The duration of the laughter yoga was 30 minutes and a total of 16 sessions were performed on a twice-weekly basis.

The laughter yoga practice was initiated through clapping and warm-up exercises: hands were clapped keeping hands in parallel with each other and ensuring that the fingertips touched each other. To increase the energy level of the group, a rhythmic beat was added to the clapping in the form of 1-2, 1-2-3. While this was being sung a rhythm was tapped out on the floor by moving the feet up and down. Eye contact was constantly maintained with the participants. In the second phase, deep breathing exercises were performed. Participants were encouraged to inhale from the diaphragm. Individuals were asked to put their hands on their belly and inhale through the nose and then slowly exhale through the mouth. After the deep breathing exercise, the participants were encouraged to laugh through playing children's games in the third phase.

Blood samples were taken from all individuals who participated in the study, through their AVF fistulas by using 3.5 mL gel-based tubes and following antiseptic rules. Blood samples which were fully coagulated were centrifuged at 1500xg for 10 minutes and serums were obtained. The serum samples were separated into portions and kept at -80 °C until the analysis.

The patients were asked to mark their level of pain during relaxation or activities on a 10 cm vertical or horizontal line. In addition, there were forms which were numbered from 1-10 or from 1-100. The number 0 is found at the beginning of the line, and the number 10 is located at the end of the line. A value of 0 shows that there is no pain, and the value 10 expresses unendurable pain. GAS is a common scale in the assessment of pain level. A patient is asked to mark the perceived pain on this line, and the marked point is measured in cm

The PSQI is a valid and consistent survey comprising of 19 questions to assess quality and amount of sleep and the existence of a sleep disorder and its level in the previous month. The scale was adapted into the Turkish language by Agargün et al. (1996). The scale consists of seven components that assess patients subjective sleep quality, sleep delay, use of sleeping medication and disfunction in daily activities. Each item scores in the range 0-3 points and the total score of the seven components gives the total PSQI score. The total score has a value between 0-21 and a high total score demonstrates a poor quality of sleep. A total PSQI score which is ≤5 indicates "good sleep", and a score which is >5 indicates "poor sleep"