Analytical performance and user-friendliness of four commercially available point-of-care devices for C-reactive protein

Introduction: Proper implementation of Point-of-Care testing (POCT) for C-reactive protein (CRP) in primary care can decrease the inappropriate use of antibiotics, thereby tackling the problem of growing antimicrobial resistance.

Objective: The analytical performance and user-friendliness of four POCT-CRP assays were evaluated: QuikRead go easy, LumiraDx, cobas b 101 and Afinion 2.

Materials and methods: Imprecision was evaluated using plasma pools in addition to manufacturer-specific control material. Trueness was assessed by verification of traceability to ERM-DA474/IFCC in parallel to method comparison towards the central laboratory CRP method (cobas c 503) using i) retrospectively selected plasma samples (n = 100) and ii) prospectively collected capillary whole blood samples (n = 50). User-friendliness was examined using a questionnaire.

Results: Between-day imprecision on plasma pools varied from 4.5 % (LumiraDx) to 11.5 % (QuikRead). Traceability verification revealed no significant difference between cobas c 503 CRP results and the ERM-DA474/IFCC certified value. cobas b 101 and Afinion achieved the best agreement with the central laboratory method. LumiraDx and QuikRead revealed a negative mean difference, with LumiraDx violating the criterion of > 95 % of POCT-CRP-results within ± 20 % of the comparison method. Regarding user-friendliness, Afinion obtained the highest Likert-scores.

Conclusion: The analytical performance and user-friendliness of POCT-CRP devices varies among manufacturers, emphasizing the need for quality assurance supervised by a central laboratory.