Self-monitoring of capillary blood glucose: changing the performance of individuals with diabetes.

Standard reflectance meters were modified by the addition of memory chips capable of storing 440 glucose determinations with corresponding time and date. These modified reflectance meters (MR) were given to 20 individuals with type I diabetes in an effort to determine the level of reliability and accuracy they could achieve on a self-monitoring regimen. During a 6-wk period these subjects measured their capillary blood glucose and recorded the results in a logbook (LB). At 2-wk intervals they visited the clinic. Data from the MR was offloaded onto an Apple IIe microcomputer (Apple Computer, Inc., Cupertino, California) and presented to the subjects in a graphic format, depicting the level of metabolic control over the previous 2 wk. The performance of subjects for the 6-wk period showed that they averaged 7 omissions from the LB for every 100 MR recordings; 1 added value in the LB for every 200 MR recordings; and 1 error in accurately copying the test value for every 100 determinations. In comparison with subjects who participated in an earlier study in which they were unaware of the memory function of the reflectance meter, performance during the current study improved in all categories. It was also observed that consistency in reliable and accurate record keeping did not diminish throughout the study period. Despite these positive changes in performance, no alteration in glycemic control was found.