title: Time-varying impact of comorbidities on mortality after liver transplantation: a national cohort study using linked clinical and administrative data.
abstract: OBJECTIVE
  We assessed the impact of comorbidity on mortality in three periods after liver transplantation (first 90 days, 90 days-5 years and 5-10 years).
  
  
  METHODS
  Prospective cohort study using records from the UK Liver Transplant Audit (UKLTA) linked to Hospital Episode Statistics (HES), an administrative database of hospital admissions in the English National Health Service (NHS). Comorbidities relevant for liver transplantation were identified from the 10th revision of the International Classification of Diseases (ICD-10) codes in HES records of admissions in the year preceding their operation. Multivariable Cox regression was used to estimate HRs for three different time periods after liver transplantation.
  
  
  METHODS
  All liver transplant centres in the NHS hospitals in England.
  
  
  METHODS
  Adults who received a first elective liver transplant between April 1997 and March 2010 in the linked UKLTA-HES database.
  
  
  RESULTS
  Patient mortality in three different time periods after transplantation.
  
  
  RESULTS
  Among 3837 recipients, 45.1% had comorbidities. Recipients with cardiovascular disease had statistically significantly higher mortality in all three periods after transplantation (first 90 days: HR=2.0; 95% CI 1.4 to 2.9, 90 days-5 years: 1.6; 1.2 to 2.2, beyond 5 years: 2.8; 1.7 to 4.4). Prior congestive cardiac failure (3.2; 2.1 to 4.9) significantly increased mortality only in the first 90 days. History of non-hepatic malignancy appeared to increase risk over all periods, but significantly only in the first 90 days (1.9; 1.0 to 3.6). A diagnosis of connective tissue disease, dementia, diabetes, chronic pulmonary and renal disease did not have a significant impact on mortality in any period.
  
  
  CONCLUSIONS
  The impact of comorbidities present at the time of transplantation changes with time after transplantation. Renal disease, pulmonary disease and diabetes had no impact on mortality in contrast to previous reports.
authors.affiliation: Clinical Effectiveness Unit, The Royal College of Surgeons of England, London, UK Department of Surgery, University of Cambridge, Cambridge, UK.
authors.forename: Chutwichai
authors.initials: C
authors.lastname: Tovikkai
authors.affiliation: Clinical Effectiveness Unit, The Royal College of Surgeons of England, London, UK Department of Health Services Research and Policy, London School of Hygiene and Tropical Medicine, London, UK.
authors.forename: Susan C
authors.initials: SC
authors.lastname: Charman
authors.affiliation: Department of Surgery, University of Cambridge, Cambridge, UK Liver Transplant Unit, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.
authors.forename: Raaj K
authors.initials: RK
authors.lastname: Praseedom
authors.affiliation: Liver Transplant Unit, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.
authors.forename: Alexander E
authors.initials: AE
authors.lastname: Gimson
authors.affiliation: Clinical Effectiveness Unit, The Royal College of Surgeons of England, London, UK Department of Health Services Research and Policy, London School of Hygiene and Tropical Medicine, London, UK.
authors.forename: Jan
authors.initials: J
authors.lastname: van der Meulen
mesh_terms: D000328:Adult; D015897:Comorbidity; D016208:Databases, Factual; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D008107:Liver Diseases / Q000401:mortality*; D016031:Liver Transplantation / Q000401:mortality* / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013222:State Medicine; D013997:Time Factors; D006113:United Kingdom / Q000453:epidemiology
keywords: CARDIOLOGY; DIABETES & ENDOCRINOLOGY; ONCOLOGY; TRANSPLANT MEDICINE; TRANSPLANT SURGERY