Abstract
Purpose :
Access to eye care remains a challenge in geographically disparate locations such as the state of Washington. The purpose of this study was to determine access to eye care by measuring driving distance between population centers and eye care providers in the state of Washington.
Methods :
The 2012 Medicare Provider Utilization and Payment Data from the Centers for Medicare and Medicaid Services were used to identify providers actively practicing as optometrists and ophthalmologists. Open Street Map data for every road and its associated speed limits were utilized in the state of Washington to calculate the shortest path defined by driving time using Dijkstra’s algorithm. The 2010 US Census geospatial data at block group resolution was meshed with Open Street Map to calculate the shortest path between populated areas and the nearest eye care provider.
Results :
Of the 25,508 optometrists and 17,071 ophthalmologists in the national Medicare Provider Utilization and Payment Data from 2012, a total of 665 optometrists and 332 ophthalmologists were identified as practicing in the state of Washington. Over 2.6 x 105 driving routes were calculated and the shortest driving path and time were collected for each optometrist to the nearest ophthalmologist. Ninety percent of the population lives within 9.36 miles and 11.76 minutes of an eye care provider (Figure 1A,B). Driving routes between eye care providers were calculated (Figure 2). 94.6% and 97.6% of optometrists practice within 30 and 60 miles of an ophthalmologist, respectively. 97.6% and 99.6% of optometrists practice within 1 and 2 hours of an ophthalmologist. The median distance and driving time to the nearest ophthalmologist were 1.81 miles and 2.16 minutes respectively (Figure 3A,B).
Conclusions :
In the state of Washington, the majority of the population lives within close proximity of an eye care provider.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.