Reagent Lot Variation Assessment: Establishing the Suitable Acceptability Criteria and Implementing an Efficient and Cost-effective Approach

Abstract

Abstract Introduction/Objective When reagent lot number change for a particular assay it is hoped that the results obtained from the new lot are comparable with those of the old lot and so will not lead to misleading clinical conclusions based on either the reference intervals or previous results on the same patient. This study has criticality evaluated and compared various methods of establishing reagent lot-to-lot verification acceptability criteria to determine the most suitable approach in Sidra Medicine Clinical Biochemistry Department in order to implement an efficient and cost-effective method of verifying new reagent lot numbers. Methods/Case Report Several methods and approach for establishing in-house acceptable criteria for determining reagent variations were critically evaluated. These methods include the use of CLSI EP26-A guidelines, proficiency testing or external quality assessment (EQA) total allowable errors (TeA) and internal quality control (IQC) in-house target SD and CV reflecting the current assay performance. A user friendly statistical template was also produced to be able to improve fhe current workflow, data entry, presentation and documentation of each test with a new reagent lot number approved and implemented for patient testing. Results (if a Case Study enter NA) A full version of Reagent Lot Variation Acceptance Table was produced showing comprehensive established criteria based from methods mentioned above. IQC and patient comparability results are entered in an excel template which automatically calculates the differences and shows if the new lot number passed or failed based on the in-house acceptability criteria established. The reagent lot-to-lot verification template is updated each month using complex excel rules to keep the acceptability limits in accordance with the most current in-house IQC target mean and SD based from the most recent monthly IQC reviews. Conclusion The comparison of different reagent lot variation acceptability criteria indeed raised awareness of the efficiency and practicality of performing reagent lot-to-lot verification. CLSI EP26-A approach was observed to have the least sample number requirement. However, one patient sample for comparison study seems not enough to justify the approval and implementation of the new reagent lot number to consider the assays AMR. The IQC SD and CAP Total Allowable Error (TeA) acceptability criteria are more effective since there is more number of patient samples used for comparability across the assays AMR.