9. Epidemiology/pharmacoepidemiology an integral part of Pharmacovigilance
Both epidemiology and pharmacoepidemiology support pharmacovigilance in addressing the safety data of routine pharmacovigilance services, in order to better understand their relevance to patients’ use of medicines in real life. Epidemiology information is included in what is known as the “Safety Specification” for each new medicine. It is part of the mandatory Risk Management Plan and describes the safety profile of the medicine, and what is uncertain and what information is missing. Preparing the Risk Management Plan itself is one element of a pharmacovigilance service.
The Risk Management Plan includes a Pharmacovigilance Plan aiming to provide more and better information about the known risks associated with a medicine, as well as to fill existing gaps in safety knowledge that was missing from clinical trials. Specifically, epidemiological information about the disease to be treated is critically important to understand what will be seen when the patient receives a therapy in real world setting and often for a longer time. For example, in what ethnic groups does this disease occur, how old are the patients, and of what gender? What other illnesses are common in these patients? What other medicines are they likely to take? How would the disease develop over time if untreated? In addition, pre-marketing studies (clinical trials) are generally not large enough to detect very rare adverse reactions to a medicine or long enough to discover new safety signals and often exclude important groups of people who will be users of a medicine.
All of this information may be the subject of pharmacoepidemiology studies – often in large populations of patients receiving the medicine post-approval (post-marketing) –allowing to follow up patients over time outside a clinical trial setting.
In addition, post-marketing epidemiologic studies can examine the effectiveness of a newly released medicine relative to a similar medicine for the same indication. This type of research is called comparative effectiveness research.