Self-Reported Long COVID Symptoms among Japanese Adults: Findings of CARE Japan Online Questionnaire-Based Prospective Cohort Study.

Publication date: May 26, 2026

We conducted a comprehensive assessment of long COVID and associated risk factors, among an online cohort of Japanese adults in omicron dominant COVID-19 period in Japan. We used data from the online questionnaire-based CARE Japan Study, that collected data on patient demographics and information on post-COVID-19 symptoms. Long COVID, was defined as the presence of ≥1 symptom for ≥3 months after the initial COVID-19 infection. We performed Kaplan-Meier survival analysis to estimate the restricted mean resolution time (RMST) of long COVID and sex-stratified multivariable Cox proportional hazards model for hazard ratios (HRs) with 95% confidence interval (CIs). The final analysis included 1071 patients with COVID-19. The cumulative prevalence of long COVID in the studied cohort was 66. 7%. 32% of the respondents with long COVID reported fatigue and runny nose, and 20%-24% reported headache, cough, nasal congestion, and sore throat. The RMST of long COVID was 311. 1 days for men and 323. 9 days for women. Younger individuals were more likely to experience long COVID than older patients. Overweight, obese or underweight patients reported long COVID more frequently than patients with normal weight. Patients with pre-existing psychological disorders or seasonal allergies showed higher risks of long COVID than participants with no pre-existing psychological disorders or seasonal allergies. The prolonged duration of symptoms may affect work ability and recovery, highlighting the need for continued follow-up and supportive care, including return-to-work support and access to outpatient services. These implications should be interpreted within the context of the cohort.

Semantics

Original Article