HSRT Evaluating Scientific Evidence 2

Question 1

A clinical trial reports a relative risk reduction of 50% for a new treatment, but the absolute risk reduction is only 1%. Which statement best reflects the clinical significance?

Accepted Answer

The absolute risk reduction suggests the clinical benefit may be modest

Answer

An absolute risk reduction of 1% means treating 100 patients prevents one additional case, suggesting the benefit may be modest despite the impressive relative figure.

Question 2

Which component of an evidence hierarchy is typically considered the weakest form of clinical evidence?

Accepted Answer

Expert opinion

Answer

Expert opinion sits at the bottom of evidence hierarchies because it is most susceptible to individual bias and lacks empirical rigor.

Question 3

A diagnostic test has a sensitivity of 95% and a specificity of 60%. In a population with low disease prevalence, the positive predictive value will be:

Accepted Answer

Very low because prevalence is low

Answer

In low-prevalence populations, even highly sensitive tests yield many false positives, resulting in a low positive predictive value.

Question 4

Researchers randomly assign participants to treatment and control groups. The primary purpose of randomization is to:

Accepted Answer

Control for all known and unknown confounders

Answer

Randomization distributes both known and unknown confounding variables equally across groups, strengthening causal inference.

Question 5

A study is described as 'double-blind.' What does this mean?

Accepted Answer

Both participants and outcome assessors are unaware of group assignment

Answer

Double-blinding means neither participants nor the researchers assessing outcomes know who received the treatment, reducing performance and detection bias.

HSRT - Health Sciences Reasoning Test Practice Test

HSRT - Health Sciences Reasoning Test Practice Test

HSRT Evaluating Scientific Evidence 2