Suboptimal performance of blood glucose meters in an antenatal diabetes clinic.

OBJECTIVE: The objective of this study was to evaluate the performance of blood glucose meters in diabetes associated with pregnancy (DP). RESEARCH DESIGN AND METHODS: Finger-prick blood glucose levels measured using six different glucose meters on 102 patients with DP attending an antenatal clinic were compared with laboratory plasma glucose results. HbA(1c) and hematocrit were also measured. RESULTS: The plasma glucose range was 2.2-9.4 mmol/L with hematocrit 33-37% and mean HbA(1c) 5.5% ± 0.56 (SD). All meters provided plasma equivalent results except one, which reported whole blood glucose that was adjusted to plasma equivalent values. The absolute glucose difference [meter--plasma glucose] was 0.232 ± 0.69 to 0.725 ± 0.62 mmol/L mean ± SD and bias ranged from 6.1 to 15.8%. Two meters were affected by hematocrit <36% (P < 0.05). CONCLUSIONS: Blood glucose meters in current use are not optimally accurate when compared with plasma glucose measurement in DP. Recognition of this deviation is essential to prevent inappropriate treatment of DP.