Table 4.

Infection

Author, year, sources of support	Study design, location, follow-up	Population, intervention	Type(s) of IUD	Outcomes of interest	Results	Strengths	Weaknesses	Grade
Alton, 2012 [11] United States Source of support not stated	Retrospective cohort, 3 sites Up to 7 years follow-up Up to 80.88 person-years among women aged <18 years Up to 330.52 person-years among women aged 18–21 years	Women aged ≤21 years (range 11–21 years) having IUD inserted Age <18 years: n=69 Age 18–21 years: n=164	LNG-IUD (n=222) CuT380A (n=11)	Infection	18 infections (7.7% of patients) reported (5 infections in women b18 years; 13 infections in women <18–21 years) 2 cases PID, both with history of STI (ages not reported) Crude RR infection for women <18 years vs. 18–21 years: 1.56 (NS, p value not given)	Multicenter trial Rates reported in person-year to account for different follow-up	Small sample and few events; no information on study power Age not included in multivariate model for infection outcome (not significant) Outcome not clearly described, diagnostic measures not reported All data from chart review; outcomes may be underestimated if women sought care from other sites Did not assess sexual behaviors, condom use as potential confounders	II-2, poor
Aoun, 2014 [12] United States No financial disclosures	Retrospective cohort Mean follow-up 37±11 months (range 19–57 months)	Women age 13–35 years who had LNG-IUD or Cu-IUD inserted for contraception (n=2138) Age 13–19 years: n=249 Age 20–24 years: n=750 Age 25–35 years; n=1139	LNG-IUD n=1746 Cu-IUD n=392	PID	Crude Rates: Age 13–19 years: 8/249 (3%) Age 20–24 years: 17/750 (2%) Age 25–35 years: 15/1139 (1%) p=.08	Multicenter Reviewed charts from office, emergency department and hospitals including laboratory and imaging results Multivariate analysis adjusted for age, race and IUD type Excluded those with no follow-up	Did not assess potential confounders such as sexual behavior or history or condom use Small number of events No power calculation	II-2, poor
Berenson, 2015 [15] United States Institute for Translational Sciences, University of Texas Medical Branch, Clinical and Translational Science Award; NIH	Retrospective cohort Nationwide US health insurance program 12 months	Women age 15–44 years with insurance claim for insertion of IUD (n=79,920) or ENG implant (n=7374) Age 15–19 years: ENG: n=2388 LNG: n=2204 Age 20–24 years: ENG: n=2014 LNG: n=8988	LNG-IUD	PID	aOR(95% CI) comparing having complication for women with ENG implant vs. those for women with LNG-IUD: Age 15–19 years: 0.23 (0.03–2.06) Age 20–24 years: 0.32 (0.04–2.42)	Large sample size Multivariate analyses performed for each outcome, adjusted for age at insertion, contraceptive type, provider type and year of insertion Excluded women without 12 months of continuous insurance coverage	Limited by diagnostic coding; potential underreporting of outcomes not captured in database Did not include parity as potential confounder	II-2, fair
Berenson, 2013 [14] United States Society for Family Planning; NIH	Retrospective cohort (health insurance claims data) Nationwide US health insurance program 12 months (58% of those with IUD insertion also had 12 months of continuous insurance coverage and included in the analysis)	Women age 15–44 years with a claim for IUD insertion by procedure code (n=90,489) Age 15–19: LNG-IUD: n=1528 CuT IUD: n=307 Age 20–24: LNG-IUD: n=7860 CuT IUD: n=2027 Age 25–44: LNG-IUD: n=61,197 CuT IUD: n=17,570	LNG-IUD CuT IUD	PID	aOR for PID (women age 15–19 years vs. 20–24 years): 1.36 (95% CI: 0.38–4.82) aOR for PID (women 15–19 age years vs. 25–44 years): 1.44 (95% CI: 0.65–3.15)	Large database Several outcomes Multivariate analysis, adjusted for age, intrauterine device type, health care provider specialty, region and year of IUD insertion Excluded women without 12 months of continuous insurance coverage	Limited by diagnostic coding; potential underreporting of outcomes not captured in database Did not include parity, sexual behavior or condom use as potential confounder No information on whether those not included in the analysis were different from sample	II-2, poor
Nygren, 1981 [18]	Prospective cohort (data from RCT two IUDs) 3 years (follow-up from Luukkainen 1979, Allonen, 1980) 21,146.5 woman-months of use	Women presenting for IUD insertion, randomized to Nova-T (n=916) or Cu T (n=945) inserted postmenstrual Nova T users: Age <20 years old: ~73 (~8%) Age 20–24 years: ~257 (~28%) >24 years: ~586 women (~64%)	Nova-T (n=916)	36-month net removal rate for infection, by age	Removal rate for infection: Age <20: 2.8 (n=2) Age 20–24: 7.3 (n=17) Age 25–29: 2.5 (n=6) Age 30–34: 2.6 (n=5) Age >35: 3.0 (n=4) p values NR	Multicenter trial Multiple providers Women not seen after insertion were not included in study Low loss to follow-up 11.4%	Graphical display of results pertaining to age and parity, no statistical testing for age or parity comparisons reported Outcome not clearly described, diagnostic measures not reported	II-2, poor
Rasheed, 2011 [20] Egypt Source of support not stated	Prospective cohort 1, 3, 6 months	Primiparous women <30 years old at time of IUD insertion 6–8 weeks after vaginal delivery Age 13–19: n=281 Age 20–30: n=571	CuT380A	Evidence of PID or removal for PID	Crude PID rates at 1 month: Age 13–19: 2/244 (0.8%) (both cases occurred in first week after insertion) Age 20–30: 0/413 No PID data reported at 3 or 6 months	Ultrasound check for proper placement and at follow-up for displacements and expulsions All primiparous, so no concern about parity as potential confounder	No assessment of potential confounders such as STI history, sexual behavior or condom use Outcome not clearly described, diagnostic measures not reported Postpartum population only, less generalizable Single site High attrition and differential loss to follow-up at 6 months (66% adolescents and 85% adults lost) Small number of events, no power calculation reported for any outcome	II-2, poor
Ravi, 2014 [21] United States American Academy of Family Physicians, NIH grant K23HD067247	Retrospective cohort Chart reviewed up to 6 months after insertion	All women age ≤35 years with IUD insertion in an NYC-area FQHC network (n=684) Age <21: n=182 Age 21–35: n=502	LNG-IUD (n=487) Cu-IUD (n=196)	PID	One case of PID in older age group	Multiple sites within FQHC network Participants with follow-up had similar baseline characteristics as those without follow-up, except for IUD payment	Groups differed at baseline by race, ethnicity, parity, IUD payment and site of insertion All data from chart review; outcomes may be underestimated if women sought care from other sites Outcome not clearly described, diagnostic criteria not reported High attrition	II-2, poor
Skajaa, 1990 [22] Denmark	Retrospective cohort 6 years Follow-up visit at 5 weeks, then annually	Women aged 14–47 who received IUD (n=1697) Age < 20 years: n=98 Age 20–24 years: n=454 Age 25–29 years: n=506 Age 30–35: n=337 Age 35+ years: n=260	Multiload Cu250 (n=717) Nova-T (n=938)	Removals due to PID requiring treatment	Cumulative 6-year complication rate per 100 women for PID (95% CI): Age < 20 years: 15.1 (8.7–25.5) Age 20–24 years: 15.4 (12.0–19.7) Age 25–29 years: 13.0 (10.1–16.8) Age 30–34 years: 9.5 (6.7–13.5) Age 35+ years: 6.2 (3.7–10.3) All: 11.9 (10.3–13.8)	Large sample size	Unclear follow-up rates and women-years and denominators used for analyses Single site Outcome not clearly described, diagnostic measures not reported Cumulative rates for each outcome did not assess or adjust for potential confounders such as parity, IUD type, previous IUD use, sexual behavior and history or condom use	II-2, poor
Suhonen, 2004 [23] Finland, Sweden Source of support not stated	RCT 12 months	Nulliparous women age 18–25 years (median age 21 years) randomized to LNG-IUD or COCs (n=193) LNG-IUD: n=94 COC (30 mcg EE/150 mcg desogestrel): n=99	LNG-IUD	Infection	No PID reported in either group	Multiple sites Parity similar between groups Similar loss to follow-up: 19/94 (20.2%) attrition in IUD and 27/99 (27.3%) in COC group	Determination of adequate randomization not reported, potential confounders uncertain Outcome not clearly described, diagnostic measures not reported Few events, powered on anticipated continuation rates, mostly likely lacking in power for other outcomes	I, fair

COC: combined oral contraceptive; Cu IUD= copper intrauterine device; EE= ethinyl estradiol; IUD= intrauterine device; LNG-IUD= levonorgestrel intrauterine device; LNG-IUS: levonorgestrel intrauterine system; NIH= National Institutes of Health; NR: not reported; NS= not significant; OC= oral contraceptive; OR= odds ratio; PID= pelvic inflammatory disease; RCT= randomized controlled trial; RR= relative risk; STI= sexually transmitted infection