Risk
The probability of harm being caused; the probability (chance, odds) of an occurrence.
Absolute risk
Risk in a population of exposed persons; the probability of an event affecting members of a particular population (e.g. 1 in 1 000). Absolute risk can be measured over time (incidence) or at a given time (prevalence).
Attributable risk
The risk associated with exposure to the monitored medicine(s). This is calculated by subtracting the background risk without the medicine(s) (reference
risk) from the risk measured while taking the medicine(s).
Relative risk
Ratio of the risk in an exposed population (absolute risk) and the risk in an unexposed population (reference risk). Relative risk is the result of a relative comparison between outcome frequency measurements, e.g. incidences.
Reference risk
Risk in a population of unexposed persons; also called baseline risk. Reference risk can be measured over time (incidence) or at a given time (prevalence). The unexposed population refers to a reference population, as closely comparable to the exposed population as possible, apart from the exposure.
Serious adverse event or reaction
A serious adverse event or reaction is any untoward medical occurrence that at any dose:
• results in death;
• results in inpatient hospitalization or prolongation of existing hospitalization;
• results in persistent or significant disability or incapacity;
• is life-threatening;
• is a congenital anomaly/birth defect.
To ensure that there is no confusion or misunderstanding about the difference between the terms “serious” and “severe”, the following note of clarification
is provided:
The term “severe” is not synonymous with serious. In the English language, “severe” is used to describe the intensity (severity) of a specific event (as in mild, moderate or severe); the event itself, however, may be of relatively minor medical significance (such as severe headache). Seriousness (not severity) which is based on the outcome of the event on the patient or action
criteria serves as the guide for defining regulatory reporting obligations.
Signal
Reported information on a possible causal relationship between an adverse event and a drug, the relationship being unknown or incompletely documented previously. Usually more than a single report is required to generate a signal, depending upon the seriousness of the event and the quality of the information. The publication of a signal usually implies the need for some kind of review or action.