Trial design
This was a single-center, randomized, controlled trial on the efficacy of VR on anxiety levels in patients candidates for coronary artery angiography. The CONSORT guidelines and the checklist was used for reporting this trial and the description of the interventions. The study contained one intervention and a control group and followed a pretest–posttest design. Each group consisted of 40 patients.
Study setting
The study was conducted at the school of nursing and midwifery, Guilan University of Medical Sciences, Rasht, Iran. Patients were enrolled from April to July 2019 in Heshmat hospital that is the central cardiac hospital at Guilan University of Medical Sciences.
Participants
Patients candidates for diagnostic coronary artery angiography through radial artery participated in this study. Eighty participants meeting the inclusion criteria were randomly assigned to one of two groups intervention (VR) and control. The participants were recruited through the angiography department in the Heshmat Cardiac Disease Hospital that was an outpatient setting. Inclusion criteria included the tendency to participate in the study, the first experience of angiography, patients without a history of neurological impairment (such as motor, visual and auditory disabilities), psychological disorders, and taking sedatives. Patients receiving psychological drugs were not included in the study. Also, the candidates were excluded if they had suffered from an inability to tolerate the virtual reality and the occurrence of anxiety symptoms such as fear of closed space. The eligible patients were identified and informed about the study objectives. After giving their preliminary informed written consent to participating in the study, the candidates were offered detailed information and had the opportunity to ask the questions of the study instrument.
Instruments
To collect the data, a personal information form and the short form of Spielberger’s situational anxiety questionnaire were used.
Personal information form
The Personal Information Form included two parts. The first part was demographic characteristics included seven questions: patient's age, gender, marital status, educational level, job title, life place, and having an experience of virtual reality. The second part included clinical indices of blood pressure, respiratory rate, and heart rate.
Short form of Spielberger state-trait anxiety inventory (STAI)
The short form of Spielberger State-Trait Anxiety Inventory (STAI) was used to measure the level of anxiety before and after angiography [24]. This Inventory is a tool used to determine the level of state-trait anxiety and included 6-items. The STAI assesses what is felt at the time of measurement. The scoring of this scale is on a four-point Likert as follows: (1) very low, (2) low, (3) high (4) very high. The range of anxiety scores is between 6 and 20. A higher score indicates greater anxiety. In the current study, Cronbach's alpha coefficient of the scale was found to be 0.80 for pre-angiography and 0.82 for post-angiography.
Sample size
Sample size calculation was based on the anxiety scores in a similar study [25]. In the study, the mean and standard deviation of anxiety score in the intervention and control group were, respectively, 9.70 ± 3.75 and 11.43 ± 4.51. Considering an alpha of 0.05, a power of 90%, β = 0.10 and d = 3, sample size was 40 patients per group; a total of 80 participants.
Randomization method and allocation concealment
Each patient scheduled for angiography who meets our inclusion criteria was asked to participate in the study. Then the participants were asked to fill out the demographic questionnaire. We recorded the number of patients who refused to participate in the study (Fig. 1).
Participants were randomly assigned to one of the two groups of intervention (VR) or control (no intervention). Randomization was carried out using the block method. Blocks of four were used to maintain proportional allocation between the experimental and the control group throughout the study. The randomization list was created using specific software: whoever assigned the participants to the experimental and/or control groups did not take part in the creation of the randomization list and wasn’t aware of its contents. For the randomization and assigning of the participants to the experimental and control groups, we used opaque envelopes. The envelopes were only opened by the nurse carrying out the intervention, after receiving consent from the participants involved in the study.
Intervention and procedure
Sixty candidates for coronary artery angiography from the cardiac center of Heshmat hospital in Rasht city (A northern city in Iran) took part in this study in two intervention and control groups (30 participants in each group). First, the participants were assessed in terms of the eligibility criteria. Next, the participants were instructed to study objectives and informed consent was obtained. 10 min before the start of coronary artery angiography, the first pre-intervention assessment was carried out. The anxiety level of the participants using STAI as well as their vital signs including; heart rate, respiratory rate, and blood pressure were measured as objective measures of anxiety immediately before the intervention in the two study groups. Blood pressure was measured using an Easy Life hand-held sphygmomanometer in a supine, right-hand position. Heart rate and respiration rate were measured with a digital watch made by CASIO. Then the intervention was done for the participants in the intervention group.
Before the start of the angiography, the subjects viewed a 5-min natural scene that was filmed at various natural locations and landscapes such as the beach, mountains, waterfalls, rivers with pleasant sounds by a VR camera. The sounds included soft music, birdsong, and waterfall sounds. A virtual reality video headset made by Remix company which had the ability to change the 360-degree angle of view at the same time as changing the position of the patient's head was used for playing VR video. Also, a Huawei mobile phone and a headphone were used to play the distraction music concurrent with virtual reality film play-back. At the end of the 5-min VR session, subjects were asked to fill out the STAI again and the vital signs were assessed for the second time. The intervention was done only in the intervention group in a private silent room. No intervention and placebo were used for patients of the control group. They completed the study questionnaire at similar times as the intervention group.
Data analysis
Data were analyzed using SPSS version 24.0 software (SPSS Inc.). Chi-square test was used to assess demographic differences between the two groups. Paired samples and independent sample t tests were used to compare the level of state anxiety. The statistical significance was set to 0.05.
Ethical consideration
This study was approved by the Ethics Committee of Guilan University of Medical Sciences, Rasht, Iran, with the ethical code of IR.GUMS.REC.1397.369. In addition, the study was registered in the Iranian Registry of Clinical Trials with the code of IRCT20140515017693N3. Written informed consent forms were signed by all participants as well as the aim of the study was described to all participants. Moreover, they were ensured that the study was voluntary and they could withdraw from the study at any time.