A clinical trial was conducted to compare the effects of ACE inhibitors and diuretics in elderly patients with hypertension. The investigators believed that ACE inhibitors provide some additional survival benefits over diuretics use in elderly subjects because of their neurohumoral effects. The study lasted 5 years and the investigators presented the following results after the completion of the study: According to the information given, which of the following is the best interpretation of the study results?
A)ACE inhibitors have no overall advantage over diuretics
B)ACE inhibitors are associated with higher risk of heart failure
C)ACE inhibitors may protect from some cardiovascular events
D)ACE inhibitors decrease the risk of mortality
E)ACE inhibitors should be used with caution in elderly patients

Question

A clinical trial was conducted to compare the effects of ACE inhibitors and diuretics in elderly patients with hypertension.  The investigators believed that ACE inhibitors provide some additional survival benefits over diuretics use in elderly subjects because of their neurohumoral effects.  The study lasted 5 years and the investigators presented the following results after the completion of the study: According to the information given, which of the following is the best interpretation of the study results?
A)ACE inhibitors have no overall advantage over diuretics
B)ACE inhibitors are associated with higher risk of heart failure
C)ACE inhibitors may protect from some cardiovascular events
D)ACE inhibitors decrease the risk of mortality
E)ACE inhibitors should be used with caution in elderly patients

Quizplus · Accepted Answer

Explanation: The scenario emphasizes the basics of study result interpretation. A hazard ratio (HR) is a measure of effect used in survival analysis (or time-to-event analysis). It has almost the same interpretation as relative risk; therefore, the study results presented can be interpreted in terms of risk. The null value for HR is 1.00: HR = 1.00 means that there is no difference in risk between the 2 groups. HR <1.00 indicates a protective effect, whereas HR >1.00 indicates a detrimental effect. The HRs for all 3 outcomes (ie, all-cause mortality, non-fatal cardiovascular events, heart failure) indicate a protective effect of ACE inhibitors; however, only the HR for non-fatal cardiovascular events is statistically significant because the 95% confidence interval does not include the null value. (Choice A) ACE inhibitors may have an overall advantage over diuretics in this age group. (Choices B and D) According to the study results, ACE inhibitors can decrease the risk of non-fatal cardiovascular events compared to diuretics in elderly patients with hypertension; although the results suggest a lower risk of all-cause mortality and heart failure, these are not statistically significant. Educational objective: A hazard ratio (HR) is a measure of effect used in survival analysis (or time-to-event analysis). The null value for HRs is 1.00: HR = 1.00 means that there is no difference in risk between the 2 groups. HR <1.00 indicates a protective effect, whereas HR >1.00 indicates a detrimental effect.

A Clinical Trial Was Conducted to Compare the Effects of ACE