Table 3. Characteristics of studies included from nationwide registries and surveillance.
Abbreviations: CVST, cerebral venous sinus thrombosis; DVT, deep vein thrombosis; SAH, subarachnoid haemorrhage; ITP, immune thrombocytopenic purpura, NA, not available
n=total number of patients
| First Author | Published journal, date of publication | Study design, study setting | Study population | Total number of patients (n) with venous or arterial events | Sex Female, % | Age (years), mean ± SD or median (range) or median (IQR) | COVID-19 tests | Vaccine type, dose | Time period from vaccination to first symptoms (days) | Diagnosis | Comorbidities and risk factors | Blood investigations | Antiplatelet antibodies and platelet-activation assay | Previous exposure to heparin | Treatment received | Outcome |
| Pottegård A [33] | The BMJ, 05 May 2021 | Population-based cohort study, Denmark and Norway | Nationwide healthcare registers; Denmark (n=148792); Norway (n=132472) | 142 | Denmark, 80.1; Norway, 77.6% | Range, 18-65, Median (IQR) age: Denmark 45 (33-55); Norway 44 (32-55) | Before vaccination, 6.2% in Denmark and 1.4% in Norway positive result for any COVID-19 tests | AstraZeneca vaccine, all first dose | NA | Total venous thromboembolic events (59); CVST (7); Pulmonary embolism (2); DVT (22) Splanchnic vein thrombosis (< 5); Arterial events (83); Ischemic heart disease (52; Intracerebral haemorrhage (8); Ischemic stroke (16); SAH (<5); ITP (<5); Bleeding events (74) | NA | Thrombocytopenia (17) | NA | NA | NA | Died (15) |
| Simpson CR [34] | Nature Medicine, 09 June 2021 | Nested incident-matched case-control study, Scotland | National prospective COVID-19 surveillance cohort in Scotland | 6205 | NA | ≥18 years | NA | AstraZeneca, all first dose; Pfizer/BioNTech, all first dose | NA | AstraZeneca: Venous thromboembolic events (893); Arterial thromboembolic events (3288); ITP (27); Haemorrhagic events (278); Pfizer/BioNTech: Venous thromboembolic events (421); Arterial thromboembolic events (1603); ITP (10); Haemorrhagic events (137) | NA | AstraZeneca vaccine: Thrombocytopenia (excluding ITP) (94); Pfizer/BioNTech: Thrombocytopenia (excluding ITP) (34) | NA | NA | NA | NA |