Comparison of Performance of Two Clinical Scales To Diagnose the Post-Thrombotic Syndrome: Correlation with Patient-Reported Disease Burden and Valvular Reflux.

Background and Objectives: There is no objective, criterion standard test to diagnose the post thrombotic syndrome (PTS). Two clinical scales have been used to classify deep vein thrombosis (DVT) patients as having or not having the PTS: the Villalta scale and the Ginsberg measure. Differences in test characteristics of these measures could help explain differing rates of PTS reported after DVT. During a Canadian prospective cohort study of long-term outcomes after DVT (The VETO Study), we carried out a substudy to evaluate agreement between the Villalta and Ginsberg measures with regard to (1) proportion of patients classified as having PTS; (2) relation to patient-reported quality of life (QOL); and (3) correlation with venous valvular reflux, a physiological indicator of chronic venous disease.

Methods: For this substudy, 259 VETO patients were assessed for ipsilateral PTS at the 1 year follow-up visit using both the Villalta scale (grades the severity of 5 symptoms and 6 signs from 0–3; a summed total score of ≥5 indicates PTS, and >14 or presence of ulcer indicates severe PTS) and the Ginsberg PTS measure (PTS defined by the presence of daily leg pain and swelling for ≥ 1 month, occurring 6 months or more after DVT, made worse by standing/walking and relieved by rest/leg elevation). Patients also completed generic (SF-36) and disease-specific (VEINES-QOL) QOL questionnaires and underwent a standardized ultrasound assessment for ipsilateral popliteal venous valvular reflux. We compared the proportion of patients classified as having PTS with each measure and assessed associations with QOL and valvular reflux.

Results: Proportion of patients classified as having PTS was 96/259 (37%) (5/96 severe) with the Villalta scale and 21/259 (8.1%) with the Ginsberg measure (kappa 0.22; 95% CI 0.13, 0.32). Agreement between measures was better for severe PTS than for any PTS. For both measures, generic and disease specific-QOL scores were significantly lower (i.e. poorer QOL) in patients with vs. without PTS; however, QOL was worse in patients with Ginsberg-PTS than in patients with Villalta-PTS. Reflux was not significantly associated with PTS for either measure.

Conclusions: The proportion of patients classified as having PTS was more than 4-fold higher with the Villalta measure than with the Ginsberg measure. While both measures showed a graded association with QOL, patients with Ginsberg-PTS had poorer QOL and higher mean Villalta scores, indicating that the Ginsberg measure identifies more severe disease. The presence of reflux was not discriminating for the diagnosis of PTS with either measure.