Developing & validating an index for measuring health in patients with AS

Kiltz U, van der Heijde D, Cieza A, Boonen A, Stucki G, Üstün B and Braun J. Developing and validating an index for measuring health in patients with ankylosing spondylitis. Rheumatology. 2011; 50(5): 894-898. Abstract.