the performance of the point of care test poct i chroma psa method using internal and external quality assessment schemes united kingdom external quality assessment service ukneqas and randox international quality assessment service riqas

1. Abstract 1.1. Objective : We set out to address and widen the knowledge about the i-CHROMA ™  PSA method in its performance using the (Internal Quality Control) IQC and with a wide range of PSA methods enrolled in the United Kingdom National External Assessment Scheme (UKNEQAS) and Randox International Quality Assessment Scheme (RIQAS). 1.2. Design and Methods : Thirty-three Internal Quality Controls (IQC), and distributions of the UKNEQAS PSA scheme between February 2013 and December 2014 and samples from the RIQAS scheme  were analysed for PSA using the i-CHROMA ™  PSA method. The PSA results obtained from samples of the NEQAS and RIQAS were  compared with the other PSA methods included in the schemes. 1.3. Results : The PSA estimations for IQC material were 2.48 - 4.13 ng/ml, with an average of 3.5 ng/ml. All estimations apart from the first one of 2.48 ng/ml, fell within the lower and higher values of 2.6 ng/ml and 4.33 ng/ml, respectively.  The i-CHROMA ™  PSA method’s results correlated very well with the PSA estimations of the methods enrolled in the external quality schemes (RIQAS and UKNEQAS). The bias ranged between -2.99 ng/ml and +6.8 ng/ml with an average of +0.88 ng/ml with the methods in the RIQAS and +0.53 ng/ml and + 2.65 ng/ml with an average of +1.46 ng/ml with the methods in the UKNEQAS . 1.4. Conclusion:  The i-CHROMA ™  PSA method performed quite well with the IQC with almost all the values falling within the central, lower and higher values. The i-CHROMA ™  PSA method also showed a very good correlation with the other PSA methods enrolled in the EQA schemes: RIQAS and UKNEQAS, showing a positive bias greater than 1.0 ng/ml in over 50% of the methods. Therefore, it is important to take these positive biased into consideration when using the i-CHROMA ™  PSA method and adjust the reference ranges accordingly. 2. Keywords :  I-CHROMA ™ ;  Point of Care; POCT; Prostate Specific Antigen; PSA Assay Method