Hospital service areas (HSAs) are organized by towns and are based on inpatient discharges where the diagnosis indicated the need for immediate care. Plurality inclusion rules result in towns being assigned to the HSA corresponding to the plurality of discharges. HSA analyses are used to compare data for residents of 13 geographic regions of Vermont who were provided inpatient and select outpatient services in any Vermont, New Hampshire, New York, or Massachusetts hospital. HSAs are defined by the Vermont Department of Banking, Insurance, Securities, and Healthcare Administration (BISHCA). Information on HSAs can be obtained online at - http://www.bishca.state.vt.us/health-care/research-data-reports/vermont-hospital-utilization-reports-vhur or at - http://healthvermont.gov/research/hospital-utilization.aspx (see frequently asked questions). The VDH Public Health Statistics program periodically updates HSA GIS data. Last updated: 2004.