Performance of Xylazine Qualitative Immunoassays Designed for Drug Checking in Urine Samples

Two immunoassay strips designed for drug checking showed strong sensitivity and specificity at their detection thresholds; however, most samples testing positive for xylazine were below those thresholds, resulting in most participants with true xylazine exposure not being accurately identified. Prospectively designed urine point-of-care strips are necessary to help inform the relationship between xylazine exposure and its related consequences.