title: Impact of hospital proportion and volume on primary percutaneous coronary intervention performance in England and Wales.
abstract: OBJECTIVE
  To quantify the determinants of primary percutaneous coronary intervention (PCI) performance in England and Wales between 2004 and 2007.
  
  
  RESULTS
  All 8653 primary PCI cases admitted to acute hospitals in England and Wales as recorded in the Myocardial Ischaemia National Audit Project (MINAP) 2004-2007. We studied the impact of the volume of primary PCI cases (hospital volume) on door-to-balloon (DTB) times and the proportion of patients treated with primary PCI (hospital proportion) on 30-day mortality and employed regression analysis to identify reasons for DTB time variations with a multilevel component to express hospital variation. The proportion of patients receiving primary PCI increased from 5% in 2004 to 20% in 2007. Median DTB times reduced from 84 min in 2004 to 61 min in 2007. Median DTB times decreased as the number of primary PCI procedures increased. The 30-day all-cause mortality rate for hospitals performing primary PCI on >25% of ST-elevation myocardial infarction patients [5.0%; 95% confidence interval (CI): 3.9-6.1%] was almost double that of hospitals performing primary PCI on more than 75% (2.7%; 95% CI: 2.0-3.5%). Time-of-day, year of admission, sex, and diabetes significantly influenced DTB times. Hospital variation was evident by a hospital-level DTB time standard deviation of 12 min.
  
  
  CONCLUSIONS
  There was a large variation in DTB times between the best and worst performing hospitals. Although patient-related factors impacted upon DTB times, the volume and proportion of patients undergoing primary PCI were significantly associated with delay and early mortality-hospitals with the highest proportion of primary PCI had the lowest mortality.
authors.affiliation: Centre for Epidemiology and Biostatistics, University of Leeds, Level 8, Worsley Building, Clarendon Way, West Yorkshire, Leeds LS2 9JT, UK.
authors.forename: Robert M
authors.initials: RM
authors.lastname: West
authors.forename: Brian A
authors.initials: BA
authors.lastname: Cattle
authors.forename: Marianne
authors.initials: M
authors.lastname: Bouyssie
authors.forename: Iain
authors.initials: I
authors.lastname: Squire
authors.forename: Mark
authors.initials: M
authors.lastname: de Belder
authors.forename: Keith A A
authors.initials: KA
authors.lastname: Fox
authors.forename: Roger
authors.initials: R
authors.lastname: Boyle
authors.forename: Jim M
authors.initials: JM
authors.lastname: McLenachan
authors.forename: Philip D
authors.initials: PD
authors.lastname: Batin
authors.forename: Darren C
authors.initials: DC
authors.lastname: Greenwood
authors.forename: Chris P
authors.initials: CP
authors.lastname: Gale
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000592:standards / Q000706:statistics & numerical data*; D004632:Emergency Medical Services / Q000592:standards / Q000706:statistics & numerical data; D004739:England / Q000453:epidemiology; D005260:Female; D006276:Health Facility Size / Q000706:statistics & numerical data*; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008485:Medical Audit; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality / Q000628:therapy*; D009204:Myocardial Revascularization / Q000706:statistics & numerical data; D015912:Thrombolytic Therapy / Q000706:statistics & numerical data; D013997:Time Factors; D014852:Wales / Q000453:epidemiology