+1 Recommend
1 collections
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Impact of symptom variability on clinical outcomes in COPD: analysis of a longitudinal cohort

      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.



          We compared clinical characteristics of COPD patients according to symptom variability and evaluated the effect of symptom variability during the first year of enrollment on clinical outcomes of COPD.


          We analyzed COPD patients’ data from the Korean Obstructive Lung Disease (KOLD) cohort. Symptom variability was defined based on the value of standard deviation (SD) of mMRC scores obtained every 3 months during the follow-up period of the first year. Patients were divided into 2 groups: the consistent (SD of mMRC scores =0) and variable (SD of mMRC scores >0) groups. Clinical characteristics and outcomes were compared in terms of symptom variability.


          A total of 407 patients were included in the analysis. Patient age was 67.2 years and 97.8% of the subjects were male. Initial mMRC was 1.5 and the SD of mMRC scores during the first year was 0.5. There were 137 subjects (33.7%) in the consistent group and 270 (66.3%) in the variable group. The variable group showed a lower FEV 1 ( P=0.019) and a higher mMRC score ( P=0.001). The annual incidence of acute exacerbation of COPD (AE-COPD) tended to be higher in the variable group ( P=0.078) and that of severe AE-COPD was higher in the variable group than in the consistent group ( P=0.002). The variable group showed a higher proportion of annual exacerbators ( P=0.001) and frequent exacerbators ( P=0.017). In multivariate logistic regression analysis, the variable group was significantly associated with annual exacerbators (OR =1.963, P=0.011) and frequent exacerbators (OR =2.090, P=0.055).


          COPD patients with symptom variability may have higher exacerbation risk as well as lower lung function and more severe respiratory symptoms.

          Related collections

          Most cited references 17

          • Record: found
          • Abstract: found
          • Article: not found

          Patient insight into the impact of chronic obstructive pulmonary disease in the morning: an internet survey.

          To determine diurnal variability of symptoms in chronic obstructive pulmonary disease (COPD) and to assess the impact of COPD upon patients' morning activities and routines. Quantitative internet interviews with 803 COPD patients from Europe and the USA, including 289 patients with severe COPD. Severe COPD was defined according to regular use of COPD medication, third level of breathlessness or above using the modified Medical Research Council (MRC) dyspnoea scale (MRC dyspnoea score > or =3) and one or more COPD exacerbations in the preceding 12 months. Morning was the worst time of day for COPD symptoms, particularly in patients with severe COPD (reported by 46% of severe patients). In these patients, shortness of breath was the most frequently reported symptom, correlating strongly with problems experienced with morning activities. Morning activities most affected by COPD were walking up and down stairs, putting on shoes and socks, making the bed, dressing, showering or bathing and drying. The majority of patients were not taking their medication in time for it to exert its optimal effect. Many patients consider the impact of COPD on morning activities to be substantial. Physicians should question patients about morning activities to assess disease impact and to advise regarding the optimal time to use therapy. This was an internet-based questionnaire survey and possible bias in patient selection and self-reported diagnosis of COPD and its severity should be taken into account.
            • Record: found
            • Abstract: found
            • Article: found
            Is Open Access

            Observational study to characterise 24-hour COPD symptoms and their relationship with patient-reported outcomes: results from the ASSESS study

            Background Few studies have investigated the 24-hour symptom profile in patients with COPD or how symptoms during the 24-hour day are inter-related. This observational study assessed the prevalence, severity and relationship between night-time, early morning and daytime COPD symptoms and explored the relationship between 24-hour symptoms and other patient-reported outcomes. Methods The study enrolled patients with stable COPD in clinical practice. Baseline night-time, early morning and daytime symptoms (symptom questionnaire), severity of airflow obstruction (FEV1), dyspnoea (modified Medical Research Council Dyspnoea Scale), health status (COPD Assessment Test), anxiety and depression levels (Hospital Anxiety and Depression Scale), sleep quality (COPD and Asthma Sleep Impact Scale) and physical activity level (sedentary, moderately active or active) were recorded. Results The full analysis set included 727 patients: 65.8% male, mean ± standard deviation age 67.2 ± 8.8 years, % predicted FEV1 52.8 ± 20.5%. In each part of the 24-hour day, >60% of patients reported experiencing ≥1 symptom in the week before baseline. Symptoms were more common in the early morning and daytime versus night-time (81.4%, 82.7% and 63.0%, respectively). Symptom severity was comparable for each period assessed. Overall, in the week before baseline, 56.7% of patients had symptoms throughout the whole 24-hour day (3 parts of the day); 79.9% had symptoms in ≥2 parts of the 24-hour day. Symptoms during each part of the day were inter-related, irrespective of disease severity (all p < 0.001). Early morning and daytime symptoms were associated with the severity of airflow obstruction (p < 0.05 for both). Night-time, early morning and daytime symptoms were all associated with worse dyspnoea, health status and sleep quality, and higher anxiety and depression levels (all p < 0.001 versus patients without symptoms in each corresponding period). In each part of the 24-hour day, there was also an association between symptoms and a patient’s physical activity level (p < 0.05 for each period). Conclusions More than half of patients experienced COPD symptoms throughout the whole 24-hour day. There was a significant relationship between night-time, early morning and daytime symptoms. In each period, symptoms were associated with worse patient-reported outcomes, suggesting that improving 24-hour symptoms should be an important consideration in the management of COPD. Electronic supplementary material The online version of this article (doi:10.1186/s12931-014-0122-1) contains supplementary material, which is available to authorized users.
              • Record: found
              • Abstract: found
              • Article: found
              Is Open Access

              Study Design and Outcomes of Korean Obstructive Lung Disease (KOLD) Cohort Study

              Background The Korean Obstructive Lung Disease (KOLD) Cohort Study is a prospective longitudinal study of patients with chronic obstructive pulmonary disease (COPD), asthma, or other unclassified obstructive lung diseases. It was designed to develop new classification models and biomarkers that predict clinically relevant outcomes for patients with obstructive lung diseases. Methods Patients over 18 years old who have chronic respiratory symptoms and airflow limitations or bronchial hyper-responsiveness were enrolled at 17 centers in South Korea. After a baseline visit, the subjects were followed up every 3 months for various assessments. Results From June 2005 to October 2013, a total of 477 subjects (433 [91%] males; 381 [80%] diagnosed with COPD) were enrolled. Analyses of the KOLD Cohort Study identified distinct phenotypes in patients with COPD, and predictors of therapeutic responses and exacerbations as well as the factors related to pulmonary hypertension in COPD. In addition, several genotypes were associated with radiological phenotypes and therapeutic responses among Korean COPD patients. Conclusion The KOLD Cohort Study is one of the leading long-term prospective longitudinal studies investigating heterogeneity of the COPD and is expected to provide new insights for pathogenesis and the long-term progression of COPD.

                Author and article information

                Int J Chron Obstruct Pulmon Dis
                Int J Chron Obstruct Pulmon Dis
                International Journal of Chronic Obstructive Pulmonary Disease
                20 September 2019
                : 14
                : 2135-2144
                [1 ]Department of Pulmonology, Allergy and Critical Care Medicine, CHA Bundang Medical Center, CHA University , Seongnam, Republic of Korea
                [2 ]Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine , Seoul, Republic of Korea
                Author notes
                Correspondence: Ji-Hyun LeeDepartment of Pulmonology, Allergy and Critical Care Medicine, CHA Bundang Medical Center, CHA University , 59 Yatap-ro, Bundang-gu, Seongnam463-712, Republic of KoreaTel +82 31 780 5205Fax +82 31 780 2992Email
                © 2019 Kim et al.

                This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at and incorporate the Creative Commons Attribution – Non Commercial (unported, v3.0) License ( By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms (

                Page count
                Figures: 2, Tables: 6, References: 26, Pages: 10
                Original Research

                Respiratory medicine

                copd, symptom, variability, exacerbation, death, lung function


                Comment on this article