Rapid Testing for the Diagnosis of Pulmonary Tuberculosis and Rifampicin Resistance: A Review of Cost-Effectiveness

Tuberculosis (TB) is a chronic multisystemic infectious disease caused by Mycobacterium tuberculosis. WHO estimates that approximately one-quarter of the world’s population is infected with M. tuberculosis. Globally, approximately 10 million people had TB in 2019, and there were approximately 1.2 million deaths attributable to the disease. The enormous health and economic burden caused by the disease make it a major public health issue. In Canada, active TB infection rates are one of the lowest in the world. There were 1,796 active cases of TB nationwide in 2017, mostly in foreign-born individuals and the Canadian Indigenous population. TB can affect almost all body systems, such as the central nervous system (e.g., TB meningitis), gastrointestinal tract (e.g., intestinal TB), and cardiovascular system (pericardial TB). Pulmonary TB is a debilitating disease affecting primarily the lungs. The main symptom of pulmonary TB is chronic cough that lasts for 2 weeks or longer. Other symptoms include fever, hemoptysis, anorexia, and loss of weight. TB is treated with antimicrobial agents such as rifampicin and isoniazid and it is completely curable with treatment with the appropriate agent for the appropriate duration. Early diagnosis and treatment are of utmost importance because TB is highly infectious, transmitted through droplet spread, and associated with long-term complications. The diagnostic tests for TB include chest radiography, sputum smear microscopy, sputum culture, and rapid and simultaneous TB and antibiotic susceptibility testing for pulmonary TB and rifampicin resistance. The Xpert M. tuberculosis complex and resistance to rifampicin (MTB/RIF) test is a Health Canada–approved rapid diagnostic test for pulmonary TB that uses polymerase chain reaction–based nucleic acid amplification to detect M. tuberculosis and rifampicin resistance. The results are available within 2 hours. It uses a disposable cartridge in which the sputum sample and reagent are mixed. The cartridge is then placed in the Xpert machine and automatically processed. The test is automated with a minimal training requirement and the results are rapidly available; therefore, Xpert testing can be useful in settings with resource constraints where the infection rates are high, such as in the northern regions of Canada. The objective of the current report is to review the evidence regarding the cost-effectiveness of the rapid and simultaneous TB and antibiotic susceptibility testing for pulmonary TB and rifampicin resistance. This report is an upgrade from a CADTH report (Summary of Abstracts) published in June 2020. Another report focused on the diagnostic accuracy of the rapid and simultaneous tuberculosis and antibiotic susceptibility testing for pulmonary TB and rifampicin resistance. These reports are components of a larger CADTH Condition Level Review on tuberculosis. More information on CADTH’s Condition Level Review of tuberculosis can be found in the CADTH website