title: Active asthma and the prevalence of physician-diagnosed COPD.
abstract: BACKGROUND
  Despite the considerable overlap of asthma and chronic obstructive pulmonary disease (COPD), the extent to which the two diagnoses are the manifestations of the same disease remains unresolved. We conducted these analyses to evaluate the role of active asthma in the prevalence of physician-diagnosed COPD.
  
  
  METHODS
  From 2006 through 2010, 74,209 adults aged 18-99 years and with a history of asthma participated in the Behavioral Risk Factor Surveillance System (BRFSS) Asthma Call-back Survey and responded to interview-administered questionnaires via telephone. We used publicly available data from 71,639 (97%) participants to identify respondents with and without active manifestations of asthma and self-reported, physician-diagnosed COPD. We generated population-weighted estimates of physician-diagnosed COPD prevalence and conducted linear regression to estimate associations between active asthma status and the prevalence of COPD among current smokers, former smokers, and lifetime nonsmokers separately.
  
  
  RESULTS
  Physician-diagnosed COPD was reported in an estimated 29% of the population with any history of asthma, including both active and inactive asthma. Age-specific prevalences of physician-diagnosed COPD were consistently higher among adults with active asthma than adults without active asthma. Compared to inactive asthma, active asthma was associated with an 8.3% [95% confidence interval (CI) 6.1, 10.5] higher prevalence of physician-diagnosed COPD among lifetime nonsmokers, a 20.6% (95% CI 18.0, 23.3) higher prevalence among former smokers, and a 26.7% (95% CI 22.5, 30.9) higher prevalence among current smokers.
  
  
  CONCLUSIONS
  Among adults with a history of asthma, active manifestations of asthma may play an important role in the epidemiology of COPD.
authors: Air Pollution and Respiratory Health Branch, Division of Environmental Hazards and Health Effects, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway NE, Mailstop F-60, Atlanta, GA, 30341, USA, zif7@cdc.gov.
authors: Maria C
authors: MC
authors: Mirabelli
authors: Suzanne F
authors: SF
authors: Beavers
authors: Arjun B
authors: AB
authors: Chatterjee
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000175:diagnosis / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D005260:Female; D019538:Health Care Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D010820:Physicians; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000453:epidemiology*; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D016540:Smoking Cessation; D000074606:Smoking Prevention; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology; D055815:Young Adult