Glucose Self-monitoring in Non-Insulin-Treated Patients With Type 2 Diabetes in Primary Care Settings: A Randomized Trial

Abstract

Importance: The value of self-monitoring of blood glucose (SMBG) levels in patients with non-insulin-treated type 2 diabetes has been debated.

Objective: To compare 3 approaches of SMBG for effects on hemoglobin A1c levels and health-related quality of life (HRQOL) among people with non-insulin-treated type 2 diabetes in primary care practice.

Design, setting, and participants: The Monitor Trial study was a pragmatic, open-label randomized trial conducted in 15 primary care practices in central North Carolina. Participants were randomized between January 2014 and July 2015. Eligible patients with type 2 non-insulin-treated diabetes were: older than 30 years, established with a primary care physician at a participating practice, had glycemic control (hemoglobin A1c) levels higher than 6.5% but lower than 9.5% within the 6 months preceding screening, as obtained from the electronic medical record, and willing to comply with the results of random assignment into a study group. Of the 1032 assessed for eligibility, 450 were randomized.

Interventions: No SMBG, once-daily SMBG, and once-daily SMBG with enhanced patient feedback including automatic tailored messages delivered via the meter.

Main outcomes and measures: Coprimary outcomes included hemoglobin A1c levels and HRQOL at 52 weeks.

Results: A total of 450 patients were randomized and 418 (92.9%) completed the final visit. There were no significant differences in hemoglobin A1c levels across all 3 groups (P = .74; estimated adjusted mean hemoglobin A1c difference, SMBG with messaging vs no SMBG, -0.09%; 95% CI, -0.31% to 0.14%; SMBG vs no SMBG, -0.05%; 95% CI, -0.27% to 0.17%). There were also no significant differences found in HRQOL. There were no notable differences in key adverse events including hypoglycemia frequency, health care utilization, or insulin initiation.

Conclusions and relevance: In patients with non-insulin-treated type 2 diabetes, we observed no clinically or statistically significant differences at 1 year in glycemic control or HRQOL between patients who performed SMBG compared with those who did not perform SMBG. The addition of this type of tailored feedback provided through messaging via a meter did not provide any advantage in glycemic control.

Trial registration: clinicaltrials.gov Identifier: NCT02033499.

Figure 1.. The Monitor Trial CONSORT Flow Diagram

SMBG indicates self-monitoring of blood glucose.

Figure 2.. Mean Hemoglobin A_1c by Study Arm Over Time and Daily Proportions of Patients Testing in the SMBG Groups

A, Model-estimated mean hemoglobin A_1c values obtained by fitting a quadratic polynomial regression with linear mixed models using all observed hemoglobin A_1c values, including those at interim visits, but excluding any following insulin use. The model included 1875 total hemoglobin A_1c measurements from 450 patients; only 10 patients contributed no interim hemoglobin A_1c measurements and the median number was 4. The intervals represent pointwise 95% CIs for each group, and the P values compare the average of the SMBG groups with the no SMBG group. B, Daily proportions of patients in the SMBG groups uploading a result with the meter on each study day. Lines represent locally weighted smoothing using local quadratic polynomials across the observed proportions. SMBG Indicates self-monitoring of blood glucose.