A Comparison of Villalta-Prandoni Scale and Venous Clinical Severity Score in the Assessment of Post Thrombotic Syndrome

Background: Post-thrombotic syndrome (PTS) is the most important late complication of acute deep venous thrombosis (DVT), with as many as two-thirds of patients developing symptoms of pain, edema, hyperpigmentation, or ulceration. Although several instruments are available for evaluation of the severity of PTS, including the VillaltaePrandoni scale (VPS) and Venous Clinical Severity Score (VCSS), no studies have yet compared the 2 instruments. The purpose of this study is to compare the 2 instruments as part of a larger randomized controlled study that assessed the impact of graduated compressive stockings in the prevention of PTS. Methods: Sixty-nine consecutive patients with acute DVT documented by duplex ultrasonography were randomized to treatment with 30-40 mm Hg graduated compressive stockings (GCS) or no stockings. Patients were followed clinically at months 1, 3, 6, 12, 18, and 24 after the diagnosis of DVT. PTS as defined by the VPS and VCSS were assessed at these follow-up visits. Based upon the VPS, PTS was scored as absent (score < 3 or 3 without objective criteria), mild to moderate (score >= 3 with 1 objective criteria), or severe (score >= 4). For the VCSS, PTS was considered to be absent (score <= 3), mild to moderate (score 4-7), or severe (score >= 8). The 2 instruments were compared for mild to moderate and severe disease using the Pearson chi-squared test and gamma statistic. Results: Good correlation was detected in the ability of VPS and VCSS instruments to detect mild to moderate disease (gamma statistic 0.71-0.98; P < 0.05). For severe disease, a statistically significant correlation was not found in the ability of the 2 instruments to detect disease (gamma statistic 0.5-0.98; P > 0.05), especially at 12 and 24 months. Conclusion: Both VPS and the VCSS scoring systems are important tools in the identification and follow-up of PTS. There exists agreement between the 2 instruments for detecting mild to moderate disease. For severe disease however, VCSS may possibly be a more sensitive instrument.