Symptoms of post COVID-19 condition and diseases/conditions diagnosed after COVID-19 in Japanese patients: A real-world study using a claims database.

Background: More than 200 symptoms of post coronavirus disease (COVID-19) condition (PCC) impacting patients' quality of life have been reported. This study describes the symptoms of well-known PCC and diseases/conditions diagnosed after COVID-19 and analyzes the trends in well-known PCC according to the epidemic waves in the Japanese population.

Methods: Patients with a COVID-19 diagnosis in the JMDC claims database were matched 1:1 with individuals without COVID-19 diagnosis (controls) based on sex, year and month of birth, and risk factors for aggravation. The first month of COVID-19 diagnosis from January 2020-March 2022 was the index month, and the observation period was from July 2019 to 6 months from the index month (patients) and July 2019-September 2022 (controls).

Results: Of 263,456 each of patients and controls after matching, 51.8 % were aged 18-49 years, 56.3 % were male, and 24.5 % had risk factors for aggravation. One in 18 patients experienced well-known PCC 2-3 months after severe acute respiratory syndrome cornonavirus 2 infection, with the highest odds ratio (OR) being for pulmonary thromboembolism (29.37), followed by smell/taste disorder (13.34) and respiratory failure (8.28). Some of the common diseases/conditions diagnosed after COVID-19 comprised those of the genitourinary system, eye and adnexa, and ear and mastoid process and certain infectious and parasitic diseases. Overall, the risk difference decreased from the first to the sixth wave, but the OR was >1.00 for most symptoms even during the sixth wave.

Conclusions: PCC symptoms showed a declining trend over time but persisted. Physicians and patients need to recognize PCC symptoms.