Impact of lab-based drug checking services on syringe service program engagement in Maryland, USA

The introduction of synthetic substances into the unregulated drug supply has driven a surge in overdose deaths, posing significant public health challenges in timely substance identification, engagement with people who use drugs (PWUD), and access to treatment. Maryland's rapid analysis of drugs (RAD) program, piloted through syringe service programs (SSPs), provides a proactive harm reduction strategy by integrating mail-in, laboratory based drug checking with broader public health services to enhance surveillance and improve engagement with PWUD. We aim to investigate the association of offering RAD drug checking with SSP metrics such as encounters with PWUD and access to wound care.

To investigate the association of RAD affiliation with SSP engagement and service metrics, a hierarchical linear model was employed to estimate percent changes in metrics such as encounters, naloxone distribution, and instances of overdose education. Metrics were analyzed on a log scale to account for skewness and variability across sites, with site-specific effects and random variation modeled to capture both baseline differences and the impact of RAD affiliation.

Sites that became RAD affiliated saw an increase in many of the recorded metrics, such as wound care services per quarter (131%) and the number of participants per quarter (74%) while other metrics, such as testing, showed smaller changes. When adjusting for baseline trends of non-RAD affiliated behavior, most of the metrics still trend towards a positive association with RAD affiliation, but only Wound Care and Counseling reach statistical significance given the small number of sites remaining non-RAD affiliated for the full duration of data collection.

Participation in the RAD program shows a positive association with an increase in engagement and service delivery within Maryland's SSPs, suggesting it may be considered as a valuable public health intervention for improving outcomes for PWUD. However, further research is needed to explore causality and influence of factors like broader public health initiatives.