A randomized trial of a new asthma medication in 400 patients shows no difference in FEV1 decline (primary endpoint: -120 mL/year in both groups; p=0.18). Investigators perform 40 unplanned subgroup analyses and report a significant benefit in left-handed women older than 70 years (n=12; p=0.04), with no prior mechanistic hypothesis. Baseline characteristics were balanced between groups. Which statistical problem most directly threatens validity of this subgroup finding?

  1. A)Data dredgingGABARITO
  2. B)Lead time bias
  3. C)Spectrum bias
  4. D)Confounding by indication
  5. E)Healthy worker effect

Explicação

Data dredging, also called p hacking, occurs when many unplanned analyses are performed until a statistically significant result appears by chance. The more comparisons that are made, the greater the false positive risk. Post hoc subgroup findings should there... Ver explicação completa e trilha adaptativa →

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