General Aim:
This RCT aims to assess the effectiveness of a muscle relaxation intervention with guided imagery (EG1) compared to hypnosis with guided imagery intervention (EG2) and a neutral guided imagery placebo (ACG) and a group that does not receive any psychological intervention (PCG), in DFU healing, physiological indicators of healing prognosis, and quality of life (QoL), in patients with diabetic foot and a chronic ulcer.
This study will also examine, qualitatively, the perspectives of patients and their respective family caregivers regarding the interventions (EG1 and EG2) and placebo sessions in order to check the treatments' effectiveness.
Specific aim:
1. To compare the impact of both experimental groups (EG1 and EG2) on psychological stress markers, in DFU healing, physiological indicators of healing prognosis, and QoL compared to the (PCG); between pre and post-intervention in the EG1 and EG2, controlling for clinical and sociodemographic variables, adherence to DFU care, and patients' literacy.
Nested qualitative study specific aims:
2. To understand the perspectives of patients and family caregivers on the efficacy of EG1 and EG2 interventions versus ACG sessions to the DFU healing, comparing cases with a positive evolution (healing of the DFU) with cases with a negative evolution (DFU non-healing).
Sample size calculation:
Using Sakpal formula (2010), and according to the descriptive results of the pilot study (Ferreira et al., 2022), considering the difference in the mean (1.93) and standard deviation (6) of the treatment versus passive control groups, with a statistical power of 80% and a statistical significance level of 5%, a definitive RCT will require 152 participants. Considering a dropout rate for intervention sessions of 11%, a definitive RCT with four groups will require a sample of 169 participants, with 42 patients per group (Ferreira et al., 2022).
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 an 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. Afterward, 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 confirm the presence of significant clinical levels of stress, anxiety or depression, and if the patient is eligible, at the end of that week, the participant will be randomized into one of four 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 (EG1), hypnosis (EG2), or neutral guided imagery (ACG). If allocated to the PCG, the patient will not receive any psychological or placebo session. 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. At T0, T1 and T2 a blood and DFU swab sample will be collected for the evaluation of the physiological variables. Plasma and peripheral blood mononuclear cells (PBMC)s will be separated from the blood samples and frozen at -80ºC for analysis by the biochemical team member. Blood lymphocyte populations will be analyzed by flow cytometry and the quantification of blood cell populations will be performed by an automated hematological cell counter on fresh blood samples. The medical and nurse team member, as well as the lab technicians will not be aware of which group participants belong to.
The interviews with patients who completed the four sessions of EG1, EG2, and ACG, as well as their informal caregivers, will be conducted separately, two weeks after T1, by a different researcher than the one involved in the sessions conduction, to reduce the bias of social desirability.
Data analysis:
All standard statistical analyses will be done using the Rstudio, R version 3.6.2 (R Core Team, 2019) and the SPSS statistics, v. 24.0 (IBM SPSS Statistics for Windows, IBM Corp, Armonk, New York). The baseline data of the treatments and control groups will be compared, using chi-squared test for binary variables and the t-test for continuous variables. The comparison between experimental groups (EG1 and EG2) and control groups (ACG and PCG) will be analyzed through Generalized Mixed Models.
A semi-structured interview guide consisting of open-ended questions will be administered to approximately 12 patients that benefited from interventions (EG1, EG2) and placebo (ACG) sessions), and 12 informal caregivers indicated by those patients. This script will remain unchanged throughout the interviews. The audio recording of the interviews will be done using a tablet, transcribed verbatim, and anonymized in order to safeguard participants and data confidentiality. The transcripts of the interviews will be analyzed in the same order as conducted, using the thematic content analysis technique, and the NVivo software (QSR International PtyLtd, 2018).
