Performance of two clinical scales to assess quality of life in patients with post-thrombotic syndrome

Abstract

ObjectiveWe directly compared the Villalta scale and the Venous Clinical Severity Score (VCSS) to determine which of the two measures would be better at capturing clinically important cases of post-thrombotic syndrome (PTS) and PTS severity compared with patient-reported quality of life (QOL) scores. MethodsWe performed a secondary analysis of the ATTRACT (acute venous thrombosis: thrombus removal with adjunctive catheter-directed thrombolysis) trial study population. We calculated the correlations of the Villalta scores and VCSSs with QOL scores (short-form 36-item health survey [SF-36] physical component summary [PCS] and mental component summary [MCS]; and VEINES [venous insufficiency epidemiological and economic study]-QOL/symptom [VEINES-QOL/Sym] questionnaire) at each study visit (6, 12, 18, and 24 months of follow-up). The correlation of the random intercept (mean scores) and random slope (rate of change of the scores) among the Villalta scores, VCSS, and VEINES-QOL/Sym scores was assessed using a multivariate longitudinal model. ResultsThe median correlation between Villalta scores and VCSSs was 0.72. The median correlation between the Villalta scores and VEINES-QOL and VEINES-Sym scores at all follow-up visits was −0.68 and −0.71, respectively. The median correlation between the Villalta scores and SF-36 PCS and MCS scores was −0.51 and −0.31, respectively. For the VCSSs, the median correlation with the VEINES-QOL and VEINES-Sym scores at all follow-up visits was −0.39 and −0.41, respectively. The median correlation between the VCSSs and SF-36 PCS and MCS scores was −0.32 and −0.13, respectively. The correlations between the random effects in the multivariate longitudinal models showed a similar pattern. The effect of covariate adjustment by age, sex, and body mass index was minor. ConclusionsThe Villalta scores and VCSSs correlated strongly. The Villalta scale showed a substantially greater correlation with venous disease-specific and general QOL scores compared with the correlation with the VCSS. Our findings suggest that when a single scale is used to assess for clinically meaningful PTS, the Villalta scale will better capture the effects of PTS on patient-reported QOL.