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document
Statistical aspects of early termination in the beta-blocker heart attack trial . The Beta-Blocker Heart Attack Trial was a randomized double blind controlled trial comparing propranolol with placebo in 3837 patients with a recent myocardial infarction . The trial was terminated on recommendation of the Policy and Data Monitoring Board 9 months before the scheduled closing date . The propranolol group , at the time of the decision , had a 26 % lower mortality ( z = 2.82 ) . Many issues were considered in this decision . These included the magnitude of the overall results ; consistency of results across subgroups , clinical centers , and cause of death ; and completeness of follow-up . Two basic statistical methods were used in declaring the overall mortality results significant . The first method evaluated the current survival data taking into account the issue of repeated significance testing . The second method evaluated whether the observed trend was so impressive that the conclusion was unlikely to change even if the trial should continue to the scheduled end . These two methods , as well as other considerations led to the recommendation to discontinue the trial .
78382
Intervention_Pharmacological
propranolol
78383
Intervention_Control
placebo
78384
Intervention_Pharmacological
propranolol
78385
Outcome_Mortality
mortality
78386
Outcome_Mortality
overall mortality
78387
Outcome_Mortality
survival data
78388
Participant_Sample-size
3837