Behavioural Change Techniques in Health Coaching-Based Interventions for Type 2 Diabetes Patients: A Systematic Review

Background: Given the high rates globally of Type 2 Diabetes Mellitus (T2DM), there is a clear need to target health behaviours through person-centred interventions. Health coaching is one strategy that has been widely recognised as a tool to foster positive behaviour change. However, it has been used inconsistently and has produced mixed results. This systematic review sought to explore the use of behaviour change techniques (BCTs) in health coaching interventions and identify which BCTs are linked with increased effectiveness in relation to HbA1C reductions. Methods: : Studies were systematically identified through database searches for relevant randomised controlled trials (RCTs) in papers published between January 1950 and April 2020. Included papers were screened on the reported use of BCTs based on the BCT taxonomy. The effectiveness of included interventions was assessed by using Cohen’s d. Results: : Twenty-one RCTs were identified. Thirteen interventions were shown to have medium to large effects on HbA1c reduction ( d= 0.50 to d= 1.30). Twenty-three BCTs were identified, with a mean of 5.3 (SD = 3.6) BCTs used in each study. Of these, Goal setting (behaviour) and Problem solving were the most frequently identified BCTs. The intervention with the largest effect size ( d= 1.30) used five different BCTs: Goal setting (behaviour), Problem Solving, Goal setting (outcome), Self-monitoring of outcome of behaviour, and framing/reframing. However, there was little evidence to link the use of specific BCTs to reductions in HbA1c across the studies included in the review Conclusion: A relatively small number of BCTs have been used in RCTs of health coaching interventions for T2DM. Moreover, other possible BCTs directly related to the theoretical underpinnings of health coaching were absent. It is recommended that key BCTs are identified at an early stage of intervention development, although further research is needed to examine the most effective BCTs to use in health coaching interventions.