Patterns in the number of patients seen hourly in a community hospital emergency department

The hourly and daily patient load data from Tri-City Hospital was analyzed using statistical and graphic analysis for the period between April 1, 1976 and October 31, 1976. This analysis revealed repetitive patterns in the patient load data, both in the daily data, with a seven-day cycle peaking on Saturday or Sunday, and the intraday data with a bimodal daily cycle with peaks between 10:00 am and 1:00 pm, followed by a high evening peak between 7:00 pm and 8:00 pm. Methods were introduced which, by simple calculation, can determine these cycles and those deviant days that exceed the norm early in the day.