title: Changes in mortality on weekend versus weekday admissions for Acute Coronary Syndrome in the United States over the past decade.
abstract: BACKGROUND
  We assessed in-hospital mortality and utilization of invasive cardiac procedures following Acute Coronary Syndrome (ACS) admissions on the weekend versus weekdays over the past decade in the United States.
  
  
  METHODS
  We used data from the Nationwide Inpatient Survey (2001-2011) to examine differences in all-cause in-hospital mortality between patients with a principal diagnosis of ACS admitted on a weekend versus a weekday. Adjusted and hierarchical logistic regression model analysis was then used to identify if weekend admission was associated with a decreased utilization of procedural interventions and increased subsequent complications as well.
  
  
  RESULTS
  13,988,772 ACS admissions were identified. Adjusted mortality was higher for weekend admissions for Non-ST-Elevation Acute Coronary Syndromes [OR: 1.15, 95% CI, 1.14-1.16] and only somewhat higher for ST-Elevation Myocardial Infarction [OR: 1.03; 95% CI, 1.01-1.04]. Additionally, patients were significantly less likely to receive coronary revascularization intervention/therapy on their first day of admission [OR: 0.97, 95% CI: 0.96-0.98 and OR: 0.75, 95% CI: 0.75-0.75 for STEMI and NSTE-ACS respectively]. For ACS patients admitted during the weekend who underwent procedural interventions, in-hospital mortality and complications were higher as compared to patients undergoing the same procedures on weekdays.
  
  
  CONCLUSIONS
  For ACS patients, weekend admission is associated with higher mortality and lower utilization of invasive cardiac procedures, and those who did undergo these interventions had higher rates of mortality and complications than their weekday counterparts. This data leads to the possible conclusion that access to diagnostic/interventional procedures may be contingent upon the day of admission, which may impact mortality.
authors.affiliation: Division of Cardiology, University of California, Irvine, USA; Department of Preventive Medicine, Division of Biostatistics, Keck School of Medicine, University of Southern California, USA.
authors.forename: Mahdi
authors.initials: M
authors.lastname: Khoshchehreh
authors.affiliation: Scripps Clinic, Division of Interventional Cardiology, La Jolla, CA, USA.
authors.forename: Elliott M
authors.initials: EM
authors.lastname: Groves
authors.affiliation: Division of Cardiology, University of California, Irvine, USA.
authors.forename: David
authors.initials: D
authors.lastname: Tehrani
authors.affiliation: Department of Internal Medicine, University of California, Irvine, USA.
authors.forename: Alpesh
authors.initials: A
authors.lastname: Amin
authors.affiliation: Division of Cardiology, University of California, Irvine, USA; Department of Internal Medicine, University of California, Irvine, USA.
authors.forename: Pranav M
authors.initials: PM
authors.lastname: Patel
authors.affiliation: Division of Cardiology, University of California, Irvine, USA; Department of Internal Medicine, University of California, Irvine, USA. Electronic address: smalik@uci.edu.
authors.forename: Shaista
authors.initials: S
authors.lastname: Malik
mesh_terms: D054058:Acute Coronary Syndrome / Q000401:mortality* / Q000628:therapy; D000368:Aged; D015331:Cohort Studies; D005260:Female; D017052:Hospital Mortality / Q000639:trends*; D006760:Hospitalization / Q000639:trends; D006801:Humans; D008297:Male; D008875:Middle Aged; D010343:Patient Admission / Q000639:trends*; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D013997:Time Factors; D014481:United States / Q000453:epidemiology
keywords: Acute Coronary Syndrome; In-hospital mortality; NSTE-ACS; STEMI; Weekend effect