FREE UWorld Evidence-Based Content Questions and Answers

Question 1

A randomized controlled trial (RCT) studying the effectiveness of a new antihypertensive drug reports a relative risk (RR) of 0.75 (95% CI: 0.60–0.90, 𝑝<0.05). What does this finding suggest?

Accepted Answer

The drug reduces the risk of hypertension-related events by 25%.

Answer

A relative risk (RR) of 0.75 means that the risk of hypertension-related events in the drug group is 75% of the risk in the control group. To find the percentage reduction in risk, subtract the RR from 1 (1 - 0.75 = 0.25). This indicates a 25% reduction in risk. The 95% confidence interval (0.60–0.90) does not include 1, and the p-value is less than 0.05, confirming that this reduction is statistically significant.

Question 2

According to current guidelines, what is the first-line treatment for a 55-year-old male with newly diagnosed Stage 1 hypertension and no other comorbidities?

Accepted Answer

Lifestyle modifications

Answer

According to current hypertension guidelines (e.g., ACC/AHA), for a patient with newly diagnosed Stage 1 hypertension and no other comorbidities, lifestyle modifications are the recommended first-line treatment. These include dietary changes, regular physical activity, weight management, and limiting alcohol intake. Pharmacological therapy is typically initiated if lifestyle changes are insufficient after a certain period or if the patient has higher risk factors or Stage 2 hypertension.

Question 3

In evidence-based practice, what is the primary purpose of a likelihood ratio in diagnostic testing?

Accepted Answer

To calculate the probability of disease after testing

Answer

Likelihood ratios (LRs) are a key component in evidence-based practice for diagnostic testing. They quantify how much a positive or negative test result changes the probability of a disease. LRs are used to convert pre-test probability into post-test probability of disease, helping clinicians update their diagnostic certainty after a test is performed.

Question 4

A cohort study observes that patients who exercise regularly have a lower incidence of diabetes. Which of the following is true about this type of study?

Accepted Answer

It measures the incidence of diabetes in an exposed and unexposed group.

Answer

A cohort study is an observational study design where a group of individuals (a cohort) is followed over time. Researchers compare the incidence of a specific outcome (like diabetes) between a group exposed to a factor (e.g., regular exercise) and a group not exposed. While cohort studies can identify associations and measure incidence, they do not involve randomization and therefore cannot definitively establish causality like randomized controlled trials.

Question 5

A 40-year-old smoker is counseled on lung cancer prevention. What is the most effective intervention to reduce their risk of lung cancer?

Accepted Answer

Smoking cessation

Answer

Smoking is the leading preventable cause of lung cancer and many other serious health conditions. For a smoker, the single most effective intervention to significantly reduce their risk of lung cancer and improve overall health is to quit smoking. While other interventions like screening or diet can play a role, addressing the primary risk factor has the greatest impact on prevention.

UWorld Practice Test

UWorld Practice Test

FREE UWorld Evidence-Based Content Questions and Answers