This randomized controlled study was included 5-to 10-year-old boys who were referred to a pediatric hospital in Turkey for circumcision between June and September 2019. The sample size for the study was calculated using the G-Power 3.0.10 program and t-test for comparison of two independent groups with an effect size of 0.8, an alpha level and margin of error of 0.05, and a power of 95%. The sample size was determined to be 70; each of the experimental and control groups included 35 children. Data were collected from 98 children. Of them, 14 children were excluded from the study because two could not obtain approval from their families to participate in the study, four had previous surgical interventions, six had chronic and mental illnesses, and two had vision problems. The inclusion criteria for the study were agreement to participation in the study, age between 4 and 10 years, no vision or hearing problems, no history of surgical intervention, and no chronic and mental health problems. Children who met the inclusion criteria and who had written and verbal consents from their parents for participation in the study were divided into 2 groups. The experimental group consisted of 40 children who received a VR application, and the control group consisted of 38 children who received standard healthcare. A randomized block design method was used to randomize the participants to the groups. The randomization list was prepared by a third person and was given to the investigator only during the application.

Instruments The data were collected using a participant information form to obtain details about baseline characteristics; children's fear scale (CFS) and children's anxiety meter scale (CAM-S) were used to evaluate fear and anxiety in children during both the pre- and postoperative periods, and the Wong-Baker faces pain rating scale (WBS) was used to evaluate the levels of postoperative pain in children. A white colored "VR BOX 3.0" with VR glasses (a headset with a screen covering the children's eyes) was used in this study. It was compatible with iOS and Android operating systems and 4-6-inch screen smartphones. The VR device, which is activated through applications installed on smartphones, divides the image into two equal windows, providing the necessary viewfinder range for panoramic view. The distance between the mobile phone and the lens can be adjusted for each user. The VR glasses do not require any power or electrical connection, except the mobile phone, during their use. The weight of the VR glasses is 0.414 kg. Soundproof headsets are used to provide immersive VR.

Procedure Sociodemographic data of the children and their mothers were collected using the participant information form. Then, the children rated their fear and anxiety on the scales using a pen. Similar assessments were performed by their mothers and the investigator. The investigator explained the use of VR glasses to the children in the VR group. The investigator selected two VR programs to be watched by the children. In the VR program named Amazon, the child perceives himself to be walking among the trees in the Amazon forests. The other VR program gives the child a feeling of water skiing. Before commencement of the study, the VR applications were administered to five children aged between five and ten years, and these children shared no negative feedback about the VR programs. Before the surgery, the children were allowed to watch the VR program of their choice, the average duration of which was 4.5 minutes, using the VR glasses. Parts of the device that come in contact with the children's faces were cleaned before each application. After the surgery, the children, their mothers, and the investigator re-evaluated the fear and anxiety in children using the CFS and the CAM-S. The pain levels in children during the postoperative period were evaluated by both their mothers and the nurse. The same evaluations were performed in children in the control group who received routine clinical care.