title: Antibiotic treatment is associated with reduced risk of a subsequent exacerbation in obstructive lung disease: an historical population based cohort study.
abstract: OBJECTIVE
  The risk of a subsequent exacerbation after treatment of an exacerbation with oral corticosteroids without (OS) or with (OSA) antibiotics was evaluated in a historical population based cohort study comprising patients using maintenance medication for obstructive lung disease.
  
  
  METHODS
  The Pharmo database includes drug dispensing records of more than 2 million subjects in The Netherlands. Eligible were patients >or=50 years who in 2003 were dispensed >or=2 prescriptions of daily used inhaled beta(2) agonists, anticholinergics and/or corticosteroids, and experienced at least one exacerbation before 1 January 2006. Exacerbation was defined as a prescription of OS or OSA. The times to the second and third exacerbations were compared using Kaplan-Meier survival analysis. Independent determinants of new exacerbations were identified using multivariable Cox recurrent event survival analysis.
  
  
  RESULTS
  Of 49,599 patients using maintenance medication, 18 928 had at least one exacerbation; in 52%, antibiotics had been added. The OS and OSA groups were comparable for potential confounding factors. Median time to the second exacerbation was 321 days in the OS group and 418 days in the OSA group (p<0.001); and between the second and third exacerbation 127 vs 240 days (p<0.001). The protective effect of OSA was most pronounced during the first 3 months following treatment (hazard ratio (HR) 0.62; 99% CI 0.60 to 0.65). In the OSA group, mortality during follow-up was lower (HR 0.82; 99% CI 0.66 to 0.98).
  
  
  CONCLUSIONS
  Treatment with antibiotics in addition to oral corticosteroids was associated with a longer time to the next exacerbation, and a decreased risk of developing a new exacerbation.
authors.affiliation: Department of Internal Medicine, Division of Infectious Diseases, Tropical Medicine and AIDS, and Centre for Infection and Immunity Amsterdam (CINIMA), F4-217, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands. i.roede@amc.uva.nl
authors.forename: B M
authors.initials: BM
authors.lastname: Roede
authors.forename: P
authors.initials: P
authors.lastname: Bresser
authors.forename: P J E
authors.initials: PJ
authors.lastname: Bindels
authors.forename: A
authors.initials: A
authors.lastname: Kok
authors.forename: M
authors.initials: M
authors.lastname: Prins
authors.forename: G
authors.initials: G
authors.lastname: ter Riet
authors.forename: R B
authors.initials: RB
authors.lastname: Geskus
authors.forename: R M C
authors.initials: RM
authors.lastname: Herings
authors.forename: J M
authors.initials: JM
authors.lastname: Prins
mesh_terms: D000280:Administration, Inhalation; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D015331:Cohort Studies; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008173:Lung Diseases, Obstructive / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012307:Risk Factors
chemical_list: D000305:Adrenal Cortex Hormones; D000900:Anti-Bacterial Agents