Background: Patients with chronic end-stage renal disease (ESRD) commonly experience chronic pain, which significantly impair their quality of life. This pain is often exacerbated by maladaptive cognitive appraisals, in particular pain catastrophizing. This study investigated the effectiveness of progressive muscle relaxation (PMR) on pain intensity, pain catastrophizing, and health-related quality of life on patients undergoing with ESRD.

Methods: This randomized controlled parallel study was conducted in a governmental hospital in Jordan in 2024. Participants (N= 104) were randomly assigned to an experimental group offered five sessions of 30 minutes of PMR per week over a total period of five weeks and a control group, which receives standard treatment. The outcomes were measured by Arabic validated scales such as the Pain Catastrophizing Scale, Numerical Pain Rating Scale and the Renal Disease Quality of Life questionnaire at baseline and the end of the intervention.

Patients with chronic end-stage renal disease (ESRD) commonly experience chronic pain, which significantly impair their quality of life. This pain is often exacerbated by maladaptive cognitive appraisals, in particular pain catastrophizing. This study investigated the effectiveness of progressive muscle relaxation (PMR) on pain intensity, pain catastrophizing, and health-related quality of life on patients undergoing with ESRD.

This study using a pretest-post-test randomized controlled parallel design was conducted in a Dialysis facility in a Government Military Hospitals. This facility is the biggest in the middle east that includes 58 dialysis machines and treats 2,200-2,240 patients monthly. The participants were chosen by a convenience sampling method and then randomly allocated into experimental and control groups. Research assistant who did not participate in any phase of the study (e.g. recruitment or measurement) performed the participants' allocation using a cluster random assignment method explained below.

The sample size was calculated using G*power 3.1.9.4. The estimated sample size was 102 given an independent t-test, a medium effect size of 0.5, an alpha of 0.05, and a power of 0.8. Considering a 15% attrition rate, 117 participants are needed for the sample. The final necessary sample size was 120 individuals after 3 persons were added to be more cautious. Out of the 170 individuals that had their eligibility evaluated, 120 were found to be eligible and consented to take part. 104 of them finished the study, and their data was analysed. Due to health concerns, the remaining 16 participants decided to leave the study prior to the collection of baseline data.

After getting the approval of the Institutional Research Board (IRB), the research investigator approached hospital management requesting them to allow the study to be carried out at their hospital. Upon consent, the researcher interviewed the subjects individually on their study objectives and processes. The informed consent statement was forwarded to all the participants who had agreed to participate in the research. The participants were then randomly assigned to the experimental group and the control group using a cluster random assignment to avoid contamination. To implement this assignment approach, a list of participants who met the criteria for the research was made, along with their shifts (A, B, and C). Participants received hemodialysis three times a week on either Sunday, Tuesday, and Thursday (STT) or Monday, Wednesday, and Saturday (MWS). The above arrangement resulted in six clusters: two shifts per week (STT or MWS) × three shifts per day (A, B, and C). The clusters (STT Shift A, 2) STT Shift B, 3) STT Shift C, 4) MWS Shift A, 5) MWS Shift B, and 6) MMWS Shift C were defined by a mixture of hemodialysis days and shifts. Listing all six clusters-each with twenty subjects according to the sample size calculation-was an initial procedure. Following that, these clusters were randomly assigned to the control or experimental groups. Randomizing participants was carried out using a random number generation technique to ensure an unbiased assignment. This random assignment method was used by an investigator who had no involvement in recruiting participants and was blind to the participant list.

After randomization, baseline assessments of the study sociodemographics and dependent variables were conducted in the hemodialysis unit before the intervention started. At the end of the intervention, which occurred five weeks following the actual MBI training, the study dependent variables were assessed again. A qualified research assistant collected the data without taking part in other study components. A qualified research assistant collected the data without taking part in other study components. This research assistant has a strong background in nephrology and is a registered nurse. Every measurement in the hemodialysis unit was conducted in private, with similar settings (e.g., temperature) and conditions (e.g., sitting position). There was nobody there when they finished the questionnaire.

This study employed five weekly 30-minute sessions of Progressive Muscle Relaxation (PMR) based on the ABC relaxation theory. The PMR intervention involve tense-and-release exercises for 11 different muscle groups, including hands, arms, sides, back, shoulders, face, neck, stomach, chest, legs, and feet. For five to ten seconds, each muscle group is contracted, and for twenty to thirty seconds, it is relaxed. The sensations of stress and relaxation were the participants' main concern. To release any residual tension, they looked at each muscle group after the workout. With the exception of the time needed for measurements and instructions, the entire operation took roughly thirty minutes.

Participants in the experimental group attended three weekly PMR sessions during their five weeks of hemodialysis. In order to allow participants to practice the PMR procedure during hemodialysis sessions, it was recorded on audio. These recordings were provided to them via email or WhatsApp, depending on their option. This audio recording was made utilizing Smith's protocol by a certified study researcher who holds a higher degree in nursing and has extensive experience practicing and delivering mind-body therapies. The audio recording was confirmed and authenticated by two psychologists with strong PMR backgrounds. The researcher managed any interruptions, kept the PMR delivery under control, protected confidentiality, and made sure they could practice efficiently. Although it was not required, participants were encouraged to practice the PMR at home during the five-week trial period. Prior to the trial, participants in both groups were told to stick to their regular schedules and refrain from pursuing alternative or psychiatric therapy to elevate their mood. They were also requested to inform the researcher if they decided to seek such treatments during the study time. They were also requested to notify the researcher if they used analgesics during the study period.

Before the intervention started, a face-to-face instructional session was held to help participants better understand it. Consequently, the participants in the experimental group attended an additional 2-hour education session during which the researcher gave them thorough information regarding the purpose and approach of the intervention. During the workshop, participants learnt the basics of the PMR program and were given a detailed walkthrough of the full intervention process. Participants were encouraged to ask questions and take part in conversations to ensure they understood the intervention. The control group received no interaction from the researcher. However, following the conclusion of the investigation, the control group participants were given the audio recordings of the intervention protocol along with an explanation of them.

Version 25 of the statistical package for social science was used to analyze our data. To provide an overview of the study results, descriptive statistics were applied. Because the data was not normally distributed, we described categorical variables with frequency and percentage and continuous variables with median and IQR. Histogram, the Shapiro-Wilk test, and skewness and kurtosis indices were used to examine the normality across groups. The homogeneity of variance was examined using Levene's test. If continuous variables' data did not follow the normal distribution and had unequal variances, non-parametric tests such as Mann-Whitney U tests and Wilcoxon Signed Ranks Test replaced parametric tests including independent tests and dependet t-tests respectively.

A chi-square test was performed to study whether there were baseline differences on sociodemographic categorical variables between the study groups. Mann-Whitney U tests were used to compare the difference between two independent groups at baseline and after the intervention as normality and/or homogeneity of variance were violated. To find out if the mean scores improved within the study groups, a Wilcoxon Signed Ranks Test was run, since not all data followed a normal distribution.

This study obtained a approval by the IRB at Jordan University of Science and Technology. The consenting participants were made to read and sign a consent form after which they were allowed to engage in the study. They were assured that they would not face any impact on their access to care in case they refuse to participate. The participants were informed that their names were converted to numbers because of their anonymity and that the research information would be stored safely in an encrypted file cabinet which can only be accessed by the investigators. No eligible patient was excluded due to her or his racio- ethnic background. The intervention was stopped, and the doctor was notified right away if the participants experienced discomfort.

Inclusion Criteria:

• The patients with ESRD who had a smartphone
• aged eighteen years or above
• and received hemodialysis at least thrice a week

Exclusion Criteria:

• The patients with ESRD patients who received psychotherapy
• or took regular psychopharmacological and analgesic treatment