4Van der Linden S, Valkenburg HA, Cats A. Evaluation of diagnostic criteria for ankylosing spondylitis. A proposal for modification of the New York criteria [ J]. Arthritis Rheum, 1984,27 (4) :361-368.
5Dincer U, Cakar E, Kiralp MZ, et al. Diagnosis delay in patients with ankyIosing spondylitis:possible reasons and proposals for new diag- nosticcriteria [ J ]. Clin Rheumatol,2008,27 ( 4 ) :457-462.
6Rudwaleit M. New approaches to diagnosis and classification of axial and peripheral spondyloarthritis [ J ]. Curr Opin Rheumatol, 2010,22 (4) :375-380.
7Mehrzad H, Amir G, Alireza K, et al. Ankylosing spondylitis in iran ; late diagnosis and its causes[ J]. Iran Red Crescent Med J,2014, 16 (4) :e11798.
8Feldtkeller E. Age at disease onset and delayed diagnosis of spondy- loarthropathies[ J. Z Rheumatol, 1999,58 ( 1 ) :21-30.
9Rudwaleit M, Khan MA, Sieper J. The challenge of diagnosis and classification in early ankylosing spondylitis: do we need new criteria [J] ? Arthritis Rheum, 2005,52(4) :1000-1008.
10Boyer GS, Templin DW, Bowler A, et al. A comparison of patients with spondyloarthropathy seen in specialty clinics with those identi- fied in a communitywide epidemiologic study. Has the classic case misled us[J] ? Arch Intern Med, 1997,157(18) :2111-2117.