A study compares pain scores (measured on a 0-10 ordinal scale) before and after physiotherapy in 15 patients. The differences are not normally distributed. The most appropriate test to determine if physiotherapy significantly changed pain scores is:
- A Wilcoxon signed-rank test ✓
- B Paired t-test
- C Mann-Whitney U test
- D Independent samples t-test
Correct answer: A. Wilcoxon signed-rank test
Explanation
The Wilcoxon signed-rank test is the non-parametric equivalent of the paired t-test, used for paired data when differences are not normally distributed. Mann-Whitney U test is for two independent groups. Paired t-test requires normally distributed differences. Independent t-test is for unpaired data. The paired nature and non-normality together determine the choice.
Reference: B K Mahajan's Methods in Biostatistics, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.