title: Outcomes of Basic Versus Advanced Life Support for Out-of-Hospital Medical Emergencies.
abstract: BACKGROUND
  Most Medicare patients seeking emergency medical transport are treated by ambulance providers trained in advanced life support (ALS). Evidence supporting the superiority of ALS over basic life support (BLS) is limited, but some studies suggest ALS may harm patients.
  
  
  OBJECTIVE
  To compare outcomes after ALS and BLS in out-of-hospital medical emergencies.
  
  
  METHODS
  Observational study with adjustment for propensity score weights and instrumental variable analyses based on county-level variations in ALS use.
  
  
  METHODS
  Traditional Medicare.
  
  
  METHODS
  20% random sample of Medicare beneficiaries from nonrural counties between 2006 and 2011 with major trauma, stroke, acute myocardial infarction (AMI), or respiratory failure.
  
  
  METHODS
  Neurologic functioning and survival to 30 days, 90 days, 1 year, and 2 years.
  
  
  RESULTS
  Except in cases of AMI, patients showed superior unadjusted outcomes with BLS despite being older and having more comorbidities. In propensity score analyses, survival to 90 days among patients with trauma, stroke, and respiratory failure was higher with BLS than ALS (6.1 percentage points [95% CI, 5.4 to 6.8 percentage points] for trauma; 7.0 percentage points [CI, 6.2 to 7.7 percentage points] for stroke; and 3.7 percentage points [CI, 2.5 to 4.8 percentage points] for respiratory failure). Patients with AMI did not exhibit differences in survival at 30 days but had better survival at 90 days with ALS (1.0 percentage point [CI, 0.1 to 1.9 percentage points]). Neurologic functioning favored BLS for all diagnoses. Results from instrumental variable analyses were broadly consistent with propensity score analyses for trauma and stroke, showed no survival differences between BLS and ALS for respiratory failure, and showed better survival at all time points with BLS than ALS for patients with AMI.
  
  
  CONCLUSIONS
  Only Medicare beneficiaries from nonrural counties were studied.
  
  
  CONCLUSIONS
  Advanced life support is associated with substantially higher mortality for several acute medical emergencies than BLS.
  
  
  BACKGROUND
  National Science Foundation, Agency for Healthcare Research and Quality, and National Institutes of Health.
authors.forename: Prachi
authors.initials: P
authors.lastname: Sanghavi
authors.forename: Anupam B
authors.initials: AB
authors.lastname: Jena
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Newhouse
authors.forename: Alan M
authors.initials: AM
authors.lastname: Zaslavsky
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004632:Emergency Medical Services / Q000379:methods* / Q000592:standards*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008020:Life Support Care / Q000379:methods* / Q000592:standards*; D008297:Male; D006278:Medicare; D009203:Myocardial Infarction / Q000628:therapy; D017063:Outcome Assessment, Health Care; D057216:Propensity Score; D012131:Respiratory Insufficiency / Q000628:therapy; D020521:Stroke / Q000628:therapy; D016896:Treatment Outcome; D014481:United States; D014947:Wounds and Injuries / Q000628:therapy