[A method for ascertaining the seasonal pattern of hospital emergency department visits]

A suitable method is set forth in this study for isolating and describing high frequency seasonal variations which may occur in some sets of time series in the healthcare setting. If the simultaneous presence of seasonal variations within a day, a week and a year is not taken into account, the estimates of seasonal behaviours may be noticeably distorted and the decisions made by those in charge of managing healthcare services based thereupon might be erroneous. The proposed procedure, based upon taking simultaneous periodic changes jointly into consideration is applied to an hourly series of patients visiting an hospital emergency room in Tenerife. The results obtained indicate that the most frequent visits take place in February and March, Mondays being the days on which the greatest demand occurs and the early morning hours of the day showing the minimum demands. A long-term growth is also observed. And, above all, the proposed method is shown to provide some advantages over other approaches in which each one of the seasonal variations is estimated as if the others do not exist.