title: Extended regimens of combined hormonal contraception to reduce symptoms related to withdrawal bleeding and the hormone-free interval: a systematic review of randomised and observational studies.
abstract: OBJECTIVE
  To assess whether continuous and extended regimens (CRs/ERs) of combined hormonal contraceptives (CHCs) improve symptoms related to withdrawal bleeding or the hormone-free interval and to compare the efficacy, safety, and cost of CRs/ERs to those of conventional 28-day regimens.
  
  
  METHODS
  A literature search of the PubMed database was conducted for randomised clinical trials (RCTs) and observational studies published in any language between 2006 and 2013.
  
  
  RESULTS
  Sixteen RCTs and 14 observational studies evaluated issues related to our objectives. CRs/ERs, whose efficacy and safety were comparable to those described for conventional regimens, were preferred due to their improvement of symptoms related to withdrawal bleeding or the hormone-free interval and the lower costs resulting from the reduced incidence of these symptoms.
  
  
  CONCLUSIONS
  The contraceptive efficacy and safety of CR/ER use of CHCs is at least equal to that of 28-days conventional regimens, and this use may have some cost savings. CRs/ERs are recommended for women willing to take a CHC for treatment of symptoms related to withdrawal bleeding or the hormone-free interval.
authors: * Department of Obstetrics and Gynaecology, University of Granada , Spain.
authors: Nicolás
authors: N
authors: Mendoza
authors: Paloma
authors: P
authors: Lobo
authors: Roberto
authors: R
authors: Lertxundi
authors: Marta
authors: M
authors: Correa
authors: Esteban
authors: E
authors: Gonzalez
authors: Alberto
authors: A
authors: Salamanca
authors: Rafael
authors: R
authors: Sánchez-Borrego
mesh_terms: D003277:Contraceptives, Oral, Combined / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D064887:Observational Studies as Topic; D016032:Randomized Controlled Trials as Topic; D013375:Substance Withdrawal Syndrome / Q000209:etiology; D016896:Treatment Outcome; D014592:Uterine Hemorrhage / Q000209:etiology
chemical_list: D003277:Contraceptives, Oral, Combined
keywords: Combined hormonal contraceptives; Continuous regimen; Contraception; Extended regimen; Hormone-free interval; Withdrawal bleeding