clinical trials. Non-serious adverse events are typically captured separately at a level lower than pharmacovigilance. AE and SAE information, which may also include relevant information from the patient's medical background, are reviewed and assessed for both causality and degree of seriousness by the study investigator. This information is forwarded to a sponsoring entity (typically a pharmaceutical company or academic medical center) that is responsible for the reporting of this information, as appropriate, to drug regulatory authorities. Spontaneous reporting Spontaneous reports are termed spontaneous as they take place during the clinician's normal diagnostic appraisal of a patient, when the clinician is drawing the conclusion that the drug may be implicated in the causality of the event. Spontaneous reporting system (SRS) relies on vigilant physicians and other healthcare professionals who not only generate a suspicion of an adverse drug reaction, but also report it. It is an important source of regulatory actions such as taking a drug off the market or a label change due to safety problems. Spontaneous reporting is the core data-generating system of international pharmacovigilance, relying on healthcare professionals (and in some countries consumers) to identify and report any adverse events to their national pharmacovigilance center, health authority (such as the European Medicines Agency or FDA), or to the drug manufacturer itself. Spontaneous reports are, by definition, submitted voluntarily although under certain circumstances these reports may be encouraged, or "stimulated", by media reports or articles published in medical or scientific publications, or by product lawsuits. In many parts of the world adverse event reports are submitted electronically using a defined message standard. One of the major weaknesses of spontaneous reporting is that of under-reporting, where, unlike in clinical trials, less than 100% of those adverse events occurring are reported. Further complicating the assessment of adverse events, AE reporting behavior varies greatly between countries and in relation to the seriousness of the events, but in general probably less than 10% (some studies suggest less than 5%) of all adverse events that occur are actually reported. The rule-of-thumb is that on a scale of 0 to 10, with 0 being least likely to be reported and 10 being the most likely to be reported, an uncomplicated non-serious event such as a mild headache will be closer to a "0" on this scale, whereas a life-threatening or fatal event will be closer to a "10" in terms of its likelihood of being