Cost-effectiveness of QuantiFERON-TB Gold In-Tube versus tuberculin skin test for diagnosis and treatment of Latent Tuberculosis Infection in primary health care workers in Brazil.

OBJECTIVES

The goal of this study was to perform a cost-effectiveness analysis from the public health system perspective, comparing five strategies for Latent Tuberculosis Infection (LTBI) diagnosis in primary health care workers in Brazil.

DESIGN

Analytical model for decision making, characterized by cost-effectiveness analysis.

SETTING

Primary Care Level, considering primary health care workers in Brazil.

PARTICIPANTS

An analytical model for decision making, characterized by a tree of probabilities of events, was developed considering a hypothetical cohort of 10,000 primary health care workers, using the software TreeAge Pro™ 2013 to simulate the clinical and economic impacts of new diagnostic technology (QuantiFERON®-TB Gold in-Tube) versus the traditional tuberculin skin test.

METHODS

This model simulated five diagnostic strategies for LTBI in primary health care workers (HCW) in Brazil: tuberculin skin testing using ≥5 mm cut-off, tuberculin skin testing ≥10 mm cut-off, QuantiFERON®-TB Gold in-Tube, tuberculin skin testing using ≥5 mm cut-off confirmed by QuantiFERON®-TB Gold In-Tube if TST positive, tuberculin skin testing using ≥10 mm cut-off confirmed by QuantiFERON®-TB Gold In-Tube if TST positive.

PRIMARY AND SECONDARY OUTCOME MEASURES: The outcome measures are the number of individuals correctly classified by the test and the number of Tuberculosis cases avoided.

RESULTS

The most cost-effective strategy was the tuberculin skin test considering ≥10mm cut-off. The isolated use of the QuantiFERON®-TB Gold In-Tube revealed the strategy of lower efficiency with incremental cost-effectiveness ratio (ICER) of US$ 146.05 for each HCW correctly classified by the test.

CONCLUSIONS

The tuberculin skin test using ≥10 mm cut-off was the most cost-effective strategy in the diagnosis of Latent Tuberculosis Infection in primary health care works in Brazil.