CLC Research Methods & Evidence-Based Practice 2

Question 1

In a case-control study examining a rare laboratory error type, researchers compare 50 cases with 200 controls. What is the primary measure of association used?

Accepted Answer

Odds ratio

Answer

Odds ratio is the appropriate measure in case-control studies because incidence cannot be calculated directly from such designs.

Question 2

A laboratory implements a new QC algorithm. To assess its diagnostic performance, staff calculate sensitivity and specificity. Which combination best minimizes patient harm from missed critical values?

Accepted Answer

High sensitivity, low specificity

Answer

High sensitivity minimizes false negatives, ensuring critical values are rarely missed, which is paramount for patient safety.

Question 3

A systematic review pools five studies on turnaround time interventions. Cochran's Q test yields p=0.02. What does this indicate?

Accepted Answer

Significant heterogeneity exists among studies

Answer

A significant Cochran's Q (p<0.10) indicates substantial statistical heterogeneity, warranting caution in pooling results.

Question 4

Which of the following best describes the principle of 'intention-to-treat' analysis in a randomized controlled trial of a new laboratory workflow?

Accepted Answer

Analyzing participants based on the group they were assigned to, regardless of adherence

Answer

Intention-to-treat analysis preserves randomization and avoids bias by analyzing all participants in their originally assigned groups.

Question 5

A laboratory director reviews a study with an I² value of 78%. What is the most appropriate interpretation?

Accepted Answer

High heterogeneity; a random-effects model or subgroup analysis is warranted

Answer

I² above 75% indicates high heterogeneity, suggesting a random-effects model or investigation of sources of variability is needed.

(CLC) Certified Laboratory Consultant Practice Test

(CLC) Certified Laboratory Consultant Practice Test

CLC Research Methods & Evidence-Based Practice 2