Clinical Impact and Cost-Effectiveness of Xpert MTB/RIF Testing in Hospitalized Patients with Presumptive Pulmonary Tuberculosis in the United States.
Clin Infect Dis. 2016 Dec 10;:
Authors: Cowan JF, Chandler AS, Kracen E, Park DR, Wallis CK, Liu E, Song C, Persing DH, Fang FC
BACKGROUND: Microscopic examination of acid-fast stained sputum smears is the current standard of care in the United States to determine airborne infection isolation (AII) of inpatients with presumptive pulmonary tuberculosis (PTB). However, nucleic acid amplification testing (NAAT) with the Xpert® MTB/RIF Assay (Xpert) may be more efficient and less costly.
METHOD: This prospective observational cohort study enrolled a consecutive sample of 318 AII-eligible inpatients from a public hospital in Seattle, Washington from March 2012 to October 2013. Sputum samples were collected from each inpatient and analyzed using smear microscopy, culture, drug susceptibility testing, and NAAT. The performance, clinical utility (AII duration and survival), and cost-effectiveness from an institutional perspective were compared for five testing strategies.
RESULTS: Among the 318 admissions with presumptive PTB, 20 (6.3%) were culture-positive for Mycobacterium tuberculosis The sensitivity of one Xpert, two Xperts, two smears or three smears compared to culture was: 0.85 (95%CI 0.61-0.96), 0.95 (95%CI 0.73-1.0), 0.70 (95%CI 0.46-0.88), and 0.80 (95%CI 0.56-0.93), respectively. A cost-effectiveness analysis of the study results demonstrated that an Xpert test on one unconcentrated sputum sample (assuming equivalent results for unconcentrated and concentrated sputum samples) is the most cost-effective strategy (99.9% preferred at willingness-to-pay of $50,000 USD) and on average would save 51.5 patient-hours in AII and up to $11,466 relative to microscopy without a compromise in sensitivity.
CONCLUSION: In hospitalized patients with presumptive PTB in a low burden setting, NAAT can reduce AII and is comparably sensitive, more specific, and more cost-effective than smear microscopy.
PMID: 27940948 [PubMed - as supplied by publisher]