Criteria for validating assessment tools potassium 40 dating formula
Objective To prospectively validate the HERDOO2 rule (Hyperpigmentation, Edema, or Redness in either leg; D-dimer level ≥250 μg/L; Obesity with body mass index ≥30; or Older age, ≥65 years), which states that women with none or one of the criteria can safely discontinue anticoagulants after short term treatment. Setting 44 secondary or tertiary care centres in seven countries.
Participants Of 3155 consecutive eligible participants with a first unprovoked venous thromboembolism (VTE, proximal leg deep vein thrombosis or pulmonary embolism) who completed 5-12 months of short term anticoagulant treatment, 370 declined to participate, leaving 2785 enrolled participants. Interventions Women with none or one of the HERDOO2 criteria were classified as at low risk of recurrent VTE and discontinued anticoagulants (intervention arm), whereas anticoagulant management for high risk women (≥2 HERDOO2 criteria) and men was left to the discretion of the clinicians and patients (observation arm).
Patients with malignancy arising after diagnosis of index VTE but before enrolment were not eligible for inclusion.
Patients with previous episodes of provoked VTE were eligible.
The baseline assessment took place 5-12 months after the index VTE event, while patients were still receiving oral anticoagulant treatment.
We documented demographic data, causes, and diagnostic or therapeutic management of the index VTE event.
Women who met two or more criteria and all men were classified as high risk.
Index VTE had to have been managed for 5-12 months with an appropriate anticoagulant treatment, including initial treatment with either unfractionated heparin, low molecular weight heparin, rivaroxaban, or apixaban, followed by 5-12 months of oral anticoagulant treatment with vitamin K antagonists (target international normalised ratio 2-3), dabigatran, rivaroxaban, apixaban, or edoxaban.
In the primary analysis, 17 low risk women who discontinued anticoagulants developed recurrent VTE during 564 patient years of follow-up (3.0% per patient year, 95% confidence interval 1.8% to 4.8%).