What is the primary purpose of chain-of-custody in urine drug testing?

• A. To accelerate reporting and reduce turnaround time.
• B. To verify the patient's identity using biometric data at collection.
• C. To ensure the integrity and admissibility of the specimen by documenting possession, transfer, and handling from collection to reporting.
• D. To encrypt sample data and limit access to results.

Answer: (C)

The main idea behind chain-of-custody in urine drug testing is to preserve the specimen’s integrity and ensure its results are defensible in court or regulated settings by creating a documented, auditable trail of every hands the sample passes through from collection to reporting. This means every step is recorded—who collected it, who handled or transferred it, when and where it was stored or transported, and how it was sealed and labeled—so that no one can dispute that the sample being tested actually came from the correct person and was kept under proper conditions. This continual chain prevents tampering, substitution, or mishandling and ties the result to a specific individual with a clear history of custody. While other aspects like identifying the patient or securing data are important, they address different concerns; the chain-of-custody focus is on maintaining sample integrity and ensuring the result is admissible and trustworthy.