Observational studyNPJ primary care respiratory medicine2018
'Exacerbation-free time' to assess the impact of exacerbations in patients with chronic obstructive pulmonary disease (COPD): a prospective observational study.
Observational study in NPJ primary care respiratory medicine, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 13 papers, 3 of them syntheses that pooled it.
What it found
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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
13 citing papers in PubMed, 3 syntheses or guidelines pooled it, 20 citations in OpenAlex.
- Red cell distribution width related to the severity of the disease in patients with AECOPD.Biomarkers in medicine · 2025Pooled it
- Prevalence and clinical characterisation of thyroid dysfunction in COPD: a systematic review and meta-analysis.Frontiers in medicine · 2025Pooled it
- The prevalence and related factors of fatigue in patients with COPD: a systematic review.European respiratory review : an official journal of the European Respiratory Society · 2021Pooled it
- A Smart Mobile Health Tool Versus a Paper Action Plan to Support Self-Management of Chronic Obstructive Pulmonary Disease Exacerbations: Randomized Controlled Trial.JMIR mHealth and uHealth · 2019Trial
- Effect of Erdosteine on COPD Exacerbations in COPD Patients with Moderate Airflow Limitation.International journal of chronic obstructive pulmonary disease · 2019Trial
- Quercetin in COPD: A Multi-Target Approach to Modulate Inflammation, Oxidative Stress, and Epithelial Dysfunction.International journal of molecular sciences · 2026Review
- Characteristics and actions in high-risk COPD in unstable patients: The EPOCONSUL audit.PloS one · 2025Article
- Association of low attenuation area scores with pulmonary function and clinical prognosis in patients with chronic obstructive pulmonary disease.Open life sciences · 2024Article
- Effects of Adherence to an mHealth Tool for Self-Management of COPD Exacerbations.International journal of chronic obstructive pulmonary disease · 2023Article
- Giving Voice to People - Experiences During Mild to Moderate Acute Exacerbations of COPD.Chronic obstructive pulmonary diseases (Miami, Fla.) · 2022Article
- Compliance and Utility of a Smartphone App for the Detection of Exacerbations in Patients With Chronic Obstructive Pulmonary Disease: Cohort Study.JMIR mHealth and uHealth · 2020Article
- Healthcare Professionals' Preferred Efficacy Endpoints and Minimal Clinically Important Differences in the Assessment of New Medicines for Chronic Obstructive Pulmonary Disease.Frontiers in pharmacology · 2019Article
- Assessing the Usefulness of the Prevexair Smartphone Application in the Follow-Up High-Risk Patients with COPD.International journal of chronic obstructive pulmonary diseaseArticle
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
8 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
COPD exacerbations are commonly quantified as rate per year. However, the total amount of time a patient suffers from exacerbations may be stronger related to his or her disease burden than just counting exacerbation episodes. In this study, we examined the relationship between exacerbation frequency and exacerbation-free time, and their associations with baseline characteristics and health-related quality of life. A total of 166 COPD patients reported symptom changes during 12 months. Symptom-defined exacerbation episodes were correlated to the number of exacerbation-free weeks per year. Analysis of covariance was used to examine the effects of baseline characteristics on annual exacerbation frequency and exacerbation-free weeks, Spearman's rank correlations to examine associations between the two methods to express exacerbations and the Chronic Respiratory Questionnaire (CRQ). The correlation between exacerbation frequency and exacerbation-free weeks was -0.71 (p < 0.001). However, among frequent exacerbators (i.e., ≥3 exacerbations/year, n = 113) the correlation was weak (r = -0.25; p < 0.01). Smokers had less exacerbation-free weeks than non-smokers (β = -5.709, p < 0.05). More exacerbation-free weeks were related to better CRQ Total (r = 0.22, p < 0.05), Mastery (r = 0.22, p < 0.05), and Fatigue (r = 0.23, p < 0.05) scores, whereas no significant associations were found between exacerbation frequency and CRQ scores. In COPD patients with frequent exacerbations, there is substantial variation in exacerbation-free time. Exacerbation-free time may better reflect the burden of exacerbations in patients with COPD than exacerbation frequency does.
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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.