12 Jun Major Depressive Disorder: How Well Does Coding Reflect Adverse Events?

MedicalResearch.com Interview with:
Emma Maund, PhD student
Nordic Cochrane Centre
Copenhagen, Denmark

MedicalResearch: What are the main findings of the study:

Answer: For statisticians to analyse adverse events recorded in a clinical trial, it is necessary that events described by the original investigators are coded to terms in a specialised medical coding dictionary. Our study assessed the effects of coding and coding conventions on summaries and tabulations of adverse events data on suicidality within clinical study reports of nine randomised controlled trials of duloxetine for the treatment of major depressive disorder. Trials used either the medical coding dictionary COSTART (Coding Symbols for a Thesaurus of Adverse Reaction Terms) or the larger and more recent dictionary MedDRA (Medical Dictionary for Regulatory Activities). We found suicides were clearly identifiable in all formats of adverse event data. Suicide attempts 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 in trials using COSTART where the closest matching term available was depression.

MedicalResearch: Were any of the findings unexpected:

Answer: Authors of systematic reviews mainly use tabulated coded data for the assessment of harms. It was therefore surprising to find that such data may not accurately represent the underlying individual patient data solely due to the coding dictionary and coding conventions used.

MedicalResearch: What should clinicians and patients take away from your report:

Answer: The use of coding dictionaries and coding conventions used may inadvertently obscure events that are important in summary tables of adverse event data.

MedicalResearch: What recommendation do you have for future research as a result of this study:

Answer: Our research highlights the need for independent researchers to have access to detailed data from trials, including original investigator reported terms of harms. Researchers with access to such data, particularly of older trials, should recode these terms using the latest version of MedDRA, which can enable a more accurate assessment of harms to be made. Researchers with access to tables of coded data of harms only should consider whether the coding dictionary and coding conventions used affect the robustness of their assessment.

Citation:

Coding of adverse events of suicidality in clinical study reports of duloxetine for the treatment of major depressive disorder: descriptive study

Maund E ,Tendal B ,Hróbjartsson A ,Lundh A ,Gøtzsche PC. Coding of adverse events of suicidality in clinical study reports of duloxetine for the treatment of major depressive disorder: descriptive study. BMJ 2014;348:g3555

Last Updated on December 21, 2014 by Marie Benz MD FAAD