India questions WHO's methodology to estimate COVID-19 mortalities

India on Saturday questioned the World Health Organisation's methodology to estimate COVID-19 mortalities in the country, saying using such mathematical modelling cannot be applied to estimate the death figures for such a vast nation of geographical size and population.

The Union health ministry issued a statement in response to a New York Times article titled “India Is Stalling WHO's Efforts to Make Global Covid Death Toll Public” dated April 16, saying the country has on several occasions shared its concerns with the global health body over the methodology used.

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India has been in regular and in-depth technical exchanges with the World Health Organisation (WHO) on the issue. The analysis, which uses mortality figures directly obtained from Tier I set of countries, uses a mathematical modelling process for Tier II countries (which includes India), the ministry said. 

"The model gives two highly different sets of excess mortality estimates when using the data from Tier I countries and when using unverified data from 18 Indian states. Such a wide variation in estimates raises concerns about validity and accuracy of such a modelling exercise," the ministry said in the statement.

According to the health ministry, India has shared its concerns with the methodology along with other member states through a series of formal communications, including six letters issued to WHO (on November 17, December 20, 2021; December 28, 2021; January 11, 2022; February 12, 2022; and March 2, 2022) and virtual meetings held on December 16, 2021, December 28, 2021, January 6, 2022, February 25, 2022, and the SEARO Regional Webinar held on February 10, 2022.

During these exchanges, specific queries have been raised by India along with other member states — China, Iran, Bangladesh, Syria, Ethiopia and Egypt — regarding the methodology, and use of unofficial sets of data.

"WHO is yet to share the confidence interval for the present statistical model across various countries," the statement said.

"India has asserted that if the model is accurate and reliable, it should be authenticated by running it for all Tier I countries and if the result of such exercise may be shared with all member states," it said.

India is a country of continental proportions, climatic and seasonal conditions vary vastly across different states and even within a state and therefore, all states have widely varied seasonal patterns.  "Thus, estimating national level mortality based on these 18 states data is statistically unproven," the statement stated.

The Global Health Estimates (GHE) 2019 on which the modelling for Tier II countries is based, is itself an estimate. “The present modelling exercise seems to be providing its own set of estimates based on another set of historic estimates while disregarding the data available with the country,” the statement said.

"It is not clear as to why GHE 2019 has been used for estimating expected death figures for India, whereas, for the Tier 1 countries, their own historical datasets were used when it has been repeatedly highlighted that India has a robust system of data collection and management," it stated.

WHO has conveyed that a combination of these variables was found to be most accurate for predicting excess mortality for a sample of 90 countries and 18 months (January 2020-June 2021). The detailed justification of how the combination of these variables is found to be most accurate is yet to be provided by WHO, the statement noted.

"The test positivity rate for Covid in India was never uniform throughout the country at any point of time. But, this variation in Covid positivity rate within India was not considered for modelling purposes. "Further, India has undertaken COVID-19 testing at a much faster rate than what WHO has advised. India has maintained molecular testing as the preferred testing method and used Rapid Antigen for screening purposes only. Whether these factors have been used in the model for India is still unanswered," the statement stated.

"While India has remained open to collaborate with WHO as data sets like these will be helpful from the policy-making point of view, India believes that in-depth clarity on methodology and clear proof of its validity are crucial for policymakers to feel confident about any use of such data.," the statement said.

"It is very surprising that while New York Times purportedly could obtain the alleged figures of excess COVID-19 mortality in respect to India, it was unable to learn the estimates for other countries," the statement added.