Patients with atrial fibrillation discharged from hospital after gastrointestinal bleeding while receiving antithrombotic treatment Ｉ
Restarted treatment regimens were single or combined antithrombotic drugs with oral anticoagulation and antiplatelets. Ｃ
Ｏ Risks of all cause mortality, thromboembolism, major bleeding, and recurrent gastrointestinal bleeding. Follow-up started 90 days after discharge to avoid confounding from use of previously prescribed drugs on discharge.
Firstly, the Danish national patient registry 1978年以降の入院を全て記録、退院時病名はICDでコード 1996年以降は全ての手術（procedures and surgical operations）を記録
Secondly, the Danish national prescription registry 1995年以降の薬局での処方を記録
Finally, the Danish civil registration system 生死についての情報を記録
今回の研究手法 Selection bias の調整ーStudy populationー
Inclusion criteria Af患者で抗血栓薬使用中に消化管出血をきたした全ての患者患者 （while receiving single or combined antithrombotic treatment with a vitamin K antagonist, dabigatran, rivaroxaban, aspirin, clopidogrel, prasugrel, or ticagrelor）
In the Danish national patient registry, 97% to 100% truly had ischaemic stroke —that is, the positive predictive value was 97% to 100%. The positive predictive value for transient ischaemic attack ranges from 57.9% to 68.4%.