Xpert®MTB/RIF for the Diagnosis of Tuberculosis in a Remote Arctic Setting: Impact on Cost and Time to Treatment Initiation

Abstract

BackgroundTuberculosis (TB) remains a significant health problem in the Canadian Arctic. Substantial health system delays in TB diagnosis can occur, in part due to the lack of capacity for onsite microbiologic testing. A study recently evaluated the yield and impact of a rapid automated PCR test (Xpert®MTB/RIF) for the diagnosis of TB in Iqaluit (Nunavut). We conducted an economic analysis to evaluate the expected cost relative to the expected reduction in time to treatment initiation, with the addition of Xpert®MTB/RIF to the current diagnostic and treatment algorithms used in this setting.MethodsA decision analysis model compared current microbiologic testing to a scenario where Xpert®MTB/RIF was added to the current diagnostic algorithm for active TB, and incorporated costs and clinical endpoints from the Iqaluit study. Several sensitivity analyses that considered alternative use were also considered. We estimated days to TB diagnosis and treatment initiation, health system costs, and the incremental cost per treatment day gained for each individual evaluated for possible TB.ResultsWith the addition of Xpert®MTB/RIF, costs increased while days to TB treatment initiation were reduced. The incremental cost per treatment day gained (per individual investigated for TB) was $164 (95% uncertainty range $85, $452). In a sensitivity analysis that considered hospital discharge after a single negative Xpert®MTB/RIF, the Xpert®MTB/RIF scenario was cost saving.InterpretationAdding Xpert®MTB/RIF to the current diagnostic algorithm for TB in Nunavut appears to reduce time to diagnosis and treatment at reasonable cost. It may be especially well suited to overcome some of the other logistical barriers that are unique to this and other remote communities.

Addressing tuberculosis among Inuit in Canada

“…Initially part of a research program, this test has now become widely available to test sputa for many residents of eastern Nunavut for the presence of TB. It has been shown that quicker diagnosis of active TB results in earlier treatment (preventing progression of the disease) and less transmission of TB (10). These results have the potential to translate into significant benefits for patients and the health care system.…”

Model-based economic evaluations of diagnostic point of care tests were rarely fit for purpose

“…The introduction of a POCT changed the location of testing in eight models (26,28,41,53,72,85,89,91) (Table 3). This was predominantly a move from secondary to primary care settings, with one model examined the provision of testing in a pharmacy setting (28).…”

The use of technology to improve health care to Saskatchewan’s First Nations communities

“…If the test is negative, it rules out TB quickly and prevents unnecessary isolation. If the test is positive, it can lead to early diagnosis, rapid initiation of treatment and shorter exposure time of active TB to other community members (17,18).…”