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

The true difference is exactly 5.25 mmHg

Answer

There is a 95% probability the null hypothesis is false

Answer

The p-value is 0.95

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

8% of patients will respond to treatment

Answer

The treatment reduces risk by 8%

Answer

8 patients experienced adverse events

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

Selection bias

Answer

Information bias

Answer

Confounding bias

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

Drug dose causes an 85% improvement in response

Answer

85% of patients responded to the drug

Answer

The regression slope is 0.85

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

It doubles

Answer

It is quartered

Answer

It remains the same

Question 6

In a 2×2 contingency table used for a case-control study, which measure of association is most appropriate?

Accepted Answer

Odds ratio

Answer

Relative risk

Answer

Attributable risk

Answer

Hazard ratio

Question 7

A pharmacokinetic study shows a drug's half-life follows a log-normal distribution. What transformation would make it approximately normal?

Accepted Answer

Log transformation

Answer

Square root transformation

Answer

Reciprocal transformation

Answer

Z-score standardization