title: Coding of adverse events of suicidality in clinical study reports of duloxetine for the treatment of major depressive disorder: descriptive study.
abstract: OBJECTIVE
  To assess the effects of coding and coding conventions on summaries and tabulations of adverse events data on suicidality within clinical study reports.
  
  
  METHODS
  Systematic electronic search for adverse events of suicidality in tables, narratives, and listings of adverse events in individual patients within clinical study reports. Where possible, for each event we extracted the original term reported by the investigator, the term as coded by the medical coding dictionary, medical coding dictionary used, and the patient's trial identification number. Using the patient's trial identification number, we attempted to reconcile data on the same event between the different formats for presenting data on adverse events within the clinical study report.
  
  
  METHODS
  9 randomised placebo controlled trials of duloxetine for major depressive disorder submitted to the European Medicines Agency for marketing approval.
  
  
  METHODS
  Clinical study reports obtained from the EMA in 2011.
  
  
  RESULTS
  Six trials used the medical coding dictionary COSTART (Coding Symbols for a Thesaurus of Adverse Reaction Terms) and three used MedDRA (Medical Dictionary for Regulatory Activities). Suicides were clearly identifiable in all formats of adverse event data in clinical study reports. Suicide attempts presented in tables included both definitive and provisional diagnoses. Suicidal ideation and preparatory behaviour were obscured in some tables owing to the lack of specificity of the medical coding dictionary, especially COSTART. Furthermore, we found one event of suicidal ideation described in narrative text that was absent from tables and adverse event listings of individual patients. The reason for this is unclear, but may be due to the coding conventions used.
  
  
  CONCLUSIONS
  Data on adverse events in tables in clinical study reports may not accurately represent the underlying patient data because of the medical dictionaries and coding conventions used. In clinical study reports, the listings of adverse events for individual patients and narratives of adverse events can provide additional information, including original investigator reported adverse event terms, which can enable a more accurate estimate of harms.
authors.affiliation: Nordic Cochrane Centre, Rigshospitalet Department 7811, Copenhagen, Denmark em@cochrane.dk.
authors.forename: Emma
authors.initials: E
authors.lastname: Maund
authors.affiliation: Nordic Cochrane Centre, Rigshospitalet Department 7811, Copenhagen, Denmark.
authors.forename: Britta
authors.initials: B
authors.lastname: Tendal
authors.affiliation: Nordic Cochrane Centre, Rigshospitalet Department 7811, Copenhagen, Denmark.
authors.forename: Asbjørn
authors.initials: A
authors.lastname: Hróbjartsson
authors.affiliation: Nordic Cochrane Centre, Rigshospitalet Department 7811, Copenhagen, Denmark Department of Infectious Diseases, Hvidovre University Hospital, Hvidovre, Denmark.
authors.forename: Andreas
authors.initials: A
authors.lastname: Lundh
authors.affiliation: Nordic Cochrane Centre, Rigshospitalet Department 7811, Copenhagen, Denmark.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Gøtzsche
mesh_terms: D018759:Adrenergic Uptake Inhibitors / Q000009:adverse effects* / Q000627:therapeutic use; D016907:Adverse Drug Reaction Reporting Systems / Q000592:standards*; D000928:Antidepressive Agents / Q000009:adverse effects* / Q000627:therapeutic use; D059019:Clinical Coding; D003865:Major Depressive Disorder / Q000188:drug therapy*; D000068736:Duloxetine Hydrochloride; D006801:Humans; D016032:Randomized Controlled Trials as Topic / Q000592:standards*; D017367:Selective Serotonin Reuptake Inhibitors / Q000009:adverse effects* / Q000627:therapeutic use; D013405:Suicide; D013876:Thiophenes / Q000009:adverse effects* / Q000627:therapeutic use
chemical_list: D018759:Adrenergic Uptake Inhibitors; D000928:Antidepressive Agents; D000068736:Duloxetine Hydrochloride; D017367:Selective Serotonin Reuptake Inhibitors; D013876:Thiophenes