480822
Fed Regist. 2013 Jul 2;78(127):39869-99
23833808
Contraception. 2014 Feb;89(2):97-102
24332745
Obstet Gynecol. 2012 Oct;120(4):983-8
22996129
Am J Public Health. 1995 Apr;85(4):494-503
7702112
Hum Reprod. 2008 Jun;23 (6):1338-45
18372257
Pediatrics. 2014 Oct;134(4):e1257-81
25266435
Perspect Sex Reprod Health. 2006 Jun;38(2):90-6
16772190
Obstet Gynecol. 2011 Jul;118(1):184-96
21691183
Contraception. 2015 Mar;91(3):185-92
25500324
Contraception. 2015 Jan;91(1):49-56
25282161
N Engl J Med. 2016 Mar 3;374(9):843-52
26962904
Obstet Gynecol. 2011 May;117(5):1105-13
21508749
N Engl J Med. 2012 May 24;366(21):1998-2007
22621627
Fam Med. 2012 Oct;44(9):637-45
23027156
MMWR Morb Mortal Wkly Rep. 2011 Jan 14;60(1):1-4
21228760
J Adolesc Health. 2013 Mar;52(3):284-92
23298980
NCHS Data Brief. 2014 Dec;(173):1-8
25500343
Perspect Sex Reprod Health. 2014 Sep;46(3):157-63
25040577
Contraception. 2010 Oct;82(4):391
20851236