Comparative performance evaluation of DRI and KIMS immunoassays for forensic drug screening in urine

Rapid and reliable detection of illicit drugs such as methamphetamine and Δ9-tetrahydrocannabinol (THC) is critical in forensic toxicology. Immunoassay-based screening methods offer time-efficient alternatives to instrumental techniques, especially for high-throughput forensic applications. This study aims to comparatively evaluate the analytical performance of two widely used DRI and KIMS immunoassay platforms in detecting these drugs in human urine samples, with a focus on forensic applicability. A total of 866 urine samples were analyzed using both DRI and KIMS-based immunoassays. Key performance metrics such as sensitivity, specificity, cross-reactivity, and cut-off concordance were assessed. All results were compared to mass spectrometry-confirmed reference data. Both platforms demonstrated acceptable performance for preliminary drug screening. However, variations were observed in detection sensitivity for THC and in false-positive rates for methamphetamine. In conclusion, both systems are suitable for high-throughput forensic drug screening. And the findings provide practical guidance for forensic laboratories selecting immunoassay platforms for drugs of abuse screening.