Table 1.
Hospital cohort and database studies
| Study (country) | Study type | Enrollment period | N (CTPA n) | Follow‐up period | Study population | Setting | Thromboprophylaxis |
|---|---|---|---|---|---|---|---|
| Hospital studies | |||||||
| Benito et al. (2020) (Spain) 13 | Prospective | March–April 2020 | 1275 (76) | Median (IQR): PE, 15.5 (9.8) days; no PE, 7 (11) days a , b | COVID‐19 patients admitted to hospital | Single hospital | Patients with PE: 28/32 LMWH, of which prophylactic, 93%; higher‐risk prophylactic, 7% Median (IQR), 6 (9) days of LMWH |
| Berger et al. (2020) (USA) 14 | Retrospective | March–April 2020 | 2377 (NR) | 35–73 daysc | COVID‐19‐positive patients admitted to hospital | Multi‐hospital health system | Before admission, 201/2377 (8.5%) |
| Bilaloglu et al. (2020) (USA) 15 | Retrospective | March–April 2020 | 3334 (NR) | 45–120 daysc | COVID‐19‐positive patients admitted to hospital, including 829 in ICU | Single hospital | Low‐dose prophylaxis was used in most patients after admission |
| Bunel et al. (2021) (France) 16 | Retrospective | March–April 2020 | 1097 (157) | NR | COVID‐19 patients admitted to hospital | Single hospital | LMWH, varying intensity Patients with CTPA (due to stagnation or worsening): 94.3%; 100% in ICU; 93% in ward. Patients with PE: 100% in ICU; 86.7% in ward |
| Doses: none, 5.7%: low prophylactic, 24.8%; high prophylactic, 57.3%; therapeutic, 12.1% | |||||||
| Choi et al. (2020) (USA) 18 | Retrospective | March–May 2020 | 1739 (571d) | 21–64 daysc | COVID‐19‐positive patients admitted to hospital | Community hospital and quaternary referral center | Enoxaparin or UFH, varying dose |
| COVID‐ICU group (2021) (France, Belgium, and Switzerland) 17 | Prospective cohort study | February–May 2020 | 4244 (NR) | 90 days | Critically ill adults with COVID‐19 treated in ICU (including 2233 on mechanical ventilation from Day 1 in ICU) | 138 hospitals | NR |
| Esenwa et al. (2021) (USA) 19 | Retrospective | March–May 2020 | 4299 (NR) | NR | COVID‐19‐positive patients admitted to hospital | Three New York hospitals | 47.0%–50.4% across ethnicity groups |
| Fang et al. (2020) (UK) 20 | Retrospective | March–April 2020 | 2157 (93) | 14–41 daysc | COVID‐19‐positive patients, including 1200 admitted to hospital | Single hospital | NR |
| Fauvel et al. (2020) (France) 21 | Retrospective | February–April 2020 | 2878 (1240) | Median (IQR), 6.8 (5–12) daysa | COVID‐19 patients admitted to hospitale | 24 centers | Before hospitalization, PE versus no PEf: Therapeutic dose anticoagulation, 4.9% versus 11.5% (p = 0.044) |
| During hospitalization, PE versus no PE (LMWH or UFH): Prophylactic dose, 18.4% versus 67.0% (p < 0.001) Intermediate dose, 5.1% versus 8.8% | |||||||
| Giannis et al. (2021) (USA) 22 | Retrospective | March–April 2020 | 10,871 (NR) | NR | COVID‐19 patients admitted to hospitalg | Multi‐hospital system | Of patients with VTE or death within 8 h of presentation: None, 99.3% Prophylactic, 0.7% |
| Gonzalez‐Fajardo et al. (2021) (Spain) 23 | Retrospective | March–April 2020 | 2943 (NR) | NR | COVID‐19‐positive patients admitted to hospital who required assessment for thrombotic events (261 in ICU) | Single hospital | Of 58 patients with PE: Prophylactic dose, 15 (26%) Therapeutic dose, 1 (2%) |
| Grillet et al. (2020) (France) 8 | Retrospective | To April 2020 | 2003 (100) | NR | COVID‐19‐positive patients, including 280 admitted to hospital | Single hospital | NR |
| Gupta et al. (2020) (USA) 24 | Retrospective | March–April 2020 | 2215 (NR) | 61–92 daysc | COVID‐19‐positive patients admitted to ICU | Multiple US hospital ICU departments | 8.4% using home anticoagulation before admission |
| Kartsios et al. (2021) (UK) 25 | Retrospective | February–April 2020 | 1583 (NR) | 8–97 daysc | COVID‐19‐positive patients admitted to hospital | Three hospitals | On thromboprophylaxis at time of VTE (not all PE), 5 of 11 patients with VTE post COVID‐19 diagnosis |
| Lee et al. (2021) (USA) 9 | Retrospective | March–May 2020 | 3727 (86) | NR | COVID‐19‐positive patients | Hartford healthcare system | Nearly all inpatients received at least systemic and mechanical thromboprophylaxis; regimens varied |
| Linschoten et al. (2020) (13 countries) 26 | Retrospective | March–July 2020 | 3011 (NR) | Median (IQR), 7 (4–14) daysa | COVID‐19 patients admitted to hospital, including 837 in ICUh | International patient registry | NR |
| Miró et al. (2020) (Spain, France) 11 | Retrospective | March–April 2020 | 8880 (320) | NA | COVID‐19 patients treated in EDi | 8 EDs | NR |
| Miró et al. (2021) (Spain) 12 | Retrospective | March–April 2020 | 63,822 (NR) | NA | COVID‐19 patients diagnosed in EDc | 50 EDs | NR |
| Monfardini et al. (2020) (Italy) 27 | Retrospective | March 2020 | 1207 (34) | ≥2 weeksj | COVID‐19‐positive patients admitted to hospital | Single hospital | Before PE: 8/25 received LMWH (32%) |
| Nordberg et al. (2021) (Sweden) 28 | Retrospective | March–May 2020 | 1162 (NR) | Median 162 days | COVID‐19‐positive patients admitted to hospital | Single hospital | Patients who developed PE while in hospital (n = 22), 14 (64%) were treated with LMWH (prophylactic, 8; elevated prophylactic, 5; treatment dose, 1). Patients with PE at admission, no prior anticoagulation was reported |
| Piazza et al. (2020) (USA) 10 | Retrospective | March–April 2020 | 1114 (NR) | 30 days | COVID‐19‐positive patients: outpatients, 715; on ward, 229; in ICU, 170 | Integrated health network | Therapeutic/prophylactic: ICU, 25.3%/89.4% Ward, 9.2%/84.7% Outpatient, 2.3%/0.1% |
| Planquette et al. (2021) (France) 29 | Retrospective | March–April 2020 | 1042 (269) | 30–81 daysc | |||
| COVID‐19 patients admitted to hospitale | Two Paris hospitals | Patients with PE: prophylactic anticoagulation, 55%; therapeutic anticoagulation, 6.9% | |||||
| Rashidi et al. (2021) (Iran) 7 | Prospective | February–April 2020 | 1529 (12) | ≥45 days | Patients discharged after hospitalization for COVID‐19, 45‐day follow‐up | Three hospitals | Prophylaxis (LMWH or UFH), 1490/1529 (97.4%) |
| Spiegel‐enberg et al. (2021) (Netherlands) 30 | Retrospective | March–May 2020 | 1154 (NR) | Median (IQR): TAC use, 7 (4–11) days; no TAC use, 7 (4–13) daysa | COVID‐19 patients admitted to hospitalk | Six hospitals | 16.5% were previously using therapeutic anticoagulants due to AF (76%), history of VTE (13%), or other reasons 88.8% of the remaining patients received LMWH during hospitalization After PS matching, 164 patients with therapeutic anticoagulation and 410 without were included |
| Tsakok et al. (2021) (UK) 31 | Retrospective |
March–April 2020 December 2020–January 2021 |
1560 (wave 1, 35; wave 2, 193) | NR | COVID‐19 patients admitted to hospital | Single hospital | NR |
| Whyte et al. (2020) (UK) 32 | Retrospective | March–May 2020 | 1477 (214) | NR | COVID‐19 patients admitted to hospital (including 222 in ICU) | Single hospital | Admitted patients: LMWH (UFH in ICU) Of patients scanned >24h after admission, 124/132 (93.9%) were on anticoagulation |
| Database studies | |||||||
| Aktaa et al. (2021) (UK) 33 | Retrospective, database study | March–July 2020 | 84,728 (NR) | NR | COVID‐19‐positive patients admitted to hospital with any TE | English hospital admissions | NR |
| Cates et al. (2020) (USA) 34 | Retrospective, database study | March–May 2020 | 3948 (NR) | Median (IQR), 8.6 (3.9–18.6) daysa | COVID‐19 patients admitted to hospital | Veterans Health Administration database | NR |
| Cho et al. (2021) (South Korea) 36 | Retrospective, database study | February–May 2020 | 7327 (NR) | Mean (SD), 20.9 (13.1) days | All adult COVID‐19‐positive patients in HIRA database, including 6911 hospitalized patients | Korea HIRA database | NR |
| Dalager‐Pedersen et al. (2021) (Denmark) 37 | Retrospective, database study | February–May 2020 | 9460 (NR) | 30 days | All COVID‐19 cases in Denmark, including 1540 hospitalized patients | National databases: Danish CRS database, Microbiological database, National Patient Registry and National Prescription database | NR |
| Piroth et al. (2021) (France) 35 | Retrospective | March–April 2020 | 89,530 (NR) | Until end of hospital stay | COVID‐19‐positive patients admitted to hospital | All hospital admissions in France—PMSI database | NR |
| Ray et al. (2021) (Canada) 38 | Retrospective, database study | January–June 2020 | 6991 (NR) | 31–198 daysc | All COVID‐19‐positive patients in healthcare database | Ontario healthcare database | NR |
Abbreviations: AF, atrial fibrillation; CTPA, computed tomography pulmonary angiogram; ED, emergency department; EHR, electronic health record; HCO, healthcare organization; HIRA, Health Insurance Review and Assessment; ICU, intensive care unit; IQR, interquartile range; LMWH, low‐molecular‐weight heparin; NA, not applicable; NOAC, non‐vitamin K antagonist oral anticoagulant; NR, not reported; PE, pulmonary embolism; PMSI, Programme de Médicalisation des Systèmes d'Information; PS, propensity score; SD, standard deviation; TAC, therapeutic anticoagulant; TE, thromboembolism; UFH, unfractionated heparin; VKA, vitamin K antagonist; VTE, venous thromboembolism.
a
Duration of hospitalization.
b
IQR reported as width of range.
c
Maximum follow‐up period for patients in hospital at the end of the enrollment period.
d
Compression ultrasound or CTPA.
e
Diagnosis based on PCR or typical imaging characteristics.
f
Mostly VKA and NOAC in PE group.
g
Diagnosis method not reported.
h
Includes all adult patients admitted to hospital with highly suspected COVID‐19; PCR testing was not a requirement.
i
Clinical or microbiological diagnosis.
j
All patients were dead or discharged after 2 weeks.
k
Diagnosis by PCR (97%) or clinical features in combination with a CT scan with a very high level of suspicion.