Alternate Site Glucose Testing: A Crossover Design

Abstract

A crossover design study was conducted to determine if reducing pain, by using alternative sites off the finger tip, would increase testing frequency and improve clinical outcome as measured by hemoglobin A1c (HbA1c). Subjects with type 1 and type 2 diabetes tested with the FreeStyle meter (group 1) or tested with their original meter (group 2). After three months the subjects used the alternate meter. Testing frequency and blood glucose concentrations were recorded for the month before the study began and monthly thereafter. HbA1c was tested initially, at the crossover point, and at study conclusion. Insulin users increased testing frequency from 2.4 to 3.0 tests/day. Testing frequency for non–insulin users remained the same at 1.5 tests/day. Testing frequency was the same with the FreeStyle and the original meters. The average HbA1c was 7.4% (SD 1.5%) initially, 7.3% (SD 1.5%) at the crossover point, and 6.9% (SD 1.1%) at study conclusion. There was no significant difference in HbA1c measurements between meter types. Preference rankings were 76% for FreeStyle, 20% for their original meter, and 4% preferred both meters equally. This population tended to be in good glycemic control with 70% having HbA1c at ≤8.0 at study initiation. Subjects preferred testing with the FreeStyle meter (76%), but did not increase testing frequency. Study participants tended to be in good testing compliance and glycemic control with little room for improvement. A population in poor glucose control might show differences in outcome with off site monitoring.