The VR system in this study was designed and developed in accordance with the VR–CORE–VR1 guidelines [20]. Our VR design team was a multidisciplinary team comprising users and technicians. The rehabilitation program was developed in 3 stages. The first stage was based on inspiration gained through empathy. Specifically, interviews were held with 2 patients who were invited to share their rehabilitation experiences and express their perspectives and opinions to facilitate the design of an effective VR-based treatment program. The interview questions in this stage considered (1) smart device use behavior and (2) willingness and acceptability to use VR rehabilitation systems. The second stage involved ideation through team collaboration. Specifically, our team comprised experts in surgery, rehabilitative physicians, and software engineering, as well as a case manager. Innovative ideas were generated through methods such as brainstorming and collective ideation, and the ideas that were most suitable for prototyping were then compiled. The third stage involved prototyping based on user feedback. Specifically, further discussions were held with the aforementioned 2 patients to obtain further information. Our team then built prototypes to test 3 VR rehabilitation exercises prior to implementation (Table 1). Ultimately, we extracted 3 key sets of limb motions that are described as follows. The first motion was a Whac-A-Mole–like game that involved the abduction of the shoulder (no more than 90°). The second motion was wiping a table and involved external forearm rotation. The third motion was combing one’s hair and involved flexion of the shoulder (no more than 90°) (Figures 1-3). This study used the PC-based Oculus Quest 2 head-mounted display (HMD) to provide the most immersive VR experience possible.

This qualitative study was guided by the phenomenological methodology; it focused on investigating the perceived experience of using VR rehabilitation and then used an inductive approach and the Colaizzi [25] interview data analysis method to identify themes from the VR rehabilitation experiences.

Ethical approval for this study was granted by the Human Trials Ethics Committee of Chang Gung Memorial Hospital, Taiwan (202001617A3C501). All the participants provided written informed consent to participate in this study.

This study was conducted at a medical center in Taiwan that receives up to 20 new patients with breast cancer per month.

The criteria for participation in this study were as follows: (1) a new diagnosis of breast cancer and being hospitalized for surgical treatment; (2) being aged 20 to 65 years; (3) being able to read and speak Mandarin Chinese or Taiwanese; (4) being willing to use a wearable VR HMD and having sufficient cognitive ability to understand and follow instructions, as well as to interact with the VR environment; (5) having sufficient physical ability (self-reported) to use the VR equipment in the VR rehabilitation program; and (6) being willing to be interviewed. After surgical treatment for breast cancer, patients were invited to a rehabilitation consultation to ask about their willingness to try VR rehabilitation and were recruited to participate in this study. The recruitment period ran from September to December 2021, with 18 patients interviewed.

First, the participants filled out a questionnaires on demographic data (including age, gender, and type of breast surgery), the Distress Thermometer (DT) questionnaire, and the Chinese Health Questionnaire–12 (CHQ-12). The DT is a visual analog scale for routine screening for distress in all patients with cancer; scores range from 0 (indicating no distress) to 10 (indicating extreme distress). A cutoff score of ≥7 is optimal for distress in patients with a new diagnosis [26]. The CHQ-12 was modified from the General Health Questionnaire–12, a widely used psychometric test for screening mental problems, with a score of ≥4 indicating psychological distress [27].

After completing the questionnaires, a face-to-face interview was conducted with each participant for approximately 30 minutes. Interview guides were developed by the research team, which included an expert in qualitative studies and a clinical nurse specialist in breast cancer. After the content of the first interview was analyzed, the interview questions were discussed and modified with the research team.

During the interview process, the researchers actively listened and continuously clarified any perspectives and meanings that the participants wanted to express. Participants were allowed to freely express their views. All interviews were audiorecorded. After the data analysis, the researchers reviewed the data with the patients to ensure data accuracy and completeness.

According to Kyngäs [28], an inductive approach, which is common in qualitative research, should be used when no prior research has addressed a specific phenomenon or if existing knowledge is fragmented. Because prior studies had not investigated the experiences of patients with breast cancer to evaluate the effectiveness of VR-based rehabilitation, our study used an inductive approach to content analysis, which involved data reduction, data grouping, and, finally, concept formation. The content was analyzed with the Colaizzi [25] phenomenological analysis method, which involves a 7-step procedure for content analysis. Specifically, 3 researchers analyzed the data and grouped them into themes to enhance comprehension. First, the interview transcript was read to obtain an idea of its overall meaning. Second, a researcher extracted significant statements relevant to the purpose of the study. Third, each statement considered meaningful was recorded for accurate representation of the research data. Fourth, the researcher classified significant statements into categories based on their meaning. Fifth, the researcher grouped similar categories together and organized them into themes. Sixth, all themes presented were combined to produce an exhaustive description. Seventh, the results were presented to each participant for feedback and to verify their accuracy.

To enhance the trustworthiness of our study, we referred to the Guba and Lincoln [29] quality criteria of credibility, transferability, dependability, and confirmability.

To establish confidence in the credibility of the findings, triangulation was used to examine the consistency of the data. Researchers presented their summaries of the categories and themes from data analysis and discussed any uncertainty about any category or theme by replaying and reanalyzing the interview recording.

High transferability was ensured through the interview process, including the stability of observations and the interrater reliability. As an interviewer, the researcher was attentive to the interviewees’ experiences and avoided bias arising from their values and beliefs. The interviewer was conscious about avoiding misperceptions about what the interviewees were saying to ensure the stability of observations. There was only 1 interviewer, hence interrater reliability was not measured.

The study had high dependability, as the data collecting procedures were approved by an expert in qualitative methodology, and the themes and subthemes that emerged were consistent among all researchers after the coding and recoding procedure during the data analysis.

Finally, during the data analysis stage, 3 researchers who were not part of the study team confirmed the collected data by distinguishing between the units of the main themes and subthemes to verify the main themes’ theoretical saturation and thus achieved confirmability.

Table 2 shows the participants’ characteristics. The mean age of the participants was 46.66 (SD 8.05) years; 17 participants were female (95%) and 1 was male (5%); 11 were married (61%); 11 (61%) were full-time workers; and 7 (39%) were housekeepers or had no formal employment. Regarding the types of surgery received, 9 participants (50%) underwent mastectomy and sentinel lymph node biopsy, 4 (23%) underwent mastectomy and axillary lymph node dissection, 2 (11%) underwent mastectomy and reconstruction, and 3 (16%) underwent modified radical mastectomy. All participants had DT scores less than 7, indicating no distress. In the CHQ-12 items, some participants reported having shaking or numbness of limbs (n=3, 17%), losing a great deal of sleep because of worry (n=4, 22%), and losing confidence in themselves (n=4, 22%) (items 4, 5, and 8). However, all participants had CHQ-12 scores less than 4, indicating no mental problems. Finally, 7 (39%) and 11 (61%) of the participants reported moderate (4-6) and mild (1-3) wound pain on the Numeric Rating Scale for Pain, respectively.

The following 3 themes were inductively extracted from the interview data: (1) VR was powerful in facilitating rehabilitation, (2) early and repetitive upper limb movements were an advantage of VR rehabilitation, and (3) extensive VR use had challenges to be overcome. Tables 3-5 present these themes in greater detail alongside their subthemes and interviewee statements.

To the best of our knowledge, this study is the first phenomenological study to investigate the feasibility of an immersive VR experience for facilitating postoperative rehabilitation in patients with breast cancer. Through inductive thematic analysis, our study found VR to be an effective and suitable intervention for our patient population. Tables 3 and 4 address feasibility in relation to 2 of the 3 inductive themes of this study: “VR was powerful in facilitating rehabilitation” and “early and repetitive upper limb movements are an advantage of VR rehabilitation.” Table 5 reveals the key finding that the high costs of VR hardware and software limit its at-home use. These results further support the recommendations of the VR CORE group [20]. However, the high cost of VR equipment remains a concern.

This study found that “power” was an essential concept and that power was cultivated through knowledge and companionship. One key finding related to this inductive theme was the knowledge obtained by the individual. In our study, most of the participants were skeptical about their early postoperative rehabilitation, and some had no idea how to proceed with it; however, through VR, these patients gained information about rehabilitation, which then led to behavioral changes. A previous study noted the importance of people’s need to know which approach they should adopt to improve their health [30]. In addition, most patients with breast cancer desire information concerning recovery details; in particular, they want real-time, transparent information regarding appropriate rehabilitative measures [21]. Our findings were consistent with those of the 2 aforementioned studies. Another present finding was related to companionship; specifically, the participants reported that they felt as if a medical care team was with them in their rehabilitation in the VR world. This finding is notable because not every patient with breast cancer receives a rehabilitation exercise consultation after surgery. Our interactive VR system provides clear information regarding the commencement and completion of rehabilitation exercises, and its prompts align with how the clinical rehabilitation program operates (eg, 20 prompts for each motion). The literature notes that an ideal user experience must include interaction with VR applications in order to encourage and support users to complete clinical activities; this assertion is consistent with our findings [31].

VR elicited engagement in early postoperative rehabilitation in most of this study’s patients, seemingly stemming from their reduced fear of movement and their enhanced motivation. Early postoperative rehabilitation in patients who have undergone breast cancer surgery aims to improve shoulder mobility, arm mobility, or both. VR is believed to be as effective as conventional physiotherapy in improving upper limb function to facilitate the maintenance of activities of daily living [32]. Some of the participants in this study were initially apprehensive to undertake postoperative rehabilitation primarily because of fear related to insufficient knowledge of the appropriate degree of movement. Nevertheless, our VR rehabilitation system was based on the concept of gamification; the participants who used the system were attracted to the game screen, and consequently, their negative feelings—including fear, pain, and discomfort—were temporarily alleviated. In this manner, the VR system considerably enhanced the participants’ motivation to engage in rehabilitation; this finding was consistent with those of previous studies [18,33]. In addition, the game design can be adjusted according to the needs of the patient to prevent patients from giving up on movements that are either difficult or so simple that the desired training outcomes cannot be achieved by performing them.

The participants in this study were required to wear HMDs; thus, they could not see their surroundings during rehabilitation. Related studies that have recommended VR have stated that when using such technology, a space of at least 70 cm × 70 cm is required; however, in our study, the participants took a seated position to minimize the risk of tripping and thus needed only to pay attention to whether the seat back was affecting exercise safety. Although research has shown that the cost of HMDs has fallen in recent years [15], VR devices remain unaffordable for many people in Taiwan. Therefore, even if patients with breast cancer are interested in using this emerging technology for rehabilitation, doing so without an HMD is difficult. In addition, the development and maintenance costs of VR software and hardware are high, and thus, the cost of VR equipment remains a challenge for large-scale implementation in postoperative rehabilitation.

Motion sickness (MS) is a common physiological response to VR immersion [34]. Previous studies have shown that behavioral and dietary strategies and physical therapy, such as listening to music or chewing gum [35], are effective in alleviating MS symptoms. Although each movement in our VR rehabilitation system was accompanied by music with a brisk tempo, 3 of the patients in this study still experienced MS due to unsuitable seat height. A previous study demonstrated that positive emotions can relieve MS [36]; we found that most patients have positive emotions while using VR for rehabilitation. Accordingly, this paper suggests that the use of VR should be combined with emotional assessments to effectively prevent MS. With regard to feasibility, we found that the present VR system met the patients’ needs, conformed to their values, and satisfied their expectations. The system also provided an engaging and interactive rehabilitation environment that stimulated the patients’ motivation to engage in early and continuous rehabilitation and, in turn, reduced their risk of developing defensive functional impairments. Nevertheless, the accessibility of VR proved to be a challenge because of the difficulty of using VR technology at home. Thus, such interventions may tend to be limited to in-hospital use because not every patient can afford to purchase VR equipment and software.

This study has some limitations. First, we did not conduct a pilot study of the interview guide. However, after the content of the first interview was analyzed, the interview questions were discussed and modified with the research team to identify and address any potential issues in the data collection methods. It may be recommended to incorporate a pilot study in future research to ensure validity and robustness. Second, the development of VR technology to facilitate postoperative rehabilitation in patients with breast cancer is still in its infancy. In this study, only 3 rehabilitation exercises were developed and clinically tested. The facilitators of and barriers to rehabilitation were investigated. To determine the clinical efficacy of the proposed VR system, a large-scale randomized controlled trial is needed.

Feasibility research related to health care is crucial for generating novel ideas and improvements to provide more effective care for patients. From the perspective of this study, rehabilitation is an iterative, active, and educational process of problem-solving that must focus on a patient’s behavior. VR technology was effective in facilitating rehabilitation by providing knowledge and companionship to participants. It helped reduce fear of movement and enabled early and repetitive upper limb movements. However, safety concerns, high equipment costs, and potential side effects like MS were reported as challenges to extensive VR use.