Calendar patterns in the occurrence of cardiac arrest

Our objective was to determine whether monthly and daily patterns existed in cardiac arrests in a 7 emergency department (ED) cohorts in New Jersey. We conducted a retrospective analysis of a computerized database over an 11-year period containing 2,370,233 patient visits and 6,827 nontraumatic cardiac arrests. Time-series regression revealed colder months having more cardiac arrests, especially for patients >_65 years of age. In that age group, December and March were highest with 17% more (P =.002) than the average of nonsignificant months. August was the lowest with 19% (P =.001) fewer cardiac arrests. Day-of-week variation was found only for patients <65 years of age. Saturdays and Mondays had more arrests than nonsignificant days, 15% (P <.0001) and 9% (P =.01), respectively. We conclude that there are monthly and daily patterns in cardiac arrests, with more arrests in the colder months for those greater than or equal to65 years of age, and more for ages <65 on Saturdays and Mondays. (Am J Emerg Med 2002;20:513-517. Copyright (C) 2002, Elsevier Science (USA). All rights reserved.)