Key points are not available for this paper at this time.
A controlled study of 138 subjects demonstrated that the clinical history may be sensitive (95%) and specific (85%) in the differential diagnosis of ankylosing spondylitis when reliance on five specific historic features is made. Back pain that is insidious in onset, in a patient younger than 40 years, persisting for at least three months, associated with morning stiffness and improving with exercise is characteristic of inflammatory spinal disease. (JAMA237:2613-2614, 1977)
Andrei Călin (Mon,) studied this question.