Adverse Drug Reaction Onsets in Uganda's VigiBase ® : Delayed International Visibility, Data Quality and Illustrative Signal Detection Analyses.

Introduction: Developing countries can improve their pharmacovigilance systems by analysing their own medication safety data.

Objective: The aims of this study were to characterize Uganda's reported adverse drug reaction (ADR) onsets in 2012-2015 that were registered on VigiBase® by 31 December 2017, to document delays in international visibility and the influence of covariates on this delay from ADR onsets in 2013 + 2014, to examine data quality, and to illustrate analytical approaches for safety data, particularly for patients receiving antiretroviral therapy (ART).

Methods: International delay was defined as elapsed time from complete ADR onset date to entry date on VigiBase® , with covariates examined using Cox proportional hazards regression. Simple random sampling was used to locate the paper-based ADR forms for data quality assurance. Disproportionality for signal detection focused on serious singleton ADR onsets in patients receiving ART.

Results: Uganda's VigiBase® had 1018 patient entries with complete ADR onset dates: 260 in 2012, 293 in 2013, 305 in 2014 and 160 in 2015. Only 16% (154/953) of ADR onsets in 2012-2015 were in patients aged < 20 years for whom randomly sampled ADR forms were less fully completed; 87% (889/1018) comprised a singleton sign/symptom; half were serious. Median delay from ADR onset to international visibility was 11 months for ADR onsets in 2013 + 2014, and longest for healthcare professionals other than pharmacists and physicians. Disproportionality for serious ADR onsets in patients receiving ART included anaemia with zidovudine, renal impairment with tenofovir, Stevens-Johnson syndrome with nevirapine and skin rash with efavirenz.

Conclusions: Barely one ADR onset per day was registered on VigiBase® from those submitted to Uganda's National Pharmacovigilance Centre during 2012-2014; only one in six was from patients aged < 20 years. Paediatric pharmacovigilance requires more emphasis in Uganda. Delays from reported ADR onset to international visibility on VigiBase® need to reduce dramatically. Quality assurance revealed rectifiable data entry deficits. Signal detection performed well for patients receiving ART.