BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS 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.
Adult ; Aged ; Aged, 80 and over ; Female ; Humans ; Male ; Middle Aged ; COVID-19/complications* ; Japan/epidemiology* ; Post-Acute COVID-19 Syndrome/psychology* ; Quality of Life ; Retrospective Studies ; Surveys and Questionnaires ; East Asian People

Objectives: To determine the effect of hot bathing on blood circulation, we analyzed pressure wave using Wave Intensity (WI), which is defined as changes in blood pressure (dP)×changes in blood flow velocity (dV) during hot bathing, as the index for assessment.
Methods: Using a combined Doppler and ultrasonic echo-tracking system, we recorded changes in vascular diameter (dD) and dV of the common carotid artery simultaneously in six healthy subjects before (Pre-bathing), during (Bathing), and 10 minutes after bathing (41°C) (Post-bathing). We then measured the product of their changes at fixed intervals as WI and evaluated the positive component of the early systolic phase (FE) (representing the forward-traveling pressure wave), negative components following FE (B) (representing the reflection pressure wave), and the appearance time of (RT). RT was measured as the percentage ratio.
Results: 1) The magnitudes of FE and B tended to decrease during 10min of bathing (Bathing) and recover to the level of the pre-bathing stage after 10min of bathing. 2) The value of RT measured after 10min of bathing (Post-bathing) was significantly longer than the level before bathing (Pre-bathing).
Conclusion: The effect of the reflection pressure wave (i. e., the after load on the vascular system) decresses during hot bathing. We can thus conjecture that the time phase of appearance of the reflecting pressure wave is delayed when the arrival time of the forwardtraveling pressure wave to the periphery is delayed and the propagation of the reflection pressure wave from the periphery slows down due to the expansion of vessels during hot bathing. Hot bating can therefore be expected to reduce after loads of healthy adult subjects.