FPGEE Biostatistics 2

Question 1

A clinical trial reports a 95% confidence interval for the difference in mean blood pressure reduction as (2.1, 8.4 mmHg). Which conclusion is most appropriate?

Accepted Answer

We are 95% confident the true difference lies between 2.1 and 8.4 mmHg

Answer

A 95% CI means that 95% of such intervals constructed from repeated sampling would contain the true population parameter.

Question 2

In a study, the Number Needed to Treat (NNT) is calculated as 8. What does this mean?

Accepted Answer

8 patients must be treated for one additional patient to benefit

Answer

NNT is the reciprocal of the absolute risk reduction and represents how many patients need treatment for one additional benefit.

Question 3

Which type of bias occurs when patients who drop out of a clinical trial differ systematically from those who complete it?

Accepted Answer

Attrition bias

Answer

Attrition bias (also called dropout bias) occurs when loss to follow-up is related to the outcome, distorting results.

Question 4

A study finds r = 0.85 between drug dose and therapeutic response. What does this Pearson correlation coefficient indicate?

Accepted Answer

There is a strong positive linear relationship between dose and response

Answer

A Pearson r of 0.85 indicates a strong positive linear association, but does not imply causation.

Question 5

A researcher increases sample size from 100 to 400. How does this affect the standard error of the mean?

Accepted Answer

It is halved

Answer

Standard error = SD/√n; quadrupling n doubles √n, so the SE is halved.

FPGEE Exam Practice Test

FPGEE Exam Practice Test

FPGEE Biostatistics 2