Effectiveness and cost of rapid and conventional laboratory methods for Mycobacterium tuberculosis screening.
OBJECTIVE
Because delay in the diagnosis of tuberculosis (TB) contributes to the spread of disease and the associated mortality risk, the authors examined the effectiveness and cost of recent advances in methods of diagnosing TB and testing for drug susceptibility, comparing these rapid methods to traditional approaches.


METHODS
Decision analysis was used to compare newer rapid and older nonrapid methods for diagnosing TB and testing for drug susceptibility. The average time to diagnosis, average time to treatment, average mortality, and cost of caring for patients evaluated for TB were compared.


RESULTS
Using a combination of solid medium and broth cultures, nucleic acid probes for identification, and radiometric broth drug susceptibility testing would lead 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 1000 patients evaluated (31%) and the average cost per patient would drop by $272 (18%).


CONCLUSIONS
In this era of cost containment, it is important to incorporate test sensitivity and specificity when evaluating technologies. Tests with higher unit costs may lead to lower medical expenditures when diagnostic accuracy and speed are improved. U.S. laboratories should employ available rapid techniques for the diagnosis of TB.
Heymann
S J
SJ
Department of Health and Social Behavior, Harvard School of Public Health, Boston, MA 02115, USA.
Brewer
T F
TF
Ettling
M
M
D001431:Bacteriological Techniques / Q000191:economics / Q000592:standards*; D003363:Cost Control; D003362:Cost-Benefit Analysis; D003663:Decision Trees; D004352:Drug Resistance, Microbial; D005102:Health Expenditures / Q000706:statistics & numerical data; D006801:Humans; D008403:Mass Screening / Q000191:economics / Q000379:methods*; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D015995:Prevalence; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors; D014376:Tuberculosis / Q000175:diagnosis* / Q000191:economics / Q000382:microbiology* / Q000401:mortality / Q000517:prevention & control; D014481:United States / Q000453:epidemiology