In recent years, medicines agencies have tended to make the pre-authorisation clinical evaluation of drugs less stringent, claiming that the evaluation can be completed post authorisation. Germany’s experience shows that this is deceptive.

The authors of a study investigated the post-authorisation studies requested from pharmaceutical firms by the German public authorities. These studies are supposed to identify in daily practice adverse effects not detected by the initial trials. Between 2008 and 2010, 558 post-authorisation studies were registered in Germany.

Much of the descriptive documentation in these studies was very vague, and 72% did not specify the study protocol.

In 50% of the studies, each doctor monitored fewer than 8 patients.

The authors of the study found no adverse reaction reports related to these 558 studies in the German pharmacovigilance database. Only 5 studies resulted in a scientific publication.

The authors of the study conclude that most of these studies are not designed to advance knowledge, but are seeding marketing studies aimed at encouraging prescribing habits in doctors by including them in pseudo-studies.

"A bird in hand is worth two in the bush", so the saying goes, and this is borne out by the facts: large-scale evaluation of drugs prior to authorisation, which involves identifying potentially severe adverse effects, is better than post-authorisation marketing "studies".

©Prescrire 1 January 2018

"Post-marketing studies: deception on a large scale" Prescrire Int 2018; 27 (189): 25. (Pdf, free).