Systolic blood pressure is recorded in 30 hypertensive patients before starting an exercise programme and again after 12 weeks in the same patients. The differences are normally distributed. Which test is most appropriate to assess whether the programme changed blood pressure?
- A Independent samples t-test
- B Paired t-test ✓
- C Chi-square test
- D One-way ANOVA
Correct answer: B. Paired t-test
Explanation
The same subjects are measured twice, producing matched pairs of observations, and the differences are normally distributed. The paired t-test compares the mean of within-subject differences against zero and uses each patient as their own control, eliminating inter-individual variability. An independent t-test would be appropriate only if two separate groups were compared, and ANOVA applies to three or more groups.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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