Enhanced Emergency Medical Services Case Definition to Identify Suspected Nonfatal Opioid Overdose–Related Incidents in Rhode Island

Abstract

Objectives: To improve rapid detection and response to spikes in suspected nonfatal opioid overdoses in the community, the Rhode Island Department of Health (RIDOH) sought to modify its case definition to align with newly released guidance from the Council of State and Territorial Epidemiologists (CSTE). Methods: RIDOH used CSTE guidance to create 2 alternative criteria (CSTE-guided and RIDOH-modified CSTE) to replace one of RIDOH’s original criteria. We gathered emergency medical services (EMS) records from 4 months in 2022 to determine whether they met any criteria, and we reviewed them to determine the accuracy of identifying an opioid overdose. We calculated the positive predictive value for each criterion individually and as a complete case definition (RIDOH original definition, CSTE-guided definition, and RIDOH-modified CSTE definition). Results: The RIDOH-modified CSTE case definition was adopted because it had a positive predictive value of 91.5% in identifying nonfatal opioid overdose–related EMS incidents, similar to the original definition (91.3%) and higher than the CSTE-guided definition (82.2%). The RIDOH-modified CSTE case definition identified 624 additional nonfatal opioid overdoses in EMS data from 2018 through 2022, a 7% increase from the original definition. Conclusions: The RIDOH-modified CSTE case definition increased RIDOH’s ability to detect suspected nonfatal opioid overdoses while maintaining the accuracy of the case definition. With the new case definition, RIDOH aims to improve allocation of resources to communities experiencing increased overdose burden.