In the article by Meune et al in the September 2011 issue of Arthritis & Rheumatism (pages 2790–2796), an error for the correcting factors applied to FVC and DLCO/alveolar volume was introduced. The third and fourth sentences of the Statistical Analysis section (page 2791) should have read “To calculate RPS indicative of higher risk, some measurements that decrease with advancing disease were corrected by subtracting the observed value from the highest value measured in the sample. For example, FVC and DLCO/alveolar volume were corrected to 150% of predicted − FVC and 100% of predicted − DLCO/alveolar volume, respectively.” In addition, the last sentence of the Patients Included in the Derivation Sample section (page 2792) should have read “We calculated the Cochin RPS score as follows: RPS = 0.0001107(age) + 0.0207818(150 − FVC) + 0.04905(100 − DLCO/alveolar volume).”

We regret the error.