John Parkinson is a Data and Pharmaco-epidemiology Consultant. He previously worked as Director of the Clinical Practice Research Datalink (CPRD) at the MHRA, which developed out of the General Practice Research Database (GPRD) and NIHR Research Capability Programme. He has been instrumental in enabling record linkage of NHS data and of its wide use in the many aspects of pharmacoepidemiology as well as providing input to the pharmaceutical industry on studies and types of studies that companies may find helpful in their quest to make available effective and safe medicines