During the study 22 podiatrists treated one or more persons from the RCT who experienced diabetes and were at high-risk of developing foot ulcers. Eighteen podiatrists followed the three-day basic training or the three-day basic and one-day booster training, and four podiatrists were not trained in MI (Table 1). Participating podiatrists were aged between 25 and 51 years (median 29.5), 12 (54.5%) were female, and experience as podiatrist ranged from 2 to 26 years (median 7.00). Non-MI-trained podiatrists were only women (p = 0.044) and had more years of experience (p = 0.039) than the MI-trained podiatrists. Seven podiatrists, five of the MI-trained and two of the non-MI-trained podiatrists, had little MI knowledge before the start of the study via a course/lecture during their podiatry training or through self-study.

Table 1 Demographic data of the podiatristsMITI results

Fourteen audio recordings from the MI-trained and four audio recordings from the non-MI-trained podiatrists were 15 min or longer and were rated with the MITI. These recorded consultations occurred between 6 and 22 months after following the MI-training.

Two of the four “global scores” (empathy and change talk), one of the five core “behaviour counts” (affirm) and one of the other behaviour counts (simple reflections) were rated significantly higher for the MI-trained podiatrists (Table 2). Comparing the results of the four MITI summary scores with the “beginner proficiency level” thresholds [49], one MI-trained podiatrist met all four thresholds, four MI-trained podiatrists met three thresholds and also four MI-trained podiatrists met two thresholds (Table 3). Two MI-trained podiatrists and two of the non-MI-trained podiatrists met none of the four thresholds.

Table 2 MITI coding results of audiotaped interactions of MI-trained (N = 14) and non-MI-trained podiatrists (N = 4)Table 3 MITI summary scores of audiotaped interactions of MI-trained (N = 14) and non-MI-trained podiatrists (N = 4)Interview results

The interviews had a median interview length of 17 min (range 13–32 min). The interview results can be found below described in the five main topics. From the interviews 28 subtopics were identified (see ‘Additional file 3’). Only quotes with rich value for understanding of the sub codes are mentioned below. A complete list with all quotes belonging to each subtopic is provided in ‘Additional file 4’.

Main topic 1. Podiatrists’ perspective regarding the goal of MI

The podiatrists indicated partnership (relational component of MI), cultivating change talk (technical component of MI) and motivating patients as the goals of MI. They thought that MI helped them to speak with patients on an equal level and gave them the possibility to achieve a specific goal together with the patient. Besides this, MI enabled them to encourage patients to think about their own perspectives.

“That you make the patient think about why something might (not) work for him/her and very often then they come to new insights” (Pod07)

MI moreover addressed the intrinsic motivation of patients to change their behaviour.

“The goal of MI is to activate people from within themselves to apply to something, as in this study a certain therapy. So it is not something that is imposed by us, but that they understand themselves why it is necessary and that it comes from themselves, intrinsic motivation” (Pod02)

Additionally, podiatrists indicated that MI involves using other communication techniques, such as reflective listening, asking reflective questions and softening sustain talk.

Main topic 2. Experiences related to MI-training Subtopic 2.1. New insights

During and after the MI-training, the podiatrists gained new insights. They indicated they had learned that partnership (relational component of MI) means to speak with patients on an equal level, that it is important to reflect on patients’ ideas, and that their task is broader than only providing information. The podiatrists also realised that it is not beneficial to persuade without the patient’s permission, that it is important to express fewer prejudices towards the patient and that they should try to avoid conflict in their working alliance with the patient. In addition, the podiatrists also gained new insight regarding cultivating change talk (aspect belonging to the technical component of MI). Changing the podiatrists’ communication style helped patients to think from their own perspective. With regards to the other MI-techniques the podiatrists learned that asking open questions instead of closed ones led to more insight into the patients’ motives and needs, and that using silences could be useful to let patients think from their own perspective instead of overwhelming them with expertise-based advice.

Subtopic 2.2. Behavioural change for podiatrist

Some of the podiatrists realised that the use of the MI-techniques will be a substantial behaviour change for themselves, because they recognised that their traditional communication techniques were (very) different from the MI-techniques.

"It really made me realise that I was used to use such a different [traditional] communication technique during the last years, and it also made me realise that it is also a very substantial adjustment for me to change that” (Pod04)

Subtopic 2.3. Applicability of MI

Other podiatrists indicated that the MI-techniques would easily be applicable since their usual communication techniques were similar to those used in MI. Also, the practice-oriented approach and the use of many examples during the MI-training made applying MI in practice easy for the podiatrists.

“I found out that I actually already unconsciously applied certain things in practice in the same way. That's all named as motivational interviewing. I thought that sounds very familiar to me...It was nice to hear that you actually already did something and they tell you how to do it. That you think: I actually already did that unconsciously” (Pod01)

Nevertheless, some podiatrists indicated that as point for improvement it would even be better to match the MI-training content more closely to the specific target groups, the examples given should be more related to the users and recipients of MI. A second point for improvement, most podiatrists reported that they would like to have feedback regarding their application of MI, so it is clear to them whether they apply the MI-techniques correctly in practice.

Subtopic 2.4. Multimodal training method

With regards to the multimodal training method, podiatrists experienced alternating between listening, interaction with the trainer, and exercises with each other during the MI-training, and the small training group pleasant. They also valued that the trainer was able to tailor the MI-training content to their knowledge. Besides these positive experiences, some podiatrists had also some points for improvement and suggested that the experience of the MI-training would have been better if it had been possible to meet physically instead of video conferencing (due to COVID-19 restrictions), and they felt that the quantity of information supplied was too much for the relatively short training time.

Subtopic 2.5. Importance of repeating MI-training information

Repetition of the (content of) MI-trainings was indicated as important. It was particularly useful for the podiatrists to receive the monthly emails, and to have the one-day booster training to refresh their knowledge and remind them to consciously apply MI in practice. However, as a point for improvement, the podiatrists mentioned that more repetition of the (content of) MI-trainings was necessary so to become familiar with using MI in daily clinical practice.

Main topic 3. Podiatrists’ experiences with MI in practice Subtopic 3.1. Partnership

Within the relational component of MI, the podiatrists experienced that partnership was normal to them because they were used to collaborating with the patient. The podiatrists reported that this partnership became easier due to thinking along and/or asking questions; that it ensured the podiatrist spoke with the patient on an equal level; that working together was easier with a motivated patient; and that the use of MI even led to better results of podiatry (less diabetic foot problems) or behavioural changes in patients.

MI-adherent behaviours like affirmation and seeking collaboration were experienced as necessary to keep a patient motivated. It was important to connect with the patient and not only to provide information. Other MI-techniques, such as giving information and persuasion with permission were mentioned as important because patients are not always familiar with the possible treatment options for their diabetic feet. However, the podiatrists realised that they needed permission to persuade, otherwise patients would probably not show a behavioural change. Yet there was one podiatrist who found it difficult to stop automatic repair and advice reflexes which means that the podiatrist tries to solve the problem for the patient.

Subtopic 3.2. Change talk

The experiences of the podiatrists differed regarding cultivating change talk within the technical component of MI. Some podiatrists mentioned positive experiences, e.g., that the use of MI by the cultivation of change talk made patients think from their own perspective and that it provided in-depth conversations between the podiatrist and patient. On the other hand, several podiatrists reported negative experiences, e.g., they experienced this technique as difficult because it was novel for them and therefore was a point for self-. Change talk was also experienced as difficult by the podiatrists, because some patients in this patient group were not always familiar with the treatment options for diabetes foot disease.

Subtopic 3.3. Acceptance

Within the relational component empathy, the podiatrists had different experiences with acceptance of the patient’s choice, opinion and/or behaviour. They thought it was natural to accept the patients’ choices, opinions, and/or behaviours, and they experienced that by accepting this the podiatrist was letting the patients think for themselves. However, the podiatrists realised that they also needed to give the patients time to let them think for themselves about possible changes.

“And if it really doesn’t work right away, then I’ll just take a little longer and let the patient come back sometime or give them more time to think about it…The more compelling I come across, or the more I demand of the patient, the greater the patient’s shield becomes against me, so therefore I give people a little more rest and time [to think]” (Pod16)

Besides this, the podiatrists also mentioned that it can be difficult to accept the wishes of non-cooperative patients.

Subtopic 3.4. Compassion

The podiatrists mentioned that they did not experience any problems with compassion within the relational component empathy, because they thought that helping others without benefiting themselves belonged to their mindset towards patients as a healthcare provider.

Subtopic 3.5. Ask open questions

Regarding the MI-technique open questions, the podiatrists’ experiences differed. Some podiatrists mentioned that they found it easy to ask open questions, while others experienced more difficulty in asking open questions than expected, particularly asking about the reason why a patient did not want to change.

“Especially asking questions, asking open questions is more difficult than I thought, because you actually think you always ask open questions, but you actually ask much more closed questions [than you think]. And if you have someone who is very closed off and you ask closed questions, you actually get very little information” (Pod03)

Subtopic 3.6. Applicability of MI

The podiatrists had different experiences regarding the applicability of MI. Some podiatrists reported that they experienced no problems changing from their usual approach to the MI-related communication techniques. This was because these communication techniques were similar to their own techniques. Conversely, some other podiatrists mentioned that applying the tips and tricks of the MI-training made the use of MI feel unnatural and uncomfortable, because the podiatrist had to ask the patient more questions than usual. However, the application of MI during a foot examination made the use of MI feel more natural.

There were also other reasons why the podiatrists experienced difficulties using MI. A couple of them mentioned that it was difficult because there were other matters that had to be discussed during an appointment, and also due to their own working method. Furthermore, the podiatrist’s empathy of the patient’s situation made it difficult to continue using the MI-techniques, as evidenced by Pod04 comment:

“For example, there is a home situation in which people very quickly say ‘I’ll take my shoes off’. I find it very difficult to motivate those people, because I understand why those people take their shoes off” (Pod04)

There were some podiatrists who reported that the use of MI was difficult due to negative experiences and because other communication techniques seemed more effective to them. This created doubts about the applicability of MI in practice.

The podiatrists experienced that the application opportunities for MI depended on the characteristics of the patient and on the level of their familiarity with the patient. For example, the use of MI was easier with established patient relationships and more difficult with unknown patients. Some podiatrists mentioned that the use of MI was also experienced as difficult if the patient was not engaging, while others mentioned that a “challenging” patient encouraged them to apply MI.

“With certain difficult patients where communication does not run completely smoothly, then you would rather think of applying MI. You think about, how can I collaborate with the patient, so that we can work together towards one goal” (Pod13)

Subtopic 3.7. Behavioural change for podiatrist

Some podiatrists experienced the use of MI as development or even led to a behavioural change for themselves.

“I’ve been working as a podiatrist for 10 years so you’re also completely set in your own ways and your own things…it is indeed a complete change, the use [of MI] itself is still quite difficult” (Pod15)

Therefore, the podiatrists mentioned that they had not (yet) always applied MI in daily clinical practice, despite some of them being aware that the traditional communication techniques were no longer the solution. In general, the podiatrists realised that to ensure an integrated, fruitful, or smoother application of MI, that frequent use of MI was required. This would be necessary because there is a risk that information from the MI-training would become diluted or completely forgotten from usage. Some podiatrists thought that they applied MI already unconsciously, because they were already using it; others reported to be consciously engaged. In addition, not all podiatrists used the exact theoretical version of the MI-techniques as taught during the MI-training, but used the details that they thought they could apply to themselves.

Subtopic 3.8. Added value of MI

Many of the podiatrists believed MI was of added value, especially cultivating change talk, one of the technical components of MI. The use of MI helped to make patients think for themselves, to make conscious choices and even led to behavioural changes in patients. In addition, it was reported that cultivating change talk was especially of added value for podiatrists who had difficulty evocating a behavioural change in their patients.

The podiatrists also reported that the added value of MI depended on the characteristics of the patient, whereby MI was of added value for, e.g., non-adherent/uninformed/unmotivated patients. Besides this, they experienced that patients have to be open minded to MI in order for it to have added value and that MI had only an added value for patients with whom they had frequent contact.

Subtopic 3.9. Dealing with resistance to orthopaedic shoes

A combination of some of the MI-techniques were used by a few podiatrists to deal with resistance to orthopaedic shoes, including partnership, which is one of the relational MI components. In addition, the podiatrists accepted the patients’ resistance and informed patients about the treatment options for their foot disease. By informing patients about these unfamiliar possibilities, the podiatrist encouraged the patients to think for themselves.

Main topic 4. Patients’ experiences observed and mentioned by the podiatrist

In addition to their own experiences, the podiatrists were also asked about the observed experiences of the patients regarding the use of MI in their consultations. Related to partnership (relational component of MI) and cultivating change talk (technical component of MI) the podiatrists mentioned different observed patients’ experiences. Many podiatrists reported that the patients experienced working together with the podiatrist as pleasant. Besides this, a single podiatrist reported that some patients showed a more open attitude. However, they also mentioned that it took time for some patients to get used to working together with the podiatrist, because they were unfamiliar with this way of communicating with their podiatrist. They also observed that cultivating change talk made the patients realise that they themselves could contribute to behavioural change and made them see the importance of wearing orthopaedic shoes. However, it also gave the patient insight into their behaviour which was not always welcomed, because this was confronting for the patient. In addition, within the MI-adherent behaviours, the podiatrists mentioned that the confirmation from the podiatrist that things were going well was experienced as pleasant by the patient. Conversely, the podiatrists reported that some patients experienced the (open) questions in MI-style as unpleasant. Because of their digital patient reporting system the podiatrist already had to ask a lot of questions, and therefore in some cases the use of MI might not be applicable.

Main topic 5. Recommendations

Most podiatrists in this study recommended MI to all other podiatrists, where they emphasised partnership within the relational component of MI and cultivation of change talk within the technical component. This is because working together with the patients ensured that behavioural change could be reached through cultivating change talks, which made the patient think for them self. The podiatrists also reported other outcomes with the use of MI. It provided the podiatrist with some background knowledge about communication techniques and led to better conversations. MI also sensitises the podiatrist to quickly recognize whether a patient showed sustain talk or change talk.

Some podiatrists even recommended adding MI within the primary podiatry education, because this would ensure regular repetition of the content of MI-training. In addition, it also provided the podiatrist with insight into and allow them to focus on patients’ expectations and wishes from the beginning of their education. However, a couple of podiatrists recommended the use of MI, but had doubts about including MI in the podiatry training since it might be better to follow an MI-training once the podiatrists had obtained experience in practice.

Data triangulation

The results of the quantitative and qualitative components were combined through triangulation to obtain outcomes from different perspectives and contextualise the results of the MI-training. The MI-trained podiatrists appeared to have acquired basic knowledge and skills regarding MI, but had not yet become MI-experts. The observed communication behaviours in the MITI-scored consultations showed that the podiatrists applied less complex MI-related skills with regard to the relational and technical components of MI that is supported by what they were able to mention during the interviews. The MI-trained podiatrists showed clearly better MITI results on partnership, empathy and cultivating change talk compared to the non-MI-trained podiatrists and demonstrated their understanding of partnership and cultivating change talk in the interviews. The acquired knowledge and skills enabled the communication between podiatrists and their patients in a collaborative and empathetic way, which stimulated behaviour change in the patient towards adherence with recommended foot self-care. However, more complex MI-related skills were minimally applied by the podiatrists in practice and were not mentioned in the interviews with the MI-trained podiatrists. One of those skills was applying complex reflections. The MITI results showed that the threshold for complex reflections was only achieved by two of the fourteen MI-trained podiatrists, compared to two of the four non-MI-trained podiatrists. However, the MI-trained podiatrists used many more reflections, both simple and complex, compared to the non-MI-trained podiatrists.

Most MITI results correspond well with the interview results, although one contradiction was found. The MITI results showed a difference between the MI-trained and non-MI-trained podiatrists on the MI non-adherent behaviour variable ‘persuade without permission’. Here, the non-MI-trained podiatrists tended to score better. Possibly, MI-trained podiatrists know that giving advice is allowed, but that they simply forgot to ask the patient for permission to give advice or to ask what the patient thinks of their advice. This means that the MI-trained podiatrists use the MI-techniques only partially and that the non-MI-trained podiatrists give less advice than the trained podiatrists. This is in line with the interview results, because only one MI-trained podiatrist realised that giving advice without permission may not lead to a behaviour change in the patient. Additionally, the qualitative results showed that the podiatrists experienced the use of MI as patient dependent, e.g., MI is more difficult to apply with an already motivated person or a person who is not open to it. This is also clearly seen in the MITI results per podiatrist. During one conversation with a patient, the podiatrist applied the basic principles of MI at a beginner’s level, while during another conversation the same podiatrist did not apply MI at all. However, the MITI results also showed a contradiction with the interview results. The fact that the MI-trained podiatrists scored significantly better on the relational component empathy than the non-MI-trained podiatrists was unexpected, because during the interviews the podiatrists indicated that compassion belongs to their mindset towards patients.