title: Risk of an asthma exacerbation after bariatric surgery in adults.
abstract: BACKGROUND
  Research on nonsurgical weight loss interventions has failed to demonstrate consistent efficacy on asthma control, although these interventions resulted in only modest weight reductions.
  
  
  OBJECTIVE
  We sought to test the hypothesis that bariatric surgery is associated with a rapid and sustained decrease in risk of asthma exacerbation.
  
  
  METHODS
  We performed a self-controlled case series study of 2261 obese patients with asthma aged 18 to 54 years who underwent bariatric surgery using the population-based emergency department (ED) and inpatient sample in 3 states (California, Florida, and Nebraska). The primary outcome was an ED visit or hospitalization for asthma exacerbation from 2005 through 2011. We used conditional logistic regression to compare each patient's risk of the outcome event during sequential 12-month periods using presurgery months 13 to 24 as the reference period.
  
  
  RESULTS
  During the reference period, 22.0% (95% CI, 20.3% to 23.7%) of patients had an ED visit or hospitalization for asthma exacerbation. In the subsequent 12-month presurgery period, the risk did not materially change (21.7%; 95% CI, 20.0% to 23.4%), with an odds ratio (OR) of 0.98 (95% CI, 0.85-1.13) compared with the reference period. By contrast, significantly fewer ED visits or hospitalizations for asthma exacerbation occurred within 12 months after bariatric surgery (10.9%; 95% CI, 9.6% to 12.2%), corresponding to an OR of 0.42 (95% CI, 0.35-0.50). Similarly, in the subsequent period of 13 to 24 months after bariatric surgery, the risk remained significantly lower (10.9%; 95% CI, 9.6% to 12.2%), corresponding to an OR of 0.42 (95% CI, 0.35-0.50).
  
  
  CONCLUSIONS
  In obese patients the risk of an ED visit or hospitalization for asthma exacerbation decreased by half after bariatric surgery. This reduction suggests the effectiveness of significant weight loss on asthma morbidity.
authors: Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Mass. Electronic address: khasegawa1@partners.org.
authors: Kohei
authors: K
authors: Hasegawa
authors: Harvard Interfaculty Initiative in Health Policy, Cambridge, Mass.
authors: Yusuke
authors: Y
authors: Tsugawa
authors: Division of General Internal Medicine, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Mass.
authors: Yuchiao
authors: Y
authors: Chang
authors: Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Mass; Division of Rheumatology, Allergy, and Immunology, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Mass.
authors: Carlos A
authors: CA
authors: Camargo
mesh_terms: D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D050110:Bariatric Surgery; D002140:California; D016022:Case-Control Studies; D005260:Female; D005431:Florida; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009329:Nebraska; D009767:Obesity, Morbid / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D016017:Odds Ratio; D012306:Risk; D016896:Treatment Outcome; D015431:Weight Loss
keywords: Acute asthma; bariatric surgery; emergency department; hospitalization; obesity; self-controlled case series study; weight reduction