Population
Patients with acute bleeding due to post-partum haemorrhage or trauma (2 studies, n= 28,333).
Intervention
Antifibrinolytic drugs (aprotinin, tranexamic acid, aminocaproic acid, and aminomethylbenzoic acid).
Comparison
Placebo.
Outcome
Baseline characteristics to estimate the risk of death as a result of bleeding were divided into four categories: Low (0–5%), intermediate (6–10%), high (11–20%), and very high (>20%). Most patients had a low baseline risk of death as a result of bleeding (23,008 [81%]). Deaths as a result of bleeding occurred in all baseline risk categories with 240 (1%), 202 (8%), 232 (14%), and 357 (30%) deaths in the low-, intermediate-, high-, and very high-risk categories, respectively. The effectiveness of tranexamic acid did not vary by baseline risk when given within 3 hours after bleeding onset. There was no increased risk of vascular occlusive events with tranexamic acid and it did not vary by baseline risk categories.