Table 1

Odds ratio (OR) analysis of haemorrhagic transformation in trials of thrombolytic agents in acute ischaemic stroke

TrialAll types of haemorrhagesSymptomatic haemorrhagesFatal haemorrhages
Agent oddsPlacebo oddsOR (agent/placebo)95% CIAgent oddsPlacebo oddsOR (agent/placebo)95% CIAgent oddsPlacebo oddsOR (agent/placebo)95% CI
NINDS I+II34/27811/3013.31.66–6.7320/2922/31010.62.46–45.829/3031/3119.21.16–73.36
  • The response to rt-PA or streptokinase treatment is shown by the OR for different trials. The OR is measured by dividing the odds for a certain outcome event of the rt-PA group (numerator) by the odds for this event of the placebo group (denominator). An OR of 1 means that the thrombolytic agent did not affect the incidence of haemorrhages. If the 95% CI does not cover unity, the incidence of haemorrhages is significantly enhanced or diminished by the treatment. — = not available. In all trials a significant increase in all types of haemorrhages, of symptomatic haemorrhages, and of fatal haemorrhages was found. The NINDS trial showed the highest relative risk for fatal haemorrhages.