A data safety monitoring board reviews efficacy outcomes every 3 months during a large stroke prevention trial enrolling 2,400 patients. The biostatistician notes that repeated looks at accumulating data—currently showing a trend toward reduced ischemic stroke incidence (p=0.08 at interim analysis)—increase the chance of a false positive result unless the significance threshold is adjusted downward. No safety signals have emerged. Which statistical concept is being described?
- A)Alpha spendingGABARITO
- B)Regression to the mean
- C)Effect modification
- D)Verification bias
- E)Allocation concealment
Explicação
When investigators perform multiple interim analyses, the overall probability of a type I error increases unless alpha is controlled across repeated looks. Alpha spending approaches distribute the allowable false positive rate over the course of the trial. Thi... Ver explicação completa e trilha adaptativa →