D R Anderson

Dr D R Anderson, Queen Elizabeth II Health Sciences Centre, Halifax, Nova Scotia, Canada; david.anderson@dal.ca

STUDY DESIGN

Design:

randomised, controlled, non-inferiority trial.

Allocation:

concealed.*

Blinding:

blinded (clinicians, outcome assessors during initial assessment, and adjudication committee).*

STUDY QUESTION

Setting:

outpatient clinics, emergency departments, and inpatient units of 5 academic healthcare centres in Canada and the USA.

Patients:

1417 patients ⩾18 years of age (mean 53 y, 62% women) who presented with signs and symptoms of acute pulmonary embolism (PE; acute onset of new or worsening shortness of breath, chest pain, haemoptysis, pre-syncope, or syncope), with or without signs of deep venous thrombosis (DVT); and were assessed to be clinically likely (Wells model score ⩾4.5) or unlikely (score <4.5) to have PE but with a positive D-dimer test. Exclusion criteria included PE or DVT diagnosis in the previous 3 months; unchanged pulmonary symptoms in the previous 2 weeks; need for …