Low covid fatality rate a statistical illusion1 min read . Updated: 10 Sep 2020, 09:11 AM IST
A new study debunks India’s claim of a low case fatality rate, and says it could be much worse than other countries if adjusted for age-wise variations
India has repeatedly cited its low rate of covid-related deaths to claim that it has dealt with the pandemic better than others. This is partly because of India’s large young population, who are less likely to die of covid-19. But if the fatality rate is adjusted for age variations, India fares much worse than other countries, finds a new study.
In a working paper published by the US National Bureau of Economic Research, Minu Philip of New York University and others estimate age-adjusted case fatality rates (CFR) for India based on data from 14 other countries.
To adjust for age variations, the authors assume that India has similar age-wise case fatality rates as in other comparison countries. Using India’s age-wise patient distribution, this method predicts what the country’s overall case fatality rate would be if an Indian patient in each age group were as likely to die as in each comparison country.
The model finds that India’s case fatality rate would be lower in most cases than it actually is. This shows that India’s actual CFR—around 1.7% as per latest data—is too high rather than too low.
The authors use South Korea’s example, as its CFR is comparable to India’s. But if India had an age-wise fatality rate similar to South Korea’s, its overall CFR would have been far lower, at 0.74%, the paper says.
The same holds even for countries such as the Netherlands or Spain, whose case fatality rates are well over 10%.
Using these findings, the paper warns against the use of the overall case fatality rate because “crude aggregates" often hide the fact that the news may be worse, or even better. The government should instead release detailed data segregated by age groups, the authors conclude.
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