A cardiologist wants to study the effect of an antihypertensive drug. He notes down the initial systolic blood pressure (mmHg) of 50 patients and then administers the drug to them. Which of the following is most appropriate statistical test of significance to measure the change in blood pressure after a weeks treatment ?

**Core Concept**
The cardiologist wants to measure the change in blood pressure after administering an antihypertensive drug to a group of patients. This involves comparing the initial and final blood pressure readings of each patient, requiring a statistical test to assess the significance of the observed change.

**Why the Correct Answer is Right**
The most suitable statistical test for this scenario is the **paired t-test**. This test is used to compare the means of a continuous variable (in this case, blood pressure) between two related groups, such as the initial and final readings of the same patients. The paired t-test takes into account the paired nature of the data, allowing for a more accurate assessment of the change in blood pressure after treatment.

**Why Each Wrong Option is Incorrect**
**Option A:** The **ANOVA (Analysis of Variance)** test is used to compare the means of three or more groups, which is not applicable in this scenario where we are comparing the same group of patients before and after treatment.
**Option B:** The **Chi-Square test** is used for categorical data, which is not suitable for comparing continuous data like blood pressure readings.
**Option C:** The **Wilcoxon Signed-Rank test** is a non-parametric alternative to the paired t-test, but it is not the most appropriate choice when the data meets the assumptions for a parametric test like the paired t-test.

**Clinical Pearl / High-Yield Fact**
When comparing paired data, it's essential to use a paired test to account for the paired nature of the data, which can lead to more accurate and reliable results.

**Correct Answer:** C. Wilcoxon Signed-Rank test

✓ Correct Answer: A. Paired t-test