Safety Signals Using Proportional Reporting Ratios From Company and Regulatory Authority Databases

Databases held by regulatory agencies and by pharmaceutical companies may be used to detect safety signals. We compared the utility of a company safety database with those from two large regulatory authority databases in assessing potential safety signals in order to understand how the different sources may be used. Proportional reporting ratios (PRRs) were calculated from the company database for historical events that had led to changes in prescribing information (PI) and were compared to PRRs calculated in external databases (the US Food and Drug Administration Freedom of Information database and the UK Adverse Drug Reactions On-line Information Tracking database). For most events there was agreement between all of the databases. For some selected historical events we have shown that if a company database is large enough and a wide range of therapeutic areas is covered then there is insignificant difference between PRRs calculated from the company database and larger external databases.