Please select the eligibility criteria that correspond to the clinical trial below.
Title: Reduced-dosed Rivaroxaban and Standard-dosed Rivaroxaban Versus ASA in the Long-term Prevention of Recurrent Symptomatic Venous Thromboembolism in Patients With Symptomatic Deep-vein Thrombosis and/or Pulmonary Embolism
Brief Summary: This is a multicenter, randomized, double-blind, event-driven, superiority study for efficacy.

Patients with confirmed symptomatic DVT (Deep Vein Thrombosis) or PE (Pulmonary embolism) who completed 6 or 12 months of treatment of anticoagulation are eligible for this trial


Options:
A: Inclusion Criteria:

• At least one diagnosis code for COVID-19 (International Classification of Diseases (ICD)-10: U07.1 or B34.2) during hospitalization

Exclusion Criteria:

• None
B: Inclusion Criteria:

* Patients with confirmed symptomatic PE and/or DVT who have been treated for 6 to 12 months and did not interrupt anticoagulation for longer than 1 week

Exclusion Criteria:

* Legal lower age limitations (country specific) Indication for therapeutic-dosed anticoagulants Indication for antiplatelet therapy or a conventional non-steroid anti-inflammatory drug (NSAID) Hepatic disease which is associated with coagulopathy leading to a clinically relevant bleeding risk Calculated creatinine clearance \< 30 mL/min
C: Inclusion Criteria:

* Confirmed diagnosis of COVID-19 by RT-PCR or serology with presence of IgM positive antibodies;
* Lung image (X-ray or chest CT) with involvement of at least 25% of the parenchyma;
* O2 saturation in ambient air less than or equal to 93%
* Alteration of inflammatory tests

  * D-Dimer above the reference value and
  * Elevation of C-reactive protein, ferritin or lactic dehydrogenase
* Sign the consent form.

Exclusion Criteria:

* QT interval prolongation
* Imminence of orotracheal intubation (intubation prediction in the first 4 hours after randomization)
* Women who are pregnant or breastfeeding
* Corticosteroid allergy or intolerance
* Chronic corticosteroid users (prednisone equivalent \> 10 mg daily)
* Patients diagnosed with cancer with increased bleeding potential
* Patients in hemodialysis
* History of peptic ulcer
* Herpes zoster infection
* History or active treatment of tuberculosis
* Systemic fungal infection
* Use of anticoagulation due to previous pathology
* Glaucoma
* Live virus vaccine up to 90 days before randomization
* Known coagulopathy or thrombocytopenia (\<40,000/mm3) or hypofibrinogenemia (\< 50 mg/dL)
* Recent bleeding
* Another limiting comorbidity for administering the therapies provided for in this protocol in in researcher's opinion
D: Inclusion Criteria:

1. Positive SARS-CoV-2 diagnostic (on pharyngeal swab of deep airways material)
2. Positive pressure ventilation (either non-invasive or invasive) from \> 24 hours
3. Invasive mechanical ventilation from \< 96 hours
4. P/F ratio \< 150
5. D-dimer level \> 6 x upper limit of local reference range
6. PCR \> 6 fold upper limit of local reference range

Exclusion Criteria:

1. Age \< 18 years
2. On-going treatment with anticoagulant drugs
3. Platelet count \<100.000/mmc
4. History of heparin-induced thrombocytopenia
5. Allergy to sodium enoxaparine or other LMWH, unfractionated heparin or metylprednisolone;
6. Active bleeding or on-going clinical condition deemed at high risk of bleeding contraindicating anticoagulant treatment
7. Recent (in the last 1 month prior to randomization) brain, spinal or ophthalmic surgery
8. Chronic assumption or oral corticosteroids
9. Pregnancy or breastfeeding or positive pregnancy test. In childbearing age women, before inclusion, a pregnancy test will be performed if not available;
10. Clinical decision to withhold life-sustaining treatment or "too sick to benefit";
11. Presence of other severe diseases impairing life expectancy (e.g. patients are not expected to survive 28 days given their pre-existing medical condition);
12. Lack or withdrawal of informed consent.

Answer: B