OBJECTIVES:

To study the impact of Long COVID-19 during 2020-2021 in the US.

The COVID-19 story is not just about surviving the acute illness, many patients also experience long-term illness. Acute COVID-19 refers to the typical illness that most patients experience immediately after being infected with the SARS-CoV-2 virus. The typical symptoms include fever, cough, and difficulty breathing, which can last anywhere from a few days to four weeks. Long COVID-19 refers to the persistent symptoms that some patients experience after four weeks of infection.

METHODS:

A retrospective study was performed on 222,381 unvaccinated patients diagnosed with COVID -19 between 20 March 2020 to 31 March 2021 with relevant ICD-10-CM diagnosis recorded in the Optum® de-identified Market Clarity Dataset. These patients were followed-up for 9 months. Patients were divided into two cohorts - acute (<4 weeks) and long (≥4 weeks) patients. These patients were checked for symptoms in the physician notes and diagnosis codes using EHR and claims data respectively.

RESULTS:

The number of patients affected with long COVID-19 (97,616) was higher as compared to acute COVID-19 (66,873). Based on physician notes, in both cohorts, respiratory symptoms were the most prevalent and were present in 17.1% of each cohort. About 3.5% of acute COVID-19 patients had neurological symptoms and this percentage increased to 11.1% in long COVID-19 patients. Cardiovascular symptoms were present in 8.2% of acute COVID-19 patients and 12.5% of long COVID-19 patients. Based on ICD-10 code diagnosis, the top 3 symptoms for acute COVID-19 were breathing difficulties (15.8%), cough (13.1%), body ache (11.7%) and for long COVID-19 were breathing difficulties (20.8%), body ache (18.3%), bowel changes (13.9%).

CONCLUSIONS:

Most acute COVID-19 patients showed an increase in general and respiratory symptoms. Whereas long COVID-19 patients showed an increase in cardiovascular and neurological symptoms along with respiratory symptoms.