Nearest facility minimum distance

Meta Data Name: Nearest facility minimum distance  
Date Added: April 25, 2025  
Author: Mahjabin Kabir Adrita  
Date Last Modified: April 25, 2025  
Last Modified By: [Your Name]

Theme:  
Healthcare facility access metrics

Data Location:  
You can find the variables described in this document in the CSV files https://uofi.box.com/s/zb9beahqrzxwsfagk9va0z54bt55kb8n.  

CSV files are organized by ZCTA (ZIP Code Tabulation Area). Each row represents a 2020 ZCTA with a calculated distance to the nearest OTP.  

Data Source(s) Description:  
Data Source(s) Description:  
Facility locations were sourced from the Substance Abuse and Mental Health Services Administration (SAMHSA) (https://findtreatment.gov/) and cleaned for analysis. The dataset includes four categories of treatment facilities:  

1. **Mental Health**:  
   Facilities that provide therapy, psychotropic medication, or other services to address mental health issues, reduce symptoms, and improve behavioral outcomes.  

2. **Health Care Centers**:  
   Community-based, patient-directed organizations offering comprehensive, culturally competent, high-quality primary health care services to vulnerable populations, including people experiencing homelessness, agricultural workers, public housing residents, and veterans.  

3. **Opioid Treatment Programs (OTPs)**:  
   Certified facilities that administer and dispense FDA-approved medications (e.g., methadone) for long-term treatment of opioid use disorder. These facilities must also provide counseling, behavioral therapies, and recovery supports under the Medications for Opioid Use Disorder (MOUD) model.  

4. **Substance Use Treatment Facilities**:  
   Facilities offering treatment for substance use disorders through integrated medical and mental health services. Services may include behavioral counseling, medication-assisted treatment, withdrawal symptom management, co-occurring mental health treatment (e.g., depression, anxiety), and long-term relapse prevention.  
   - **Subcategories**: Substance use treatment facilities are further classified by the primary medication used in treatment:  
     - **Methadone**  
     - **Buprenorphine**  
     - **Naltrexone**  

ZCTA boundary files were sourced from the U.S. Census Bureau, 2020 TIGER/Line Shapefiles.

Description of Data Source Tables:  
The raw OTP dataset includes facility name, address, state, ZIP code, phone number, services offered, and geocoded coordinates (latitude and longitude).  

Description of Data Processing:

**Tract and Zip Code**  
*Distance*  
Centroids were calculated for ZCTA geometries. For each centroid, the minimum Euclidean distance in miles was calculated to the nearest OTP location. This metric is used as a proxy for geographic access to treatment.  

**Script/Method**:  
Analysis was conducted in Python using geopandas and shapely. Script available in `code/access_otp_distance.py` (or your repo path).

Key Variable and Definitions:

| Field Name     | Description                                                                 |
|----------------|-----------------------------------------------------------------------------|
| `ZCTA5CE20`    | 5-digit ZIP Code Tabulation Area code (2020)                                |
| `GEOID20`      | Unique geographic identifier (same as ZCTA5CE20)                            |
| `CLASSFP20`    | Class code for ZCTA (`B5` = ZIP Code Tabulation Area)                       |
| `MTFCC20`      | MAF/TIGER Feature Class Code (`G6350` = ZCTA5)                              |
| `FUNCSTAT20`   | Functional status of the ZCTA (`S` = Significant area)                      |
| `ALAND20`      | Land area in square meters                                                  |
| `AWATER20`     | Water area in square meters                                                 |
| `INTPTLAT20`   | Latitude of the internal point (centroid) of the ZCTA                       |
| `INTPTLON20`   | Longitude of the internal point (centroid) of the ZCTA                      |
| `minDist_mi`   | Minimum distance (in miles) from ZCTA centroid to the nearest facility  |

Data Limitations:  
* The `otpMinDis` variable uses Euclidean (straight-line) distance from centroid to facility. It does not account for road networks, travel times, or real-world geographic barriers.
* ZCTA centroids are geometric, not population-weighted.
* OTP dataset reflects facility availability as of the date of download; it may not capture newly opened or closed facilities.

Comments/Notes:  
This dataset covers all ZCTAs in the 50 U.S. states and the District of Columbia. It does not include U.S. territories or other outlying areas.