Self-monitoring of glucose in type 2 diabetes mellitus:a Bayesian meta-analysis of direct and indirect comparisons

ABSTRACT

Objective: To evaluate the relative effectiveness of interventions with self-monitoring blood glucose and self-monitoring of urine glucose, versus interventions without self-monitoring, in terms of HbA1c reductions in type 2 diabetes mellitus.

Methods: Thirteen published full reports on randomised controlled trials investigating the effects of self-monitoring glucose were identified by a systematic search of Medline, Embase, the Cochrane Library (1966–Nov 2005) and previous reviews. Three types of studies were included: self-monitoring of blood glucose versus no self-monitoring, self-monitoring of blood glucose versus self-monitoring of urine glucose and self-monitoring of blood glucose with regular feedback versus monitoring without feedback. The internal validity of studies was assessed systematically by two reviewers, using 13 criteria of a validated list. Results from the three types of studies were analysed simultaneously with a Bayesian meta-analysis of direct and indirect comparisons.

Results: Adjusted for baseline HbA_1c level and internal validity, interventions with self-monitoring of blood glucose showed a reduction in HbA_1c of 0.40 percentage-points (%) (95% credible interval [CrI] 0.07 to 0.70%) in comparison to interventions without self-monitoring. Regular feedback more than doubled the HbA_1c reduction. Self-monitoring of urine glucose showed comparable results to interventions without self-monitoring (0.02% decrease in HbA_1c; 95% CrI –0.62 to 0.70%). There is a 88% probability that interventions with self-monitoring blood glucose are more effective than interventions with urine glucose monitoring (relative reduction in HbA_1c is 0.38%, 95% CrI –0.30 to 1.00%).

Conclusion: The randomized clinical trials performed to date provided positive results on the effectiveness of interventions with self-monitoring of blood glucose in type 2 diabetes mellitus. Regular medical feedback of the monitored HbA_1c levels is important. Furthermore, self-monitoring of blood glucose is likely to be more effective than self-monitoring of urine glucose.

Key words: :

• Bayesian
• Blood glucose
• Diabetes
• HbA1c
• Meta-analysis
• Self-monitoring
• Urine glucose