Statistics Research & Evidence-Based Practice 4

Question 1

A funnel plot in meta-analysis is asymmetrical. This MOST likely suggests:

Accepted Answer

Publication bias or small-study effects

Answer

Asymmetry in a funnel plot often indicates publication bias, where small negative studies are underrepresented.

Question 2

Random assignment in an experiment is MOST important for:

Accepted Answer

Controlling known and unknown confounding variables

Answer

Randomization distributes both measured and unmeasured confounders across groups, supporting causal inference.

Question 3

An IRB (Institutional Review Board) primarily ensures that research:

Accepted Answer

Protects the rights and welfare of human subjects

Answer

IRBs evaluate study protocols to protect participants from harm and ensure ethical standards are met.

Question 4

In a regression study, multicollinearity refers to:

Accepted Answer

High correlation among predictor variables, making it difficult to isolate their individual effects

Answer

Multicollinearity occurs when predictors are highly correlated, inflating standard errors and destabilizing coefficient estimates.

Question 5

Which level of the evidence hierarchy is LOWEST?

Accepted Answer

Expert opinion and case reports

Answer

Expert opinion and case reports sit at the bottom of the evidence pyramid because they are most susceptible to bias.

Statistics Practice Test