title: Accuracy of asthma and COPD diagnosis in Australian  general practice: a mixed methods study.
abstract: BACKGROUND
  Spirometry is the 'gold standard' for diagnosing asthma and chronic obstructive pulmonary disease (COPD) but is rarely  used in general practice.
  
  
  OBJECTIVE
  To compare doctor diagnoses with patient reports/spirometry and to determine doctors' perceptions of spirometry.
  
  
  METHODS
  Patients prescribed inhaled medication were recruited from 31 practices. Doctor diagnoses were extracted from practice records.  Patients completed a questionnaire and spirometry before and after bronchodilator. In-depth interviews were conducted with a sample of  doctors.
  
  
  RESULTS
  Doctor diagnoses were available for 278 patients: asthma 192 (69%), COPD 38 (14%), asthma/COPD 40 (14%), and eight  patients (3%) with other conditions. The diagnosis of asthma was correctly reported by 93% of patients, but only by 61% of those with  COPD alone. Among those with both diagnoses, 83% reported asthma and 48% reported COPD. Of those with a diagnosis of COPD,  65% had fixed airflow limitation. Conversely, only 14% of those had been diagnosed with COPD alone. There was no significant difference  in reversibility in forced expiratory volume in 1 second between diagnoses. While recognising the value of spirometry in differentiating  between asthma and COPD, most general practices only used spirometry in diagnostically difficult cases.
  
  
  CONCLUSIONS
  Doctor-diagnosed asthma is accurately reported by patients. However, COPD remains substantially under-diagnosed.  Spirometry needs to be more widely used to improve the accuracy of respiratory diagnoses in general practice.
authors.affiliation: Epidemiology and Preventive Medicine, Monash University, Melbourne, Victoria, Australia.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Abramson
authors.forename: Rosa L
authors.initials: RL
authors.lastname: Schattner
authors.forename: Nabil D
authors.initials: ND
authors.lastname: Sulaiman
authors.forename: Eleonora A
authors.initials: EA
authors.lastname: Del Colle
authors.forename: Rosalie
authors.initials: R
authors.lastname: Aroni
authors.forename: Francis
authors.initials: F
authors.lastname: Thien
mesh_terms: D001249:Asthma / Q000175:diagnosis* / Q000188:drug therapy; D001315:Australia; D001993:Bronchodilator Agents / Q000627:therapeutic use; D005260:Female; D058006:General Practice / Q000592:standards / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010818:Practice Patterns, Physicians' / Q000592:standards / Q000706:statistics & numerical data; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000188:drug therapy; D013147:Spirometry; D011795:Surveys and Questionnaires
chemical_list: D001993:Bronchodilator Agents