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.