ACRP ACRP Biostatistics and Data Analysis 2

Question 1

What is the role of a Data Safety Monitoring Board (DSMB) in a clinical trial?

Accepted Answer

To independently monitor accumulating data and recommend stopping or modifying the trial if safety or efficacy criteria are met

Answer

A DSMB is an independent committee that periodically reviews unblinded interim data to protect participant safety and ensure trial integrity.

Question 2

What is a Type I error in statistical testing?

Accepted Answer

Concluding that a treatment is effective when it is not (false positive)

Answer

A Type I error (alpha error) occurs when the null hypothesis is rejected incorrectly, falsely concluding that an ineffective treatment works.

Question 3

What is stratified randomization and when is it used?

Accepted Answer

Randomization that ensures balance of key prognostic factors (e.g., age, disease severity) across treatment groups

Answer

Stratified randomization controls for important baseline variables by ensuring they are equally distributed between treatment arms, improving comparability.

Question 4

What is the primary purpose of a statistical analysis plan (SAP) in a clinical trial?

Accepted Answer

To pre-specify all statistical methods and analyses before data unblinding to prevent bias

Answer

The SAP documents all planned analyses before unblinding, ensuring results are not influenced by knowledge of outcome data (post-hoc analysis bias).

Question 5

What does 'multiplicity' refer to in clinical trial statistics?

Accepted Answer

The inflation of the Type I error rate when performing multiple statistical tests

Answer

When multiple endpoints or comparisons are tested, the probability of at least one false positive increases; multiplicity adjustments (e.g., Bonferroni) control this inflation.

ACRP - Association of Clinical Research Professionals Practice Test

ACRP - Association of Clinical Research Professionals Practice Test

ACRP ACRP Biostatistics and Data Analysis 2