A comparison of glucose concentration in paired specimens collected in serum separator and fluoride/potassium oxalate blood collection tubes under survey 'field' conditions.

There are no direct comparisons of blood glucose values in samples collected with barrier serum tubes (SST) and NaF/potassium oxalate (NaF/KOx) plasma tubes. Collection of samples in SST tubes can offer considerable savings and specimen processing advantages for national level surveys. Serum and plasma samples were collected under 'field conditions' from a single draw of 3692 individuals participating in the Canadian Health Measures Survey. The samples were analyzed retrospectively using the VITROS GLU Slide method (glucose oxidase-based). There was a high rate of hemolysis in the NaF/KOx tubes (86.2%) while hemolysis was infrequently observed with the SST tubes (2%). Comparing only blood draws where no hemolysis was observed in both tubes (n=495; paired t-test) showed no effect of tube type on serum/plasma glucose concentrations. This was also observed when data was restricted to cases when only SST samples were not hemolyzed (n=3546; paired t-test). These data show that both collection tubes can be used under survey collection and processing conditions to measure glucose with our assay system with no difference in reported results.