title: Nationwide linkage analysis in Scotland-Has mortality following hospital admission for Crohn's disease changed in the early 21st century?
abstract: BACKGROUND
  National Scottish data were used to compare 3-year mortality in patients hospitalized for Crohn's disease (CD) between 1998-2000 and 2007-2009.
  
  
  METHODS
  The linked Scottish Morbidity Records database was used to identify patients admitted with CD during two periods: Period 1 (1998-2000) and Period 2 (2007-2009). 3-year mortality and standardized mortality ratio (SMR) were determined and multivariable logistic regression analysis of associated factors was performed. Mortality was determined following four admission types: surgery-elective, surgery-emergency, medical-elective and medical-emergency. 3-year mortality was compared between study periods using age-standardized rates.
  
  
  RESULTS
  The number of patients per 100,000 population hospitalized with CD per year was unchanged (15.7 [Period 1]; 14.4 [Period 2]). Overall crude and adjusted 3-year mortality rates were also unchanged (crude mortality 9.0%-9.1%, adjusted mortality odds ratio [OR]=0.87, 95% confidence interval [CI] 0.65-1.17; p=0.36). The adjusted 3-year mortality increased following elective surgery (Period 1: 1/303 [0.3%]; Period 2: 9/261 [3.4%]); OR=13.5 [CI 1.66-109.99]) and decreased following emergency medical admission (Period 1: 99/779 [12.7%]; Period 2:86/802 [10.7%]; OR=0.68 [CI 0.47-0.97]). Directly age-standardized mortality rates were similar (Period 1:338/10,000 person years [CI 282-394]; Period 2:333/10,000 person years [CI 276-390], p=0.2). On multivariable regression, age, deprivation status, comorbidity and the length of hospital stay were associated with mortality in both periods. High 3-year mortality was observed during both periods in patients between 50 and 64years (Period 1: 33/298 [11.1%, SMR=4.8 [CI 3.44-6.63], Period 2: 33/296 [11.1%, SMR=5.9 [4.14-8.22]) and over 65years(Period 1: 94/275 [34.2%, SMR=2.78 [CI 2.42-3.62], Period 2: 78/251 [31.1%, SMR=3.31 [2.64-4.11]).
  
  
  CONCLUSIONS
  Nationwide linkage data demonstrate that overall 3-year mortality after hospitalization for CD is high, especially in patients over 50years, and has not altered between the time periods 1998-2000 and 2007-2009.
authors.forename: Nicholas T
authors.initials: NT
authors.lastname: Ventham
authors.forename: Nick A
authors.initials: NA
authors.lastname: Kennedy
authors.forename: Andrew
authors.initials: A
authors.lastname: Duffy
authors.forename: David N
authors.initials: DN
authors.lastname: Clark
authors.forename: Alison M
authors.initials: AM
authors.lastname: Crowe
authors.forename: Alastair D
authors.initials: AD
authors.lastname: Knight
authors.forename: R John
authors.initials: RJ
authors.lastname: Nicholls
authors.forename: Jack
authors.initials: J
authors.lastname: Satsangi
keywords: Crohn's disease; Inflammatory bowel disease; Mortality