P44

Evaluation of three different CRP Point of Care Testing instruments

Slavena Mandic1,*, Marie Palmblad1, Laura Goobar Larsson1

1Department of Outpatient Laboratory Services and Preanalysis, Karolinska University Laboratory, Stockholm, Sweden

Introduction: C-reactive protein (CRP) is an acute phase protein. CRP is frequently measured with point of care testing (POCT) instruments. There are a number of devices, such as QuickRead go (Orion), Afinion (Alere) and i-Chroma (Bodytech Med Inc.), used for measurements of CRP in POCT.

Objectives: To evaluate i-Chroma, QuickRead go and Afinion for CRP testing with respect to analytic performance and ease of use.

Methods: The analytic performance was determined by comparison with central laboratory instruments DXC800 (Beckman-Coulter) and Modular P (Roche Diagnostics). Patient samples, with varying CRP levels (5-205 mg/L), were analyzed on DXC800 and Modular P, and in parallel on all the three POCT devices. Regression analysis and bias were calculated. Imprecision was evaluated by control measurements. Seronorm (SERO AS), L1 (15 mg/L) and L2 (75 mg/L) were analyzed five times per level in five days. Within-series and total imprecision were determined by analysis of variation (ANOVA). Evaluation of the user-friendliness was also performed.

Results: The results achieved in this evaluation are summarized and presented in the table below.

Results summary

 

Afinion

QRgo

iChroma

Within-series imprecision 

CV (%) L1/L2

6.5/4.3

3.4 /1.3

8.9/10.0

Total imprecision

CV (%) L1/L2

6.5/5.3

4.3/3.6

9.7/10.9

r2 ModularP/DXC800

0.97/0.98

0.98/0.98

0.94/0.95

Bias (%)

ModularP/DXC800

                           

10.9/-1.1

8.7/-2.8

5.5/-5.9

Conclusion: Within-series and total imprecision were higher and r2 lower for i-Chroma compared to Afinion and QuickRead go. When evaluating user-friendliness, Afinion demonstrated the highest scores followed by QuickRead go. i-Chroma demanded more operation steps and operator precision.

Keywords: Method