EFFECTIVENESS AND COST OF RAPID AND CONVENTIONAL LABORATORY METHODS FOR MYCOBACTERIUM-TUBERCULOSIS SCREENING

Objective. Because delay in the diagnosis of tuberculosis (TB) contrib utes to the spread of disease and the associated mortality risk, the a uthors examined the effectiveness and cost of recent advances in metho ds of diagnosing TB and testing for drug susceptibility, comparing the se rapid methods to traditional approaches. Methods. Decision analysis was used to compare newer rapid and older nonrapid methods for diagno sing TB and testing for drug susceptibility. The average time to diagn osis, average time to treatment, average mortality, and cost of caring for patients evaluated fbr TB were compared. Results. Using a combina tion of solid medium and broth cultures, nucleic acid probes for ident ification, and radiometric broth drug susceptibility testing would lea d to diagnosis on average 15 days faster and to appropriate therapy on average five days sooner than methods currently employed by many U.S. laboratories. The average mortality would drop by five patients per 1 000 patients evaluated (31%) and the average cost per patient would dr op by $272 (18%). Conclusions. In this era of cost containment, it is important to incorporate test sensitivity and specificity when evaluat ing technologies. Tests with higher unit costs may lead to lower medic al expenditures when diagnostic accuracy and speed are improved. U.S. laboratories should employ available rapid techniques for the diagnosi s of TB.