MTLAWS Drug Testing Screening Laboratory Practice Test

Proficiency testing measures how accurately a laboratory can produce results by comparing blinded test samples with known values. This external quality assessment uses materials where the true result is preset, so when the lab runs these samples, any deviation from the assigned values reveals how accurate and reliable the methods and instruments are. This helps identify bias, systematic errors, or issues with procedure or calibration, and it guides corrective actions to maintain trustworthy results. That’s why the best choice is about verifying accuracy against known standards—it directly assesses whether the lab’s results are correct, not about appearances, donor opinions, or non-lab training. Regulatory bodies expect labs to participate in proficiency testing to demonstrate reliable performance and meet quality standards.