Unveiling substance use disparities in Washtenaw County

In 2020, Washtenaw County appeared less vulnerable to substance use according to the MI Substance Use Vulnerability Index. But this ranking masked numerous disparities within the county, which is known for stark disparities in health and wealth. 

In 2023, Michigan unveiled a new Zip Code Level Substance Use Vulnerability Index. 

To calculate substance use vulnerability, this index takes the CDC’s social vulnerability index and aggregates it at the zip code level, adding healthcare connectedness indicators, such as distance from acute care facilities and pharmacies. 

Specifically the index, combines substance use burden factors and substance use resource factors.

Substance use burden factors

  • 5-year overdose rate; 
  • 3-year non-fatal overdose ED visit rate; 
  • drug-related arrest rate; 
  • opioid prescription rate

Substance use resources factors 

  • percentage of the population within a 30-minute drive of a treatment center; 
  • percentage of the population within a 15-minute drive of syringe services programs; 
  • buprenorphine prescribing rate. 

Unsurprisingly, some areas in Washtenaw County showed low vulnerability, but others were marked as high-risk zones. 

In zip codes comprising Webster, Lima, Lodi, and parts of Ann Arbor, the 5-year overdose average remains below 6.5 deaths per 100,000. 

However, in zip codes encompassing Ypsilanti and Sylvan, the 5-year overdose average surges to between 40.3 and 54.7 deaths per 100,000, respectively. 

This discrepancy underscores the significant variation in substance use vulnerability across different areas within Washtenaw County.

By offering a more granular understanding of vulnerability, Michigan’s new substance use vulnerability index helps decision-makers target interventions where they are most needed. 

As Washtenaw County navigates the complexities of the opioid crisis, these data-driven insights can serve not only as a needs assessment but as a roadmap for strategic resource allocation, ensuring that substance use recovery programs are tailored to populations that need it most. 

To access the Zip Code Level Substance Use Vulnerability Index, go to the MDHHS Opioid Resources website’s publicly available data.