# Japanese nationwide survey to track the impact of long COVID over 3 years

## TL;DR

A 3-year study in Japan found that long COVID leads to lasting physical and mental health issues, along with economic burdens, even as some symptoms improve over time.

## Contribution

This is the first Japanese nationwide survey tracking long COVID's impact over 3 years, revealing persistent symptoms and economic effects.

## Key findings

- Fatigue and dyspnea persisted in long COVID patients over 3 years, while anosmia and dysgeusia declined.
- Patients with continuous or multiple symptoms had significantly lower quality of life and presenteeism scores.
- The study highlights the mental and economic burdens of long COVID lasting up to 36 months post-diagnosis.

## Abstract

The long-term impact of symptom classification on quality of life (QOL) and economic outcomes among individuals with long coronavirus disease (COVID) remains poorly understood. This study aimed to clarify the situation of long COVID in Japan by analyzing patients using cluster classification.

This multicenter, retrospective cohort study enrolled 515 patients with COVID-19 and followed up for 36 months via standardized questionnaires. Patients were classified based on: 1) symptom trajectory over time and 2) symptom cluster profiles at 3 months.

While the number of symptoms decreased, fatigue and dyspnea frequently persisted, whereas anosmia and dysgeusia declined. Cough and sputum decreased gradually. The proportion of patients with 5–9 symptoms increased. The mean (interquartile range) presenteeism scores were lower in the continuous (60 [50–80]) and relapse groups (65 [48–80]) than in the recovered group (70 [50–80]). The multiple symptoms cluster had the worst SF-36, presenteeism, and absenteeism scores (47.2 [44.7–49.8], 48.8 [27.5–72.5], and 10.9 [0.0–11.0], respectively).

Patients with continuous and multiple symptoms experienced persistently lower QOL and greater economic burden up to 36 months after COVID-19 diagnosis. The long-term effects of long COVID are not only physical but also mental and economical. Thus, further research is needed to clarify the economical and physiological impact of long COVID.

The online version contains supplementary material available at https://doi.org/10.1265/ehpm.25-00293.