Question 1

A clinical trial compared Ranolazine to placebo for the primary end point of recurrent ischemia. The hazard ratio (HR) was 0.87 with a 95% confidence interval (CI) of 0.76–0.99 and a p-value of 0.03. What does this result suggest about the effectiveness of Ranolazine?

Accepted Answer

Ranolazine significantly reduces the risk of recurrent ischemia compared to placebo.

Question 2

Based on the table, what is the interpretation of the hazard ratio for cardiovascular death (HR = 0.92, 95% CI: 0.69–1.22, p = 0.56) when comparing Ranolazine to placebo?

Accepted Answer

There is no statistically significant difference in cardiovascular death between Ranolazine and placebo.

Question 3

If the confidence interval for a hazard ratio includes 1, what does this imply about the statistical significance of the result?

Accepted Answer

The result is not statistically significant.

Question 4

For the outcome 'MI (myocardial infarction)', the hazard ratio is 0.99 (95% CI: 0.77–1.28, p = 0.94). What is the best interpretation?

Accepted Answer

Ranolazine does not significantly affect the risk of myocardial infarction compared to placebo.

Question 5

Which of the following outcomes showed a statistically significant reduction with Ranolazine compared to placebo, based on the table?

Accepted Answer

Recurrent ischemia

Question 6

The p-value for the outcome 'Recurrent ischemia with electrocardiographic changes' is 0.03. What does this indicate?

Accepted Answer

There is a statistically significant difference between Ranolazine and placebo for this outcome.

Question 7

If a hazard ratio is less than 1 and the p-value is less than 0.05, what does this generally indicate about the treatment?

Accepted Answer

The treatment is associated with a statistically significant reduction in the event rate.

Question 8

For the outcome 'Hospitalization for heart failure', the hazard ratio is 0.97 (95% CI: 0.67–1.41, p = 0.87). What does this suggest?

Accepted Answer

Ranolazine does not significantly affect the risk of hospitalization for heart failure.

Question 9

Which of the following best describes the meaning of a hazard ratio (HR) of 0.87 for recurrent ischemia?

Accepted Answer

The rate of recurrent ischemia is 13% lower in the Ranolazine group compared to placebo.

Question 10

If the p-value for an outcome is 0.03, what is the probability that the observed effect is due to chance?

Accepted Answer

3%

Question 11

Which outcome in the table has a hazard ratio closest to 1, and what does this imply?

Accepted Answer

MI (myocardial infarction); Ranolazine has no effect compared to placebo.

Question 12

A hazard ratio of 0.87 with a 95% CI of 0.76–0.99 for recurrent ischemia means:

Accepted Answer

Ranolazine significantly reduces recurrent ischemia, and the true effect is likely between a 1% and 24% reduction.

Question 13

If a clinical trial reports a hazard ratio of 0.87 (95% CI: 0.76–0.99) and a p-value of 0.03 for an outcome, what can be concluded?

Accepted Answer

The treatment significantly reduces the risk of the outcome.

Question 14

Which of the following is true about the effect of Ranolazine on 'Failure of therapy' based on the table (HR = 0.97, 95% CI: 0.87–1.09, p = 0.62)?

Accepted Answer

There is no statistically significant difference between Ranolazine and placebo.

Question 15

What does a p-value of 0.03 indicate in the context of this clinical trial?

Accepted Answer

There is a 3% probability that the observed effect is due to chance.

Biostatistics and Clinical Trial Interpretation: Key Concepts and Applications

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