title: Prediction of COPD-specific health-related quality of life in primary care COPD patients: a prospective cohort study.
abstract: BACKGROUND
  Health-related quality of life (HRQL) is an important patient-reported outcome for chronic obstructive pulmonary disease (COPD).
  
  
  OBJECTIVE
  We developed models predicting chronic respiratory questionnaire (CRQ) dyspnoea, fatigue, emotional function, mastery and overall HRQL at 6 and 24 months using predictors easily available in primary care.
  
  
  METHODS
  We used the "least absolute shrinkage and selection operator" (lasso) method to build the models and assessed their predictive performance.
  
  
  RESULTS
  were displayed using nomograms.
  
  
  RESULTS
  For each domain-specific CRQ outcome, the corresponding score at baseline was the best predictor. Depending on the domain, these predictions could be improved by adding one to six other predictors, such as the other domain-specific CRQ scores, health status and depression score. To predict overall HRQL, fatigue and dyspnoea scores were the best predictors. Predicted and observed values were on average the same, indicating good calibration. Explained variance ranged from 0.23 to 0.58, indicating good discrimination.
  
  
  CONCLUSIONS
  To predict COPD-specific HRQL in primary care COPD patients, previous HRQL was the best predictor in our models. Asking patients explicitly about dyspnoea, fatigue, depression and how they cope with COPD provides additional important information about future HRQL whereas FEV1 or other commonly used predictors add little to the prediction of HRQL.
authors.affiliation: Department of General Practice, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Lara
authors.initials: L
authors.lastname: Siebeling
authors.affiliation: Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Jammbe Z
authors.initials: JZ
authors.lastname: Musoro
authors.affiliation: Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Ronald B
authors.initials: RB
authors.lastname: Geskus
authors.affiliation: Institute of General Practice and Health Services Research, University of Zurich, Zurich, Switzerland.
authors.forename: Marco
authors.initials: M
authors.lastname: Zoller
authors.affiliation: Department of Respiratory Medicine, University Hospital of Zurich, Zurich, Switzerland.
authors.forename: Patrick
authors.initials: P
authors.lastname: Muggensturm
authors.affiliation: 1] Institute of General Practice and Health Services Research, University of Zurich, Zurich, Switzerland [2] Horten Centre for Patient-Oriented Research, University of Zurich, Zurich, Switzerland.
authors.forename: Anja
authors.initials: A
authors.lastname: Frei
authors.affiliation: Institute of Social and Preventive Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: Milo A
authors.initials: MA
authors.lastname: Puhan
authors.affiliation: Department of General Practice, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Gerben
authors.initials: G
authors.lastname: ter Riet
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000175:diagnosis; D011788:Quality of Life; D011795:Surveys and Questionnaires