. 2020 Dec 4;2020(1):634–641. doi: 10.1182/hematology.2020000150

Table 2.

Summary of major bleeding outcomes across major SRs and RCTs comparing aspirin and placebo

Study reference	Indication	Aspirin dose compared with placebo	No. of major bleeding events: aspirin vs placebo	RR/HR
ECLAP³⁴	Primary thromboprophylaxis for polycythemia vera	Aspirin 100 mg daily	3 vs 2	RR, 1.62 (0.27-9.71)
RCT, 2004; n = 518	Primary thromboprophylaxis for polycythemia vera	Aspirin 100 mg daily	3 vs 2	RR, 1.62 (0.27-9.71)
INSPIRE²⁵	Recurrent VTE prevention	Aspirin 100 mg daily	9 vs 7	HR, 1.31 (0.48-3.53)
RCT, 2014; n = 1224	Recurrent VTE prevention	Aspirin 100 mg daily	9 vs 7	HR, 1.31 (0.48-3.53)
POISE-2⁴⁸	Perioperative administration of aspirin in patients undergoing noncardiac surgery	Aspirin 200 mg daily	230 vs 188	HR, 1.23 (1.01-1.49)
RCT, 2014; n = 10 010		Aspirin 200 mg daily	230 vs 188	HR, 1.23 (1.01-1.49)
Mahmoud et al, 2019⁴⁹	Primary cardiovascular prevention	Aspirin mostly, 75-100 mg	1301 vs 901	RR, 1.47 (1.31-1.65)
SR, 11 RCTs; n = 157 248	Primary cardiovascular prevention	Aspirin mostly, 75-100 mg	1301 vs 901	RR, 1.47 (1.31-1.65)
Zheng et al, 2019⁵⁰	Primary cardiovascular prevention	Aspirin ≤100 mg daily	1195 vs 834	HR, 1.54 (1.35-1.76)
SR, 11 RCTs; n = 134 470	Primary cardiovascular prevention	Aspirin ≤100 mg daily	1195 vs 834	HR, 1.54 (1.35-1.76)

Major bleeding as defined by criteria set in each individual randomized control trial or systematic review.

HR, hazard ratio; INSPIRE, International Collaboration of Aspirin Trials for Recurrent Venous Thromboembolism; n, number of patients; POISE-2, Perioperative Ischemic Evaluation 2; RR, relative risk; SR, systematic review and meta-analysis.