Point-of-care C-reactive protein testing in febrile children in general practice

Background: Point-of-care testing for C-reactive protein (CRP) may be helpful in differentiating viral from bacterial infection. Such a device should give results comparable to laboratory testing. The aim was to evaluate two point-of-care CRP tests (Nycocard and QuikRead) in febrile children in general practice, compared to a reference immunoturbidimetric assay.

Methods: A cross-sectional study was carried out of febrile children aged 3 months to 6 years presented to a general practice out-of-hours service. Children were visited at home where blood was taken for tests, within 24 h after presentation. The Nycocard test was performed at home, whereas the QuikRead and reference test were performed in the laboratory.

Results: A total of 76 children were enrolled. All three CRP tests were performed in 59 children. The mean difference between the reference test and Nycocard and QuikRead was 0.6 and -6.1 mg/L, respectively. The slope of the Passing-Bablok regression was 0.95 (95% Cl 0.9-1.0) and 0.83 (95% Cl 0.81-0.85) for the Nycocard and QuikRead tests, respectively.

Conclusions: Up to a concentration of 160 mg/L, the Nycocard test correlated well with the reference test, while the QuikRead test underestimated concentrations above 60 mg/L. The Nycocard test seems a good candidate for CRP point-of-care testing in general practice.