External Validation of the DASH prediction rule: a retrospective cohort study

Background The DASH prediction model has been proposed as a guide to identify patients at low risk of recurrence of venous thromboembolism (VTE), but has never been validated in an independent cohort. Aims To validate the calibration and discrimination of the DASH prediction model. We were also willing to evaluate the DASH score in a predefined patient subgroup aged >65 years. Methods Patients with a proximal unprovoked DVT or PE, who received a full course of VKA or DOAC (>3 months) and having D-Dimer measured after treatment withdrawal were eligible. The DASH score was computed based on D-Dimer after therapy withdrawal and personal characteristics at the time of the event. Recurrent VTE events were symptomatic proximal or distal DVT/PE and were analyzed with a time-dependent analysis. Observed 12 and 24months recurrence rates were compared to recurrence rates predicted by the DASH model. Results We analyzed a total of 827 patients, of whom 100 (12.1%) had an objectively documented recurrence. As compared with the original DASH cohort, there was a greater proportion of subjects having a “low risk” ( 65 years (0.54) vs. younger ones (0.72). Conclusions These results confirm the validity of DASH prediction model, particularly in young subjects. The recurrence risk in elderly patients (>65 years) was, however, >5% even with the lowest DASH scores. This article is protected by copyright. All rights reserved.