A randomized, double-blind, placebo-controlled trial is conducted to evaluate the efficacy of a novel glucagon-like peptide-1 (GLP-1) receptor agonist for the secondary prevention of major adverse cardiovascular events (MACE). The study enrolls patients with type 2 diabetes mellitus and established cardiovascular disease. Participants are randomized in a 1:1 ratio to receive either the GLP-1 receptor agonist or a placebo, in addition to standard of care.
Over a 3-year follow-up period, the investigators report the following outcomes:
| Group | Total Patients () | MACE Occurred |
|---|---|---|
| Placebo | ||
| GLP-1 Receptor Agonist |
Based on the study results, what is the number needed to treat (NNT) with the novel GLP-1 receptor agonist to prevent one major adverse cardiovascular event over the 3-year follow-up period?
Answer: 20 patients
Answer
20
The number needed to treat (NNT) is an epidemiological measure used to evaluate the clinical impact of an intervention. It is calculated as the inverse of the Absolute Risk Reduction (ARR), using the formula . First, determine the event rates for both groups. The Control Event Rate (CER) is (), and the Experimental Event Rate (EER) is (). The ARR is the absolute difference between these two rates: (). The NNT is therefore . This indicates that patients must be treated with the novel GLP-1 receptor agonist over a 3-year period to prevent one major adverse cardiovascular event.
Step-by-Step Solution
Key Concept
The Number Needed to Treat (NNT) is the inverse of the Absolute Risk Reduction (ARR) and represents the number of patients who must receive a specific intervention over a defined time period to prevent one additional adverse outcome.