Delivering motivational interviewing early post stroke: standardisation of the intervention

We applied Motivational Interviewing (MI) techniques, early after stroke, to facilitate psychological adjustment to life post-stroke. In our trial, MI-plus-usual-care increased the likelihood of normal mood at 3-months post-stroke, compared to usual-care alone. Whilst appropriate training, manuals, and supervision may increase adherence to core principles of this complex intervention, unintended variability in implementation inevitably remains. We aimed to explore the impact of variability on participant outcome.

Using our trial data (411 participants), we explored variation in MI delivery, examining: therapist characteristics (stroke care expertise/knowledge, psychology training); MI content (fidelity to MI techniques assessed with Motivational Interviewing Treatment Integrity code, describing therapist behaviours as MI-consistent, MI-neutral or MI-inconsistent); and MI dose (number/duration of sessions).

The four MI therapists (two nurses/two psychologists) had varying expertise and MI delivery. Across therapists, mean average session duration ranged 29.5-47.8 min. The percentage of participants completing the per-protocol four sessions ranged 47%-74%. These variations were not related to participant outcome. There were uniformly high frequencies (>99%) of MI-consistent and MI-neutral interactions, and low frequencies (<1%) of MI-inconsistent interactions.

Variation in therapist characteristics and MI dose did not affect participant outcome. These may have been tolerated due to high fidelity to MI principles.IMPLICATIONS FOR REHABILITATIONMotivational Interviewing (MI) can help reduce depression in stroke survivors when delivered early after stroke.The effectiveness of our MI intervention depends on the delivery of high quality MI; in particular, interactions with low levels of MI-inconsistency, and high global MI ratings, ideally delivered over more than one session, each lasting at least 30 minutes.Provided high quality MI is being delivered, the intervention can still have a beneficial effect on participant outcome, even with flexibility and variation in therapist characteristics, and duration and number of sessions, which may be inevitable in a clinical context.