NEW DELHI: An important study carried out by 10 super specialty hospitals of a major corporate chain across five states has shown that the second wave of Covid had a markedly higher mortality rate as compared to the first one last year.
The retrospective research by the Max group of hospitals on clinical outcomes of nearly 20,000 patients showed that 40% more patients died between January and mid-June this year, as compared to those between April-December last year. The fatalities were particularly higher in younger patients, the research results said.
The results from the study “Differentials in the characteristics of Covid-19 cases in Wave-1 and Wave-2 admitted to a network of hospitals in North India” have now been released on BioRxiv, the preprint server for medical sciences.
For the study, medical records of a total of 14,398 cases admitted in the first wave to the Max network of hospitals in north India -- Delhi, Uttar Pradesh, Uttarakhand, Punjab, and Haryana -- and 5,454 cases admitted in the same hospitals during the second wave were compared.
Overall, in each wave, almost two-thirds were males and females were admitted slightly more in the second wave as compared to the first wave while the age group 60+ years continued to have a disproportionately large share, nearly 40%.
Relative to their population (less than 10% at the all-India level) 60+ age group was nearly four times as likely to be admitted and patients of age less than 45 years comprised 28.3% and 27.1% in the first and second wave.
However, the most striking finding, which the researchers noted, was the overall higher severity of the disease at admission and a significantly higher mortality rate in the second wave, especially in younger patients.
In the second wave, 10.5% of the admitted patients, for instance, died as compared to 7.2% in the first wave and the increase in mortality was seen in both males and females. Younger patients, aged less than 45 years, saw the sharpest increase in mortality to 4.1% from 1.3% in the first wave and not only was the mortality higher this year for patients in ICU (19.8% vs 25.1%) but steeply higher even for those admitted inwards (0.5% vs 3.1%).
Since there were no significant demographic differences in the population during these two waves, various other factors such as increased comorbidity and higher occurrence of secondary bacterial and fungal infections may have contributed towards increased mortality, the scientific exercise led by Max group director Sandeep Budhiraja concluded.
Additionally, said the paper, as reports indicate that a higher percentage of infections having been caused by delta variant (B.1.617.2) of SARSCoV2 in the second wave, which was not only more transmissible but also potentially more lethal, could be another important factor.
“Late presentation of patients in wave 2 due to non-availability of hospital beds could also have contributed towards higher mortality,” it said.
Importantly, the study showed that more patients required oxygen support this time (74.1% vs 63.4%). But on a rather positive note, more than one-fifth (21.4%) of patients stayed for less than 5 days in the hospital this year compared to 15.7% in the first wave. Cases with a long stay of over 15 days also reduced from 10.4% in the first wave to 7% in the second.