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This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.

A motivational communication approach may help people with type 2 diabetes eat more healthily, but may be no better than usual care for changing other behaviours or improving health. The technique involves exploring any ambivalence to change, listening and reflecting non-judgmental questions back to people, alongside helping them to set agendas for changing habits and behaviours. In this review, a range of different professionals conducted the interviews.

This review of 14 trials looked at a range of outcomes and showed a consistent impact of motivational interviewing on healthy eating. Compared with usual care, no difference was found on measures of physical activity (six trials), alcohol reduction (two trials), stopping smoking (three trials), waist circumference (two trials) or cholesterol levels (five trials). Usual care was not described and trial differences meant that results could not be pooled in a meta-analysis. Caution is required in the interpretation of this study as multiple outcomes were assessed but there was a tendency to report only positive findings. The size of any effect was not assessed in any way or synthesised by meta-analysis for example, so it is hard to tell if the change in behaviour led to useful changes in risk factors such as weight or blood sugar levels.

Motivational interviewing is not a single intervention; it includes different specific techniques to encourage behaviour change and does require training and time for delivery. For commissioners, it is worth noting that the interventions tested were intensive, requiring between one and five 30 to 90 minute sessions and economic analysis was not undertaken.

This evidence doesn’t support the wide adoption of motivational interviewing, as described in this review because it is not known yet why many studies showed no effect. Next steps could be to identify which components of the interventions worked, how intensive they need to be and what the impact of prior skill and training in delivery of the intervention was.

Why was this study needed?

Diabetes affects around four million people living in the UK. Around 90% have type 2 diabetes that, if not managed well, can cause serious long-term health problems including heart disease, stroke, blindness and amputations leading to disability. Good management includes education for a healthy diet, exercise and maintaining blood glucose levels within safe limits.

Motivational interviewing is a counselling approach used to motivate people to change their behaviour, so could be useful in encouraging good diabetes self-management. It typically involves open-ended questions, reflective listening and support for patient-autonomy and self-belief in their capacity to change.

The review says motivational interviewing has mainly been used as an ‘add-on’ to other treatments for type 2 diabetes. This review claims to be the first to look specifically at trials using motivational interviewing for adults with type 2 diabetes.

What did this study do?

The systematic review included 14 randomised controlled trials of 4,289 adults with type 2 diabetes. Two were based in the UK. The trials compared motivational interview based interventions with usual care (not defined) or an intervention other than motivational interviewing. Multiple behavioural targets were included, for example smoking, healthy eating, physical activity and some clinical outcomes or risk factors, such as blood pressure and glucose were also measured, in some trials.

Motivational interview sessions were delivered by nurses, general practitioners, dieticians, or diabetes educators, included between one and five 30 to 90 minute sessions, with most sessions (in 11 of 14 trials) delivered face-to-face.

Variation between the trials was too high to pool the results in meta-analyses. Bias was assessed but a summary score for each study was not provided, so overall risk of bias was unclear. As such, the study findings should be treated with some caution.

What did it find?

  • Seven out of 14 trials assessed healthy eating. Four found participants receiving motivational interviewing had a significant improvement in healthy eating compared to usual care. The magnitude of the impact was not reported, only that it was statistically significant.
  • Compared to usual care, motivational interviewing was found to have no significant effect on physical activity (six trials; 1,884 participants), alcohol reduction (two trials; 1,192 participants) stopping smoking (three trials; 994 participants), waist circumference (two trials; 309 participants) or cholesterol levels (five trials; 2,797 participants).
  • Three trials (1,029 participants) assessed self-management of diabetes, but only one trial found motivational interviewing to have a significant effect on this behaviour compared to usual care.
  • Four of 14 trials assessing blood glucose levels (565 participants) found people who received motivational interviewing had significant improvements compared to usual care.
  • Two trials assessed weight reduction. One (217 participants) found significant weight loss in those receiving motivational interviewing compared to those that received usual care, the other (22 participants) found significantly more weight loss after six months but not at 18 months compared to those receiving usual care.
  • Only one of six trials assessing blood pressure and one of eight trials assessing body mass index found motivational interviewing had a significant effect compared to usual care.

What does current guidance say on this issue?

NICE’s 2012 guidance on type 2 diabetes mentions motivational interviewing as one part of a multifaceted intensive lifestyle-change programme. Motivational interviewing, or similar techniques adapted to groups, were mentioned as options to help explore and reinforce participants' reasons for wanting to change and their confidence about making changes.

What are the implications?

Variation in trial design and the interventions themselves make it difficult to identify best-practice strategies. The evidence was most consistent for promoting dietary changes but was still very mixed. For example, only four of seven trials showed improvement. The other three trials showed no effect.

A consideration for implementing this type of intervention will be providing adequate training to practitioners, in this review up to 80 hours of training were reported. Devising ways that the intervention, if effective, can be delivered accurately will also be key to effective delivery.

Complex interventions such as programmes for behaviour change often include components of motivational interviewing techniques. It is not known how widely these concepts are already in practice in the UK. There is an ongoing NIHR cohort study on health coaching for people with multiple morbidities, due to report findings in 2017 (NIHR CLASSIC study).


Citation and Funding

Ekong G and Kavookjian J. Motivational interviewing and outcomes in adults with type 2 diabetes: A systematic review. Patient Educ Couns. 2015. [Epub ahead of print].

This study was partially funded as a gift from the Blue Cross/Blue Shield of Alabama Caring Foundation.



NICE. Type 2 diabetes: prevention in people at high risk. PH38. London. National Institute for Health and Care Excellence; 2012.

NICE. Behaviour change: general approaches. PH6. London. National Institute for Health and Care Excellence; 2007.

NIHR. HS&DR - 12/130/33: Comprehensive Longitudinal Assessment of Salford Integrated Care (CLASSIC): a study of the implementation and effectiveness of a new model of care for long-term conditions [internet]. 2014.

Produced by the University of Southampton and Bazian on behalf of NIHR through the NIHR Dissemination Centre

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Among the 14 trials, eight described motivational training procedures and duration.

Areas of focus for motivational training included exploration of patient ambivalence, reflective listening, asking open-ended questions and agenda-setting.

Training period durations ranged from 10 to 80 hours among the eight studies reporting training details.

Five studies did not detail the training of interviewers, but simply stated that they were motivational interview trained. One study did not include any references to training details or duration.

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