Incorrect Values for Intractable and Cluster Headaches at Enrollment Shown in Figure 1 and Incorrect Prevalence of Headache at Ten Years in Text of the Article by Hanly et al (Arthritis Rheum, November 2013). Issue 6 (June 2014) - Hanly, John G.; Urowitz, Murray B.; O'Keeffe, Aidan G.; Gordon, Caroline; Bae, Sang‐Cheol; Sanchez‐Guerrero, Jorge; Romero‐Diaz, Juanita; Clarke, Ann E.; Bernatsky, Sasha; Wallace, Daniel J.; Ginzler, Ellen M.; Isenberg, David A.; et al.