Table 3.

Number needed to treat with aspirin during 5 years to prevent one CVD event.

	Observed events at 5 years		Aspirin (assuming 12% RRR)
	Number	Incidence (%)	Incidence (%)	ARR (%)	NNT
Overall
All	60	1.75	1.54	0.21	476
CAC=0	15	0.70	0.62	0.08	1,190
CAC 1–99	19	2.28	2.01	0.27	365
CAC≥100	26	5.94	5.23	0.71	140
CAC≥400	12	8.33	7.33	1.00	100
ASCVD Risk <5%
All	9	0.54	0.48	0.06	1,543
CAC=0	4	0.30	0.26	0.04	2,778
CAC 1–99	3	1.08	0.95	0.13	772
CAC≥100	2	2.78	2.45	0.33	300
CAC≥400	1	8.33	7.33	1.00	100
ASCVD Risk 5–20%
All	44	2.85	2.51	0.34	292
CAC=0	10	1.31	1.15	0.16	636
CAC 1–99	15	3.04	2.68	0.36	274
CAC≥100	19	6.70	5.90	0.80	124
CAC≥400	8	8.60	7.57	1.03	97
ASCVD Risk >20%
All	7	3.32	2.92	0.40	251
CAC=0	1	1.54	1.36	0.18	541
CAC 1–99	1	1.67	1.47	0.20	499
CAC≥100	5	6.14	5.40	0.74	136
CAC≥400	3	7.77	6.84	0.93	107

Results presented as number or %. Follow-up was censored at 5 years. The 10-year ASCVD risk was estimated using the Pooled Cohort Equations.

Abbreviations: ARR = Absolute Risk Reduction; ASCVD = atherosclerotic cardiovascular disease events; CAC = coronary artery calcium; CVD = cardiovascular disease; NNT = number needed to treat; RRR = relative risk reduction