Abstract
Small instruments for self‐monitoring of blood glucose (BG) are now available to the patients, and a continuous quality control of these instruments is necessary. This study compared different small BG monitoring instruments with the Hemo‐Cue instrument, which in turn was compared with the Kodak Ektachem 700 XR‐C, the routine method at our laboratory. We also studied whether venous or capillary blood specimens made any difference, and the influence on the results of the time delay between sampling and analysis.
Venous and capillary blood samples were obtained from 191 diabetic patients attending an out‐patient diabetes clinic, and glucose tests were performed in three small instruments (Glucometer Elite [n=112], Accutrend [n=56] or One Touch ll[n=23]) in parallel with HemoCue (n=191) and Kodak Ektachem 700 XR‐C(n=191).
Blood glucose analysed with the small instruments often used by patients for self‐monitoring, showed a close relationship with HemoCue. However, one instrument (Accutrend) gave constantly lower values (0.7±1.0 mmol/l: p < 0.001). HemoCue was shown to be in good agreement with the routine method used at the hospital laboratory. The difference between venous and capillary samples was significant (0.12±0.57 mmol/l p < 0.001) but of no practical importance. However, the time between sampling and analysis was important, since blood glucose decreased 1.6±0.8 mmol/l after an average delay of 3.8hr. The glycolysis occurs despite correct sampling in tubes containing heparin‐fluoride.