title: Effect of a concomitant diagnosis of allergic rhinitis on asthma-related health care use by adults.
abstract: BACKGROUND
  Asthma and allergic rhinitis (AR) frequently coexist, but have usually been studied separately in health economic analyses.
  
  
  OBJECTIVE
  To determine the incremental effect of documented AR on health care resource use in adults with asthma.
  
  
  METHODS
  A retrospective cohort study using data from a UK general practice database for the period 1998-2001 enrolled subjects 16-55 years of age, with one or more asthma-related general practitioner (GP) visits during a 12-month follow-up period. The study outcomes were asthma-related hospitalizations, GP visits, and prescription drug costs during the 12-month follow-up period for patients with and without physician-diagnosed AR.
  
  
  RESULTS
  Concomitant AR was documented in 4,611 (16.9%) of the total sample of 27,303 adults with asthma. Compared with those with asthma alone, patients with concomitant AR experienced more GP visits (5.2 vs. 4.2; P<0.0001) and more of them were hospitalized for asthma (0.76% vs. 0.45%; P<0.01) during the 12-month follow-up period. In multi-variable regression analyses, AR was predictive of hospitalization for asthma (odds ratio 1.52, 95% confidence interval (CI) 1.03-2.24) and was associated with an increase in the annual number of asthma-related GP visits (mean increase per patient 0.42, 95% CI 0.42-0.43) and annual asthma-related drug costs (mean increase GBP 5.1, 95% CI 5.0-5.3).
  
  
  CONCLUSIONS
  Adults with asthma and documented concomitant AR experienced more asthma-related hospitalizations and GP visits, and incurred higher asthma drug costs than did adults with asthma alone. A unified treatment strategy for asthma and AR might reduce the costs of treating these conditions.
authors.affiliation: Department of General Practice and Primary Care, University of Aberdeen, Foresterhill Health Centre, Aberdeen, UK.
authors.forename: D
authors.initials: D
authors.lastname: Price
authors.forename: Q
authors.initials: Q
authors.lastname: Zhang
authors.forename: V S
authors.initials: VS
authors.lastname: Kocevar
authors.forename: D D
authors.initials: DD
authors.lastname: Yin
authors.forename: M
authors.initials: M
authors.lastname: Thomas
mesh_terms: D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000150:complications / Q000188:drug therapy / Q000191:economics*; D015331:Cohort Studies; D016527:Drug Costs; D005194:Family Practice / Q000191:economics*; D017048:Health Care Costs; D006760:Hospitalization / Q000191:economics; D006792:House Calls / Q000191:economics; D006801:Humans; D008875:Middle Aged; D016017:Odds Ratio; D012044:Regression Analysis; D012189:Retrospective Studies; D012221:Rhinitis, Allergic, Perennial / Q000150:complications / Q000188:drug therapy / Q000191:economics*; D012306:Risk