Dr. Khanna has received consultant fees, speaking fees, and/or honoraria (less than $10,000 each) from Actelion, Gilead, Bayer, Pfizer, Digna, United Therapeutics, Roche, and Sanofi-Aventis.
Evaluation of Test Characteristics for Outcome Measures Used in Raynaud's Phenomenon Clinical Trials
Article first published online: 28 MAR 2013
Copyright © 2013 by the American College of Rheumatology
Arthritis Care & Research
Volume 65, Issue 4, pages 630–636, April 2013
How to Cite
Gladue, H., Maranian, P., Paulus, H. E. and Khanna, D. (2013), Evaluation of Test Characteristics for Outcome Measures Used in Raynaud's Phenomenon Clinical Trials. Arthritis Care Res, 65: 630–636. doi: 10.1002/acr.21858
- Issue published online: 28 MAR 2013
- Article first published online: 28 MAR 2013
- Accepted manuscript online: 12 SEP 2012 10:54PM EST
- Manuscript Accepted: 5 SEP 2012
- Manuscript Received: 30 APR 2012
- NIH/National Institute of Arthritis and Musculoskeletal and Skin Diseases. Grant Number: K24AR063120
Randomized controlled trials (RCTs) in Raynaud's phenomenon (RP) have shown conflicting efficacy data. Also, there is no consensus on the outcome measures that should be used. Our objectives were to assess the reliability of individual core set measures used in 3 RCTs, evaluate the placebo response for individual core set measures, and determine if a composite of individual core set measures will decrease the placebo response, which may improve our ability to see treatment effects in future trials.
We analyzed core set measures from 249 patients in the placebo-treated groups from 3 RCTs. Core set measures analyzed included the Raynaud's Condition Score (RCS); patient and physician assessment of RP; pain, numbness, and tingling during an RP attack; average number of attacks/day; and duration of attacks. Intraclass correlation coefficients (ICCs) were calculated during the run-in period to the RCTs.
ICCs of ≥0.70 were observed for the RCS, attack symptoms, and average attacks/day. A high placebo response rate was observed for all individual core measures except the duration of attacks. For the RCS, the placebo response ranged from 56% with ≥10% improvement to 19.5% with ≥60% improvement. In contrast, placebo response rates of 10–20% were observed when several core set measures were combined to develop a composite score.
Outcome measures used in RCTs of RP are associated with marked variability. A combination of outcome measures is associated with low placebo responses. Future studies are needed to assess if a composite score will be able to differentiate placebo from an effective agent.