The minimally important difference and patient acceptable symptom state for the Raynaud's condition score in patients with Raynaud's phenomenon in a large randomised controlled clinical trial.

Abstract

The Raynaud's condition score (RCS) is a validated outcome measure for Raynaud's phenomenon (RP). To assess the minimally important difference (MID) and patient acceptable symptom state (PASS) for RCS in patients with RP. and methods Patients with active RP (n=162) (mean RCS >25 (0-100 visual analogue scale) participated in a placebo-controlled, crossover randomised clinical trial (RCT). Data from the two treatment groups were combined for this analysis. Retrospective and prospective anchors were administered during the RCT. MID groups were defined as the group who reported being somewhat better (anchor #1) and a one-step change from "unbearable" to "very severe", etc (anchor #2). Patients were considered to have achieved PASS if they rated their Raynaud's condition as "very mild" or "mild" at the last study visit. The mean age of participants was 48.9 years and the mean baseline RCS was 46.4 points. The RCS change score for the MID improvement group ranged from -13.9 to -14.3 points and PASS estimate was 34.0 points. The MID and PASS estimates for RCS are 14-15 points for improvement and 34 points, respectively, on a 0-100 scale in a large RCT of patients with active RP. This information can aid in interpreting RCS in future RP trials.