Impact of Self-Monitoring Blood Glucose on Glycaemic Control Among Insulin-Treated Patients With Diabetes Mellitus in Northeastern Tanzania: A Randomised Controlled Trial

Introduction: Tracking of blood glucose levels by patients and care providers remains an integral component in the management of diabetes mellitus (DM). Evidence, primarily from high-income countries, has illustrated the effectiveness of self-monitoring of blood glucose (SMBG) in controlling DM. However, there is limited data on the feasibility and impact of SMBG among patients in the rural regions of sub-Saharan Africa. This study is aimed at assessing SMBG, its adherence, and associated factors on the effect of glycaemic control among insulin-treated patients with DM in northeastern Tanzania. Materials and Methods: This was a single-blinded, randomised clinical trial conducted from December 2022 to May 2023. The study included patients with DM who had already been on insulin treatment for at least 3 months. A total of 85 participants were recruited into the study and categorised into the intervention and control groups by a simple randomization method using numbered envelopes. The intervention group received glucose metres, test strips, logbooks, and extensive SMBG training. The control group received the usual care at the outpatient clinic. Each participant was followed for a period of 12 weeks, with glycated haemoglobin (HbA(1c)) and fasting blood glucose (FBG) being checked both at the beginning and at the end of the study follow-up. The primary and secondary outcomes were adherence to the SMBG schedule, barriers associated with the use of SMBG, and the ability to self-manage DM, logbook data recording, and change in HbA(1c). The analysis included descriptive statistics, paired t-tests, and logistic regression. Results: Eighty participants were analysed: 39 in the intervention group and 41 in the control group. In the intervention group, 24 (61.5%) of patients displayed favourable adherence to SMBG, as evidenced by tests documented in the logbooks and glucometer readings. Education on SMBG was significantly associated with adherence. Structured SMBG improved glycaemic control with a HbA(1c) reduction of -1.01 (95% confidence interval (CI) -1.39, -0.63) in the intervention group within 3 months from baseline compared to controls of 0.18 (95% CI -0.07, 0.44) (p<0.001). Conclusion: Structured SMBG positively impacted glycaemic control among insulin-treated patients with DM in the outpatient clinic. The results suggest that implementing a structured testing programme can lead to significant reductions in HbA(1c) and FBG levels. Trial Registration: Pan African Clinical Trials Registry identifier: PACTR202402642155729.