title: Prevalence and burden of breathlessness in patients with chronic obstructive pulmonary disease managed in primary care.
abstract: OBJECTIVE
  Breathlessness is a primary clinical feature of chronic obstructive pulmonary disease (COPD). We aimed to describe the frequency of and factors associated with breathlessness in a cohort of COPD patients identified from the Clinical Practice Research Datalink (CPRD), a general practice electronic medical records database.
  
  
  METHODS
  Patients with a record of COPD diagnosis after January 1 2008 were identified in the CPRD. Breathlessness was assessed using the Medical Research Council (MRC) dyspnoea scale, with scoring ranging from 1-5, which has been routinely administered as a part of the regular assessment of patients with COPD in the general practice since April 2009. Stepwise multivariate logistic regression estimated independent associations with dyspnoea. Negative binomial regression evaluated a relationship between breathlessness and exacerbation rate during follow-up.
  
  
  RESULTS
  The total cohort comprised 49,438 patients diagnosed with COPD; 40,425 (82%) had any MRC dyspnoea grade recorded. Of those, 22,770 (46%) had moderate-to-severe dyspnoea (MRC ≥ 3). Breathlessness increased with increasing airflow limitation; however, moderate-to-severe dyspnoea was also observed in 32% of patients with mild airflow obstruction. Other factors associated with increased dyspnoea grade included female gender, older age (≥ 70 years), obesity (BMI ≥ 30), history of moderate-to-severe COPD exacerbations, and frequent visits to the general practitioner. Patients with worse breathlessness were at higher risk of COPD exacerbations during follow-up.
  
  
  CONCLUSIONS
  Moderate-to-severe dyspnoea was reported by >40% of patients diagnosed with COPD in primary care. Presence of dyspnoea, including even a perception of mild dyspnoea (MRC = 2), was associated with increased disease severity and a higher risk of COPD exacerbations during follow-up.
authors.affiliation: Respiratory Epidemiology, GlaxoSmithKline R&D, Uxbridge, United Kingdom.
authors.forename: Hana
authors.initials: H
authors.lastname: Müllerová
authors.affiliation: Observational Data Analytics, GlaxoSmithKline R&D, Research Triangle Park, North Carolina, United States of America.
authors.forename: Chao
authors.initials: C
authors.lastname: Lu
authors.affiliation: Observational Data Analytics, GlaxoSmithKline R&D, Research Triangle Park, North Carolina, United States of America.
authors.forename: Hao
authors.initials: H
authors.lastname: Li
authors.affiliation: Global Health Outcomes, GlaxoSmithKline R&D, Uxbridge, United Kingdom.
authors.forename: Maggie
authors.initials: M
authors.lastname: Tabberer
mesh_terms: D000368:Aged; D015331:Cohort Studies; D016208:Databases, Factual; D004417:Dyspnea / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D063868:Patient Outcome Assessment; D015995:Prevalence; D011320:Primary Health Care; D062486:Public Health Surveillance; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000503:physiopathology; D012129:Respiratory Function Tests; D012307:Risk Factors; D012720:Severity of Illness Index