The State of Arizona is served by 38 Hospital Service Areas (HSA) according to the Dartmouth Atlas of Healthcare. Each one of these HSAs represent the zip code geography from which most Medicare patients access their hospital care. The HSA is labeled with the name of the community with the hospital(s) that provide that care. Some HSAs cover large geographies, some smaller. Some have multiple hospitals, and some have only one. This study was conducted to better understand the differences and similarities of these HSAs, to catalogue different capabilities and to understand how care capabilities change from our most rural to our most urban communities.
This study provides administrators and planners with a broad quantified understanding of the connection between local patient utilization and local hospital capabilities. This understanding is at the service line level and much more complex than sizing inpatient demand to a specific population with the anticipation of growth. In this study we categorize the types of Arizona HSAs and stratify their patients’ demand by services offered Locally and in Total.
Arizona’s HSAs were categorized into five types: Tertiary, Large Community, Medium Community, Small Community, and Critical Access. Clear differentiations were found from Medium thru Tertiary based on criteria including: presence and volume of specific cardiac, neurosurgery, and orthopedic surgeries and procedures; NICU presence; ICU presence and beds, medical / surgical beds; overall IP and OP surgical volume. A clear division of capabilities between Small Community Hospitals and Critical Access Hospitals was not easily found.
Total utilization rates – which include all BDOC originating from residents in each HSA regardless of service location – ranged from a low of 410.2 BDOC/1,000 population in Large Community HSAs to a high of 499.9 in Critical Access HSAs.
Local utilization rates – which include BDOC originating from a resident in each HSA only where that service was provided within the local HSA – showed higher variation from a low of 76.6 BDOC per 1,000 population in Small Community HSAs to a high of 365.2 BDOC per 1,000 population in Tertiary HSAs.
The percent of total IP BDOC provided within the local HSA ranges from a low of 18.5% in Small Community HSA types to a high of 75.9% in Tertiary HSA types.
Medicine, Surgery, Mental Health & Substance Abuse, and Maternal/Child Health service line local utilization rates all trend up from Small to Tertiary HSA Types. Notably, there is almost no local utilization of IP Mental Health & Substance Abuse in Critical Access and Small Community HSAs, indicating a lack of capacity for those services.
Based on 85% occupancy rates, the number of beds needed to meet local demand with local capability ranges from a low of 0.25 beds per 1,000 population in Small Community HSA types to 1.18 for Tertiary HSA types.
Understanding the variance of service line capabilities by HSA type will allow administrators and planners to develop and model a range of solutions to make strategic service line plans with confidence. While no two hospitals are the same, this study narrows your planned capability scenarios.
By Bryan Hannley, Tim Snyder and Elizabeth Ayarbe-Perez | August 2020