In a trial comparing a new antidiabetic drug with placebo, the null hypothesis states that:
- A The new drug is superior to placebo
- B The observed difference is due to a real treatment effect
- C There is no difference in mean HbA1c reduction between the two groups ✓
- D The sample size is adequate to detect a difference
Correct answer: C. There is no difference in mean HbA1c reduction between the two groups
Explanation
The null hypothesis always posits no difference between the groups being compared; significance testing attempts to reject it. Option A describes the alternative hypothesis, option B describes what rejecting the null would suggest, and option D relates to study power, not hypothesis formulation. A p-value is the probability of obtaining results at least as extreme as those observed if the null hypothesis were true.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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