Effectiveness of Transtheoretical Model‐Based Motivational Interviewing on Glycemic Control Among Adults With Type 2 Diabetes: A Systematic Review and Meta‐Analysis of Randomized Control Trials

ABSTRACT Background Optimal glycemic control is known to be challenging for people with type 2 diabetes (T2D) due to the maintenance of long‐term self‐management behavior. Incorporating the transtheoretical model (TTM) components into motivational interviewing (MI) has been applied to promote self‐management behaviors such as physical activity in T2D patients. However, the effectiveness of the TTM‐based MI intervention in improving glycemic control, self‐management, and self‐efficacy in adults with T2D remains unclear. Aim This systematic review and meta‐analysis of randomized controlled trials aimed to estimate the effect of a TTM‐based MI intervention on glycemic control, self‐management, and self‐efficacy in adults with T2D patients. Methods We searched five electronic databases up to September 13, 2023. Two researchers independently screened records, extracted data, and assessed study quality using the Cochrane Risk of Bias Tool 2.0. Pooled effects were estimated in standardized mean differences (SMDs) or mean differences (MDs) using fixed‐ and random‐effects models. Sensitivity analysis and meta‐regression explored the reasons for heterogeneity. Results Thirty trials with 4214 participants were identified. The TTM‐based MI intervention significantly reduced HbA1c (MD = −0.92, 95% CI [−1.08, −0.75], p < 0.001, I 2 = 65%), FPG (SMD = −1.06, 95% CI [−1.38, −0.73], p < 0.001, I 2 = 93%), and 2hPG (MD = −1.42 mmol/L, 95% CI [−1.83, −1.00], p < 0.001, I 2 = 89%), with high, moderate, and low certainty of evidence, respectively. The intervention also improved self‐management (SMD = 1.47, 95% CI [1.16, 1.78], p < 0.001, I 2 = 80%) and self‐efficacy (SMD = 1.53, 95% CI [1.04, 2.02], p < 0.001, I 2 = 92%). Meta‐analysis revealed that MI treatment dose and initial glycemic status contributed to the high heterogeneity. Linking Evidence to Action The TTM‐based MI intervention can be a promising intervention for understanding patients' stage of change with tailored strategies and MI techniques to facilitate behavior change, resulting in improved glycemic control, self‐management, and self‐efficacy in T2D patients. Nevertheless, given the moderate to high risk of bias in the included studies, further rigorous randomized controlled trials should be conducted to examine the effectiveness of TTM‐based MI interventions. Short and multiple sessions that comply with the fidelity of MI in the intervention plans are suggested in daily nursing routine for diabetes self‐management education.