Analytical performance of a platform for point-of-care CRP testing in adults consulting for lower respiratory tract infection in primary care.

C-reactive protein (CRP) is a biomarker widely used for disease severity assessment and treatment of inflammatory conditions. Point-of-care testing (POCT) devices should ideally be rapid and provide similar results to standard tests done in laboratories. Two thousand nine hundred twenty-two serum samples were obtained from adult patients presenting to primary care with symptoms of lower respiratory infection in a European diagnostic study. The analytic performance of the CRP QuikRead POCT device (Orion Diagnostica) was evaluated by comparing results with a central laboratory method (Dimension Vista, Siemens), with both tests performed in a laboratory setting. For a CRP cut-off concentration of ≥ 30 mg/L, the QuikRead test had a sensitivity of 92.2%, and specificity of 99.4%. The mean difference between the QuikRead and the central lab test was 0.4 mg/L. The slope of the Passing-Bablok regression was 0.94 (95% CI 0.93-0.95) indicating an underestimation of CRP levels of 6% by QuikRead. CRP estimates obtained from the QuikRead test correlate well with a central laboratory assay and the measurement displays low inter-assay variation. Therefore, the QuikRead test is a good candidate for CRP testing in primary care.