Concepts for Defining Rational Service Areas for Primary Care Access

2 Question: What parameters should define a rational area for assessing primary care service delivery and access?

3 Rational Service Area – Current Rules HPSA and MUA/P both have RSA requirement May be composed of one or multiple contiguous Census recognized geographies Any area may have a single non-overlapping designation Population centers < 30 minutes apart for multiple county areas

4 Definition of ‘Rational’ – Current Approach Single whole counties if population < 250K; or Service area must consider geography within 30 minutes of population center –By drive time or public transportation under certain conditions Can include smaller communities further out Service area may be further limited by: –Physical barriers –Socioeconomics –Established neighborhoods –Existing designations or over-utilization Narrative description of why the area is rational is an important factor in the current process

5 Service Area Definition Example

6 Rational Service Areas in NPRM2 Generally consistent with existing approaches Encouraged states to develop their own statewide RSA boundary plan –Eliminate contiguous area requirement –State option to vary travel time Included other modifications

7 Rational Service Area Parameters Goal: Establish rules for defining service areas that reasonably reflect effective primary care access patterns. Considerations include: –Geographic units –Distance/Travel Time –Boundary / Contiguous area issues

8 Conceptual Overview Physical boundaries must be defined –For all designated areas and populations –Legislative requirement Designated service area = rational community access Current patterns of access may not define ideal service areas Optimal time/distance access to primary care not empirically determined –Potential policy reasons for wider versus narrowly defined service areas

9 Geographic Units What geographical units can be grouped to form Service Areas? –Current options include Census geographic units ZCTAs and Block Groups not currently used Related units (PCSAs) are Census derivatives/aggregations –Other Units to consider? Local definition of service area boundaries involves combining of geographic units

10 Distance/Travel Time “Spatial Accessibility” between providers and population Rule will define the acceptable time/distance parameters for defining a rational service area Travel time is the typical unit for defining access –Calculation varies by mode of transportation

11 Boundary/Contiguous Area: Current Model Spatial Accessibility defined around a population center 30 Minutes defines extent of contiguous area resources to be evaluated Additional factors permitted for excluding nearby resources

12 Sample Provider/Population Distribution 20 miles

New GIS-based Techniques in Literature All variations of ‘distance decay’ methods –Relates provider locations to population locations by distance within an area using new technology –Permits analyses to cross administrative boundaries –Does not automatically generate ‘service areas’ or avoid decisions regarding accessibility goals and exclusions –Recently Proposed Methods Two-Step Floating Catchment Area (Wang/Luo 2004) –Enhanced 2SFCA (Luo/Qi 2009) Compound Gravity Model (University of NM) Kernel Density Method (Guagliardo 2004)

14 Impact Testing, ‘Baseline’ Designation Universal service area coverage –Needed to test for newly designated areas –Possible national ‘baseline’ designation Potential options (possibly in combination/hierarchy) : –Counties –Primary Care Service Areas (PCSAs) –New rule-based geographic selections

15 NRMC: Service Area Decision Points Permissible geographic units (as components)? Time/distance accessibility goals? –Target, minimum, and/or maximum? –Different modes of travel? –Geographic variation? Accessible resources/boundary definition? –Contiguous area exclusion factors? –Applicability of GIS/distance-decay approaches? Variations/Role in special population designations? Statewide planning/definition of service areas?