Using intervention analysis to assess catastrophic events on business environment

This article describes the use of Autoregressive Interactive Moving Average with impact assessment (intervention analysis) on a time series. In this case, a search was made for sudden changes in the business environment when a natural disaster struck a community. The catastrophic event was hurricane Hugo. Data were obtained from a public hospital. Admissions, outpatient visits, and emergency room visits were examined. All showed a significant increase in activity, not only for the period immediately following the event, but also for at least two years following the storm. Studies indicate that the long-term clean-up and reconstruction activities may have increased this public facility's case load in a manner somewhat different from other community hospitals.