title: Medical device assessment: scientific evidence examined by the French national agency for health - a descriptive study.
abstract: BACKGROUND
  Scientific evidence supports decision-making on the use of implantable medical devices (IMDs) in clinical practice, but IMDs are thought to be far less investigated than drugs. In the USA, studies have shown that approval process of high-risk medical devices was often based on insufficiently robust studies, suggesting that evidence prior to marketing may not be adequate. This study aimed to ascertain level of evidence available for IMDs access to reimbursement in France.
  
  
  METHODS
  The objective was to examine the scientific evidence used for IMDs assessment by the French National Authority for Health. We collected all public documents summarising supportive clinical data and opinions concerning IMDs issued in 2008. An opinion qualifies the expected benefit (EB) of the IMD assessed as sufficient or insufficient, and if sufficient, the level of improvement of the expected benefit (IEB) on a scale from major (level I) to no improvement (level V). For each opinion, the study with the highest level of evidence of efficacy data, and its design were collected, or, where no studies were available, any other data sources used to establish the opinion.
  
  
  RESULTS
  One hundred and two opinions were analysed, with 72 reporting at least one study used for assessment (70.6%). When considering the study with the highest level of evidence: 34 were clinical non-comparative studies (47.2%); 29 were clinical comparative studies of which 25 randomised controlled trials (40.3%); 5 were meta-analyses of randomised controlled trials (6.9%); and 4 were systematic literature reviews (5.6%). The opinions were significantly different according to the study design (p < 0.001). The most frequent design for insufficient EB, IEB level V and IEB level IV was a non-comparative study (10/19, 52.6%; 15/24, 62.5%; and 8/15, 53.3%; respectively). For the 30 opinions with no supporting clinical study, 16 (53.3%) were based on an expert-based process, 9 (30.0%) were based on the conclusions of a previous opinion (all concluding IEB level V), and 5 (16.7%) reported no data (concluding insufficient EB for 4 and IEB level V for 1).
  
  
  CONCLUSIONS
  This study confirmed that level of evidence of clinical evaluation of IMDs is low and needs to be improved.
authors.affiliation: Hospices Civils de Lyon, Pôle Information Médicale Evaluation Recherche, Unité de Recherche Clinique, Lyon, 69003, France. laure.huot@chu-lyon.fr
authors.forename: Laure
authors.initials: L
authors.lastname: Huot
authors.forename: Evelyne
authors.initials: E
authors.lastname: Decullier
authors.forename: Karen
authors.initials: K
authors.lastname: Maes-Beny
authors.forename: Francois R
authors.initials: FR
authors.lastname: Chapuis
mesh_terms: D005602:France; D006077:Government Agencies; D006801:Humans; D015201:Meta-Analysis as Topic; D019736:Prostheses and Implants / Q000191:economics; D016032:Randomized Controlled Trials as Topic; D012051:Reimbursement Mechanisms; D013673:Technology Assessment, Biomedical