Modeling Changes of Fatal Xylazine-Involved Drug Overdoses in Connecticut Across Time.

Background: Fatal drug overdoses have involved both xylazine and fentanyl. Xylazine is a non-opioid substance used in veterinary medicine. This study aimed to model changes in fatal xylazine-involved drug overdose deaths from 2019 to 2023 in Connecticut using overdose death data from the Office of the Chief Medical Examiner. Methods: Xylazine-involved drug overdose fatality rates were calculated by number of deaths per year per 100,000 population from 2019 to 2023. We used joinpoint regression modeling to evaluate quarterly overdose rates across age, number of drugs, and drug types with a significance level of p < 0.05. Results: From 2019 to 2023, there were 1116 xylazine-involved fatal overdoses with a cumulative rate of 31.3 deaths per 100,000. Xylazine-involved overdose death rates were significantly higher in Hispanic populations compared to both non-Hispanic White and Black populations (p < 0.05). The joinpoint analyses showed that xylazine-fentanyl mortality rates significantly increased by 0.18 per 100,000 per quarter from 2019 to 2022. Xylazine-fentanyl overdoses involving at least 4 or 5 substances significantly increased. Windham, Hartford, New London, and New Haven counties had the highest xylazine-involved death rates. Conclusion: Xylazine-fentanyl deaths increased from 2019 to 2023, and often involved multiple substances (e.g., cocaine, ethanol, benzodiazepines, and oxycodone). Results show Hispanic populations, those aged 35–49, and 50+ experienced high rates of xylazine-fentanyl overdose deaths. Vulnerable populations in Connecticut for special consideration for future intervention and local resource allocation are recommended. [ABSTRACT FROM AUTHOR]