Some results on combinations of two binary screening tests

When two medical screening tests for a disease exist, it may be appealing to combine them to increase screening accuracy. Combination of two valid screening tests, where each independently has screening performance, can increase the overall disease screening performance. Some results are obtained when two binary screening tests are combined according to the Boolean Any+ strategy, as defined by Maguire (1). These results are useful and provide investigators of two screening tests a sense of what to expect of the performance of the two tests when combined. This then may be followed by a clinical trial that directly demonstrates the benefit of the combined test.