DIAGNOSTIC TEST should be evaluated in an orderly process from its dev
elopment to its dissemination, Ideally, a test should meet specific cr
iteria for each of the six levels of the hierarchical model of efficac
y described by Fryback and Thornbury (1) before it is disseminated thr
oughout the medical community, In addition, a test should be evaluated
at the six levels sequentially so that resources are not expended on
an expensive evaluation that is premature and possibly futile. What ar
e these criteria and how should they be met? The answers to these ques
tions depend on the proposed use of the test and other variables that
relate to decision making (2), A brief description of formal decision
analysis is helpful in proposing criteria for the six levels of effica
cy.