CLC Research Methods & Evidence-Based Practice 3

Question 1

A laboratory scientist wants to determine if a new hemoglobin analyzer agrees with the reference method. Which statistical approach is most appropriate?

Accepted Answer

Bland-Altman analysis

Answer

Bland-Altman analysis assesses agreement between two measurement methods by plotting the difference against the mean of paired measurements.

Question 2

In a crossover study evaluating two specimen collection protocols, the primary advantage over a parallel-group design is:

Accepted Answer

Each participant serves as their own control, reducing inter-subject variability

Answer

Crossover designs use each participant as their own control, which reduces variability due to between-subject differences and often requires fewer participants.

Question 3

Which level of evidence, according to the Oxford Centre for Evidence-Based Medicine hierarchy, provides the strongest support for a clinical laboratory guideline?

Accepted Answer

Systematic reviews of randomized controlled trials

Answer

Systematic reviews of high-quality RCTs represent Level 1 evidence, the highest tier in evidence hierarchies used for guideline development.

Question 4

A laboratory consultant conducts a study and finds p=0.04 for the primary outcome. A colleague points out the confidence interval crosses the line of no effect. Which statement is correct?

Accepted Answer

There is a contradiction; the CI and p-value should be concordant when calculated from the same data

Answer

The p-value and confidence interval are mathematically linked; if the 95% CI crosses the null value, the p-value should be >0.05, indicating a computational error.

Question 5

A pre-analytical variable study uses stratified random sampling of 500 specimens. What is the purpose of stratification?

Accepted Answer

To ensure subgroups of interest are adequately represented

Answer

Stratified sampling divides the population into subgroups (strata) and samples from each, ensuring proportional or equal representation of key characteristics.

(CLC) Certified Laboratory Consultant Practice Test

(CLC) Certified Laboratory Consultant Practice Test

CLC Research Methods & Evidence-Based Practice 3