(C-188) Completeness of Spontaneously Reported Adverse Drug Reactions in Four Developed Countries.

Background: The completeness of spontaneous adverse drug reaction (ADR) reports is essential for detecting adverse event signals. Previous studies have highlighted variations in the completeness of information reported to regulators and the importance of consumers in providing important safety information on medicine use. However, it remains unclear which information is well-reported and which information is most frequently omitted in ADR reporting databases.

Objectives: To assess the level of completeness of information of ADR reports in the freely accessible ADR reporting databases of the United States of America (USA), Canada, the United Kingdom (UK) and Denmark.

Methods: The study was conducted using ADR reports from the Canada Vigilance Adverse Reaction Online Database, the Food and Drug Administration Adverse Event Reporting System (FAERS) of the USA, the Yellow Card Scheme of the UK, and the Danish Medicines Agency’s Adverse Drug Reaction Database covering the period 2014 to 2023. The variables used to evaluate the completeness of ADR reports were selected based on the vigiGrade completeness tool. Descriptive statistics assessed the completeness of information in each ADR report, while chi-square tests analysed differences in completeness by seriousness of report.

Results: A total of 290,079 individual case safety reports (ICSRs) were analysed; 4,289 from Canada, 269,763 from FAERS, 13,624 from the UK and 2,403 from the Danish ADR reporting database. The most frequently completed information was the primary reporter, with nearly 100% completeness. The most frequently omitted information was the route of administration, with completion scores of 44% in the UK’s Yellow Card Scheme, 55% in the Danish ADR reporting database, and 58% in the Canadian ADR reporting database. In the FAERS, the event date was the most frequently omitted information with a completion rate of 50%. In the FAERS, UK, and Danish databases, serious ADR reports showed higher completeness for variables such as event date, age, sex, indication and route of administration (all p<0.001). However, in the Canadian database, non-serious reports had greater completeness for age, dose, indication and route of administration (all p<0.001), highlighting variability in reporting completeness across databases.

Conclusions: The completeness of information varies across different variables with information is frequently omitted for route of administration and event date. Enhancing awareness about providing complete information during ADR reporting is essential for collecting complete data and assessing signal detection.