Signal detection aims to identify and describe possible harm to patients, related to their use of medicines. Signal detection is a core UMC activity.
UMC regularly screens VigiBase, the WHO global database of individual case safety reports (ICSRs), to find previously unrecognised or incompletely documented suspected adverse drug reactions (ADRs). With millions of ICSRs in VigiBase, the signal detection process has to rely on a combination of computerised data-mining methodology for selection of medicine-adverse effect combinations, and subsequent clinical evaluation of reports by members of the medical and scientific team.
First-pass statistical screening: VigiBase is periodically screened using vigiRank, a statistical signal detection method that prioritises drug-ADR combinations for manual assessment by their strength of evidence. vigiRank incorporates disproportionate reporting together with aspects related to the quality and content of individual reports. The purpose is to prioritise medicine-adverse effect combinations by their strength of evidence. In addition, certain selection criteria are applied in order to further prioritise the data and to focus on particular areas of interest, such as serious ADRs, newly marketed drugs, specific drug groups or specific patient populations.
Initial manual assessment: The prioritised medicine-adverse effect combinations are individually assessed by members of a multi-disciplinary team consisting of medical doctors, pharmacists, nurses, statisticians and data scientists. They identify medicine-adverse effect combinations needing further, in-depth assessment. The initial assessment consists of checking whether the adverse effect is already adequately covered in the product information; briefly reviewing the case series to exclude other more likely causes; and deciding on whether or not the combination should be further assessed.
In-depth manual assessment: Combinations needing in-depth assessment are reviewed, either by pharmacovigilance experts at UMC or by clinical experts in the UMC Signal Review Panel. VigiBase case reports are individually assessed and summarised, and the scientific literature is reviewed for additional evidence. Then a decision is made whether or not the strength of the case indicates that a signal should be formulated and communicated.
Signal communication: Signals are communicated via VigiLyze, which is available to the national pharmacovigilance centres participating in the WHO Programme for International Drug Monitoring. Since 2012, UMC signals are then also published in the WHO Pharmaceuticals Newsletter.