Medical Journal of the Islamic Republic Of Iran

en Effect of Comorbidities on In-hospital COVID-19 Mortality across Age Groups: A Retrospective Cohort Study in Iran Infectious Disease Infectious Disease Original Research Original Research Background: COVID-19 has emerged as one of the most significant healthcare challenges globally in recent years, affecting numerous individuals and resulting in fatalities, particularly among older adults and those with comorbidities. While the influence of comorbidities on mortality in COVID-19 patients has been explored in various studies, it has not been examined across different age groups. We evaluated the impact of comorbidities on COVID-19 mortality in three distinct age groups. Methods: A total of 10,496 hospitalized patients with positive PCR results for COVID-19 in Sirjan city were included in the study. Underlying conditions, including diabetes, hypertension, cardiovascular disease, and chronic kidney disease, were documented alongside age, sex, and COVID-19 status. The chi-square test and logistic regression were employed to assess the impact of comorbidities on mortality across different age groups. Results: A total of 2,038 (19.4%) patients had at least one comorbidity. The number of deaths from COVID-19 was 466 (4.4%), of which 197 had comorbidities. Hypertension and diabetes were the most prevalent underlying conditions among COVID-19 patients, occurring in 11.9% and 8.6% of cases, respectively. The presence of comorbidities was significantly associated with mortality in the overall population (OR=3.26, 95% CI: 2.69-3.94) as well as in individuals aged between 30 and 60 years (OR=2.63, 95% CI: 1.77-3.91) and those over 60 years (OR=1.58, 95% CI: 1.26-1.99). Furthermore, the number of comorbidities influenced the mortality rate among COVID-19 patients (OR=1.65 for two comorbidities and OR=1.97 for three or more comorbidities compared to patients with one comorbidity), although it did not vary across different age groups. Conclusion: Comorbidities can influence the mortality rate associated with COVID-19 among individuals aged 30, particularly within the 30-60 year age group. While the presence of multiple comorbidities significantly elevates the risk of death in the overall population, this association was not found to be statistically significant when analyzed by age group.   COVID-19 Mortality, Comorbidities, Underlying Disease, Risk of Mortality, Age Groups 444 449 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-9735-1&slc_lang=en&sid=1 Reza Sadeghi reza.sadeghi351@yahoo.com 200319475328460097855 200319475328460097855 No Department of Public Health, Sirjan School of Medical Sciences, Sirjan, Iran Mahmood Reza Masoudi masoodi85@yahoo.com 200319475328460097856 200319475328460097856 No Department of Internal Medicine, Division of Rheumatology, Sirjan School of Medical Sciences, Sirjan, Iran Mohammad Moqaddasi Amiri m.moqaddasi@sirums.ac.ir 200319475328460097857 200319475328460097857 Yes Department of Public Health, Sirjan School of Medical Sciences, Sirjan, Iran