GeoHealth SDOH Explorer aggregates federal public health, demographic, and environmental datasets to provide census-tract-level intelligence. This page documents every data source, how scores are computed, and the limitations of the analysis. All data is sourced from U.S. government agencies and is publicly available.
Data Sources
American Community Survey 5-Year Estimates2018–2022
U.S. Census Bureau
Demographic, economic, and housing data at the census tract level including income, poverty, insurance coverage, employment, and age distribution.
Population Level Analysis and Community Estimates (PLACES)2023 Release
Centers for Disease Control and Prevention
Model-based estimates for 36 chronic disease measures at the census tract level, derived from the Behavioral Risk Factor Surveillance System (BRFSS).
Social Vulnerability Index2022
CDC/Agency for Toxic Substances and Disease Registry
Percentile-ranked index across four themes: Socioeconomic Status, Household Characteristics, Racial/Ethnic Minority Status, and Housing Type/Transportation. Used to identify communities most at risk during public health emergencies.
Environmental Justice Screening and Mapping Tool2024
U.S. Environmental Protection Agency
Environmental and demographic indicators including PM2.5, ozone, lead paint, air toxics cancer risk, traffic proximity, and Superfund site proximity.
National Plan and Provider Enumeration SystemMonthly updates
Centers for Medicare & Medicaid Services (CMS)
Registry of all healthcare providers in the U.S. Used to identify primary care physicians (PCPs), FQHCs, urgent care centers, and rural health clinics by taxonomy code and practice location.
Health Professional Shortage Area Designations2024
Health Resources and Services Administration
Federal designation identifying geographic areas, populations, or facilities with shortages of primary care, dental, or mental health providers. HPSA scores range 0–25, with higher scores indicating greater shortage.
County Business Patterns2022
U.S. Census Bureau
Annual data on business establishments, employment, and payroll by county and industry (NAICS). Used to assess employer landscape for DPC partnership potential—specifically mid-size employers (10–249 employees) and average wages.
Topologically Integrated Geographic Encoding and Referencing2022
U.S. Census Bureau
Geographic boundary shapefiles for census tracts, counties, and states. Used for map rendering and spatial operations.
SDOH Index
The SDOH Index (0–1) is a composite vulnerability score combining poverty rate, uninsured rate, unemployment rate, and CDC SVI percentile rankings. Higher values indicate greater social determinant burden. The index is computed server-side using min-max normalization across loaded tracts and equal weighting of components.
DPC Market Fit Scoring
The DPC (Direct Primary Care) Market Fit score estimates the geographic viability for Direct Primary Care practices. DPC is a membership-based primary care model where patients pay a monthly fee (typically $75–$150) for comprehensive primary care without insurance billing. The composite score (0–100) is a weighted average of five dimensions, each scored independently using min-max normalization against national reference ranges.
WEAK
0–39
MODERATE
40–59
STRONG
60–79
EXCELLENT
80–100
Data completeness is tracked per dimension. When completeness is below 100%, the score reflects only available indicators, and competition scores are capped at 70 to prevent inflated ratings.
DemandWeight: 25%
Measures the need for primary care services in the area. Higher uninsured rates, chronic disease burden, and social vulnerability indicate greater demand for accessible, affordable care models like DPC.
| Indicator | Weight | Source | Direction |
|---|---|---|---|
| Uninsured Rate | 25% | Census ACS | Higher = more demand |
| Chronic Disease Burden | 25% | CDC PLACES | Higher = more demand |
| Working-Age Population | 15% | Census ACS | Larger = bigger market |
| SVI Socioeconomic Theme | 15% | CDC/ATSDR SVI | Higher = more need |
AffordabilityWeight: 20%
Evaluates the population's ability to pay for DPC membership (typically $75–$150/month). Higher incomes, lower housing burden, and stronger employment indicate more capacity to subscribe.
| Indicator | Weight | Source | Direction |
|---|---|---|---|
| Median Household Income | 35% | Census ACS | Higher = more ability to pay |
| DPC as % of Income | 30% | Census ACS (derived) | Lower = more affordable |
| Employment Rate | 20% | Census ACS | Higher = more stable income |
| Housing Cost Burden | 15% | Census ACS | Lower = more disposable income |
Supply GapWeight: 25%
Identifies areas with insufficient primary care infrastructure. Fewer PCPs, HPSA designations, and limited safety-net facilities signal opportunities for new DPC practices.
| Indicator | Weight | Source | Direction |
|---|---|---|---|
| PCP per 100k Population | 40% | NPPES NPI | Lower = more opportunity |
| HPSA Score | 35% | HRSA HPSA | Higher = greater shortage |
| FQHC Presence | 25% | NPPES NPI | Fewer = less safety-net coverage |
EmployerWeight: 20%
Assesses the local business landscape for employer-sponsored DPC partnerships. Mid-size employers (10–249 employees) are the primary target for DPC group contracts.
| Indicator | Weight | Source | Direction |
|---|---|---|---|
| Target Establishment % | 40% | Census CBP | More mid-size = better |
| Average Annual Wage | 35% | Census CBP | Higher = can afford DPC benefit |
| Total Establishments | 25% | Census CBP | More = more prospects |
CompetitionWeight: 10%
Evaluates the competitive landscape. Areas with fewer competing facilities (FQHCs, urgent care, rural health clinics) and lower PCP density represent less saturated markets.
| Indicator | Weight | Source | Direction |
|---|---|---|---|
| Competing Facility Count | 50% | NPPES NPI | Fewer = less competition |
| PCP Density | 50% | NPPES NPI | Lower = less saturation |
Health Outcomes Benchmarking
Health outcome measures from CDC PLACES are benchmarked against national averages. Each tract value is compared to its national benchmark using a ratio. Values within 85–115% of the benchmark are marked moderate (amber). Values below 85% are marked favorable (green), and above 115% are marked as elevated (red). For preventive measures (routine checkups, dental visits), the comparison is inverted—higher is better.
CDC PLACES estimates are model-based using BRFSS data and should be interpreted as estimates, not direct measurements. Small-area estimates may have wider confidence intervals in low-population tracts.
Limitations
- Geographic coverage: All 50 US states + DC are loaded, covering ~84,000 census tracts. US territories are not yet included.
- Temporal lag: ACS 5-year estimates represent 2018–2022 averages. Rapid demographic shifts may not yet be reflected.
- Model-based estimates: CDC PLACES health measures are modeled from BRFSS survey data, not direct measurements. Confidence intervals vary by tract size.
- DPC scoring is exploratory: The market fit model uses heuristic weights and national reference ranges. It is intended for screening, not as a definitive business assessment.
- Provider data currency: NPPES data is refreshed monthly, but provider practice locations may lag behind actual moves or closures.
- County-level employer data: Census CBP employer data is at the county level and may not reflect within-county variation for large counties.
- HPSA boundaries: HRSA HPSA designations are at the county or service area level, not tract level. A tract within a non-HPSA county may still experience provider shortages.
Documentation & Source Code
Suggested Citation
GeoHealth SDOH Explorer. Data from U.S. Census Bureau American Community Survey, CDC PLACES, CDC/ATSDR Social Vulnerability Index, HRSA HPSA, CMS NPPES, Census County Business Patterns, and EPA EJScreen. Available at https://geohealth-api.vercel.app. Accessed [date].
When citing specific data, please also cite the original source agency (e.g., “CDC PLACES 2023 Release, based on BRFSS 2022 data”).