title: Pulmonary Rehabilitation in COPD According to Global Initiative for Chronic Obstructive Lung Disease Categories.
abstract: BACKGROUND
  Pulmonary rehabilitation (PR) programs are a mainstay for treatment in COPD. Lung function impairment alone does not predict beneficial effects of PR. The new COPD categories take into account assessment of symptoms, such as dyspnea and exacerbations, which may be important indications for PR. This study evaluates the effect of PR on exercise capacity, symptoms, and health status in different COPD categories.
  
  
  METHODS
  Subjects with COPD referred for PR were classified into COPD categories A, B, C, and D. Exercise capacity (6-min walk distance [6MWD] and constant work rate at 80% of peak work rate), symptoms (Mahler's index), and health status (St George Respiratory Questionnaire) were compared before and after PR programs for each COPD category. Changes were analyzed using generalized estimating equations and logistic regression models.
  
  
  RESULTS
  One hundred sixty-seven subjects were included (COPD categories A [16%], B [12%], C [31%], and D [41%]). Groups were homogeneous in age, body mass index, smoking pack-years, and comorbidities. Significant improvements in all outcomes were found after adjusting for COPD categories, age, sex, body mass index, and COPD-specific comorbidity index. All COPD categories improved exercise capacity (6MWD and constant work rate). Categories A and C had more pronounced improvements in 6MWD than categories B and D. Symptoms (Mahler's index) also improved significantly in categories A and C, whereas change was not significant in categories B and D. Global health status (St George Respiratory Questionnaire) improved significantly in all COPD categories. Despite these differences, the odds of achieving a minimum clinically important difference in each outcome were similar and without statistical significance for the A, B, and C categories when compared with D.
  
  
  CONCLUSIONS
  This study demonstrates that patients in all COPD categories may improve exercise capacity, symptoms, and health status with PR programs, and COPD categories alone may not be sufficient to discriminate which patients may benefit most from them.
authors.affiliation: Serviço de Pneumologia, Hospital Pulido Valente, Centro Hospitalar Lisboa Norte, Lisbon, Portugal. sara.alfa@netcabo.pt.
authors.forename: Sara
authors.initials: S
authors.lastname: Alfarroba
authors.affiliation: Serviço de Pneumologia, Hospital Pulido Valente, Centro Hospitalar Lisboa Norte, Lisbon, Portugal. NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal.
authors.forename: Fátima
authors.initials: F
authors.lastname: Rodrigues
authors.affiliation: NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal. Centro de Estatística e Aplicações da Universidade de Lisboa, Lisbon, Portugal.
authors.forename: Ana Luísa
authors.initials: AL
authors.lastname: Papoila
authors.affiliation: Serviço de Pneumologia, Hospital Pulido Valente, Centro Hospitalar Lisboa Norte, Lisbon, Portugal.
authors.forename: Ana Filipe
authors.initials: AF
authors.lastname: Santos
authors.affiliation: Serviço de Pneumologia, Hospital Pulido Valente, Centro Hospitalar Lisboa Norte, Lisbon, Portugal.
authors.forename: Luísa
authors.initials: L
authors.lastname: Morais
mesh_terms: D000368:Aged; D018450:Disease Progression; D004417:Dyspnea / Q000209:etiology / Q000534:rehabilitation; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000145:classification / Q000150:complications / Q000534:rehabilitation*; D012138:Respiratory Therapy / Q000379:methods / Q000706:statistics & numerical data*; D012720:Severity of Illness Index; D013223:Statistics as Topic; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
keywords: 6-min walking distance; COPD; COPD categories; Mahler's index; St George Respiratory Questionnaire; constant work rate; pulmonary rehabilitation; quality of life