Challenging evidence and assumptions: is there a role for self-monitoring of blood glucose in people with type 2 diabetes not using insulin?

BACKGROUND: There is debate in the literature about the effectiveness of self-monitoring of blood glucose (SMBG) for people with type 2 diabetes (T2DM) who do not use insulin. Several recent systematic reviews and meta-analyses conclude that SMBG does not have any clinical benefit for this group.
OBJECTIVE: We critically appraise the available evidence, and argue whether SMBG is warranted for people with non-insulin-treated T2DM.
RESULTS: Considerable heterogeneity exists amongst the literature, and aspects of the methodology of some of these studies confound interpretation of results. Recent evidence demonstrates that when SMBG is 'structured', incorporated as part of a complex intervention, and embedded within education and collaborative care, improvements in average blood glucose levels result. In contrast, studies that do not apply SMBG systematically, or that assess a low frequency SMBG regimen that precludes identification and interpretation of SMBG patterns, are not clinically effective. Psychosocial outcomes, such as self-efficacy and diabetes-related distress, and other clinical outcomes, such as hypoglycaemia detection, should also be considered as important clinical endpoints. LIMITATIONS: This is not a systematic literature review. The literature is limited by a lack of studies evaluating a 'structured' approach to SMBG.
CONCLUSIONS: It is the quality, not quantity, of SMBG that makes a difference to outcomes for people with non-insulin-treated T2DM. The benefits of 'structured' SMBG should be considered as part of a complex intervention when making decisions about policy and practice, and assumptions about the benefits of SMBG for people with non-insulin-treated T2DM should be challenged.