Impact of long-COVID on health-related quality of life in Japanese COVID-19 patients

Background The empirical basis for a quantitative assessment of the disease burden imposed by long-COVID is currently scant. We aimed to inform the disease burden caused by long-COVID in Japan. Methods We conducted a cross sectional self-report questionnaire survey. The questionnaire was mailed to 526 eligible patients, who were recovered from acute COVID-19 in April 2021. Answers were classified into two groups; participants who have no symptom and those who have any ongoing prolonged symptoms that lasted longer than four weeks at the time of the survey. We estimated the average treatment effect (ATE) of ongoing prolonged symptoms on EQ-VAS and EQ-5D-3L questionnaire using inverse probability weighting. In addition to symptom prolongation, we investigated whether other factors (including demography, lifestyle, and acute severity) were associated with low EQ-VAS and EQ-5D-3L values, by multivariable linear regression. Results 349 participants reported no symptoms and 108 reported any symptoms at the time of the survey. The participants who reported any symptoms showed a lower average value on the EQ-VAS (69.9 vs 82.8, respectively) and on the EQ-5D-3L (0.85 vs 0.96, respectively) than those reporting no symptoms considering the ATE of ongoing prolonged symptoms. The ATE of ongoing prolonged symptoms on EQ-VAS was - 12.9 [95% CI - 15.9 to - 9.8], and on the EQ-5D-3L it was - 0.11 [95% CI - 0.13 to - 0.09], implying prolonged symptoms have a negative impact on patients' EQ-VAS and EQ-5D-3L score. In multivariable linear regression, only having prolonged symptoms was associated with lower scores (- 11.7 [95% CI - 15.0 to - 8.5] for EQ-VAS and - 0.10 [95% CI - 0.13 to - 0.08] for EQ-5D-3L). Conclusions Due to their long duration, long-COVID symptoms represent a substantial disease burden expressed in impact on health-related quality of life.