Spontaneous adverse drug reaction (ADR) reporting is the mainstay of national and international drug safety evaluation in the post-approval phase. A major criticism of the method has been a high, but essentially unquantifiable, level of under-reporting by doctors. A direct comparison has been made between spontaneous ADR reporting and an observational event monitoring system for a group of more than 44 000 patients receiving one or other of a group of seven new drugs. The data suggests that underreporting by the spontaneous system may be as high as 98% for several clinical events believed to be associated with drug treatment.

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The New England Journal of Medicine 358 (2008) 1760-1761. doi:10.1056/NEJMc07084752016-03-04T18:46:15

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Crisis in sickle cell disease (SSD) patients is associated with reproducible sequential hemostatic changes indicative of intravascular fibrin formation and marked disturbance of platelet economy. With crisis onset, plasma high molecular weight fibrin(ogen) complexes are elevated and there is a transient fall in platelets. Subsequently fibrinogen and platelet counts rise, reaching their peaks respectively one and two weeks alter onset. Three SSD patients have been followed by weekly clinical and laboratory examinations for a two year control and a two year prophylactic treatment period (aspirin 650 mg, dipyridamole 50 mg b.d.). Patient symptomatic status was classified weekly as 1 (asymptomatic) through 4 (hospitalized). Increase in fibrinogen concentration was significantly correlated with patient disease status. While on treatment, the patients were asymptomatic or mildly symptomatic for 85% of the time compared to 73% of the control time.Analysis of the clinical status data (2 × n Chi square) showed a statistically significant difference in favor of the treatment (p < 0.0l) and the time spent in hospital was significantly reduced during treatment (p < 0.02).