Use of medical terminologies to describe adverse event terms in ClinicalTrials.gov

Article type
Year
Authors
Pranic S1, Mahmic-Kaknjo M1, Marusic A1
1The Croatian Cochrane Branch at the University of Split School of Medicine, Croatia
Abstract
Objective: To describe the type of medical terminology used and variability of adverse event terms in ClinicalTrials.gov in context of mandates by the Food and Drug Administration Amendments Act of 1997 to promote transparency surrounding reporting of trial data.

Study Design and Setting: Cross-sectional study on safety and efficacy trials in ClinicalTrials.gov for common drug classes: antidepressants, analgesics or anesthetics, antidepressants, anti-allergics, anti-infectives, enzyme inhibitors, and anti-inflammatory, antineoplastic, hypoglycemic, neuromuscular agents.

Methods: Registered and completed clinical trials with adverse events between 2009 and 2012. We identified trials that studied the 10 drug categories from safety and efficacy trials. We excluded trials without a drug intervention or adverse events.

Results: Out of 93 trials that studied drugs, pain was most studied (n = 5, 5.4%), followed by major depressive disorder and acne vulgaris, (both n = 4, 4.3%). Most trials were randomized (n = 63, 67.7%). MedDRA was the most commonly used (n = 30, 32.3% and n = 45, 48.44%) dictionary for serious and other adverse events (SAEs and OAEs), respectively. Predominantly, 67 (72%) trials reported OAEs, whereas 42 (45.2%) reported SAEs. The majority of drugs were an FDA indication (n = 51, 54.8%). Omitted medical terminology sources were 10 (10.8%) for trials with SAEs and 18 (19.4%) for OAEs. Of 236 lay terms for both SAEs and OAEs, the same lay term defined up to three different adverse events in 11 (11.8%) and 69 (74.2%) trials, respectively.

Conclusions: MedDRA was predominantly used to define adverse events from safety and efficacy drug trials. Variation in the use of multiple terms to convey the same adverse event term was minimal. However, many studies failed to provide a source dictionary. Without a standardized dictionary or version required by ClinicalTrials.gov, there may be a reduction in the comparability of adverse events across studies. Administrators at ClinicalTrials.gov may consider the peremptory use of MedDRA or lay terms.