title: [Factors associated with use of emergency medical service for acute myocardial infarction in Beijing].
abstract: OBJECTIVE
  To examine the current ambulance transport rates and ascertain factors associated with use of emergency medical service (EMS) in patients with acute myocardial infarction (AMI) in Beijing.
  
  
  METHODS
  Between January 1 and December 31, 2006, a cross-sectional and multicenter survey was conducted in 19 hospitals in Beijing and included patients with ST-elevation myocardial infarction (STEMI) admitted within 24 hours of onset of symptoms. Data were collected by structured interviews and medical records review within 1 week after admission. Patients were categorized into the EMS group and the self-transport group according to their modes of transport to the initial hospital. Data were analyzed by descriptive statistics, univariate and multivariate logistic analysis.
  
  
  RESULTS
  Of the 789 patients with STEMI, only 260 (33.0%) arrived at the initial hospital by EMS, while the remaining 529 (77.0%) relied on self-transport. Multivariate logistic analysis showed that age >/= 65 years (OR: 1.530, 95%CI: 1.050 - 2.230, P = 0.027), higher education level (OR: 2.032, 95%CI: 1.257 - 3.284, P = 0.004), history of coronary artery disease (OR: 0.474, 95%CI: 1.049 - 2.458, P = 0.029), unbearable symptoms (OR: 0.592, 95%CI: 1.090 - 2.520, P = 0.008), anxiety (OR: 0.760, 95%CI: 1.238 - 3.695, P = 0.006) and attribution of symptoms to cardiac origin (OR: 0.402, 95%CI: 1.020 - 2.171, P = 0.041) were independent predictors of EMS use. However, presence of pre-infarction angina significantly decreased the likelihood of using EMS (OR: 0.626, 95%CI: 0.431 - 0.907, P = 0.013).
  
  
  CONCLUSIONS
  Only one-third of patients with STEMI arrived at the hospital by EMS in Beijing. Demographics, history of coronary artery disease, symptoms characteristics and cognitive factors of patients were associated with the EMS use.
authors.forename: Li
authors.initials: L
authors.lastname: Song
authors.forename: Hon-bing
authors.initials: HB
authors.lastname: Yan
authors.forename: Jin-gang
authors.initials: JG
authors.lastname: Yang
authors.forename: Yi-hong
authors.initials: YH
authors.lastname: Sun
authors.forename: Shu-shan
authors.initials: SS
authors.lastname: Liu
authors.forename: Chao
authors.initials: C
authors.lastname: Li
authors.forename: Da-yi
authors.initials: DY
authors.lastname: Hu
mesh_terms: D000368:Aged; D002681:China; D003430:Cross-Sectional Studies; D004632:Emergency Medical Services / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000628:therapy*