In a clinical trial, the calculated p-value is 0.04. A 95% confidence interval for the mean difference is reported as (0.2 to 4.8 units). Which statement is most accurate about the relationship between p-value and confidence interval in this context?

• A The p-value and CI provide redundant information and either alone is sufficient
• B The p-value proves the treatment is clinically effective; the CI is only for statistical purposes
• C Since CI excludes zero, the null hypothesis is accepted
• D The CI is more informative than the p-value as it quantifies the magnitude and precision of the effect ✓

Explanation

A confidence interval provides more information than a p-value: it indicates the direction, magnitude, and precision of the effect estimate. The p-value only tells whether the result is statistically significant; it does not convey effect size. A CI that excludes zero (or the null value) corresponds to p < 0.05, confirming statistical significance. However, statistical significance does not equal clinical significance—the effect size must also be assessed. The null hypothesis is rejected (not accepted) when CI excludes zero.

Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.