title: Ethnic variations in asthma hospital admission, readmission and death: a retrospective, national cohort study of 4.62 million people in Scotland.
abstract: BACKGROUND
  Our previous meta-analysis found that South Asians and Blacks in the UK were at a substantially increased risk of hospital admission from asthma. These estimates were, however, derived from pooling data from a limited number of now dated studies, confined to only three very broad ethnic groups (i.e. Whites, South Asians and Blacks) and failed to take account of possible sex-related differences in outcomes within these ethnic groups. We undertook the first study investigating ethnic variations in asthma outcomes across an entire population.
  
  
  METHODS
  This retrospective 9-year cohort study linked Scotland's hospitalisation/death records on asthma to the 2001 census (providing ethnic group). We calculated age, country of birth and Scottish Index of Multiple Deprivation adjusted incident rate ratios (IRRs) for hospitalisation or death by sex for the period May 2001-2010. We calculated hazard ratios (HRs) for asthma readmission and subsequent asthma death.
  
  
  RESULTS
  We were able to link data on 4.62 million people (91.8% of the Scottish population), yielding over 38 million patient-years of data, 1,845 asthma deaths, 113,795 first asthma admissions, and 107,710 readmissions (40,075 of which were for asthma). There were substantial ethnic variations in the rate of hospitalisation/death in both males and females. When compared to the reference Scottish White population, the highest age-adjusted rates were in Pakistani males (IRR = 1.59; 95% CI, 1.30-1.94) and females (IRR = 1.50; 95% CI, 1.06-2.11) and Indian males (IRR = 1.34; 95% CI, 1.16-1.54), and the lowest were seen in Chinese males (IRR = 0.62; 95% CI, 0.41-0.94) and females (IRR = 0.49; 95% CI, 0.39-0.61).
  
  
  CONCLUSIONS
  There are very substantial ethnic variations in hospital admission/deaths from asthma in Scotland, with Pakistanis having the worst and Chinese having the best outcomes. Cultural factors, including self-management and health seeking behaviours, and variations in the quality of primary care provision are the most likely explanations for these differences and these now need to be formally investigated.
authors.affiliation: Edinburgh Migration, Ethnicity and Health Research Group, Usher Institute of Population Health Sciences and Informatics, The University of Edinburgh, Teviot Place, Edinburgh, EH8 9AG, UK. aziz.sheikh@ed.ac.uk.|Asthma UK Centre for Applied Research, Usher Institute of Population Health Sciences and Informatics, The University of Edinburgh, Edinburgh, UK. aziz.sheikh@ed.ac.uk.|Division of General Internal Medicine and Primary Care and Department of Medicine, Harvard Medical School, Boston, MA, USA. aziz.sheikh@ed.ac.uk.
authors.forename: Aziz
authors.initials: A
authors.lastname: Sheikh
authors.affiliation: Department of Child Health, School of Medicine, University of Aberdeen, Aberdeen, UK.
authors.forename: Markus F C
authors.initials: MF
authors.lastname: Steiner
authors.affiliation: Edinburgh Migration, Ethnicity and Health Research Group, Usher Institute of Population Health Sciences and Informatics, The University of Edinburgh, Teviot Place, Edinburgh, EH8 9AG, UK.
authors.forename: Genevieve
authors.initials: G
authors.lastname: Cezard
authors.affiliation: Edinburgh Migration, Ethnicity and Health Research Group, Usher Institute of Population Health Sciences and Informatics, The University of Edinburgh, Teviot Place, Edinburgh, EH8 9AG, UK.|Cardiovascular Epidemiology Unit, The Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK.
authors.forename: Narinder
authors.initials: N
authors.lastname: Bansal
authors.affiliation: Edinburgh Migration, Ethnicity and Health Research Group, Usher Institute of Population Health Sciences and Informatics, The University of Edinburgh, Teviot Place, Edinburgh, EH8 9AG, UK.|NHS National Services Scotland, Edinburgh, UK.
authors.forename: Colin
authors.initials: C
authors.lastname: Fischbacher
authors.affiliation: Edinburgh Migration, Ethnicity and Health Research Group, Usher Institute of Population Health Sciences and Informatics, The University of Edinburgh, Teviot Place, Edinburgh, EH8 9AG, UK.|Asthma UK Centre for Applied Research, Usher Institute of Population Health Sciences and Informatics, The University of Edinburgh, Edinburgh, UK.
authors.forename: Colin R
authors.initials: CR
authors.lastname: Simpson
authors.affiliation: Edinburgh Migration, Ethnicity and Health Research Group, Usher Institute of Population Health Sciences and Informatics, The University of Edinburgh, Teviot Place, Edinburgh, EH8 9AG, UK.
authors.forename: Anne
authors.initials: A
authors.lastname: Douglas
authors.affiliation: Edinburgh Migration, Ethnicity and Health Research Group, Usher Institute of Population Health Sciences and Informatics, The University of Edinburgh, Teviot Place, Edinburgh, EH8 9AG, UK.
authors.forename: Raj
authors.initials: R
authors.lastname: Bhopal
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000706:statistics & numerical data; D001249:Asthma / Q000208:ethnology* / Q000401:mortality*; D044383:Black People / Q000706:statistics & numerical data; D002648:Child; D002675:Child, Preschool; D005006:Ethnicity / Q000706:statistics & numerical data*; D005260:Female; D015438:Health Behavior / Q000208:ethnology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010343:Patient Admission / Q000706:statistics & numerical data*; D010359:Patient Readmission / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012606:Scotland / Q000453:epidemiology; D012648:Self Care / Q000706:statistics & numerical data; D044465:White People / Q000706:statistics & numerical data; D055815:Young Adult