Out-of-hospital cardiac arrest frequency and survival: evidence for temporal variability. Resuscitation 2010 Feb;81(2):175-81
Date
11/28/2009Pubmed ID
19942338Pubmed Central ID
PMC2815250DOI
10.1016/j.resuscitation.2009.10.021Scopus ID
2-s2.0-74449093072 (requires institutional sign-in at Scopus site) 84 CitationsAbstract
AIM: Some cardiac phenomena demonstrate temporal variability. We evaluated temporal variability in out-of-hospital cardiac arrest (OHCA) frequency and outcome.
METHODS: Prospective cohort study (the Resuscitation Outcomes Consortium) of all OHCA of presumed cardiac cause who were treated by emergency medical services within 9 US and Canadian sites between 12/1/2005 and 02/28/2007. In each site, Emergency Medical System records were collected and analyzed. Outcomes were individually verified by trained data abstractors.
RESULTS: There were 9667 included patients. Median age was 68 (IQR 24) years, 66.7% were male and 8.3% survived to hospital discharge. The frequency of cardiac arrest varied significantly across time blocks (p<0.001). Compared to the 0001-0600 hourly time block, the odds ratios and 95% CIs for the occurrence of OHCA were 2.02 (1.90, 2.15) in the 0601-1200 block, 2.01 (1.89, 2.15) in the 1201-1800 block, and 1.73 (1.62, 1.85) in the 1801-2400 block. The frequency of all OHCA varied significantly by day of week (p=0.03) and month of year (p<0.001) with the highest frequencies on Saturday and during December. Survival to hospital discharge was lowest when the OHCA occurred during the 0001-0600 time block (7.3%) and highest during the 1201-1800 time block (9.6%). Survival was highest for OHCAs occurring on Mondays (10.0%) and lowest for those on Wednesdays (6.8%) (p=0.02).
CONCLUSION: There is temporal variability in OHCA frequency and outcome. Underlying patient, EMS system and environmental factors need to be explored to offer further insight into these observed patterns.
Author List
Brooks SC, Schmicker RH, Rea TD, Aufderheide TP, Davis DP, Morrison LJ, Sahni R, Sears GK, Griffiths DE, Sopko G, Emerson SS, Dorian P, ROC InvestigatorsAuthor
Tom P. Aufderheide MD Professor in the Emergency Medicine department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AgedFemale
Heart Arrest
Humans
Male
Prospective Studies
Survival Rate
Time Factors