Subjects who present to the Massachusetts General Hospital (MGH) ED or EDOU who meet all inclusion and no exclusion criteria.

Intervention: Telephone follow-up at 7 and 30 days.

Subjects who present to the Brigham and Women's Hospital (BWH) ED or EDOU who meet all inclusion and no exclusion criteria.

Intervention: Telephone follow-up at 7 and 30 days.

1. Contemporary controls: subjects diagnosed with Venous Thromboembolism (VTE) in the ED and who are not eligible for outpatient treatment

2. Historical controls:

   1. Subjects enrolled in the prospective and retrospective SPEED-D study (PI: Kabrhel) and diagnosed with PE between 2006-2012.
   2. Subjects diagnosed with VTE in the MGH and BWH ED in the 18 months prior to the use of the clinical outpatient treatment of PE protocol.

Prospectively enrolled subjects will have a 7- and 30-day phone call.

To compare patients diagnosed with VTE after protocol implementation to those diagnosed with VTE prior to protocol implementation in terms of four measures of efficiency:

A) ED length of stay - defined as time from ED registration to departure from the ED (to either the inpatient floor or to the EDOU).

B) ED disposition time - defined as time from ED registration to bed request.

C) Hospital length of stay - defined as time from ED registration to departure from the hospital.

D) Cost - defined as the estimated cost of care including diagnostic testing, imaging, hospital inpatient/observation unit stay, medication/pharmacy costs.

To assess the safety of outpatient VTE treatment, specifically with regards to:

A) recurrent venous thromboembolism;

B) bleeding (major or minor);

C) unscheduled return to hospital for any reason;

D) death from any cause: occurring up to 30 days after their discharge.