Assessment of interventionist motivational interviewing experience and competence

Those delivering the intervention (RAs) typically had approximately 3 years’ experience of delivering physical activity interventions; in addition, two had formal psychological or counselling workshop training prior to this trial. However, all RAs had experience of physical activity programming training in a range of settings. This was predominantly in local authority, gym, health or university contexts and did not focus on health behaviour change. All of the RAs had an educational background in sport and exercise science, psychology, physical activity and wellness at undergraduate and postgraduate level.

At the initial MI training sessions an evaluation was made of the competence of the RAs in delivering the technical and relational components of MI. All of the RAs were able to competently describe and demonstrate the level 1 skills of MI, which focused on a higher ratio of open to closed questions, increased client talk time, simple reflections and summarising. In addition, the RAs were able to identify the components and characteristics of the ‘spirit’ of MI. By the end of the first training block (2 days equivalent) the group could identify the use of affirmation compared with praise although found it more difficult to apply this consistently in practice and still tended to fall into a ‘righting reflex’ of problem-solving rather than eliciting opportunities and resources from the client.

At the first formal assessment, independently coded using MITI (see Appendix 7, Table 61; first assessment), the RAs were consistently using level 2 MI skills, which included reflective listening, directional open questions (e.g. optimism for change, intention to change, advantages and disadvantages of change) and tools such as decisional balance, readiness and confidence rulers and action planning. This level of proficiency was in line with the clinician behaviour scores reported in Table 3.

The global rating scores (evocation, collaboration, autonomy/support, direction and empathy) across both assessment period 1 (9 months from first training) and assessment period 2 (18 months from first training) were consistent and the mean scores reflected a level of competence in all RAs with respect to ‘direction’ and a level of proficiency/competence in respect to ‘evocation’ and ‘empathy’. The per cent MI adherent clinician behaviours were all at 100% at phase 1 and/or 2.

With regard to behaviour counts (e.g. per cent complex reflections, per cent open questions and reflection to question ratio), the per cent open questions increased across all RAs from baseline, the reflection to question ratio increased from phase 1 to phase 2 across all RAs and the open questions to complex reflections ratio was higher than anticipated across all RAs.

Independent assessment of interventionist delivery (Motivational Interviewing Treatment Integrity assessment)

The MITI coded sessions were independently assessed by a qualified MI coder and a number of aspects were highlighted as positive and effective in addition to there being areas for enhancement. Although ‘direction’ scored as proficient on the global ratings scale, feedback indicated a need for greater recognition of individual participants’ level of readiness, values and the strength of change talk.⁸⁴ This was highlighted as requiring a greater use of more challenging complex reflections and a greater use of strategies to elicit and strengthen change talk. The RAs scored highly for levels of empathy, however, and similarly demonstrated a high level of client engagement, which is a common aspect of MI ‘spirit’. Although the use of ‘direction’ across all RAs was consistently high, most RAs did not sufficiently demonstrate empathy and autonomy support, which are global MI measures.

The relationship between motivational interviewing fidelity and levels of physical activity

There is moderate evidence to suggest that MI fidelity is associated with physical activity as measured by mean TEE per day (kcal) at 3 months (p = 0.027), that is, the level of physical activity of participants at follow-up was associated with the overall fidelity of delivery of the RA who delivered their MI intervention.

Figure 25 shows the means of mean TEE per day at 3 months with their associated 95% CIs stratified by RA ranked by their global fidelity rating. It should be noted that RA1, RA2 and RA3 had a similar global proficiency rating of 3.5. Grouping these RAs together showed a stronger association between MI fidelity and mean TEE per day at 3 months (p = 0.003). As observed from Figure 25, RAs with a higher global proficiency rating are associated with higher physical activity levels at 3 months. These results should be interpreted with caution, however, given that some RAs delivered a lower number of sessions, as observed by huge uncertainty around their estimated means. Moreover, the sessions were brief and it was not possible to demonstrate all MI processes in some RA sessions that were coded. RA6 does not appear in Figure 25 because she delivered very few sessions and was subject to MITI recording only over a short period after initial training.

FIGURE 25

Means of mean TEE per day (kcal) stratified by RA who delivered the MI sessions.