Is Pt-VAS Necessary for Evaluation of Boolean Remission?

Abstract

We have investigated the importance of patient global assessment with visual analogue scale (Pt-VAS) in Boolean evaluation as an index of disease activity remission in patients with rheumatoid arthritis (RA). Among 298 RA patients referred to our institution, Boolean evaluation indicated that among 4408 treatment opportunities, remission was evident in 2052, whereas Pt-VAS indicated remission for all four components on 1618 occasions. Pt-VAS demonstrated a significantly close correlation with the patient's clinical situation, in particular the Pain Score and health assessment questionnaire (HAQ). As Pt-VAS increased, there was a gradual reduction of sensitivity and an increase of specificity for the group in which tender joint count (TJC), swollen joint count (SJC), and C-reactive protein (CRP) were within 1. With regard to sensitivity, all measurements demonstrated more than 90% simplified disease activity index (SDAI) remission, but within 10 mm the specificity was less than 50%. Up to 30 mm, both sensitivity and specificity were more than 90%, while within 20 mm specificity was almost 80%. Therefore, we conclude that in Boolean evaluation of remission, Pt-VAS might be acceptable within 20 mm.