This study is an observational, single-arm and national single-center pilot study, performed at the University Hospital Muenster, Germany.
Every participant got a one-time intervention of VR and were followed up for one hour.
The study took place at the University Hospital Muenster, an urban, tertial care hospital with a relatively large catchment area. The study population consisted of patients, who got treatment by the PCCS of the University Hospital Muenster. Information, informed consent, questionnaires and VR-sessions as the post interventional questionnaires were offered and answered in the patient rooms. During the VR intervention, patients were lying in their bed or sitting on a chair, adapted to their personal preferences and physical conditions. Patients were observed during the session and half an hour post-interventional by a medical student. On the same day or one day after the VR intervention a team member of the PCCS collected the VR-questionnaire. After involvement of the palliative care treatment every patient was seen by the PCCS until hospital discharge. The screening was performed by the physicians of PCCS team, supported by nurses specialized in palliative care.
Due to the study design no further follow up was done. The recruitment period started in September 2018 and patient enrollment was completed in May 2019.
Informed consent was obtained from all patients. The study protocol conformed to the ethical guidelines of the 1975 Declaration of Helsinki and was a priori approved by the local ethics committee of the University of Muenster (2018-168-f-s). In addition, the study was registered (ClinicalTrials.gov Identifier: NCT03698526).
The feasibility trial includes data from 45 patients with advanced life-limiting and progressive diseases. 90% were suffering from a progressive malignant disease (Table 1). Besides one patient, all participants got inpatient treatment at the University Hospital Muenster with involvement of the palliative care consult service. The main complexity was to coordinate patient-screening by the outpatient palliative care service and visits due to scheduling conflicts.
The palliative care team screened their patients for following inclusion criteria: a minimum age of 18 years, progressive life-limiting disease with need for palliative care and the possibility to understand information and give written consent in the case of agreement. We excluded patients, who could not consent, with hearing or visual impairment and - because there is a very small supposed risk of VR-induced seizures - patients with brain tumors, brain metastases or seizures in history. People, which suffered from claustrophobia or vertigo attacks were also excluded as well. This was due to manufacturer’s information that using the device can potentially result in discomfort in people prone to motion sickness.
The primary outcome was self-reported pain intensity measured by a visual analogue scale (VAS). The patients marked their pain intensity on a horizontal line, 100 mm in length, ranging between “no pain” (0 mm) and “very strong pain” (100 mm).
Pre- and postinterventional, patients reported their currently pain level. The immediate postinterventional questionnaire referred particularly to the pain during the treatment. The following questions addressed the pain intensity after the VR intervention. Each participant was also required to give a marking line one hour after the end of the treatment. To analyze the VAS-scores, the given value was measured in millimeter and converted to centimeters with one decimal place (e.g. if the line was set at 52mm it corresponds to a value of 5.2).
In addition, patient characteristics and procedural data were collected pre- and postinterventional.
Furthermore, to evaluate a potential difference between pain perception before and after the VR session, the PAIN OUT questionnaire was completed by the participants pre- and postinterventional. Normally used for patients satisfaction with their post-operative pain treatment, we focused on evaluation of different entries. Beside questions about acute pain the PAIN OUT questionnaire includes queries relating to presence and duration of chronic pain. Core element is the International Pain Outcomes Questionnaire (IPO), which is mainly using 11-point (0-10) numeric rating scales and binary items. If patients were in too much pain, to ill or not able to fill in the questionnaire, they were interviewed. Standard practice was the self-completion.
To measure the health-related quality of life (HRQoL), we used the EQ-5D-5L questionnaire in German.
Intervention / VR technique
We chose the Samsung Gear VR and PICO G2 4K VR offered by AppliedVR (AppliedVR, 16760 Stagg St Unit 216, Van Nuys, CA 91406, USA, https://www.appliedvr.io/). It has been explicitly developed for medical handling and had been applicable for the clinical use before (e.g. [21, 22, 29]. The first device contains of a head-mounted display (HMD), which can be connected to a Samsung Galaxy S7. In the second one the display is directly integrated (Figure 1). Motion sensors allow controlling the device via head movements. A virtual symbol appears to select between different modules and menu items.
To ensure hygienic cleanliness we sanitized the device before and after each use as well as the head- and mobile phone. In case of isolated patients, the foam cushioning was changed. The app offers several immersive, 360-degree videos to relax, distract or escape – according to the personal wishes and individual needs of the patient.
The user can select between several videos und four games (Bear Blast, Shape your Path, Feeding Frenzy and Germ Buster). The other videos can be roughly separated in the categories travel (Iceland and London), relaxation (some different beaches and lonely places with features to add on, Tibetan singing bowls, meditation) and animals (Dolphins Healing, Seal Hospital, Wild West, Farm Sanctuary).
To assess the health-related quality of life patients completed the EQ-5D-5L health questionnaire. This procedure took place at the same day as the VR intervention. Preinterventional patients declared if they were able to understand English, have had any experiences with VR-technology before or had heart about its usage of it in medical settings.
Pre- and postinterventional patients indicated their pain level using the VAS. Following the VR intervention, subjects were requested to record their pain intensity for the points during, immediately after and one hour after the treatment.
Subsequently we investigated side effects like dry eyes, headache, dizziness or drowsiness. Furthermore we queried, if the patient felt happiness or sadness, how they rated the experience on an ordinal scale (1-4, very good, good, satisfactory or bad) and if they wanted to get a VR experience again.
In addition, all participants were asked, if they agreed with other forms, namely the Pain-OUT questionnaire. Developed to measure postoperative pain and give feedback to the treating team, it should be answered before and after the VR intervention. We were interested in the question, if there may will be different feedbacks.
Statistical and qualitative analysis
Descriptive statistics were used to analyze demographic data. We summarized continuous variables mainly by the mean and standard deviation, partially the median if specified. Categorical variables are presented as absolute and relative frequencies.
Tests for normal distribution of pain scores measured by VAS were performed with Kolmogorov-Smirnov and Shapiro-Wilk tests.
Continuous parameters were analyzed using the Wilcoxon-Mann-Whitney-Test. Two-sided p-values of ≤ 0.05 were considered statistically significant.
Statistical analyses were performed using the SPSS Software (IBM Corp. Released 2017. IBM SPSS Statistics for Mac, Version 25.0. Armonk, NY: IBM Corp.) and the SAS Software (Version 9.4, SAS Institute Inc., Cary, NC, USA).