commutability of a wholeblood external quality assessment material for pointofcare creactive protein glucose and hemoglobin testing background the optimal situation in external quality assessment eqa is to use commutable materials no previous study has examined the commutability of a wholeblood material for pointofcare poc testing the aim of this study was to determine the commutability of the norwegian quality improvement of laboratory examinations noklus organizations inhouse wholeblood eqa material for creactive protein crp glucose and hemoglobin for frequently used poc instruments in norway and to determine the possibility of using a common target value for each analytemethods the study was performed according to the clinical and laboratory standards institute guidelines the eqa material was pooled stabilized edta venous wholeblood containing different concentrations of the analytes the eqa material and native routine patient samples were analyzed using 17 poc and 3 hospital instruments the commutability was assessed using deming regression analysis with 95 prediction intervals for each instrument comparisonresults the eqa material was commutable for all crp and hemoglobin poc instruments whereas for glucose the material was commutable for all poc instruments at the lowest concentration analyzed 1260 mgdl 70 mmoll and for 3 poc instruments at all of the concentrations analyzedconclusions noklus eqa participants using crp and hemoglobin poc instruments now receive results that are compared with a reference target value whereas the results for participants using glucose poc instruments are still compared with methodspecific target values systematic deviations from a reference target value for the commutable glucose poc instruments can be calculated and this additional information can now be offered to these participants and to the manufacturers