OBJECTIVES: The objective of this study is to analyze the comorbidities and Charlson Comorbidity Index (CCI) among the vaccinated and unvaccinated COVID-19 patients.

METHODS: In this retrospective study, Optum’s de-identified Clinformatics® Data Mart database was used to identify all the patients above 18 years who underwent treatment for COVID-19 in the US between 1 Jan 2021 to 30 Sep 2021. The occurrence of the ICD-10 code for COVID-19 infection in the claims database was defined as the index event. The Charlson Comorbidity Index (CCI) score and top comorbid conditions were checked in the vaccinated and unvaccinated patient cohort during the 6 months pre-index period. The CCI score predicts the ten-year mortality for a patient who may have a range of comorbid conditions and each condition is assigned a score of 1,2,3 or 6, depending on the risk of dying associated with each one.

RESULTS: Out of 277,319 COVID-19 patients, 274,165 (98.9%) were unvaccinated while 3,154 (1.1%) were fully vaccinated patients. In the unvaccinated cohort, 54% of the patients were females and 46% were males as compared to 56% females and 44% males in the vaccinated cohort. 16% of unvaccinated patients and 12% of vaccinated patients had a Charlson Comorbidity Index (CCI) score >=5. In both cohorts, endocrinal diseases, CVS diseases, and musculoskeletal diseases are the top 3 comorbidities. Further statistical tests will be applied to analyze the level of significance.

CONCLUSIONS: Patients with a CCI score of >=5 are more in the unvaccinated cohort as compared to the vaccinated cohort. Further analysis of mortality data and CCI scores is required to substantiate the effectiveness of vaccines.