Background: According to the guidelines of the Department of Health (DOH)’s Health Facilities and Services Regulatory Bureau (HFSRB), accreditation of drug testing laboratories (DTLs) requires annual participation in a proficiency testing (PT) program. Since 2009, the National Reference Laboratory for Environmental and Occupational Health, Toxicology and Micronutrient Assay of the East Avenue Medical Center (NRL-EAMC) has conducted the PT program for DTLs. Objectives: This article aims to provide a general overview of the PT program conducted for screening drug testing laboratories (SDTLs) and to examine data on laboratories’ participation and performance in the PT program. Methodology: Laboratories registered for the PT program were given ten 3-mL synthetic urine specimens which may or may not contain drugs of abuse such as methamphetamine and tetrahydrocannabinol at or above the cut-off level. Laboratories analyzed the PT specimens using immunoassay test kits. The results of the analysis were reported back to NRL-EAMC. The performance of the laboratories in the PT depends on the number of incorrect responses. Results: For ten years (2009-2019), 1102 ± 188 laboratories annually participated in the program. The mean passing rate was 96.6 ± 4.8%. The number of laboratories which initially failed the PT program significantly decreased from 2009 (15.1%) to 2012 (1.5%). From 2013 to 2019, only below 2.5% of the participating laboratories initially failed the PT. On average, 48.4 ± 18.4% of the laboratories achieved an excellent performance, 34.0 ± 13.6% had a highly satisfactory performance, and 14.3 ± 5.4% got an acceptable performance. Conclusion The continued decreasing number of laboratories which failed the PT signifies the improvement of laboratories in urine drug testing. In general, some laboratories participating in the PT for the first time are the ones which initially fail the PT which could be due to a lack of experience in handling PT test items. The PT program highlights the effectiveness of quality control procedures being implemented in a drug testing laboratory.
Laboratories ; Quality Control ; Accreditation ; Methamphetamine