Summary
Post-thrombotic syndrome (PTS) is a long-term complication of deepvein thrombosis
(DVT). The Villalta scale is the recommended tool for diagnosing PTS, but requires
a clinician’s assessment in addition to patient self-assessment. In the present study,
we validated a self-administered tool for patient reporting of leg symptoms and signs
as a mean to assess PTS. We first validated a form for patient self-reported Villalta
(PRV1), then developed and validated a visually assisted form (PRV2). The validity
of PRV1 and PRV2 was assessed in patients diagnosed with DVT between 2004 and 2012.
Median time from DVT to inclusion was 5.1 and 3.5 years for PRV1 (n=162) and PRV2
(n=94), respectively. Patients were requested to complete the PRV form before a scheduled
visit. PTS diagnosed by the original Villalta scale during the visit served as the
reference method. PRV1 showed only moderate agreement for diagnosing PTS compared
with the original Villalta scale (kappa agreement 0.60, 95 % CI 0.48–0.72), whereas
PRV2 showed very good agreement (0.82, 95 % CI 0.71–0.94). In the validation of PRV2,
PTS was diagnosed in 54 (57 %) patients according to the original Villalta scale and
in 60 (64 %) by PRV2. The sensitivity of PRV2 to detect PTS was 98 % and the specificity
was 83 %. We conclude that the visually assisted form for PRV is a valid and sensitive
tool for diagnosing PTS. Such a tool could be applied in further clinical studies
of PTS, making studies less resource demanding by reducing the need for in-person
clinic visits.
Supplementary Material to this article is available online at www.thrombosis-online.com.
Keywords
Deep-vein thrombosis - long-term complication - patient-reported outcome - post-thrombotic
syndrome - Villalta scale