In the article by Haglund et al in the December 2012 issue of Arthritis Care & Research (pages 1886–1894), a syntax error was recognized in the calculations of the Hospital Anxiety and Depression (HAD) score. Due to multicollinearity with the Bath Ankylosing Spondylitis Function Index, Bath Ankylosing Spondylitis Disease Activity Index, and EuroQol 5-domain, the HAD anxiety and depression score should not have been included in the logistic regressions as a covariate. The authors have performed new calculations based upon separate inclusions of the HAD in the multiple logistic regression analysis together with the other covariates. The corrected tables are available from the corresponding author. This error does not affect the conclusion of the article.
We regret the error.