MEDICAL-RESOURCE USE FOR SUSPECTED TUBERCULOSIS IN A NEW-YORK-CITY HOSPITAL

OBJECTIVE: To compare resource use by diagnostic outcome among hospita l admissions during which tuberculosis (TB) was suspected. DESIGN: Ret rospective study based on chart review and microbiology laboratory dat a. SETTING: The department of medicine in a municipal hospital serving central Brooklyn, New York. PARTICIPANTS: We identified all adult adm issions in 1993 during which TB was suspected. We assigned each admiss ion to one of four mutually exclusive groups defined by the results of microbiological tests (acid-fast bacilli [AFB] smear and culture): cu lture-positive and smear-positive (C+S+); culture-positive and smear-n egative (C+S-); culture-negative and smear-positive (C-S+); or culture -negative and smear-negative (C-S-). Each admission was divided into t wo separate periods to which the utilization of medical resources was assigned: the diagnostic and the postdiagnostic periods, which were se parated by the date of receipt of the first definitive culture report. RESULTS: Data on 519 admissions (93 C+S+; 57 C+S-; 30 C-S+; and 339 C -S-) were analyzed. Although C+S+ were more likely than other groups t o have an admitting diagnosis of TB, approximately one quarter of the admissions without TB (C-S+, C-S-) were admitted with the principal di agnosis of TB. For the four groups, C+S+, C+S-, C-S+, and C-S-, the re spective rates of TB isolation and anti-TB treatment, and median lengt hs of isolation were 98%, 87%, and 34 days; 74%, 74%, and 7 days; 83%, 83%, and 15 days; and 44%, 29%, and 0 days. During the diagnostic per iod, the rate and length of isolation were similar in the AFB-smear-po sitive groups (C+S+ and C-S+). We estimated that admissions without cu lture-proven TB (C-S+ and C-S-) accounted for 3,174 (36%) of the 8,712 days of TB isolation expended and for 65% of the 16,671 days of anti- TB treatment. The vast majority of this resource consumption (2,737 [8 6%] of 3,174 days of isolation) occurred during the diagnostic period before a definitive culture result was known. CONCLUSIONS: Our results suggest that prolonged diagnostic uncertainty and misclassification o f cases due to false-positive and false-negative smears are associated with substantial medical-resource consumption. New diagnostic modalit ies that reduce the period of diagnostic uncertainty could reduce the utilization of resources later found to be unnecessary (Infect Control Hosp EPidemiol 1998;19:747-753).