For the diagnosis of SLE, 6 tests are done of which 4 came as positive and 2 negative. For the confirmation the following must be known:

For the confirmation we need to know the amount of previously unrecognised disease that is diagnosed as a result of screening effo. It depends on sensitivity and specificity of the test, prevalence of the disease, paicipation of the individuals in the detecting programme. So in a test to diagnose SLE, there should be the previous probability and the sensitivity an specificity of tests. Ref: Park's Textbook of Preventive and Social Medicine, 21st Edition, Page 56