In an RCT comparing two drugs, despite randomisation, the drug-A group has more smokers at baseline. This imbalance is BEST addressed by:
- A Increasing the sample size post-hoc
- B Stratified analysis or multivariate regression to control for smoking ✓
- C Restricting the analysis to non-smokers
- D Repeating the randomisation
Correct answer: B. Stratified analysis or multivariate regression to control for smoking
Explanation
Residual confounding despite randomisation (especially in small trials) is controlled analytically by stratified analysis or multivariate regression, adjusting for the confounder (smoking) in the final analysis. Post-hoc sample size increase is not feasible; restricting to non-smokers loses data and generalisability; re-randomisation is not ethical once the trial has begun.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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