Trends and Patterns of Adverse Drug Reaction Reporting in Sierra Leone: A Retrospective Analysis of VigiFlow Data...

Adverse drug reactions (ADRs) present significant obstacles for healthcare systems, impacting both patient safety and the effectiveness of treatments. Despite this, there is a scarcity of research on ADR reports in Sierra Leone, especially over long periods. This study aims to investigate the characteristics and reporting patterns found in the Sierra Leone pharmacovigilance database managed through VigiFlow.

This study analyzes reports of ADRs from Sierra Leone's national pharmacovigilance database, VigiFlow, spanning from January 2008 to December 2022. Data collected included patient demographics (age, sex), reporter characteristics (type of reporter, year of reporting), and ADR-specific information (suspected medication, indication, ADR types (MedDRA), seriousness, outcome, actions taken, and time to onset), and completeness score. Descriptive statistics, chi-square tests, and the Kruskal-Wallis test with Bonferroni-adjusted post hoc tests were applied to identify patterns and associations within the dataset.

A total of 3381 individual case safety reports (ICSRs) were analysed. The majority of reports involved females (54.7%) and adults aged 18 to 44 years (51.4%). Reporting rates increased after 2015, peaking in 2021. The most frequently implicated medications were anti-infective drugs (40.7%) and antiparasitic medicines (34.1%), particularly ivermectin, albendazole, and vaccines for cholera and yellow fever. The most commonly reported ADRs were headache (13.2%), fever (12.2%), and diarrhoea (7.6%), primarily affecting the nervous system and general disorder classes. Pharmacists were responsible for 39.0% of reports and achieved the highest completeness score, with a mean of 0.78. Age was significantly associated with the seriousness, outcome, and onset time of ADRs (p < 0.001), while gender was significantly associated with onset time (p = 0.007).

ADR reporting in Sierra Leone has improved, with antiparasitic medicines and vaccines most frequently linked to reactions. Sustaining progress requires enhanced training, public engagement, and strengthened active pharmacovigilance to ensure completeness and patient safety.