title: Efficacy and side-effects profile of the ethinylestradiol and etonogestrel contraceptive vaginal ring: a systematic review and meta-analysis.
abstract: OBJECTIVE
  To assess the efficacy and tolerability (side-effects profile), and compliance of the combined contraceptive vaginal ring (CCVR) compared with combined oral hormonal contraceptives (COC).
  
  
  METHODS
  The PubMed, Embase, POPLINE, Cochrane Central Register of Controlled Trials (CENTRAL), LILACS, ClinicalTrials.gov, Clinical Trials Registry Platform (ICTRP) and CINAHL databases were searched.
  
  
  METHODS
  Electronic databases were searched for randomised clinical trials comparing the CCVR with COC with a duration of at least 3 months between 01 December and 15 December 2015. The primary outcome was efficacy. The secondary outcomes were compliance, absence of withdrawal bleeding, breakthrough bleeding, nausea and headache. Heterogeneity was assessed using I2statistic and Cochran's Q statistic. Results were expressed as odds ratios (OR) with 95% confidence intervals (CIs) using random-effects models or fixed-effects models depending on the heterogeneity.
  
  
  RESULTS
  4368 records were identified, 2844 of which were removed after duplicates and 1524 records were screened. Of these, 1503 were excluded and 21 full text articles were assessed for eligibility. After removing another 7 articles, 14 records were finally included in the qualitative and quantitative analysis. The results show a trend to higher efficacy for the CCVR in preventing pregnancy (Peto OR: 0.52 [95% CI: 0.26-1.04]) and a significantly lower presence of nausea (Peto OR: 0.66 [95% CI: 0.46-0.93]). More cycles were compliant in the CCVR group (Peto OR: 1.22 [95% CI: 1.12-1.32]) and fewer women reported breakthrough bleeding (Peto OR: 0.68 [95% CI: 0.51-0.91]).
  
  
  CONCLUSIONS
  Our findings demonstrate that the CCVR is as effective and tolerable as the COC but with a better bleeding profile.
authors.affiliation: a Araba Research Unit , Araba University Hospital , Vitoria , Spain.|b Bioaraba Research Institute , Vitoria , Spain.
authors.forename: Amanda
authors.initials: A
authors.lastname: López-Picado
authors.affiliation: b Bioaraba Research Institute , Vitoria , Spain.|c Obstetrics and Gynecology Clinical Management Unit , Araba University Hospital , Vitoria , Spain.
authors.forename: Oihane
authors.initials: O
authors.lastname: Lapuente
authors.affiliation: b Bioaraba Research Institute , Vitoria , Spain.|c Obstetrics and Gynecology Clinical Management Unit , Araba University Hospital , Vitoria , Spain.|d School of Medicine, University of the Basque Country , Vitoria , Spain.
authors.forename: Iñaki
authors.initials: I
authors.lastname: Lete
mesh_terms: D003271:Contraceptive Agents, Female / Q000008:administration & dosage* / Q000009:adverse effects; D003274:Contraceptive Devices, Female / Q000009:adverse effects* / Q000706:statistics & numerical data*; D017135:Desogestrel / Q000008:administration & dosage / Q000009:adverse effects*; D004343:Drug Implants / Q000009:adverse effects; D004997:Ethinyl Estradiol / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D006801:Humans
chemical_list: D003271:Contraceptive Agents, Female; D004343:Drug Implants; C044815:etonogestrel; D004997:Ethinyl Estradiol; D017135:Desogestrel
keywords: Contraceptive vaginal ring; meta-analysis; oral contraceptives; systematic review