title: [Preliminary results from the OPNI observatory: long-term follow-up of a cohort of women using the progestagen contraceptive implant Implanon].
abstract: OBJECTIVE
  Describe the initiation and follow-up of Implanon insertion in current office-based practice in France and estimate the rate and causes of early removals.
  
  
  METHODS
  A prospective cohort study of 1000 women having been inserted with Implanon by a representative national sample of prescribers (gynaecologists and general practitioners) was designed. The follow-up period was 3 years and the enrolment was planned for 2 years starting July 2002 according to a naturalistic design.
  
  
  RESULTS
  The results are related to an intermediate analysis describing the situation of the cohort at the date 31 December 2003. 872 women were enrolled, of whom 784 (89.9%) by gynaecologists and 88 (10.1%) by GPs. Implanon was inserted in 691 (79.2%) and 360 (52.1%) had at least one follow-up visit at this date. The mean follow-up period after insertion was 10.5 months. 38 early removals were recorded (actuarial rate at 16 months of 8.8% [CI 95% 5.0-12.7]), integrating the distribution of follow-up duration and the assumption that women with no follow-up visit the still had device.
  
  
  CONCLUSIONS
  The estimated early removal rate was lower than the result of the meta-analysis of international clinical trials but this figure should be confirmed in the final analysis of the study.
authors.affiliation: Service de gynécologie-obstétrique, institut Mère-Enfant Alix-de-Champagne, CHRU, 45, rue Cognacq-Jay, 51092 Reims, France.
authors.forename: O
authors.initials: O
authors.lastname: Graesslin
authors.forename: M
authors.initials: M
authors.lastname: Hoffet
authors.forename: P
authors.initials: P
authors.lastname: Barjot
authors.forename: A
authors.initials: A
authors.lastname: Levy
authors.forename: S
authors.initials: S
authors.lastname: Bouée
authors.forename: O
authors.initials: O
authors.lastname: Bogillot
authors.forename: N
authors.initials: N
authors.lastname: Heu
authors.forename: P
authors.initials: P
authors.lastname: Madelenat
mesh_terms: D015331:Cohort Studies; D017135:Desogestrel / Q000008:administration & dosage; D016503:Drug Delivery Systems; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D045167:Progesterone Congeners / Q000008:administration & dosage; D016896:Treatment Outcome
chemical_list: D045167:Progesterone Congeners; C044815:etonogestrel; D017135:Desogestrel