The study was conducted in accordance with the Declaration of Helsinki and was approved by the Institutional Review Board (IRB) at The Ohio State University in Columbus, Ohio, United States (2023C0182, 2023C0142). All participants provided written informed consent prior to enrollment in the SyMPLER pilot study and verbal informed consent prior to being interviewed. Research staff informed participants that they could withdraw from the study, refrain from answering any question, or stop an interview at any time without penalty. Research staff deidentified all data prior to coding and analysis. Participants received a US $25 gift card after each interview.

Research staff recruited interviewees from among participants enrolled in the SyMPLER pilot study (NCT06396598), a prospective single-arm feasibility study of the SyMPLER digital health intervention in patients with lung cancer. Lung cancer was chosen as the target of SyMPLER due to its high symptom burden across all cancer stages during the first 6 months after diagnosis [3]. The SyMPLER pilot study included adults (aged 18 years or older) with any stage thoracic malignancy (non–small cell lung cancer, small cell lung cancer, mesothelioma, or thymic carcinoma) who were within 12 weeks of their first outpatient oncology appointment at the Ohio State University Comprehensive Cancer Center. Inclusion criteria for the SyMPLER pilot study required participants to have access to a smartphone device, speak and read English, and not have been referred to outpatient palliative care prior to study enrollment. Of patients screened for the SyMPLER pilot study, >99% had access to a smartphone device. Research staff approached all screen-eligible patients for participation in the SyMPLER parent study at this National Cancer Institute Comprehensive Cancer Center.

After pilot study enrollment, research staff approached SyMPLER participants via email inviting them to participate in qualitative interviews upon meeting one of the following eligibility criteria: 3 instances of using the study app for symptom reporting or 3 months after enrollment in the SyMPLER pilot study. Reflective of other cancer SMPs reported in the literature [21,31,32], the SyMPLER pilot study defined feasible patient engagement a priori as an average of ≥1 app use per month. Using this definition, interview participants were purposively recruited [33] based on high (≥3 app uses) vs low (<3 app uses) engagement with symptom reporting during the first 3 months of SyMPLER enrollment. No additional eligibility criteria were required for participation in qualitative interviews. Research staff contacted potential participants up to 3 times via telephone to invite them to participate in interviews. For those willing to participate, verbal consent was obtained at the beginning of each interview. Recruitment for interviews ended when thematic saturation was achieved in both high and low engagement groups [34].

The research team developed a semistructured interview guide to explore participants’ perspectives on overall feasibility and acceptability of the SyMPLER intervention, helpfulness and challenges of each component, and suggestions for improvement. The interview guide was developed using a pragmatic qualitative inquiry approach [35,36] to specifically answer the research question of whether the SyMPLER intervention, and each of its component parts, was feasible and acceptable to patients with lung cancer for symptom reporting outside the health care setting. To conceptualize this inquiry, the interview guide included questions related to the 3 domains (person, disease, and environment) and 3 dimensions (symptom experience, management, and outcomes) of symptom management theory [9,10]. The interview guide, annotated by research inquiry (feasibility, acceptability, intervention component, and suggestions for improvement) and aspects of symptom management theory (domain and dimension), is provided in Multimedia Appendix 1.

If a participant requested a palliative care referral or oncology team callback for the first time after their initial interview, research staff contacted the participant to complete a second interview about their experience requesting help through the SyMPLER app. The same interview guide was used for second interviews. Pilot testing of the interview guide was not conducted as the semistructured guide was adapted during use to refine the conversational flow and probe additional details as emerging themes arose during interviews.

Participants’ contact information and demographics were collected per the SyMPLER pilot study protocol. One member of the research team (JLE) conducted telephone interviews using a semistructured interview guide (Multimedia Appendix 1) from May 2024 to May 2025. All interviews were audio recorded, transcribed verbatim, and deidentified prior to data analysis. During this qualitative study, all research team members were blinded to participants’ demographics, cancer diagnoses, and any survey responses, including ESAS-r-CS, collected during the larger SyMPLER pilot study.

Interview transcripts were coded and analyzed using both deductive and inductive thematic analysis [37]. Five members of the research team (JLA, AAG, ASM, LJR, and JLE) initially met to develop a preliminary coding dictionary based on the 8 pragmatic topics addressed in the semistructured interview guide (ie, program feasibility, acceptability, 5 intervention components, and suggestions for improvement). Coding was then completed by a primary coder (AAG) with over 10 years of qualitative coding experience using deductive, dominant thematic analysis [36,37]. The primary coder was supported by a research assistant who also participated in the coding process (AS). These 2 coders met twice weekly throughout the coding process with the senior qualitative researcher (ASM) to discuss the application of codes. Questions about application of the codes were resolved through these group discussions.

The coders (AAG and AS) and senior qualitative researcher (ASM) met twice monthly with the study’s principal investigator (JLA) to discuss ongoing findings and emergent codes characterizing participants’ perceptions of the SyMPLER intervention. These group discussions informed the refinement of code definitions and addition of emergent codes to the coding dictionary. Specifically, new codes emerged as different subthemes developed, and findings suggested the distinction between high-engagement and low-engagement participants. Findings were also discussed monthly by the broader research team, ensuring rigor and trustworthiness [38]. Saturation was reached to the extent that no additional themes were identified in the dataset [39].

The coding and analysis process was supported using ATLAS.ti (version 25.0.1; ATLAS.ti Scientific Software Development GmbH). The final codebook is provided in Multimedia Appendix 2. This work follows the Standards for Reporting Qualitative Research (SRQR; Multimedia Appendix 3; [40]).

Research staff approached 60 participants for semistructured interviews upon meeting one of the eligibility criteria, representing 63.8% (60/94) of those enrolled in the SyMPLER pilot study. Of the 31 who consented to interviews, 21 participants had high engagement with the study app, whereas 10 participants had low engagement prior to being interviewed. Individual interviews lasted a median of 19 (IQR 14.9-24.5; range 2-36) minutes. Figure 3 provides a flow diagram of recruitment, enrollment, and participant-reported reasons for declining to be interviewed.

To answer the research question of whether the SyMPLER intervention and all its components are feasible and acceptable to patients with lung cancer, participant characteristics (Table 1), qualitative themes, and suggestions for improvement are presented by and compared between high-engagement and low-engagement groups. Table 2 provides representative participant quotes listed by qualitative themes and group designation.

All interview participants had a diagnosis of lung cancer and were followed by a thoracic medical oncologist, per eligibility requirements of the SyMPLER pilot study. Most interviewees were female (21/31, 67.7%), White (29/31, 93.5%), married (24/31, 77.4%), and had private health insurance (21/31, 67.7%; Table 1). Compared to the low-engagement group, participants in the high-engagement group tended to be younger (median age: 60 years vs 64 years, IQR 51-67 years vs IQR 58-70 years), have a college degree (8/21, 38.1% vs 1/10, 10% of group), live farther from the thoracic oncology clinic (median distance: 68 miles vs 19.4 miles, IQR 37.2-95.9 miles vs IQR 11.3-52.4 miles), and have metastatic disease at study enrollment (stage 4/extensive: 16/21, 76.2% vs 2/10, 20%). Twenty-six interviewees (83.9%) used the app at least once and were exposed to all components of the SyMPLER intervention. During interviews, 5 (16.1%) participants indicated they had self-referred to palliative care, and 4 (12.3%) noted they had requested a callback from the oncology team via the study app. A total of 2 patients self-referred to palliative care after completing their initial interview, and both agreed to complete a second interview about their experiences with palliative care self-referral through the app.

Participants in both groups shared mostly positive perspectives about the SyMPLER intervention, stating that it was “user friendly,” “easy,” and “fast” (Table 2). Feasibility barriers differed by group, with high-engagement participants forgetting to report symptoms through the app (“I don’t always remember to use it”; Participant 7), while low-engagement participants cited low symptom burden (“don’t really have anything to log”; Participant 28), technology concerns (“I am electronically difficult”; Participant 23), and time constraints (“we just didn’t have time”; Participant 22). Three months after enrolling in the SyMPLER study, one participant requested help from the research staff to teach him how to navigate the app, which improved his ability to report symptoms:

Participants shared their impressions about each component of SyMPLER (Table 2). Participants in both groups reported difficulty remembering details of the online and printed educational materials (component 1) that introduced palliative care upon study enrollment (“I don’t even know what that is. Palliative care.”; Participant 20, high engagement). Some participants in the high-engagement group reported they understood palliative care better after viewing the educational materials (“it completely changed my view”; Participant 17), with some reflecting on their prior exposures to palliative care (“I had several family members that were in it”; Participant 11). While most participants in the low-engagement group had little or no recollection of the educational materials, one participant reported strong emotions after viewing the website about palliative care:

Participants in both groups reported overall positive opinions about the weekly text reminders (component 2), with some participants suggesting customization of the frequency, modality (eg, push notifications), and day/time when reminders were sent. Participants who reported symptoms through the study app (component 3) stated that the symptom survey (ESAS-r-CS [23]) was “simple,” “convenient,” and “pretty straight-forward.” Low-engagement participants cited technology-related concerns (“not being good at touching letters on a cell phone”; Participant 26) as a limitation to completing the ESAS-r-CS questionnaire via an app interface.

Participants endorsed the palliative care self-referral (component 4) as “a real good option,” although only 5 interviewees (3 high engagement; 2 low engagement) responded “yes” to this prompt. Participants in both groups cited tolerable symptom burden (“my symptoms are pretty much the normal for chemo...so, I’ve never had to use it”; Participant 7, high engagement), insufficient knowledge of palliative care (“I always put no because I didn’t understand what it was”; Participant 15, high engagement), and equivalency with hospice care (“more like end-of-life type care is sort of what we had in mind”; Participant 28, low engagement) as reasons for declining a palliative care referral. Participants indicated that palliative care may be beneficial for “other people,” while appreciating direct access via self-referral (“it wasn’t necessarily for me...but I can see the need for it and I thought it was good”; Participant 4, high engagement). One participant described how SyMPLER facilitated her ability to connect with palliative care services:

Participants also noted acceptability of the option to request a callback from their oncology team to discuss symptoms (“real helpful”), although only 4 participants used this option. Several participants voiced a preference for contacting their oncology team via telephone or patient portal (eg, MyChart) connected to the EHR.

Participants in both groups provided feedback on how to improve SyMPLER (Table 2). One participant asked for a “refresher” on the educational materials about palliative care. Participants suggested ways to make SyMPLER “more patient-centric,” such as adding additional free-text fields where patients could describe symptoms “in their own words.” Participants also expressed a desire to view reports or trends of past symptom scores (ESAS-r-CS [23]) to enable them to choose a score based on whether a symptom was better/worse than the previous day/week. To better integrate symptom reporting into their daily lives, participants requested further customization of the frequency (eg, twice weekly or biweekly) and timing (eg, day of the week or time of day) of text reminders delivered to their smartphones. Some participants also suggested that a follow-up reminder could be delivered a few days after the weekly text if they forgot to report symptoms in the app.

Most participants stated that they would recommend SyMPLER to other patients, although their reasons for recommending the program differed by group. While participants in the low-engagement group stated that they would recommend SyMPLER for the purpose of advancing cancer research (“But any help...we could provide for research purposes, I think is, can only be beneficial”; Participant 30), highly engaged participants identified how the program could improve patient care:

In this qualitative study, patients living with lung cancer identified key factors impacting their ability and willingness to use SyMPLER to report and seek help for cancer-related symptoms. By incorporating palliative care self-referral into an SMP, SyMPLER streamlines access to specialty palliative care by allowing patients to initiate a referral at their convenience, rather than waiting for their oncology teams to recognize the presence of uncontrolled symptoms and make a referral. While participants perceived that SyMPLER was helpful for providing direct access to palliative care, they also voiced uncertainty about when and why to request help from a palliative care specialist, thereby limiting use of the self-referral option. Key modifications to the intervention may enhance patient engagement with remote symptom reporting and increase their willingness to seek help for cancer symptom management.

Findings from this study should be considered in the context of symptom management theory, which describes the bidirectional interplay of an individual’s symptom experience (eg, symptom reporting) with symptom management (eg, palliative care referral and oncology team callback), ultimately impacting health outcomes such as HRQOL [9,10]. The relationship between symptom experience and management is an ideal target for intervention development, as multiple studies have demonstrated gaps in patient-clinician communication about cancer symptoms, frequently underestimating patients’ needs for symptom evaluation and treatment [7,8]. For this reason, SyMPLER aims to augment the symptom experience-management linkage by providing patients with an easy-to-use digital interface to report symptoms followed by streamlined options to seek help for uncontrolled symptoms when needed. Through purposive sampling based on level of engagement with the app, this study uniquely compares the perceptions of patients who were highly engaged in symptom reporting with those of patients who had limited use of the SMP. Between-group differences reflect how the 3 domains of symptom management theory—person, disease, and environment—influence participants’ perspectives of how SyMPLER affected their symptom experience, management, and health outcomes during cancer care [9].

Person-level variables (eg, age and education) are intrinsic to how an individual perceives and responds to the symptom experience, management options, and health changes [9]. Person-level variables play an important role in the success of any digital health intervention that relies on the patient’s ability and willingness to repeatedly engage with the technology. While nearly all patients screened for SyMPLER had smartphone access, low-engagement interviewees cited technological barriers affecting their ability to report symptoms via the study app. While smartphone ownership is associated with higher use of internet-based resources [41], disparities in digital health literacy continue to persist even among smartphone users, particularly affecting older adults [42] and individuals with lower income and/or education [43]. To address this digital divide, patients may benefit from educational outreach delivered by nursing staff or lay navigators to increase their understanding and engagement with symptom monitoring outside the health care setting [44]. The benefit of brief outreach was noted by the low-engagement participant who began reporting symptoms after asking study staff to show him how to navigate the study app. While this qualitative study was not powered to detect between-group differences in participant demographics, high-engagement interviewees tended to be younger, with a higher proportion having a college degree compared with low-engagement interviewees. Differences in person-level variables between high-engagement and low-engagement participants, if detected in the larger SyMPLER pilot study, could provide valuable information on which patients may benefit from brief educational outreach to improve engagement with symptom reporting.

Disease-level variables (eg, diagnosis and symptom burden) influence the duration, fluctuation, and trajectory of the symptom experience as well as the selection of management options that can most effectively improve symptom-related outcomes. In lung cancer, higher stage disease portends higher symptom burden [3]. This is reflected in low-engagement participants, a much lower proportion of whom had metastatic disease compared to the high-engagement group, reporting low symptom burden as a barrier to using SyMPLER for symptom reporting. While several studies have described clinical decline from metastatic disease as a barrier to completing symptom surveys [15,21], other studies report low symptom burden as a barrier to SMP engagement [45,46]. Findings from this qualitative study add credence to the paradox that patients living with cancer must feel well enough, yet not too well, to engage with an SMP. Participants in this study offered suggestions, such as the ability to view past survey responses and visualize trends in symptom scores, as potential strategies to overcome this paradox and improve long-term engagement with an SMP.

Most participants across both groups shared positive views of weekly text messages—a type of environmental cue—reminding them to report symptoms via SyMPLER. Reminders, typically delivered via SMS text or push notification to a smartphone device, are instrumental in promoting patient engagement with remote symptom monitoring [15]. Beyond SMPs, text reminders increase patient completion of health-related tasks, including cancer screenings [47], vaccinations [48], and medical appointments [49]. In SyMPLER, interviewees noted acceptance of text reminders, suggesting the cues were helpful in reminding them to complete a potentially ignorable task (eg, logging symptoms). In addition, participants described the need to customize the day and time at which text reminders are delivered to better integrate symptom reporting with the competing demands of patients’ daily lives (eg, returning to work [50]). Participants also suggested follow-up reminders, delivered when a task remains incomplete, as another strategy to encourage habitual symptom reporting in future iterations of SyMPLER.

Regarding palliative care self-referral, participants’ comments suggested a more complex picture framed by person, disease, and environmental domains. This complexity is particularly evident as most participants voiced support for palliative care self-referral while few actually used it; this may demonstrate a disconnect between perceived acceptability and real-world uptake. First, person-level variables (eg, education level) may have contributed to a participant’s ability to recall details about the educational materials introducing palliative care at study enrollment. While a single viewing of online educational materials may improve patients’ knowledge of and receptivity to palliative care [51], education alone is not enough to empower most patients to request palliative care for symptom management [52].

Second, while disease-level variables (eg, cancer stage) often drive symptom burden [3], participants were prompted to consider palliative care self-referral each time they reported symptoms via SyMPLER, regardless of symptom severity. While this enabled participants to request palliative care at any time and for any reason, participants voiced uncertainty about when or why to self-refer—an internal struggle also reported by clinicians when deciding whether to refer patients to specialty palliative care [53]. Future addition of symptom-triggered prompts when survey scores increase or exceed predefined thresholds, accompanied by “just-in-time” education about palliative care, may better inform patients when to seek help from palliative care for symptom management.

Finally, findings from this study showed how environmental variables, such as exposure to palliative and/or hospice care used by family and friends, framed participants’ perspectives about palliative care self-referral. While most participants across groups reported acceptance of SyMPLER’s palliative care self-referral option, several described palliative care as a service needed for “other people,” with 1 participant feeling emotionally triggered by the idea of palliative care, equating it to end-of-life care. These perspectives highlight the need for ongoing outreach efforts to normalize the concept of and educate patients about palliative care as an evidence-based intervention known to improve symptoms and HRQOL concurrent with cancer care [19].

This study has several limitations. First, we only interviewed participants exposed to the SyMPLER intervention. We may have obtained more diverse perspectives on remote symptom monitoring, particularly regarding technological barriers, if we had interviewed patients who declined SyMPLER enrollment due to technological concerns or lack of interest. While smartphone access was not a limitation among patients screened for SyMPLER, digital literacy may have contributed to app engagement, but this was not measured. Second, few interviewees opted for a palliative care self-referral, which limited our ability to ascertain why patients seek palliative care and whether these reasons fit within the current referral criteria recommended by consensus guidelines. As this was a qualitative study, no survey measures of symptom burden were collected at the time of interviews, although several participants reflected on how their symptoms, or lack thereof, contributed to their use of SyMPLER. Third, SyMPLER was piloted only among patients with lung cancer, which suggests opportunities to consider the impacts in other cancer populations. Although our study population lacks racial and ethnic diversity, it is well represented across education levels, insurance payer sources, and residential proximity to the cancer center. Females are overrepresented, which echoes a higher proportion of women enrolled in the SyMPLER pilot study. Finally, participant characteristics in each group differed by age, education, and cancer stage, which may have influenced patients’ engagement with SyMPLER, independent of their symptom burden.

In this qualitative study, participants offered rich perspectives on the feasibility and acceptability of SyMPLER that differed by their level of engagement with the digital SMP. Most participants noted acceptance of the option to self-refer to palliative care, although feasibility was limited by low uptake of palliative care self-referral. Like clinicians, patients struggle with when and why to consult with a palliative care specialist, suggesting a need for stronger guidance on the optimal timing for palliative care consultation during a patient’s disease course.