Anticoagulant use before COVID-19 diagnosis prevent COVID-19 associated acute venous thromboembolism or not: A systematic review and meta-analysis

Table 2 Studies reporting adjusted estimates and the factors for which they are adjusted

Ref.	Outcome	Adjusted estimates
Ageno et al[28], 2021	Mortality	Age, gender, and heparin use after admission, history of acute MI, T2D, HTN, cancer, COPD, renal function and CRP at hospital entry
Arachchillage et al[29], 2022	90-day mortality, thrombosis, and ICU admission	Age, gender, BMI, antiplatelet treatment prior to admission, autoimmune disease, malignancy, hypercholesterolaemia, heart disease, T2D, smoking status, liver disease, lung disease, existing renal failure and whether renal failure was dialysis dependent
Aslan et al[55], 2021	In-hospital mortality	Age, male gender, T2D, ferritin, d-dimer, neutrophil, lymphocyte, creatinine, CRP, SaO2, procalcitonin, DOAC, HTN, HF, AF, CAD, COPD, systolic blood pressure and hematocrit in univariable logistic regression analysis
Buenen et al[40], 2021	All-cause mortality within 30 d	Age, sex, symptom duration, home medication, and comorbidities
Covino et al[42], 2021	All-cause in-hospital death.	Age, sex, comorbidity (categorized as CCI < 3 or CCI ≥ 3), and illness severity at admission (categorized as NEWS < 6 or NEWS ≥ 6)
Gülcü et al[32], 2022	In-hospital all-cause mortality	Age, gender, HTN, DM, HF, CAD, eGFR, albumin, CRP, D-dimer, hemoglobin, platelet count, LDH, and oxygen saturation variables
Bauer et al[71], 2020	Severity	Age and gender
Ménager et al[60], 2020	7-day mortality	Age, sex, severe undernutrition, T2D, HTN, prior MI, HF, prior stroke and/or TIA, CHA2DS2-VASc score, HAS-BLED score, and eGFR
Philipose et al[66], 2020	Mortality	Age and gender
Rieder et al[37], 2022	COVID-19 related mortality	Age, gender, BMI and smoking status, the phase of disease at diagnosis, solid tumor, AF, CAD, prior MI, peripheral artery disease, HTN, cerebrovascular disease, and T2D
Rivera-Caravaca et al[38], 2021	Mortality and the composite of any thrombotic or thromboembolic event	Age, gender and ethnicity, all the included comorbidities
Rodríguez-Molinero et al[67], 2020	Mortality	Age, sex, obesity, and corticosteroids
Russo et al[48], 2022	Mortality	Age, arterial HTN, T2D, CAD, HF, previous stroke
Schiavone et al[74], 2021	Mortality	Age > 65 years, male gender, CAD, CKD, COPD, HF, OAC, PaO2/FiO2, hydroxychloroquine, tocilizumab, antivirals, heparin
Spiegelenberg et al[50], 2021	All-cause in hospital mortality and ICU admission	Age, sex, body mass index, active malignancy, COPD, T2D, HTN, CAD, MI, HF, non-ischaemic cardiomyopathy, previous heart surgery, electronic heart device, cerebrovascular accident, peripheral artery disease, immunosuppressive medication, no ICU policy
Togano et al[39], 2021	Severity (mechanical ventilation/ supplemental oxygen/SpO2 ≤ 94% on room air/tachypnea)	Age, gender, BMI, smoking, alcohol consumption, myocardial infarction/congestive heart failure, peripheral artery disease, cerebrovascular disease, dementia, paralysis, COPD, liver dysfunction, hypertension, hyperlipidemia, diabetes, obesity, leukemia, lymphoma, immunosuppression
Tremblay et al[70], 2020	All-cause mortality, mechanical ventilation	Age, gender, race, CCI and obesity
van Haaps et al[51], 2021	21-day all-cause mortality and ICU admission	Age, gender, T2D, HTN, CKD, asthma, obesity, time in pandemic, center, chronic cardiac disease, malignancy, liver disease, dementia, organ transplant, autoimmune disorder, and rheumatic disorder
Wargny et al[65], 2021	Death within 28 d	Age
Harrison et al[34], 2021	21-day all-cause in hospital mortality	Age, gender, and confounding variables
Iaccarino et al[72], 2021	Mortality, ICU admission	Age, multimorbidity (combined in the CCI score), and gender
Hozayen et al[35], 2021	Mortality	Age, sex, self-identified race/ethnicity (as a proxy for social, not biological risk factors), Elixhauser comorbidity score, and the presence/absence of any cardiovascular, immunological or hematological comorbidities
Ho et al[45], 2021	ICU admission, VTE, and mortality between date of SARS-CoV-2 diagnosis and 45 d after diagnosis	Age, sex, race/ethnicity, body mass index, CCI, HTN, T2D, and smoking history as well as the week of SARS-CoV-2 diagnosis
Denas et al[43], 2021	ICU admission and all-cause mortality	Age, sex, HF, HTN, cancer, T2D, history of stroke/TIA, previous bleeding, history of MI, peripheral artery disease, abnormal renal function, abnormal hepatic function, use of antiplatelet drugs, NSAIDs and statin use
Corrochano et al[30], 2022	All-cause mortality and ICU admission	Sex, age, CCI, and antithrombotic therapy
Chocron et al[41], 2021	In-hospital mortality and ICU admission	Sex, age, cardiovascular comorbidities (history of HTN, dyslipidemia, BMI, T2D, and current smoking), plasma creatinine level (µmol/L), CRP (mg/L), fraction of inspired oxygen, the degree of pulmonary lesions with ground-glass opacities and areas of consolidation, and the use of in-hospital anticoagulation (preventive low or high dose and therapeutic dose)

T2D: Type 2 diabetes mellitus; HTN: Hypertension; HF: Heart failure; CAD: Coronary artery disease; MI: Myocardial infarction; AF: Atrial fibrillation; TIA: Transient ischemic attack; CKD: Chronic kidney disease; COPD: Chronic obstructive pulmonary disease; VTE: Venous thromboembolism; OAC: Oral anticoagulant; DOAC: Direct oral anticoagulant; CRP: C-reactive protein; LDH: Lactate dehydrogenase; BMI: Body mass index; CCI: Charlson comorbidity index; NEWS: National Early Warning Score; ICU: Intensive care unit; NSAIDs: Non-steroidal anti-inflammatory drugs; eGFR: Estimated glomerular filtration rate; SARS-CoV-2: Severe acute respiratory syndrome coronavirus 2; COVID-19: Coronavirus disease 2019.