Potential biases influencing interpretation of data from worldwide spontaneous ADR reports

Abstract

The collection, tabulation, interpretation and reporting of safety data on marketed drugs constitute a major function for any phar­maceutical company. This activity is particularly challenging for a multinational organization when widely used therapies such as NSAIDs are involved. While spontaneous adverse reaction report­ing systems managed by companies and regulators alike might act as an alerting mechanism for unusual findings, especially rare but serious events, attempts are often made to use the same data to compare side-effect incidences between drugs. The diverse and complex medical, regulatory and socio-economic environments operating in different parts of the world often severely limit the validity of intercountry comparisons even on the same drug. For example, the relative rates of spontaneous ADR reporting based on estimated usage of piroxicam over comparable periods following in­troduction in Germany, the US, the UK and Sweden was 1 : 3 : 6 : 10, respectively.