Table 5 Number needed to screen to identify one cardiovascular event excess per year according to different estimated prevalence of significant CAD a
Prevalence of CAD ≥70% estimated by the risk score | Number of patients with CAD ≥70% | Number of patients with CAD <70% | Number of events in patients with CAD ≥70% (AR = 13%) | Number of events in patients with CAD <70% (AR = 2%) | Excess of events in patients with CAD ≥70% | Number needed to screen to identify one cardiovascular event |
|---|---|---|---|---|---|---|
5% | 5 | 95 | 0.65 | 1.90 | −1.25 | N/A |
10% | 10 | 90 | 1.30 | 1.80 | −0.50 | N/A |
15% | 15 | 85 | 1.95 | 1.70 | 0.25 | 400 |
20% | 20 | 80 | 2.60 | 1.60 | 1.00 | 100 |
25% | 25 | 75 | 3.25 | 1.50 | 1.75 | 57 |
30% | 30 | 70 | 3.90 | 1.40 | 2.50 | 40 |
35% | 35 | 65 | 4.55 | 1.30 | 3.25 | 31 |
40% | 40 | 60 | 5.20 | 1.20 | 4.00 | 25 |