Why are inaccurate tuberculosis serological tests widely used in the Indian private healthcare sector? A root-cause analysis.

Serological tests for tuberculosis are inaccurate and WHO has recommended against their use. Although not used by the Revised National TB Control Programme (RNTCP), serodiagnostics are widely used in the private sector in India. A root-cause analysis was undertaken to determine why serological tests are so popular, and seven root causes were identified that can be grouped into three categories: technical/medical, economic, and regulatory. Technical/medical: RNTCP's current low budget does not allow scale-up of the newer, WHO-endorsed technologies. Thus, under the RNTCP, most patients have access to only smear microscopy, a test that is insensitive and underused in the private sector. Because there is no accurate, validated, point-of-care test for TB, serological tests meet a perceived need among doctors and patients. Economic: While imported molecular or liquid culture tests are too expensive, there are no affordable Indian versions on the market, leaving serological tests as the main alternative. Although serological tests are inaccurate, various players along the value chain profit from their use, and this sustains a market for these tests. Regulatory: TB tests are poorly regulated and a large number of serological kits are on the market. Private healthcare in general is poorly regulated, and doctors in the private sector are outside the scope of RNTCP and do not necessarily follow standard guidelines. A clear understanding of these realities should facilitate market-based strategies that can help replace serological tests with accurate, validated tools.