Clinicians' reluctance to prescribe self-monitoring of blood glucose (SMBG) for non-insulin-treated patients who have type 2 diabetes may be because of a lack of clarity about its impact on glycated hemoglobin (HbA1c). Researchers conducted a systematic review and meta-analyses to assess the effect of SMBG versus usual care, structured SMBG versus unstructured SMBG, and SMBG readings used to adjust therapy versus usual care.
Eighteen randomized controlled trials published between 2002 and 2020 were included in the review. Overall, analysis of the trials comparing SMBG with usual care showed that SMBG reduced HbA1c. In trials with high baseline HbA1c, the reductions were significant. Analysis of trials of structured versus unstructured SMBG showed a greater reduction in HbA1c in the structured group. Analysis of trials comparing use of structured SMBG to adjust therapy with usual care showed that using SMBG readings to adjust therapy resulted in greater reductions in HbA1c. By contrast, an analysis comparing SMBG without therapy adjustment with usual care revealed no significant HbA1c improvement.
A limitation of the study is that glycemic variability and health-related quality of life weren't investigated. In addition, the authors note, 10 trials were funded by industry. There was also a high risk of bias in eight of the trials, moderate heterogeneity for one analysis, and few trials (four) for another.
Chircop J, et al Nurs Res 2021;70(6):487-97.