Risk of COVID-19 among patients with respiratory illnesses and comorbidities at Eastern Province of Sri Lanka: A retrospective study

Background: There is a general belief that patients with comorbidities have a higher risk of contracting coronavirus disease 2019 (COVID-19) and subsequent death. However, there are significant gaps in understanding these risks. Objective: The study aimed to assess the risk of COVID-19 among respiratory illness patients admitted to the hospital with comorbidities. Method: A retrospective cohort study was conducted in a hospital in Sri Lanka, where the records of 428 patients with respiratory illness were studied for COVID-19 infection and comorbidities from 2020 to 2022. Results: In this sample, 67.1% had been infected with COVID-19 and 51.6% had comorbidities. The age group ≥60 years had two times higher risk for comorbidities, and the most frequently occurring condition was hypertension (58.8%). Surprisingly, the infection rate of COVID-19 among patients with comorbidities was 28% lower compared to patients with no comorbidities, but the odds ratio (OR) for dying was greater once the patient with comorbidities was infected with COVID-19 (OR = 7.5). An increased risk of death was observed for COVID-19 patients with diabetes mellitus (OR = 2), hypertension (OR = 2.5), heart diseases (OR = 4.3), and renal diseases (OR = 2.4). Conclusion: It was surprising to find that the infection rate and risk of death due to COVID-19 were lower among patients with chronic lung diseases. This could be due to early death at the beginning of the COVID-19 pandemic, less hospital admissions for patients with chronic lung diseases, or resistance to COVID-19, and these are factors that require further exploration.