HSRT Evaluating Scientific Evidence

Question 1

A researcher claims that a new drug reduces blood pressure based solely on a study of 12 patients over two weeks. Which limitation most significantly weakens this evidence?

Accepted Answer

The sample size is too small to generalize findings

Answer

The drug has not been approved by the FDA

Answer

The study was not published in a peer-reviewed journal

Answer

The patients were not required to change their diet

Question 2

Which study design provides the strongest evidence for establishing a causal relationship between an intervention and a health outcome?

Accepted Answer

Randomized controlled trial

Answer

Cross-sectional survey

Answer

Case report

Answer

Cohort study

Question 3

A meta-analysis of 20 studies concludes that vitamin D supplementation reduces fracture risk. One study in the analysis had 10,000 participants while the others averaged 200. What is the most appropriate concern?

Accepted Answer

The large study may disproportionately influence the pooled result

Answer

The meta-analysis should not include RCTs

Answer

Meta-analyses cannot address fracture outcomes

Answer

The smaller studies should be excluded entirely

Question 4

A study reports a statistically significant result with p = 0.04. What does this indicate?

Accepted Answer

The result has a 4% chance of occurring if the null hypothesis is true

Answer

There is a 4% probability the null hypothesis is true

Answer

The effect size is clinically meaningful

Answer

The study will replicate with 96% certainty

Question 5

Researchers find a strong positive correlation (r = 0.85) between ice cream sales and drowning rates. The most accurate interpretation is:

Accepted Answer

A third variable (hot weather) likely explains both

Answer

Eating ice cream increases drowning risk

Answer

Drowning causes people to crave ice cream

Answer

The correlation proves a direct causal link

Question 6

Which of the following best describes 'publication bias' in the context of medical research?

Accepted Answer

Journals preferentially publish studies with positive or significant results

Answer

Researchers selectively report only favorable patient outcomes

Answer

Funding agencies refuse to support negative studies

Answer

Peer reviewers reject studies from unknown institutions

Question 7

An observational study concludes that coffee drinkers have lower rates of type 2 diabetes. A reviewer notes that coffee drinkers in the study also exercised more. This is an example of:

Accepted Answer

Confounding

Answer

Recall bias

Answer

Selection bias

Answer

Information bias