title: Deprivation index and dependency ratio are key determinants of emergency medical admission rates.
abstract: BACKGROUND
  Patients from deprived backgrounds have a higher in-patient mortality following an emergency medical admission; there has been debate as to the extent to which deprivation and population structure influences hospital admission rate.
  
  
  METHODS
  All emergency medical admissions to an Irish hospital over a 12-year period (2002-2013) categorized by quintile of Deprivation Index and Dependency Ratio (proportion of population <15 or ≥ 65 years) from small area population statistics (SAPS), were evaluated against hospital admission rates. Univariate and multivariable risk estimates (Odds Ratios (OR) or Incidence Rate Ratios (IRR)) were calculated, using logistic or zero truncated Poisson regression as appropriate.
  
  
  RESULTS
  66,861 admissions in 36,214 patients occured during the study period. The Deprivation Index quintile independently predicted the admission rate/1000 population, Q1 9.4 (95%CI 9.2 to 9.7), Q2 16.8 (95%CI 16.6 to 17.0), Q3 33.8 (95%CI 33.5 to 34.1), Q4 29.6 (95%CI 29.3 to 29.8) and Q5 45.4 (95%CI 44.5 to 46.2). Similarly the population Dependency Ratio was an independent predictor of the admission rate with adjusted predicted rates of Q1 20.8 (95%CI 20.5 to 21.1), Q2 19.2 (95%CI 19.0 to 19.4), Q3 27.6 (95%CI 27.3 to 27.9), Q4 43.9 (95%CI 43.5 to 44.4) and Q5 34.4 (95%CI 34.1 to 34.7). A high concurrent Deprivation Index and Dependency Ratio were associated with very high admission rates.
  
  
  CONCLUSIONS
  Deprivation Index and population Dependency Ratio are key determinants of the rate of emergency medical admissions.
authors.affiliation: Department of Internal Medicine, St James's Hospital, Dublin 8, Ireland; CARD Newman Research Fellow, University College Dublin, Belfield, Ireland.
authors.forename: Richard
authors.initials: R
authors.lastname: Conway
authors.affiliation: Department of Internal Medicine, St James's Hospital, Dublin 8, Ireland.
authors.forename: Declan
authors.initials: D
authors.lastname: Byrne
authors.affiliation: Department of Internal Medicine, St James's Hospital, Dublin 8, Ireland.
authors.forename: Deirdre
authors.initials: D
authors.lastname: O'Riordan
authors.affiliation: Department of Internal Medicine, St James's Hospital, Dublin 8, Ireland.
authors.forename: Seán
authors.initials: S
authors.lastname: Cournane
authors.affiliation: School of Geographical and Earth Sciences, University of Glasgow, University Avenue, Glasgow G12 8QQ, UK.
authors.forename: Seamus
authors.initials: S
authors.lastname: Coveney
authors.affiliation: Department of Internal Medicine, St James's Hospital, Dublin 8, Ireland. Electronic address: bernardsilke@physicians.ie.
authors.forename: Bernard
authors.initials: B
authors.lastname: Silke
mesh_terms: D000208:Acute Disease / Q000453:epidemiology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease / Q000453:epidemiology*; D003858:Dependency, Psychological; D004632:Emergency Medical Services / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007494:Ireland / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D010343:Patient Admission / Q000706:statistics & numerical data*; D011379:Prognosis; D012720:Severity of Illness Index; D012959:Socioeconomic Factors
keywords: Dependency Ratio; Deprivation Index; Emergency medical admission