ArticleBMJ open respiratory research2024
Long COVID among the first three waves of COVID-19 in Japan: a multicentre cohort study.
Article in BMJ open respiratory research, 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
2 citing papers in PubMed.
- Distinct plasma proteome signature at 3 months post-COVID-19 infection irrespective of post-COVID condition.Scientific reports · 2026Article
- Excess of infection with SARS-CoV-2 during the first versus second wave of the COVID-19 pandemic among patients with long COVID.BMC public health · 2025Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
28 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectivesSevere acute respiratory syndrome coronavirus 2 significantly impacts Japan with a high number of infections and deaths reported. Long coronavirus disease (COVID) characterised by persistent symptoms after COVID-19 has gained recognition but varies across studies. This study aimed to investigate the differences in long COVID among patients hospitalised during Japan's first three waves of the pandemic.
designMulticentre prospective cohort study.
setting26 medical facilities across Japan between February 2020 and February 2021.
participantsIn total, 1066 hospitalised patients diagnosed with COVID-19 were included with 206, 301 and 559 patients in the first, second and third waves, respectively. Data were collected using electronic data capture and patient-reported outcome forms. PRIMARY AND SECONDARY OUTCOME MEASURES: Long COVID was assessed at 3, 6 and 12 months after COVID-19 diagnosis.
resultsSignificant differences were observed between the waves in various baseline and clinical characteristics such as age, body mass index (BMI), comorbidities, the severity of COVID-19, complications and treatment during hospitalisation. Long COVID, particularly dyspnoea, was most prevalent in the first wave. Multivariate logistic regression analysis confirmed a significant positive association between the first wave and long COVID including dyspnoea after adjusting for age, sex, BMI, smoking status and COVID-19 severity.
conclusionsPatients hospitalised during the first wave had a higher risk of experiencing long COVID, especially dyspnoea, than those hospitalised during the other waves. These findings underscore the need for continued monitoring and managing long COVID in COVID-19 survivors, particularly in those hospitalised during the first wave. TRIAL REGISTRATION NUMBER: UMIN000042299.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.