Relating Manufacturers and Laboratory Terminology
The instrument specifications published by Advanced Instruments can be used as follows to establish the acceptable instrument performance limits within CLIA or laboratory specified parameters1:
The allowable limits for Accuracy are established by determining the overall allowable mean for the system by incorporating the effects of:
- Instrument nonlinearity, represented by the published Linearity specification (found in the instructions for use or on the instrument data sheet)
- Calibrator/control formulation tolerance, represented by the published Expected Range for the calibrator/control (found on the calibrator instruction sheet), or the actual calibrator/control formulation value (found on the Certificate of Analysis for the particular calibrator lot)
- Sample formulation error (if applicable), represented by the laboratory’s measured difference between the calculated mean for the actual samples and the nominal formulation or the accepted reference value.
The allowable limits for Within-run or Intermediate Precision are established by referring to the instrument Repeatability specification (found in the instructions for use or on the instrument data sheet).
The allowable limits for the Reportable Range are established by referring to the instrument Range specification (found in the instructions for use or on the instrument data sheet).
The allowable limits for any Reference Range of interest to the laboratory must be established by the laboratory based on the accuracy, precision, and known value (or accepted reference value) for the sample tested. The only restriction is that all Reference Ranges must lie totally within the established Reportable Range for the method.
1 Refer to Determining the Acceptable Range of Results for an Application Using Specifications for the Instrument and a Calibrator/Control for specific examples of the calculation.