title: The impact of diagnosed and undiagnosed current asthma in the general adult population.
abstract: BACKGROUND
  Restrictive definitions of current asthma are used in epidemiological studies to achieve a highly specific classification of subjects. However, undiagnosed asthmatics should be taken into account to correctly evaluate the impact of the disease in the general population.
  
  
  METHODS
  In an Italian multi-centre cross-sectional survey carried out in 1998-2000, 18,647 responders (20-44 years old) to a screening questionnaire were classified as having physician-diagnosed current asthma or current respiratory symptoms. Similarities in the risk factor profile and in the socioeconomic burden were considered suggestive of undiagnosed current asthma.
  
  
  RESULTS
  In Italy, the prevalence of physician-diagnosed current asthma was 4.9% (95% CI 4.4-5.4), while that of 'asthma attacks and/or use of anti-asthmatic drugs in the past 12 months without a diagnosis of asthma' (ADWD) was 1.5% (95% CI 1.3-1.7). Allergic rhinitis was highly associated with diagnosed current asthma [relative risk ratio (RRR) 12.48; 95% CI 9.12-17.07; reference category: neither asthma during lifetime nor current respiratory symptoms] and with ADWD (RRR 8.42; 95% CI 6.33-11.19). Chronic cough/phlegm was homogeneously associated with all the respiratory conditions, and the strongest relationship was with ADWD (RRR 7.79; 95% CI 4.95-12.25). Subjects with ADWD and diagnosed current asthmatics were characterised by high and homogeneous percentages of individuals who reported productivity losses (19.0 and 15.1%) and hospitalisations (9.2 and 6.2%) because of respiratory problems in the past year.
  
  
  CONCLUSIONS
  The impact of current asthma seems to be largely underestimated among Italian adults, since the individuals with ADWD may be undiagnosed current asthmatics.
authors.affiliation: Unit of Epidemiology and Medical Statistics, Department of Public Health and Community Medicine, University of Verona, Verona, Italy. simone.accordini @ univr.it
authors.forename: Simone
authors.initials: S
authors.lastname: Accordini
authors.forename: Veronica
authors.initials: V
authors.lastname: Cappa
authors.forename: Marco
authors.initials: M
authors.lastname: Braggion
authors.forename: Angelo G
authors.initials: AG
authors.lastname: Corsico
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Bugiani
authors.forename: Pietro
authors.initials: P
authors.lastname: Pirina
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Verlato
authors.forename: Simona
authors.initials: S
authors.lastname: Villani
authors.forename: Roberto
authors.initials: R
authors.lastname: de Marco
mesh_terms: D000328:Adult; D001249:Asthma / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D003371:Cough / Q000150:complications / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D012135:Respiratory Sounds; D012221:Rhinitis, Allergic, Perennial / Q000150:complications / Q000453:epidemiology; D012307:Risk Factors; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D055815:Young Adult