Clinic A has devised a differential diagnostic system between two disease types a and b based on four diagnostic blood tests I - IV conducted on 15 patients with known type a and 17 patients with known type

b. The data (in standard units) on which the system has been based are set out in Table 9.7.

Clinic B is also engaged in this differential diagnosis problem and has collected similar data on its patients but is not yet in a position to construct its own diagnostic system. Moreover, while its methods of carrying out tests III and IV are identical with those of clinic A there is considerable doubt about the comparability of tests I and II with those of clinic A. To resolve this problem aliquots of 25 blood samples have been assigned to both clinics A and B for comparison of the results of tests I and II. The results of this calibrative experiment are set out in Table 9.8.

On the basis of all this information investigate the possibility of transferring clinic A’s diagnostic system to the situation in clinic B, and prepare a full report of your findings for the two clinics.