Sentinel testing, analytical sigma metrics and a risk management approach as part of a simplified method verification/validation process.

Introduction: Verification and validation of analytical methods are crucial aspects of quality assurance in a laboratory. This study aimed to develop a risk analysis and assessment tool to streamline the process of identifying so-called 'sentinel' tests.

Materials and methods: The Roche Cobas 8000 systems were evaluated to analyze 83 serum analytes, including routine chemistry, immunoassays, and therapeutic drugs. A failure mode and effects analysis were conducted to produce an analytic risk rating. This was achieved by multiplying the scores for Sigma metrics, the score for potential damage extent, and the score for environmental factors. Each test was assigned a typical risk priority number (RPN). Tests with an RPN of ≤9 were rated as low risk and ranked as 'B'. Tests with an RPN of >10 were considered high risk and graded as 'A'.

Results: Regarding the Cobas C701/ISE, 17 of 54 methods were rated as 'A' and subject to a systematic method review process. A total of 37 methods were assigned a rank of 'B' and hence were eligible for a selective verification process. Concerning the Cobas E801, 10 out of 29 methods were classified as 'A' and, therefore, require a systematic verification process. A further nineteen methods were assigned a rank of 'B' and hence eligible for a select verification.

Conclusions: This study demonstrated the high effectiveness of the risk analysis and assessment model developed to identify sentinel tests in the lean management of the verification/validation process.