CPI Study Design & Methodology 3

Question 1

A PI wants to minimize selection bias in a clinical trial. Which allocation method is most effective?

Accepted Answer

Concealed randomization

Answer

Concealed randomization (allocation concealment) prevents investigators from predicting or influencing group assignments, minimizing selection bias.

Question 2

In a dose-response study, what does a monotonic relationship between dose and response indicate?

Accepted Answer

The response consistently increases or decreases with dose

Answer

A monotonic dose-response relationship means the response consistently moves in one direction (up or down) as the dose increases, supporting causality.

Question 3

Which term describes the ability of a study to detect a true effect when one exists?

Accepted Answer

Statistical power

Answer

Statistical power (1-β) is the probability of correctly rejecting a false null hypothesis, i.e., detecting a real effect.

Question 4

A researcher uses historical medical records to follow patients forward in time from exposure to outcome. This is a:

Accepted Answer

Historical prospective cohort study

Answer

A historical prospective cohort study uses existing records to reconstruct cohort exposure and then tracks outcomes forward in time.

Question 5

When calculating sample size for a clinical trial, increasing the desired power from 80% to 90% will:

Accepted Answer

Increase required sample size

Answer

Higher power requires detecting smaller or less likely effects, necessitating a larger sample to achieve that statistical certainty.

(CPI) Certified Principal Investigator Practice Test

(CPI) Certified Principal Investigator Practice Test

CPI Study Design & Methodology 3