alleryMedical Researcher: Patients receiving Drug Z for hypertension exhibited a 25% lower incidence of stroke over three years compared to a control group receiving standard therapy. However, the trial researchers monitored Drug Z patients every two weeks, while control patients were examined only every six months. This discrepancy in monitoring frequency suggests that the reported difference in stroke incidence may be due to:
AConfounding by closer medical surveillance and timely intervention rather than the pharmacological efficacy of Drug Z itself.
BA placebo effect operating solely on the control group of patients.
CAn inherent biological difference in stroke susceptibility between young and elderly subjects.
DMeasurement error in recording blood pressure readings during biweekly clinic visits.
EA failure to obtain informed consent from participants enrolled in the standard therapy group.
Answer & Solution
Correct answer: A. Confounding by closer medical surveillance and timely intervention rather than the pharmacological efficacy of Drug Z itself.
Frequent biweekly visits allow physicians to detect and treat early signs of health crises (confounding by surveillance), which could account for the reduced stroke rate independently of the drug's chemical properties.
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