Tang 2020.

Study characteristics
Methods	Study design: retrospective cohort Type of publication: peer‐reviewed journal publication Setting and dates: hospital, 1 January 2020‐13 February 2020 Country: China Language: English Number of centres: 1 Trial registration number: NR
Participants	Number of participants: 449 allocated (intervention = 99; comparator = 350) Age: 65.1 ± 12.0 years (mean ± SD) Gender: 268 (60%) male Comorbidities: hypertension (39.4%), diabetes (20.7%), heart diseases (9.1%) Confounding factors: prior anticoagulation (NR), surgery (NR), cancer (NR), antiplatelet use (NR), history of VTE (NR) Type of ventilator support: NR Inclusion criteria Adults (age > 18 years) with severe COVID‐19 confirmed by a PCR test Exclusion criteria Bleeding diathesis Hospital stay < 7 days Lack of information about coagulation parameters and medications Age < 18 years
Interventions	Intervention of interest: anticoagulation for ≥ 7 days UFH (10,000‐15,000 IU/d) in 5 participants, or LMWH (40‐60 mg enoxaparin/d) in 94 participants Comparator: no anticoagulants Concomitant therapy: all participants received antiviral Duration of follow‐up: 28 days after ICU admission
Outcomes	There is no differentiation between primary and secondary outcomes. Mortality Coagulation parameters
Notes	Sponsor/funding: National Mega Project on Major Infectious Disease Prevention of China, Grant/Award Number: 2017ZX10103005‐007 COIs: the study authors declare that they have no conflicts of interest.