For a first VTE attributed to a transient provoking factor, what factors make you extend anticoagulation to 6 months rather than stopping at 3 months?

For a first VTE attributed to a transient provoking factor, what factors make you extend anticoagulation to 6 months rather than stopping at 3 months?

• I stop at 3 months for most provoked VTEs if the provoking factor has resolved
• I extend to 6 months for higher-risk presentations (eg proximal DVT, large clot burden, or severe symptoms)
• I extend to 6 months if the provoking factor was minor (minor surgery, estrogen exposure, pregnancy, etc)
• I extend to 6 months if the provoking factor was major (major surgery, hospitalization with immobilization, etc)
• I obtain imaging at 3 months and extend to 6 months if there is residual clot burden
• Other