title: Review of company postmarketing surveillance studies.
abstract: OBJECTIVE
  To review postmarketing surveillance studies sponsored by the pharmaceutical industry since the introduction of voluntary guidelines in 1987 and to evaluate their contribution to monitoring drug safety.
  
  
  METHODS
  Retrospective analysis of the information submitted to the Medicines Control Agency on postmarketing surveillance studies.
  
  
  METHODS
  United Kingdom.
  
  
  METHODS
  Study designs, projected and actual sample sizes, provision of interim and final reports, number of suspected serious adverse reactions reported, identification of new drug safety hazards.
  
  
  RESULTS
  31 studies had been conducted under the guidelines, of which 27 were prospective and four retrospective. Nine studies had at least one comparator group, the remainder were uncontrolled. The median projected sample size for the studies was 5600 patients. Only five studies had achieved at least 75% of the projected sample size. 11 studies had been abandoned, predominantly because of difficulties in recruitment, and 15 were ongoing. One study had identified an important new safety hazard.
  
  
  CONCLUSIONS
  Company postmarketing surveillance studies have made only a limited contribution to the assessment of drug safety, principally because of weak study designs and difficulties in recruitment. The guidelines require modification to take this experience into account.
authors.affiliation: Medicines Control Agency, London.
authors.forename: P C
authors.initials: PC
authors.lastname: Waller
authors.forename: S M
authors.initials: SM
authors.lastname: Wood
authors.forename: M J
authors.initials: MJ
authors.lastname: Langman
authors.forename: A M
authors.initials: AM
authors.lastname: Breckenridge
authors.forename: M D
authors.initials: MD
authors.lastname: Rawlins
mesh_terms: D004345:Drug Industry; D064420:Drug-Related Side Effects and Adverse Reactions; D006801:Humans; D011358:Product Surveillance, Postmarketing / Q000379:methods*; D011446:Prospective Studies; D012107:Research Design; D012189:Retrospective Studies; D006113:United Kingdom