Stimulant-related incident surveillance using emergency medical service records in Massachusetts, 2013-2020

As stimulant use increases across the United States, emergency medical services (EMS) are crucial touchpoints in the health care system. To better measure the prevalence of stimulant use, misuse, and EMS incidents related to stimulant intoxication, definitions for stimulant-related incidents (SRIs) are needed.

We used the Massachusetts Ambulance Trip Record Information System (MATRIS) from 2013 to 2020 to develop definitions of stimulant-related incidents. EMS runs reported to MATRIS were categorized based on stimulant-related words and symptoms. The three tiers were "any stimulant use" (class 1), "problematic stimulant use" (class 2), and "acute stimulant-related incidents" (class 3). A group of four reviewers studied over 650 cases in eight rounds to refine the search terms, achieving definitions with a correct characterization of over 80% of cases that the code selected.

SRI definitions were applied against all EMS runs within Massachusetts between 2013 and 2020 (n = 6,584,836 runs). Of these, 43,538 (0.7%) met the class 1 definition, 38,669 (0.6%) met the class 2 definition, and 19,157 (0.3%) met the class 3 definition. Incidents at all tiers of severity increased over time and were more likely to occur among younger adults and males. Race and ethnicity data indicated that Hispanic/Latinx and Black non-Hispanic/non-Latinx residents formed a disproportionately large percentage of SRIs relative to their total percentage of EMS runs.

The prevalence of all three tiers of SRIs are increasing in Massachusetts, and this protocol provides a source of administrative data on stimulant use that complements sources such as hospital, treatment-based, and/or prescribing records.