Diabetic foot ulcers (DFU) are one of the most serious complications of diabetes and can lead to amputations in 85% of cases, resulting in physical, psychological, family, social and economic consequences. Psychological interventions can contribute to the improvement of wound healing and, relaxation, in particular, seems to contribute to faster wound healing. More research is needed to assess the effectiveness of different types of intervention on different types of wounds, in particular on chronic wounds such as DFU.

This is a Pilot Randomised Controlled Study of a Psychological Intervention that aims to evaluate the feasibility and acceptability of a muscle relaxation intervention with guided imagery (experimental group - EG) compared to a neutral guided imagery placebo (active control group - ACG) and a group that does not receive any psychological intervention (passive control group - PCG), to inform a future definitive Randomised Controlled Study (RCT) that tests its effectiveness. This study will also examine, qualitatively, the perspectives of patients with DFU on the relaxation intervention, in order to check its acceptability and applicability; as well as the perspectives of health professionals on this adjuvant therapy, its applicability and integration into the care system of multidisciplinary diabetic foot consultations.

Participants have a diagnosis of Diabetes Mellitus and Diabetic Foot; one or two chronic ulcers active at the time of assessment; and clinical levels of stress or anxiety or depression. Participants will be randomized by the three conditions - EG, ACG and PCG - and assessed on the day of the first consultation or nursing treatment for chronic DFU (T0), two months later (T1), and six months later (T2; follow-up). Two weeks after T1, an interview will be conducted with patients with DFU that benefited from the relaxation sessions and to the health professionals who provided them the DFU care.

The results of the present study will contribute for a better understanding of DFU progression, healing, prevention of re-ulceration and future amputations and, consequently, for the improvement of patients' quality of life.

General Aims:

This pilot RCT aims to assess the feasibility and acceptability of a muscle relaxation intervention with guided imagery (experimental group - GE) compared to a neutral guided imagery placebo (active control group - ACG) and a group that does not receive any psychological intervention (passive control group - PCG), prior to the implementation of a future definitive RCT that will assess its effectiveness.

This study will also examine, qualitatively, the perspectives of patients with DFU regarding the relaxation intervention, in order to check its acceptability and applicability; as well as the perspectives of health professionals on this adjuvant therapy, its applicability and integration into the multidisciplinary team of diabetic foot consultations.

Pilot RCT specific aims:

1. To evaluate the rates of eligibility, recruitment and adherence to the study protocol, participation in follow-up, and withdrawal. The degree of patient satisfaction with the relaxation intervention will also be assessed.

2. To verify the feasibility of the assessment protocol and to obtain preliminary estimates of the effects of the intervention on health outcome measures (degree of DFU healing, DFU-related quality of life, anxiety, depression and stress, DFU representations and physical and mental quality of life);

3. Synthesize the information to estimate the sample size required for a future definitive RCT.

   Qualitative study nested in Pilot RCT specific aims:

4. To understand the perspective of patients and health professionals about the relaxation sessions;

5. To explore the contribution of the relaxation sessions to the DFU healing and patients' quality of life;

6. To describe the changes perceived in the patient during the period of relaxation sessions;

7. To analyse the relevance of implementing relaxation sessions in the multidisciplinary team consultation of diabetic foot.

Data Analysis:

To assess the feasibility of this pilot study (aim 1), the rates of eligibility, recruitment and adherence to the study protocol, participation in the follow-up and withdrawal will be calculated and its results will be presented in percentage. The results of the degree of satisfaction with the intervention will be presented through mean and standard deviation. To obtain preliminary estimates of the intervention effects' on health outcome measures (aim 2), descriptive measures of the respective variables (means and standard deviations) will be calculated and Generalised Mixed Models will be used to check for statistically significant differences over time, in the different groups. Data will be analysed using IBM SPSS Statistics 26 for Mac. Finally, from the data obtained, the sample size for a future definitive RCT will be calculated (aim 3).

To answer the aims 4 to 7, a semi-structured interview guide consisting of open-ended questions will be administered to patients with DFU that benefited from the relaxation sessions and to the health professionals who provided them the DFU care. This script will remain unchanged throughout the interviews. The audio recording of the interviews will be done using a tablet, transcribed verbatim and anonymised in order to safeguard participants and data confidentiality. The transcripts of the interviews will be analysed in the same order as conducted, using the thematic content analysis technique (Bardin, 2016).

Sample size calculation:

The sample size calculation for a pilot RCT, considering the average effect size of 0.5, a statistical power of 80% and a significance level of 5%, revealed that 12 participants were needed in each of the groups (Cocks & Torgerson, 2013). This approach considers that a one-sided 80% confidence interval for the effect size will exclude the minimum clinically significant difference if the null hypothesis is true (Brown & Lilford, 2006).

Procedure:

The doctor or nurse, in the medical appointment, identifies patients that meet the medical inclusion criteria. Patients are invited to participate in the study by the Researcher at the end of the medical appointment and are informed about the aims of the study and the voluntary nature of participation through informed and informative consent. If patients agree to participate, they will sign the consent form. Nurses will then complete RESVECH 2.0 at the end of the appointment and doctors will complete the clinical questionnaire. Afterwards, the Researcher will accompany the patient to a room provided by the Hospital in order to administer the battery of questionnaires in the interview format.

After answering the questionnaires, the researcher will score the PSS and HADS instruments to identify the presence of significant clinical levels of stress, anxiety and depression, and if the patient is eligible, at the end of that week, the participant will be randomized into one of three possible groups.

In the next diabetic foot appointment, the respective participant will be informed about the group to which he or she has been allocated and whether will benefit, if appropriate, from four sessions of relaxation (EG) or neutral guided imagery (ACG), depending on the group. If the participant is available, the first session will take place on the same day. The following sessions will be scheduled according to the medical diabetic foot consultations. In each session, two assessments of blood pressure and heart rate will be performed, before starting the session and at the end of the session. At the end of the fourth session, the T1 assessment will be performed, with a new administration of the questionnaires. Six months after T0, the T2 (follow-up) evaluation will take place, with the last administration of the questionnaires.

The interviews with patients, who completed the four sessions of relaxation, and with health professionals, will be conducted two weeks after T1, by a different researcher than the one involved in the intervention, to reduce the bias of social desirability.

Inclusion Criteria:

• Diabetes Mellitus diagnosis;
• Diagnosis of Diabetic Foot;
• Having one or two active chronic ulcers (> 6 weeks) at the time of the assessment;
• Being followed at the Multidisciplinary Consultation of the Diabetic Foot from the Centro Hospitalar Universitário do Porto (CHUP), at the Diabetic Foot Clinic from the Centro Hospitalar do Tâmega e Sousa (CHTS) and from the Hospital de Braga;
• Presenting clinical levels of stress (scores greater than 13 for males and greater than 17 for females on the Perceived Stress Scale) or anxiety or depression (scores greater than 11 on Hospital Anxiety and Depression Scale).

Exclusion Criteria:

• The active DFU at the time of the assessment being a relapse;
• Having more than two DFU currently active;
• Being on hemodialysis treatment;
• Presence of psychosis or dementia described in the patient's medical record;
• Having cancer disease;
• Having undergone a transplant;
• Receiving psychological counselling at the time of the assessment.

For the qualitative study nested in the Pilot RCT, participants must meet the same inclusion and exclusion criteria defined above, plus being allocated to the EG and have completed the four intervention sessions. From those participants, the following cases will be selected:

• Three typical cases of patients with neuropathic foot defined by the presence of neuropathic pain (e.g., heat, tingling, electrical shock), presence of distal pulses by palpation, and loss of protective sensitivity;
• Three typical cases of patients with neuroischemic foot defined by the presence of peripheral artery disease, intense-variable pain, absence of distal pulses by palpation, and variable protective sensitivity.

Eligible participants will be randomised into the three groups into blocks of variable size, multiples of three; and will be stratified according to: i) data collection site; ii) Chronic Renal Disease; and iii) Peripheral Arterial Disease; because they are factors of poor prognosis in the DFU healing (Ferreira et al., 2014). This procedure will be performed using an online random number generator, by a researcher external to the team involved in the implementation of this study, in order to ensure the concealment of the allocation of participants by the various groups (Pandis, 2012). After this procedure, it will not be possible to conceal the group to which the patient belongs from the researcher who will perform the psychological intervention. However, health professionals (doctors and nurses) will be blinded during the entire procedure, because they fill in the RESVECH 2.0, which assesses the DFU healing.