Thematic analysis of participants’ experiences revealed that all patients and caregivers who accepted to participate in this study were satisfied, and shared positive opinions about the effectiveness of the two stress reduction interventions on the patient’s psychological wellbeing and DFU healing progression. Patients were mainly men, on average with 57 years old, and professionally inactive, while their caregivers were younger women, mostly their spouses, unemployed, caring for their relative, in average, for 11 years. This demographic characterization was expected since it is in accordance with previous descriptions of patients with DFUs and their caregivers described in national and international studies [36].

Interviews with patients yielded four key themes (common to caregivers): (1) perspectives on the intervention, (2) intervention effectiveness, (3) perceived importance of psychology in the DFU treatment, and (4) emotions and consequences associated with DFUs. Regarding their perspectives on interventions, patients had never experienced relaxation or hypnosis. They reported that interventions’ sessions were satisfactory, beneficial, and important because it improved their feeling of wellbeing as an adjuvant to medical treatment, and helped them to accept and adapt to living with a DFU. Interventions were well received by patients and perceived as effective by caregivers, indicating a high level of acceptability, which might support the adherence to this type of interventions if available in hospital settings/contexts.

Patients and caregivers made some suggestions to improve the implementation of this type of interventions as an adjuvant to medical treatment. All patients suggested that more sessions should be offered, proposing that the number of sessions should be defined according to the patient’s needs, based on an initial assessment. Patients also suggested that sessions should be implemented in a more private space. Similarly, caregivers recommended interventions to include more sessions, suggesting that they should be implemented in a non-hospital setting. Caregivers also emphasized the importance of the interventions to be offered in an initial phase of medical treatment, and before the patient’s amputation. These suggestions are useful since they reflect the perspectives and needs of patients with DFUs and their family caregivers. In fact, patient and public involvement in healthcare provision, specifically in the design, conduct and dissemination of healthcare innovation services (such as the inclusion of stress reduction interventions in the DFUs treatment) is becoming more common in advanced health care systems [37].

Half of patients who received PMR + GI reported practicing the intervention exercises at home, on their own initiative, thus presenting greater adherence in between sessions. One of those patients perceived longer lasting effects of relaxation, compared to a patient that reported having difficulties with the breathing exercises. Patients who received H + GI claimed that those sessions should be included in standard treatment for DFU, which is supported by previous research validating the beneficial clinical impact of hypnosis [38]. A substantial body of research has revealed the efficacy of hypnosis as part of the integrative treatment of many conditions that traditional medicine has found difficult to treat [39]. In fact, hypnosis has shown not only to reduce anxiety in medical conditions but also to change physiological parameters [40], being effective in the management of diabetes, including the regulation of blood sugar [23]. Although, so far, no studies have shown the effectiveness of hypnosis in accelerating DFU healing, in this study, participants’ perceptions suggest that sessions have been helpful to patients with DFUs. Nevertheless, perceived improvements by participants are subjective and were not objectively assessed by researchers.

Patients and caregivers from both groups perceived physical, behavioural, psychological, and interpersonal changes, associated with interventions, highlighting the benefits of stress reduction sessions in patients with DFUs [22, 24, 25, 41]. Considering that studies have shown that stress management improves diabetes [42], participants’ perceptions of physical improvements, such as less pain and better glycemic control, make intuitive sense.

Patients reported several emotional changes/ improvements (e.g., feeling calm, positive thinking, acceptance of the disease) that were also noticed by their caregivers. In fact, psychological interventions don’t only have positive effects in reducing negative emotions, but also may promote the development of a cognitive and emotional process of diabetes acceptance as a chronic disease, thus helping patients to cope with it.

Behavioural changes perceived by participants as an effect of interventions were associated with adherence to self-care behaviors. One patient reported a decrease in alcohol and tobacco consumption, as well as the adoption of a healthier diet, which he and his caregiver associated with the relaxation sessions. Patients also reported being more patient and less offensive, which was also corroborated by caregivers. Foot ulcers in people with diabetes are associated with high levels of morbidity, with symptoms of anxiety and depression being the most prevalent [8, 9, 43, 44]. Therefore, it makes sense that psychological interventions may have a positive effect and an indirect impact on medication adherence, empowering patients to engage in self-care behaviors, and boosting overall mood [43], as suggested by this study’s participants.

Regarding the duration of the changes resulting from interventions, participants’ opinions differed in both groups. They ranged from effects that only lasted during the session to longer-term effects, after the end of the interventions. TG2 patients and caregivers reported longer effects, as most of them expressed that the effect remained over time, and were still visible two weeks after completing the intervention. In fact, the use of hypnosis has been found to promote positive changes, with longer lasting effects. For example, previous studies have shown hypnosis as a promising therapeutic complementary intervention to reduce impulsive behaviors, over time, in obese patients [45]. Wood and colleagues [46] also showed that the hypnotic intervention altered T-cell activity what may explain the longer effects hypnosis may have on healing. Nevertheless, in this study, the duration of perceived effects were limited in time, especially in TG1, as most participants reported that effect started to vanish after the sessions.

In this study, most patients referred the importance of psychological interventions for the DFU treatment - reflecting a belief in the mind-body connection – although some patients may feel reluctant to participate in psychological interventions due to prejudice or shame, or even because they feel emotionally overwhelmed by the consequences of the disease. Therefore, psychological interventions should be available in an early period of the DFU diagnosis [43]. Caregivers also stressed the role of psychological status for successful treatments, determination, positive thinking, and acceptance of the disease, highlighting caregivers’ awareness of the importance of psychological intervention to help the patient accept the disease [47].

Patients, especially those from TG1, reported that DFUs were a source of negative emotional consequences, such as sadness, anger, revulsion, and anguish, living with the fear of amputation and trauma [8, 9, 44], and dealing with the impossibility to work. Caregivers from both intervention groups stressed the fear of amputation felt by patients. As previously suggested in the literature [48], some individuals with diabetes fear amputation worse than death. Given these negative emotions, the role of psychological interventions may be helpful to improve patient’s general wellbeing, reduce symptoms of anxiety and depression, and stimulate emotional regulation [43], particularly when patients are unemployed, inactive, and with their QoL compromised due to DFUs [44].

Regarding consequences associated with DFUs, caregivers highlighted the impact on the patient’s daily life, resulting in inactivity, isolation, depression, unemployment, and lack of social activities for the caregiver, as shown in previous studies [14, 15]. The scenario of burden appears to be exacerbated following amputation [49]. In this sense, one of the caregivers believed that stress interventions might be more beneficial before amputation surgery.

Overall, the aim of this study was to understand whether the two stress reduction interventions (PMR + GI and H + GI) had an impact on psychological factors that have been reported to have a negative effect on wound healing [50, 51]. According to participants’ perceptions, psychological interventions had a positive effect on patients’ behavioural, emotional, and interpersonal dimensions, being also associated with perceived DFU’s improvements, and reduced symptoms of psychological morbidity. These results suggest the potential positive effects of both interventions on patients’ emotional state, ulcer healing, and general wellbeing, as perceived by patients and family caregivers.

Despite the promising findings, this study has some limitations that deserve attention. This study was based on the subjective perceptions of a reduced number of participants and, as such, they need to be interpreted cautiously. Although the thematic analysis of the interviews indicated a level of coherence regarding the emerging themes, the inclusion of more participants would benefit future studies. The purposeful sampling has the potential for bias in recruitment creating a possible influence of confounders that were not controlled. All psychologists who performed the stress reduction techniques were highly trained, but there might have been bias regarding the person of the therapist and the therapist ‘s gender that was not controlled for. The non-inclusion of a group of patients with no intervention, and their respective caregivers, does not allow to determine a relationship between the intervention and the outcomes, i.e. if the perceived improvements reported by participants would also been identified by participants that did not receive any stress reduction intervention. Finally, only patients from two hospitals in the north of Portugal were involved. Therefore, future research is needed to better understand the impact of stress reduction techniques on DFU healing and psychological wellbeing.

This study provides promising data supporting the benefits of stress reduction interventions, relaxation and hypnosis, for clinically distressed patients with DFUs. If further research confirms this study’s findings, both interventions should be included as standard treatments for patients with DFUs in addition to clinical/medical treatment. Muscle relaxation interventions may be conducted by trained clinical and health psychologists that already work in the hospital, not requiring additional financial efforts. Hypnosis sessions are conducted by trained professionals in hypnotherapy, which may require some initial financial investment. However, both intervention techniques may be easily taught to patients so that they can practice self-relaxation and self-hypnosis exercises at home. To promote home practice on a daily basis, sessions may be recorded and made available to patients who should be coached in self-relaxation and self-hypnosis, using a taped script or a smartphone application. According to participants’ suggestions, psychological interventions should be available early on, when the patient begins treatment, i.e. in the first diabetic foot consultation. Thus, a stress reduction protocol that would include a careful psychological evaluation, which is common practice in other chronic diseases/ conditions, would allow clinically distressed patients’ referral to an individual/ group stress reduction intervention.

Considering patients and caregivers’ perceptions regarding DFUs healing and psychological wellbeing, during and after intervention, it would be interesting to further evaluate the benefits of implementing a psychological support/consulting service for patients with DFUs in multidisciplinary diabetic foot clinics. Distressed caregivers may also be offered a support group to help reduce overload, especially among caregivers who care for patients who suffered an amputation, have a chronic illness, report physical symptoms, and have been caregivers for several years [49].

Future studies should address the patient-caregiver dyad, over time, and better understand how relaxation and hypnosis promote QoL, adherence to medical treatment, and self-care behaviors. This would allow the creation of a psychological intervention protocolto answer patients’ needs, as well the needs of informal caregivers, and the health professional team caring for patients with DFUs.