The authors used data from a study conducted under the auspices of the Société Française de Rhumatologie to evaluate the sensitivity and specificity of the individual items of two sets of criteria for spondylarthropathy. The study included 124 patients with spondylarthropathy and 1,964 controls. They found that the spondylarthropathy criteria with the highest sensitivities and specificities were useful not only for classifying patients but also for assisting in the diagnosis of spondylarthropathy.