Health Care Service Presence, Social Vulnerability, and Opioid Overdose Rate Acceleration: A United States, County-level Analysis, 2020-2022.

Abstract

The United States continues to experience an opioid overdose epidemic with mortality patterns that reflect existing social and environmental inequities. Although research has examined various factors associated with opioid-related mortality, the relationships between social-environmental vulnerability (SEV), health care presence, and geography remain poorly characterized. To explore whether SEV accelerates opioid overdose rates and to assess how the presence of health care services-specifically opioid treatment programs (OTPs) and primary care providers (PCPs)-modifies these patterns across rural and urban contexts. A retrospective ecological analysis using hierarchical linear modeling was conducted from January 2020 to December 2022, analyzing 172,359 observations across 57,453 census tracts within 1219 US counties. The primary exposure was census-tract-level SEV, operationalized using the CDC Environmental Justice Index. Health care indicators included county-level presence of OTPs and PCPs. Areas in the highest quartile of SEV demonstrated elevated acceleration coefficients (β=3.224; SE=0.803; P<.001), with pronounced patterns observed in rural areas, though ecological design limitations preclude individual-level causal inference. Interaction analyses suggested that high-SEV counties containing both OTP and primary care resources demonstrate lower acceleration coefficients (β= -11.478, SE=5.429, P=0.035). Areas without health care presence showed higher baseline rates in overdose acceleration, particularly in urban high-vulnerability settings. High SEV was associated with accelerated opioid overdose rates during 2020-2022, particularly in rural areas. The presence of OTPs and primary care services within counties was associated with attenuated acceleration in high-vulnerability areas. This may indicate that policies prioritizing comprehensive health care services in high-SEV communities could address opioid overdose disparities.