Application of the 1982 revised criteria for the classification of systemic lupus erythematosus on a cohort of 346 Norwegian patients with connective tissue disease.

By reviewing patient's records, we evaluated the sensitivity and specificity of the 1982 revised classification criteria for systemic lupus erythematosus on a cohort of 346 Norwegian patients with connective tissue disease, seen at a rheumatology referral center in the period 1986-95. The patients with CTD other than SLE were used as controls. The number of the 1982 revised classification criteria for SLE fulfilled by each individual patient was calculated. Fifty-five of the 76 SLE patients (72%) met four or more criteria for SLE, giving a low sensitivity of 72%. Twenty-three of the 270 patients with CTD other than SLE (9%) met four or more criteria for SLE, giving an acceptable specificity of 91%. Applying the "revised/revised 1997 ACR criteria for SLE" the sensitivity would have increased to 78% and the specificity reduced to 89%. The sample of SLE patients was characterized by mild disease with a low proportion of severe internal manifestations.