title: Sildenafil (Viagra) for male erectile dysfunction: a meta-analysis of clinical trial reports.
abstract: BACKGROUND
  Evaluation of company clinical trial reports could provide information for meta-analysis at the commercial introduction of a new technology.
  
  
  METHODS
  Clinical trial reports of sildenafil for erectile dysfunction from September 1997 were used for meta-analysis of randomised trials (at least four weeks duration) and using fixed or dose optimisation regimens. The main outcome sought was an erection, sufficiently rigid for penetration, followed by successful intercourse, and conducted at home.
  
  
  RESULTS
  Ten randomised controlled trials fulfilled the inclusion criteria (2123 men given sildenafil and 1131 placebo). NNT or NNH were calculated for important efficacy, adverse event and discontinuation outcomes. Dose optimisation led to at least 60% of attempts at sexual intercourse being successful in 49% of men, compared with 11% with placebo; the NNT was 2.7 (95% confidence interval 2.3 to 3.3). For global improvement in erections the NNT was 1.7 (1.6 to 1.9). Treatment-related adverse events occurred in 30% of men on dose optimised sildenafil compared with 11% on placebo; the NNH was 5.4 (4.3 to 7.3). All cause discontinuations were less frequent with sildenafil (10%) than with placebo (20%). Sildenafil dose optimisation gave efficacy equivalent to the highest fixed doses, and adverse events equivalent to the lowest fixed doses.
  
  
  CONCLUSIONS
  This review of clinical trial reports available at the time of licensing agreed with later reviews that had many more trials and patients. Making reports submitted for marketing approval available publicly would provide better information when it was most needed, and would improve evidence-based introduction of new technologies.
authors.affiliation: Pain Research and Nuffield Department of Anaesthetics, University of Oxford, The Churchill, Headington, Oxford, UK. andrew.moore@pru.ox.ac.uk
authors.forename: R A
authors.initials: RA
authors.lastname: Moore
authors.forename: J E
authors.initials: JE
authors.lastname: Edwards
authors.forename: H J
authors.initials: HJ
authors.lastname: McQuay
mesh_terms: D007172:Erectile Dysfunction / Q000188:drug therapy*; D006801:Humans; D008297:Male; D010410:Penile Erection / Q000187:drug effects; D010726:Phosphodiesterase Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D010879:Piperazines / Q000009:adverse effects / Q000627:therapeutic use*; D011687:Purines; D016032:Randomized Controlled Trials as Topic; D000068677:Sildenafil Citrate; D013450:Sulfones
chemical_list: D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate