Association Between Aspirin Use and Risk of Aneurysmal Subarachnoid Hemorrhage: A Meta-analysis

To assess the association between aspirin use and risk of aneurysmal subarachnoid hemorrhage (aSAH).

A systematic search was performed in various databases updated on October 22, 2019. The heterogeneity test was performed for each outcome variable. Random-effect model and fixed-effect model were respectively conducted according to the heterogeneity statistics. Trial sequential analysis was used to control random errors.

Ten studies involving 1,107,616 patients were involved in this meta-analysis. No significant association was shown between aspirin users and non-aspirin users regarding the risk of aSAH (odds ratio [OR]: 0.981, 95% confidential interval [CI]: 0.773-1.312, P = 0.897]. The results of subgroup analyses indicated that the risk of aSAH was notably associated with a short-term use of aspirin (<3 months) (OR: 1.697, 95% CI: 1.175-2.452, P = 0.005), but not aspirin use for 3-12 months (OR: 1.026, 95% CI: 0.609-1.730, P = 0.922), 1-3 years (OR: 0.942, 95% CI: 0.660-1.346, P = 0.744), >3 years (OR: 0.892, 95% CI: 0.573-1.389, P = 0.612), ≤2 times per week (OR: 0.857, 95% CI: 0.560-1.313, P = 0.479), ≥3 times per week (OR: 1.104, 95% CI: 0.555-2.193, P = 0.778) and former use (OR: 1.029, 95% CI: 0.482-2.196, P = 0.941).

A short-term use of aspirin (<3 months) is associated with an elevated risk of aSAH, whereas the role of its long-term use in either decreasing or increasing the risk of aSAH still requires well-designed, large-scale randomized control trials for verification.