Improper post-marketing trials/studies

After a product has been released into a health system for use it must be monitored to ensure there are no unknown risks and safety issues. For medicines, the pharmaceutical industry voluntarily conducts most of the post-market surveillance. Arguably, there is a potential conflict of interest if suppliers are conducting trials on their own products, as they may be encouraged to hide risks and promote the product through the design and conduct of the trial/study.