Changing Pattern of Mortality in First and Second COVID-19 Waves: A Comparative Study From Kerala, India

Background and aims: India has seen a two-wave pattern of coronavirus disease 2019 (COVID-19) infections. The comparative characteristics of these two waves remain largely unknown. Changing trends in the demographic and clinical characteristics of the deceased COVID-19 patients in these two waves helped to identify the vulnerable population and guide public health interventions to decrease mortality. Methods: We obtained COVID-19 death summaries from the medical records of a large tertiary healthcare centre in North Kerala, India. Two groups of COVID-19 deaths were selected: the first group included patients who died in the first wave between 1 July 2020 and 31 December 2020 (n=311), and the second group included those who died in the second wave between 1 March 2021 and 30 June 2021 (n=431). Results: The mortality in the second wave in young patients (≤50 years) was 2.2% higher (11.8% vs. 9.6%, P=0.346) and that in elderly patients (≥80 years) was 7.7% higher (19.95% vs. 12.2%, P=0.005) compared to the first wave. The average duration from symptom onset to death also significantly decreased in the second wave. Further, there was an increased proportion of COVID-19-related deaths in patients with diabetes in the second wave (59.3% vs. 51.7%, P=0.025). The main cause of death was respiratory failure due to COVID-19 pneumonia in both waves. Conclusion: The second COVID-19 wave was different from the first wave with more deaths in the young and elderly, a shorter duration from symptom onset to death, and an increase in the proportion of deaths with diabetes, maternal deaths, and deaths in those without any pre-existing comorbidities.