title: Hospitalizations for inflammatory bowel disease among US military veterans 1975-2006.
abstract: BACKGROUND
  The Department of Veterans Affairs (VA) is the largest healthcare system in the United States. The VA database was used to analyze patterns of hospitalization for inflammatory bowel disease (IBD) among US military veterans.
  
  
  METHODS
  The study used the VA Patient Treatment File (PTF) between 1975 and 2006. Each hospital record extracted from the PTF included diagnosis, patient age, and ethnicity. Patient age was analyzed in three age groups: 0-44, 45-64, and 65+. Patient ethnicity was analyzed by two broad categories as white and nonwhite.
  
  
  RESULTS
  Among veterans, Crohn's disease was more common than ulcerative colitis and both diseases were more common in whites than in nonwhites. During the past 30 years, the age distributions of both diseases have shifted towards older patients who have come to represent an increasingly larger fraction of patients with Crohn's disease, as well as ulcerative colitis. Hospitalization rates for inflammatory bowel disease among whites recently declined, while most rates among nonwhites continued to rise throughout the observation period.
  
  
  CONCLUSIONS
  The present study revealed a time-dependent shift towards older ages in the age distribution of IBD among hospitalized veterans. These changes, which have been observed similarly in other US statistics, may reflect a birth-cohort phenomenon underlying the long-term time trends of IBD.
authors.affiliation: Portland VA Medical Center and Oregon Health & Science University (AS), P3-GI, 3710 SW US Veterans Hospital Road, Portland, OR. 97239, USA. sonnenbe@ohsu.edu
authors.forename: Amnon
authors.initials: A
authors.lastname: Sonnenberg
authors.forename: Peter A
authors.initials: PA
authors.lastname: Richardson
authors.forename: Neena S
authors.initials: NS
authors.lastname: Abraham
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003093:Colitis, Ulcerative / Q000453:epidemiology / Q000208:ethnology; D003424:Crohn Disease / Q000453:epidemiology / Q000208:ethnology; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000453:epidemiology* / Q000208:ethnology; D008875:Middle Aged; D008889:Military Personnel; D044469:Racial Groups; D012189:Retrospective Studies; D014481:United States / Q000453:epidemiology; D014493:United States Department of Veterans Affairs; D055815:Young Adult