Our sample included 10 patient-caregiver dyads (N=20) who had completed participation in a clinical trial (NCT03948100). The parent randomized controlled trial examined the efficacy of an instructor-led yoga intervention compared to a psychoeducation intervention for patient-caregiver dyads [11]. The yoga and education sessions were delivered initially in person at the hospital and then remotely via Zoom (Zoom Communications Inc) after the onset of the COVID-19 pandemic. Eligibility criteria for the parent trial included patients who were diagnosed with non–small cell lung or esophageal cancer, were undergoing at least 4 weeks of radiation therapy, had an Eastern Cooperative Oncology Group (ECOG) performance status of ≤2, and had a family caregiver willing to participate in the study. Both patients and caregivers had to be aged ≥18 years, proficient in written and spoken English, able to provide informed consent, and have access to the internet. Patients who practiced yoga within the year of diagnosis were excluded. The research team had the capability to offer loaner devices; however, all participants had access to a computer, smartphone, or tablet. After participants had completed all trial-related procedures, we invited 5 consecutive dyads from the yoga group and 5 consecutive dyads from the education group to participate in structured interviews. The interviewing of participants from both study conditions served the purpose of including the perspectives from patients and caregivers who had different levels of yoga experience in the development of the prototype for a mobile yoga app.

We recontacted participants who had completed the aforementioned parent trial by telephone, informed them that the purpose of the recontact was to seek their participation in an optional interview to provide feedback on the development of a prototype of a mobile yoga app for patients with thoracic cancers and their family members. After providing verbal informed consent, patients and caregivers completed individual, structured interviews via videoconference (Zoom), which lasted approximately 30 to 45 minutes.

During the interview, participants were asked to describe their current mobile app use. Then, using the shared screen option in Zoom, we presented participants with different mock-ups, wireframes, and yoga video samples to gather their feedback about app content, instruction preferences, and functional features. In addition to open-ended questions (eg, “Describe any suggestions to improve this screen”), we mainly included Likert scale items ranging from “not important” to “very important” to solicit specific feedback on content and features. The interview guide was developed specifically for the purpose of this study to inform design decisions. The mock-ups, along with the interview guide, can be found in Multimedia Appendix 1.

All interview recordings and field notes (capturing the date, time, interviewers, participant, and context) were professionally transcribed. Recordings and transcripts were stored on an institutional server. We used content analysis to analyze the interview transcripts. Participants’ demographic and clinical information was provided during the baseline assessment of the parent trial. The sample size of 10 dyads (ie, 20 individual interviews) was determined based on prior methodological research suggesting that saturation is typically achieved within 12 to 20 interviews in relatively homogeneous samples [22].

Two yoga therapists (RFS and NP) who were trained by a qualitative methods expert (MW) conducted the interviews. Training included the completion of 3 recorded mock interviews that the research team viewed and approved. Following the interview guide (Multimedia Appendix 1), participants were asked general questions assessing their previous experience with using mobile apps, inquiring if they had any apps on their mobile device or tablet, and which apps they used if they answered “yes.” We asked participants to evaluate features such as daily inspirational quotes, scheduling, and progress monitoring features, and the importance of including an education tab that would highlight how the yoga program can be used to manage symptoms (eg, meditations to reduce sleep disturbances, breathing exercises to help with anxiety, and physical exercises to improve fatigue). We devoted a considerable portion of the interviews to learning about participants’ preferences regarding the app-based yoga instructional videos. We played 4 videos (2 that were 90 seconds and 2 that were 40 seconds in length) in a counterbalanced order and asked questions pertaining to the instruction style. We played the shorter videos to learn about participants’ cueing preference. More specifically, we asked if participants preferred voice-over (ie, a narrator delivering the instructions) vs direct cueing (ie, the instructor speaking directly to the user). The longer yoga videos featured either 3 instructors, each demonstrating a different fitness level (ie, chair-based, intermediate standing, or full expression of the pose), or a single instructor demonstrating the yoga postures at a specific fitness level. We asked participants if the yoga videos included in the app should feature the same instructor or if several instructors should be featured and inquired about preferred instructor characteristics (age, race or ethnicity, sex, and body type). We also solicited feedback regarding the importance of contact with the instructor, such as an initial orientation with a live instructor via Zoom or another remote videoconference software and additional touchpoints throughout the program, as well as the importance of obtaining technical support. Participants rated how important it would be to have those features and indicated their preferences as part of the app design. For sex, age, body type, and race or ethnicity, they were asked to indicate the degree of importance of having a representative instructor with these characteristics, using a scale of “Important,” “Not Important,” and “Neutral.”

The MD Anderson Cancer Center Institutional Review Board (IRB) approved recontacting study participants for the purpose of the current study under a modification for protocol 2018-0503 using verbal informed consent. Participants were informed that the interviews would be audio recorded during the informed consent process, as well as again right before starting the interview. Audio files of the interviews were labeled using study IDs rather than identifying information (eg, medical record numbers or participants’ names). An institutionally vetted transcription service that was compliant with IRB regulatory procedures transcribed the audio files. During the transcription process, any identifying information was redacted. Audio files were shared with the transcription service via a secure server. Quotes were linked to demographic factors via study IDs so participants’ privacy was protected to the best of our ability. Participants received a US $40 gift card for their time.

We computed descriptive statistics to characterize the sample by role (patients and caregivers). Content analysis was used to summarize the recommendations of the participants regarding the app design. Two researchers (KM and OC) initially reviewed and coded the transcripts independently using MAXQDA (VERBI Software GmbH) and then met to discuss the coding scheme. Themes were agreed upon and finalized by the researchers. Finally, we calculated descriptive frequencies for previous app use and the importance of features and content based on the Likert scale items using SPSS (version 32.0; IBM Corp).

Demographic and clinical characteristics of participants are listed in Table 1. All participants indicated that they had previously used a mobile app on their smartphone or tablet.

Analysis of the data revealed insights into 4 key areas beneficial for app development. Participants valued the inclusion of interactive elements: 95% of participants preferred a live initial orientation with a yoga therapist who would conduct an assessment and provide recommendations for the level of practice (eg, “Having someone help someone be more comfortable and ease them into it, I think is always good,” said a female caregiver aged 24 years); 95% desired the yoga instructor’s contact information (“You cannot do away with the human contact. It’s a safety blanket,” said another female patient aged 56 years); and 90% showed interest in periodic check-ins to ensure engagement, with 65% preferring a weekly check-in (eg, “I like the once-a-week idea. Especially when you first start out,” expressed a caregiver aged 61 years; “100%. 100%. Yes, I think regular check-ins are crucial. I like a once-a-week check,” said a female patient aged 55 years).

Participants had varied preferences for the instructional style of the yoga sessions, with 45% favoring direct cueing by the instructor during the practice (eg, “It was easier to follow when she was just talking directly,” said a male patient aged 45 years), 35% of the participants opted for voice-over guidance (ie, narrator style; eg, “the voiceover might be a little bit better for me,” expressed a male patient aged 72 years), and 20% expressed no preference between direct cueing or voice-over guidance. Moreover, 45% preferred 1 video showing different instructors, each demonstrating a different level of practice difficulty (eg, “My husband and I have two different levels. I do the advanced and he do the moderate. We can see at the same time,” explained a female patient aged 56 years; “I think it makes it easier for the patient or the caregiver,” said a female patient aged 64 years), 45% preferred separate videos for each practice level (eg, “I would rather one single point to focus on. It was distracting. They were overlapping,” according to a male patient aged 59 years), and 10% expressed no preference regarding the demonstration of the different practice levels.

For content modules, participants highly favored segmented yoga practices with separate modules demonstrating mindful movements (ie, asanas), breathing exercises (ie, pranayama), and relaxation (ie, meditation; eg, “You may only have 15 minutes. You didn’t have a full hour. Just do the relaxation and your meditation. Practice just the breathing techniques,” said a male patient aged 58 years). They also found it essential to include detailed descriptions for each yoga video, such as the video length and a content breakdown.

Users emphasized a preference for a representative yoga instructor, with 80% of participants prioritizing instructors of various ages (eg, “Someone middle age or older. You wanted someone you can relate to. Someone a little bit more mature,” said a female patient aged 56 years; “I think different ages is nice. Especially if I’m over 60.” Expressed a female caregiver aged 61 years), 60% preferring instructors of various races and ethnicities (eg, “I think it’s more inclusive. People see themselves represented,” said a female caregiver aged 55 years), and 50% indicating a desire for instructors with diverse body types (eg, “I think ages would be really good, especially considering the demographic of the app. If somebody’s obese...that’s encouraging,” explained a female caregiver aged 24 years). Furthermore, 30% thought that the sex of the instructor was important (eg, “If you want the husbands to participate, they probably will want to see how a man actually performs some of the yoga,” said a male patient aged 63 years). Yet others thought that instructor characteristics were not important (eg, “I don’t think any of that matters as long as the person illustrating the technique is able to do it in a way that the observer, the trainee can understand it,” female caregiver aged 66 years).

Although over half (55%) of participants preferred a variety of instructors featured in the videos (“Three different instructors would be good,” said a male patient aged 71 years), others preferred just 1 instructor demonstrating all content (eg, “I would probably think the same instructor. You get used to 1 person or 1 person’s movements,” said a female patient aged 74 years). Additionally, 85% of participants found it important to know the instructor’s professional background, as it personalizes the app experience (eg, “I want to know about my instructor. It adds credibility,” explained a female patient aged 55 years).

Participants identified enhancements that should be included in the development of the app, with 95% of participants recommending session scheduling on a calendar (eg, “Something is scheduled and I’ve committed to it, it’s hard for me to cancel or not show up. It would encourage me to work towards consistency,” said a female caregiver aged 71 years), 95% desired a progress tracker that monitors session attendance (eg, “That way you know more or less how much you’re improving,” said a male patient aged 71 years), 90% wanted to receive practice reminders (eg, “Anything that will help,” said another male patient aged 72 years), and 90% preferred the provision of educational materials on how the yoga program can be used for symptom management (eg, “I think it’s important to know why you’re doing a particular exercise, what benefit to expect from the exercise,” expressed a female caregiver aged 66 years). Finally, 85% of participants wanted daily inspirational messages delivered via the app, with most of them preferring quotes and affirmations as well as participant testimonials (53%; eg, “Participants testimonials by all means. Any kind of motivating, inspiring quote you can get from cancer patients,” said a female patient aged 55 years).