A crossover trial compares two analgesics. After the first treatment period, a 2-week washout period is included before crossing over to the other treatment. The purpose of the washout period is primarily to:
- A Eliminate the carryover effect of the first treatment ✓
- B Reduce participant dropout
- C Allow blinding of the participants
- D Increase the power of the study
Correct answer: A. Eliminate the carryover effect of the first treatment
Explanation
In crossover trials, the washout period is used to eliminate the residual effect (carryover effect) of the first intervention before starting the second. If drug effects persist into the second period, the comparison between treatments is confounded. The washout duration is typically 5 half-lives of the drug.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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