Introducing triage logic as a new strategy for the detection of signals in the WHO Drug Monitoring Database

An important role for the WHO Programme for International Drug Monitoring is to identify signals of international drug safety problems as early as possible. The signal detection strategy, operated at the Uppsala Monitoring Centre (UMC), gave too many drug-adverse drug reaction (ADR) combinations for individual review. Therefore additional selection strategies were needed to improve the likely signal-to-noise ratio and for the UMC to complement the efforts of national centres in an efficient way.

The combinations database of the first quarter of 2001 was analysed using algorithms representing different strategies for finding relevant signals using triage logic.

The strategies that together gave a manageable number of combinations, i.e. around 600, for further consideration in a single quarter were the algorithms for 'Rapid reporting increase', 'Serious reaction and new drug' and 'Special interests'. These filters began to be used routinely on the combinations database in late 2001.

While stressing that human review is essential, triage strategies are useful when attempting analysis of large amounts of data. By definition, the use of triage strategies may exclude some potential signals from consideration, although the intention is to improve the chances of detection by focussing on areas of greatest importance.