title: Asthma Is More Severe in Older Adults.
abstract: BACKGROUND
  Severe asthma occurs more often in older adult patients. We hypothesized that the greater risk for severe asthma in older individuals is due to aging, and is independent of asthma duration.
  
  
  METHODS
  This is a cross-sectional study of prospectively collected data from adult participants (N=1130; 454 with severe asthma) enrolled from 2002 - 2011 in the Severe Asthma Research Program.
  
  
  RESULTS
  The association between age and the probability of severe asthma, which was performed by applying a Locally Weighted Scatterplot Smoother, revealed an inflection point at age 45 for risk of severe asthma. The probability of severe asthma increased with each year of life until 45 years and thereafter increased at a much slower rate. Asthma duration also increased the probability of severe asthma but had less effect than aging. After adjustment for most comorbidities of aging and for asthma duration using logistic regression, asthmatics older than 45 maintained the greater probability of severe asthma [OR: 2.73 (95 CI: 1.96; 3.81)]. After 45, the age-related risk of severe asthma continued to increase in men, but not in women.
  
  
  CONCLUSIONS
  Overall, the impact of age and asthma duration on risk for asthma severity in men and women is greatest over times of 18-45 years of age; age has a greater effect than asthma duration on risk of severe asthma.
authors.affiliation: Respiratory Institute, Cleveland Clinic, Cleveland, Ohio, United States of America.
authors.forename: Joe G
authors.initials: JG
authors.lastname: Zein
authors.affiliation: Respiratory Institute, Cleveland Clinic, Cleveland, Ohio, United States of America.
authors.forename: Raed A
authors.initials: RA
authors.lastname: Dweik
authors.affiliation: Department of Pathobiology, Cleveland Clinic, Cleveland, Ohio, United States of America.
authors.forename: Suzy A
authors.initials: SA
authors.lastname: Comhair
authors.affiliation: Center for Genomics and Personalized Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, United States of America.
authors.forename: Eugene R
authors.initials: ER
authors.lastname: Bleecker
authors.affiliation: Center for Genomics and Personalized Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, United States of America.
authors.forename: Wendy C
authors.initials: WC
authors.lastname: Moore
authors.affiliation: Center for Genomics and Personalized Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, United States of America.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Peters
authors.affiliation: Department of Medicine, The University of Wisconsin, School of Medicine and Public Health, Madison, Wisconsin, United States of America.
authors.forename: William W
authors.initials: WW
authors.lastname: Busse
authors.affiliation: Department of Medicine, The University of Wisconsin, School of Medicine and Public Health, Madison, Wisconsin, United States of America.
authors.forename: Nizar N
authors.initials: NN
authors.lastname: Jarjour
authors.affiliation: Department of Medicine, University of Texas Medical Branch, Galveston, Texas, United States of America.
authors.forename: William J
authors.initials: WJ
authors.lastname: Calhoun
authors.affiliation: Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America.
authors.forename: Mario
authors.initials: M
authors.lastname: Castro
authors.affiliation: The National Heart and Lung Institute, Imperial College, London, United Kingdom.
authors.forename: K Fan
authors.initials: KF
authors.lastname: Chung
authors.affiliation: Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, United States of America.
authors.forename: Anne
authors.initials: A
authors.lastname: Fitzpatrick
authors.affiliation: Pulmonary Division, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachussets, United States of America.
authors.forename: Elliot
authors.initials: E
authors.lastname: Israel
authors.affiliation: Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America.
authors.forename: W Gerald
authors.initials: WG
authors.lastname: Teague
authors.affiliation: Asthma Institute, The University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Sally E
authors.initials: SE
authors.lastname: Wenzel
authors.affiliation: Department of Epidemiology and Biostatistics, Case Western Reserve University-MetroHealth Medical Center, Cleveland, Ohio, United States of America.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Love
authors.affiliation: Department of Pediatric, Rainbow Babies and Children's Hospital, Cleveland, Ohio, United States of America.
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Gaston
authors.affiliation: Respiratory Institute, Cleveland Clinic, Cleveland, Ohio, United States of America; Department of Pathobiology, Cleveland Clinic, Cleveland, Ohio, United States of America.
authors.forename: Serpil C
authors.initials: SC
authors.lastname: Erzurum
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging; D001249:Asthma / Q000473:pathology* / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012720:Severity of Illness Index