Use of the HLA B27 test in Auckland

An assessment was made of the probability of HLA B27 associated disease in 74 patients who had recently been tested. Six patients had definite, 31 possible, and 37 very unlikely HLA B27 associated disease. Thirteen patients were HLA B27 positive. Fourteen tests were ordered by rheumatologists (43% HLA B27 + ve) and 60 by other doctors (12% HLA B27 + ve) p less than 0.01. Non-rheumatologists ordered an excessive number of tests in patients with a low probability of HLA B27 associated disease.