Precision and costs of techniques for self-monitoring of serum glucose levels.

The poor correlation between serum and urine glucose measurements has led to the development of new techniques for monitoring the blood glucose level in diabetic patients. Either a nurse or the patient can perform these tests, which involve spreading a single drop of blood onto a reagent strip. A colour change that is proportional to the serum glucose level can be read visually or with a reflectance meter. Evaluated against simultaneous serum glucose levels determined by the hospital biochemistry laboratory, those of the new techniques employing reflectance meters all showed excellent correlation (r2 = 0.85 to 0.96). Reagent strips used without meters showed poorer correlation (r2 = 0.69 to 0.90). The instruction given to the patients and one nurse enabled them to obtain more accurate results with one of the meters than nurses not specially trained (r2 = 0.94 and 0.92 v. 0.85 respectively). The mean cost per glucose determination with the new techniques was 75, compared with +1.45 for the laboratory determinations done with automated equipment. It was concluded that the new techniques compared well with the reference method, particularly when reflectance meters were used, and that they were easily applied by the patient, as well as the medical staff, at a reasonable cost.