Background: The value of self-monitoring of blood glucose (SMBG) for persons with type 2 diabetes who do not use insulin remains controversial. This observational study compares the likelihood of medication adherence and change in glycated hemoglobin (A1C) for non-insulin-using patients using SMBG versus those not using SMBG. The study also assessed the association between diabetes medication adherence and SMBG use.
Patients and methods: Data were extracted on 5,172 patients who began non-insulin diabetes medication between October 1, 2006, and March 31, 2009. The study assessed change in A1C associated with SMBG use and testing frequency at different categorical levels of baseline A1C. The likelihood of medication adherence for SMBG users was compared with that for non-SMBG users at different categorical levels of baseline A1C. The study further explored the interactions between SMBG use and medication adherence on change in A1C.
Results: SMBG users had greater reductions in A1C compared with nonusers when the baseline A1C was ≥ 7%. Increasing SMBG frequency was associated with greater reductions in A1C. The study also examined the associations among SMBG use, medication adherence, and change in A1C. SMBG users had greater decreases in A1C for both medication-adherent and -nonadherent patients. As expected, medication adherence was associated with greater reductions in A1C for both SMBG nonusers and users. It is interesting that medication-nonadherent SMBG users had similar reductions in A1C compared with medication-adherent non-SMBG users.
Conclusions: Both SMBG use and medication adherence were associated with similar degrees of A1C reduction after controlling for baseline A1C, suggesting that both factors may be important for attaining glycemic control.