In all, around 10 per cent of serious adverse reactions, including death, are not being reported to America's drug regulator, the Food and Drug Administration (FDA), within the statutory 15-day time-frame, if at all.
The under-reporting seems to be the fault of the drug company as much as the doctor. In fact, mechanisms within drug companies appear to be in place that delay the reporting, or conceal it altogether.
Researchers from the University of Minnesota school of medicine say they have uncovered "striking evidence" that drug companies delay the reporting of serious adverse reactions to the FDA-and especially if the patient has died.
The number of unreported adverse reactions also includes those classified as 'unexpected', in which the patient suffered a reaction that has not before been noted.
(Source: JAMA Internal Medicine, 2015; doi: 10.1001/jamainternmed.2015.3565)