Performance validation of Abbott Alinity i chemiluminescence analyzer for five thyroid function tests

Objective

To verify and evaluate the performance of the Abbott Alinity i chemiluminescence analyzer for five thyroid function tests.

Method

Referring to the relevant documents of the Clinical and Laboratory Standards Institute (CLSI) and related literature, the precision, accuracy, linear range, reference interval, and sample carryover effect of Abbott Alinity i immunoassay system for measuring FT3, FT4, T3, T4, and TSH were verified and analyzed.

Results

Precision: Repeatability ranged from 1.23 % to 6.11 %, and intermediate precision ranged from 1.84 % to 7.33 %, both meeting the quality targets (≤6.25 % and ≤8.33 %, respectively). Accuracy: The deviation between the mean value and the target value was less than 12.5 %, indicating good agreement. Linearity: For T3, T4, and TSH, the 95 % confidence intervals of the deviation from linearity (difference between measured and expected value) were entirely within the allowable deviation limits (ADL). For FT3 and FT4, manufacturer guidelines preclude dilution; thus, linearity verification was omitted. Reference interval: All test values of 20 healthy individuals were within the reference intervals provided by the manufacturer. Sample carryover effect: The sample carryover effect ranged from −0.4 % to 0.17 %, which met the requirement of less than 1 %.

Conclusion

The Abbott Alinity i analyzer demonstrated acceptable performance in precision, accuracy, linearity (for T3, T4, and TSH), reference interval, and carry-over effect for the five thyroid function tests, meeting manufacturer specifications.