Analytical performance, agreement and user-friendliness of five C-reactive protein point-of-care tests

Background. Point-of-care (POC) C-reactive protein (CRP) testing is increasingly used in primary care to assist general practitioners (GPs) in the diagnostic workup for various complaints. The present study compares analytical performance, agreement and user-friendliness of five of these POC CRP tests. Methods. The following five POC CRP tests were evaluated: Afinion and NycoCard Reader II (both Alere), Eurolyser Smart 700/340 (Eurolyser), QuikRead go and QuikRead 101 (both Orion Diagnostica). Results were compared with those of a standard immunoturbidimetric method performed on a routine analyzer (Olympus AU 2700, Beckman Coulter). Analytical performance and agreement with the laboratory standard for the five different POC tests were analyzed. Subsequently, user-friendliness of the POC tests was assessed. Results. Within-day CVs varied from 2.6% (QuikRead go) to 19.4% (Eurolyser Smart 700/340) for low CRP values (<20 mg/L), and 1.1% (QuikRead go) to 17.5% (Eurolyser Smart 700/340) for high values (>100 mg/L). Between-day CVs varied from 4.6% (Afinion) to 30.5% (Eurolyser Smart 700/340) for low values and 4.0% (QuikRead go) to 18.0% (Eurolyser Smart 700/340) for high values. With high CRP values (>100 mg/L) agreement with the laboratory standard systematically decreased for all POC tests. Regarding user-friendliness Afinion and Eurolyser Smart 700/340 were judged easiest to operate. Conclusions. Analytical performance, agreement, and user-friendliness of the POC CRP tests varied considerably, yet overall four devices showed adequate analytical performance and agreement.