After deep vein thrombosis (DVT) is diagnosed, prompt evaluation and therapeutic intervention are of paramount importance for improvement in patient-important outcomes. We systematically reviewed patient-important outcomes in patients with suspected DVT, including mortality, incidence of pulmonary embolism (PE) and DVT, major bleeding, intracranial hemorrhage, and postthrombotic sequelae. We searched the Cochrane Central Register of Controlled Trials, Ovid Medline, Embase for eligible studies, references lists of relevant reviews, registered trials, and relevant conference proceedings. Two investigators screened and abstracted data. Nine studies with 5126 patients were included for lower extremity DVT. Three studies with 500 patients were included for upper extremity DVT. Among patients with lower extremity DVT, 0.85% (95% confidence interval [CI], 0% to 2.10%) and 0% developed recurrent DVT and PE, respectively, at 3 months. Among patients with upper extremity DVT, 0.49% (95% CI, 0% to 1.16%) and 1.98% (95% CI, 0.62% to 3.33%) developed recurrent DVT and PE, respectively, at 3 months. No major bleeding events were reported for those anticoagulated, which is lower than in other systematic reviews. For both upper and lower extremity DVT, low pretest probability patients with a negative D-dimer had a comparable incidence of VTE at 3 months (∼1%) as patients with a negative ultrasound (US). At higher pretest probabilities, negative US testing with or without serial US appears to be the safer option. In this review, we summarized the outcomes of patients evaluated by various diagnostic pathways. In most instances, there was significant limitation due to small population size or lack of direct evidence of effects of using a specific pathway. This systematic review was registered at PROSPERO as CRD42018100502.