title: Factors affecting the trajectory of health-related quality of life in COPD patients.
abstract: Health-related quality of life (HR-QoL) is an important issue in patients with chronic obstructive pulmonary disease (COPD), as in other chronic illness groups. However, there is limited information on longitudinal changes in HR-QoL over time with the illness trajectory model.
  
  
  
  To identify different patterns of HR-QoL changes in longitudinal data, and reveal potential predictors affecting these trajectories.
  
  
  
  Subjects with COPD (n = 249) were drawn from the Korean Obstructive Lung Disease cohort, which was conducted from 2005 to 2012. Longitudinal data were drawn from the St George's Respiratory Questionnaire and clinical measures. Growth mixture modelling was used to estimate distinct patterns, and binary and ordinal logistic regression were used to determine factors affecting different trajectory HR-QoL patterns using STATA 12.0.
  
  
  
  Five distinct HR-QoL patterns were identified. Results show that the level of baseline HR-QoL was significantly associated with age, the BODE (Body mass index, airflow Obstruction, Dyspnea, and Exercise capacity) index at baseline, sleep disturbance, experience of exacerbation in previous year and level of depression. Distinct patterns in HR-QoL that improved vs. worsened were significantly associated with BODE index, number of respiratory symptoms and depression level.
  
  
  
  These findings suggest that comprehensive assessment and individualised management programmes are needed to improve HR-QoL in COPD patients.
authors.affiliation: Institute for Comparative Effectiveness Research in Nursing, College of Nursing, Konyang University, Daejeon, Seoul, Republic of Korea.
authors.forename: J Y
authors.initials: JY
authors.lastname: Yoo
authors.affiliation: Division of Pulmonology, Department of Internal Medicine, Institute of Chest Diseases, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Y S
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Mo-Im Kim Nursing Research Institute, Mo-Im Kim Nursing Research Institute, College of Nursing, Yonsei University, Seoul, Republic of Korea.
authors.forename: S S
authors.initials: SS
authors.lastname: Kim
authors.affiliation: Biobehavioral Research Center, Mo-Im Kim Nursing Research Institute, College of Nursing, Yonsei University, Seoul, Republic of Korea.
authors.forename: H K
authors.initials: HK
authors.lastname: Lee
authors.affiliation: Department of Biobehavioral Health Science, University of Illinois at Chicago College of Nursing, Chicago, Illinois, USA.
authors.forename: C G
authors.initials: CG
authors.lastname: Park
authors.affiliation: Mo-Im Kim Nursing Research Institute, Mo-Im Kim Nursing Research Institute, College of Nursing, Yonsei University, Seoul, Republic of Korea;
authors.forename: E G
authors.initials: EG
authors.lastname: Oh
authors.affiliation: Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Y M
authors.initials: YM
authors.lastname: Oh
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D002908:Chronic Disease; D004417:Dyspnea / Q000175:diagnosis; D017079:Exercise Tolerance; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy*; D011788:Quality of Life; D015203:Reproducibility of Results; D056910:Republic of Korea; D012307:Risk Factors; D012720:Severity of Illness Index; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires