The central government on March 28 said India has developed its own mathematical model to estimate the tuberculosis burden in the country.
Union Health Minister Mansukh Mandaviya said the model will use data sets from different programmes run by the government on tuberculosis for estimation.
“Through this system, the actual estimated data of TB incidence and mortality for the Indian population will be available by March every year. The WHO gives these estimates in October every year. India may also make such estimates for states in future using this model,” Mandaviya said.
The health minister said the mathematical model was also presented before the representatives of 40 countries, which were part of the 36th Stop TB Partnership board meeting held in Varanasi last week.
“We saw that the COVID mortality estimates by WHO were way off the mark from the actual deaths registered in India. Through this model, we can track the progress towards sustainable development goals on TB incidence and mortality,” he added.
The Health Ministry officials said the WHO estimates had put the TB incidence rate (per 100,000) in 2021 at 210 while using India's own mathematical model it was estimated to be 196 in 2022.
The TB incidence of absolute number was also estimated to be 29.50 lakh as per WHO in 2021, while using India's own mathematical model it was estimated to be 27.70 lakh in 2022.
“The WHO's TB mortality absolute numbers were estimated to be 4.94 lakh in India in 2021, but India's own mathematical model showed that it estimated to be 3.20 lakh in 2022,” an official added.
The mortality rate as per WHO (per 100,000) in 2021 was estimated to be 35, while it was found to be 23 in 2022 using the indigenous model.
New system of calculation
The officials said that the mathematical model was constructed on the basis of the natural history of the disease, individual status of infection, health care, missed or correct diagnosis, treatment coverage and outcomes including cure and death.
The model was calibrated for years between 2011 and 2025.
An official said the new model was calibrated for the observed or reported figures as inputs for prevalence rate, notification rate, mortality rate, proportion of patients being put on treatment, reduction in notification over a period of time in the public and private sector, and proportion of Latent TB infection (LTBI) in the community.
Another official pointed out that the indigenous model will reduce the missing cases of tuberculosis and that will result in mortality estimates reduction.
As per the Global TB Report 2022, the incidence of TB in India has declined by 18 percent from 256/lakh population in 2015 to 210/lakh population, which is 7 percentage points better than the global average of 11 percent.