Abstract
Purpose:
Cancer organizations recommend cost-of-care (CoC) information be provided to patients with cancer by their care teams. Little is known about the CoC conversation experiences and preferences of adolescents and young adults (AYAs) with cancer.
Methods:
Eligible participants were 18–39 years old, diagnosed with cancer, and insured. Recruitment occurred at two cancer centers in Utah from October 2019 to March 2020. Data were collected via survey and semistructured telephone interviews, which were recorded and transcribed. Interview questions pertained to willingness, perceived usefulness, and past experiences with CoC conversations with their cancer care team. Interviews were analyzed by applying two rounds of thematic content analysis. Summary statistics were calculated for demographics, health insurance literacy, and financial toxicity.
Results:
Among 24 participants, half were aged 18–25 and half were aged 26–39 at interview and survey, with many currently receiving treatment (62.5%). Four qualitative themes emerged concerning CoC conversations (1) past experiences, (2) willingness, (3) usefulness, and (4) preferred provider. In interviews, most AYAs shared interest in discussing CoC, but previous CoC conversations were infrequent. Most AYAs who had previous CoC conversation experiences brought up the topic themselves. Interview data revealed that preferred individuals to lead CoC conversations were often social workers (25.0%), nurses (20.8%), or oncologists (20.8%), while others wanted any provider knowledgeable in financial matters (20.8%).
Conclusions:
AYA patients are willing to have CoC conversations; however, they infrequently occur. Future work may include interventions that guide clinicians in initiating in-depth CoC discussions with AYAs.
Introduction
Adolescent and young adult (AYA) patients with cancer (diagnosed between the ages of 15 and 39 years) are at high risk for treatment-related financial toxicity.1,2 Financial toxicity represents the combination of financial burdens caused by the cost of cancer treatment and financial distress, which impacts a patient’s well-being and quality of life. 3 In a report commissioned by Teen Cancer America, Parsons et al. found that within the United States both the economic and human costs of cancer for AYAs are significant, with the estimated cost per person over a lifetime at $259,324. 4 Within the AYA age range, multiple financial-related life events can occur such as entering and exiting school, choosing and starting work, creating a family, and building financial independence.5,6 Thus, AYAs with cancer often experience intense financial toxicity due to a lack of resources such as savings, retirement funds, or home equity which older patients with cancer can often access to ease the financial burden of cancer treatment.7,8 Additionally, these experiences of financial burden and unmet needs vary by age, with older AYAs (i.e., those aged 26–39 years) reporting worse financial burden and more unmet needs. 2
Compared to older patients with cancer, AYAs with cancer tend to be uninsured or underinsured (having insurance coverage that is inadequate to manage costs), which can further exacerbate their financial toxicity. 9 Cost-of-care (CoC) conversations between providers and patients, as part of treatment decision-making, are an increasing focus of research to address financial needs. CoC conversations typically include discussions about out-of-pocket expenses insurance coverage for past, present, or potential health care services, and sometimes include information on other financial needs such as transporation, food, or housing costs. 10 Most patients experience no negative feelings talking about costs with a provider and report a preference to speak about finances with individuals from the cancer care team who are dedicated to helping with finances and costs. Patients want cost-related information presented to them with sympathy in a clear, concise manner with concrete solutions.11,12 Currently, limited information is available on CoC conversations, including patient and provider attitudes and/or beliefs and the barriers that prevent these conversations. 13 For the AYA cancer population, little is known about their preferences for or experiences with CoC conversations, despite their increased risk of financial toxicity.
The purpose of this study was to describe past experiences with CoC conversations and preferences for future CoC conversations among AYAs with cancer, as well as to explore potential differences between younger and older AYAs. This information was gathered by a short survey and a semistructured qualitative interview with AYAs in preparation for a larger study on health insurance navigation for this population.14–16 The survey captured demographics, health insurance information, and a validated measure of financial toxicity. The interview script included questions pertaining to AYA experiences with CoC conversations, perceived usefulness of CoC conversations, and CoC conversation preferences. AYAs with cancer on and off treatment were included to represent an inclusive view of CoC conversations and experiences throughout the process of being diagnosed and receiving treatment.
Methods
This project was conducted through the Huntsman Intermountain Adolescent and Young Adult (HIAYA) Cancer Care Program as part of clinical trial NCT04448678. The University of Utah institutional review board approved this study in accordance with the Declaration of Helsinki (IRB_00091443).
Participants and procedures
Eligible participants included English-speaking AYAs with cancer ages 18 years or older at the time of participation who were diagnosed between the ages of 15 and 39 years of age and currently insured. We focused recruitment on participants who received their treatment at HIAYA locations in the greater Salt Lake City Metropolitan area: Huntsman Cancer Institute or at an Intermountain Health location (Primary Children’s Hospital, LDS Hospital, or Intermountain Medical Center). Eligible participants were identified through a chart review of medical records, a patient navigator database, and responses to social media posts for the HIAYA Cancer Care Program. We included patients on-treatment as well as those done with treatment within the past 2 years to capture a range of experiences.
Participants were approached by the study staff to participate in the survey and interview in three different ways: (1) in oncology clinics, (2) through emails or phone calls, or (3) if they expressed interest through the HIAYA Facebook and Instagram accounts, they were then emailed and/or called to confirm eligibility. We purposefully sampled an equal number by age at participation (younger 18–25 years; older 26–39 years) to understand experiences across age due to age-related differences in insurance access in the United States, with dependent insurance coverage available for many AYAs up to age 26 years, and the fact that older AYAs report greater financial issues.2,17
Of the 51 eligible participants, 14 AYAs were unreachable and 5 declined. The five individuals who declined participation had similar characteristics (e.g., age, sex) as those who participated; however, all who declined were currently undergoing cancer treatment; that is, no one off-therapy declined. The remaining 32 engaged in interviews until the point at which data saturation was reached or that information reported in interviews became redundant. 18 Thus, saturation was reached at 24 enrolled participants who completed both the short survey and in-depth qualitative interview (8 eligible/willing participants who did not complete interviews due to saturation being achieved with equal strata of older and younger AYAs). The 8 participants were instead invited to enroll in the next phase of the study. Recruitment occurred between October 2019 and March 2020.
Before participating in the individual interview, AYAs engaged in the informed consent process and took a short survey either online or over the phone with a study staff member. Survey data was collected and stored in an electronic database (REDCap). The semistructured interviews were completed individually over the telephone and were audio recorded and transcribed by an external transcription service. On average, interviews lasted 32 minutes. At the completion of both the survey and interview, participants received one $20 gift card.
Survey items and analysis
The survey included demographics, health insurance information, the health insurance literacy measure (HILM), and the COmprehensive Score for financial Toxicity (COST) measure.19–21 The HILM is a patient-reported validated tool that uses 21 items to assess health insurance literacy and was validated among working-age adults 22–64 years of age. 19 Participants can score from 0 to 84, a higher score indicating higher literacy. The COST measure is a patient-reported 11-item tool (ranges 0–44) that examines aspects of cancer-related financial concerns and gives an overall score that indicates financial toxicity severity, with a lower score indicating worse financial toxicity. While COST was not validated specifically with AYAs, it has been used to measure financial toxicity in this population.2,22 For both the HILM and COST measures, we report mean scores and ranges. Demographics are reported through descriptive statistics.
Interview guide design
The interview guide was developed by a multidisciplinary team of health services researchers, oncologists, and health psychologists to evoke AYA experiences health insurance and financial toxicity, including CoC conversations. CoC questions revolved around prior experiences of CoC conversations, willingness to engage in CoC conversations, CoC conversation preferences, and perceived usefulness of CoC conversations. Qualitative data focused on health insurance and other financial toxicity concepts are reported elsewhere.14,23
Qualitative analysis
An inductive thematic content analysis was used to analyze the data, including two cycles of structured coding in NVivo 11.24–26 First-cycle coding, applied by two members of the research team (K.M.T.B. and A.R.W.), included independent sentence-by-sentence coding on 20% of the interviews to produce a structured coding scheme. First-cycle coding results were then reviewed, discussed, and added to the coding structure by K.M.T.B. and A.R.W. To further improve and refine the structure, an additional 20% of interview transcripts were coded which elicited changes and subsequently produced the final coding scheme. To test intercoder reliability, K.M.T.B. and A.R.W. double-coded an additional 20% of interviews. This double coding resulted in a Kappa statistic of k = 0.88, which exceeds the threshold for high intercoder agreement. 27 K.M.T.B. and A.R.W. then coded all interviews into the finalized coding structure. Once all the transcripts were coded, K.M.T.B. and A.R.W. compared common themes across AYA age groups at participation (i.e., 18–25 vs. 26–39). Age was chosen to stratify due to the growing literature that indicates developmental age has a substantial impact on financial toxicity and unmet needs of AYAs, as well as potential differences due to access to insurance by age.2,17
Results
Of the 24 AYAs who participated, a little more than half were currently receiving cancer treatment at the time of interview (62.5%; Table 1). Slightly over half, 58.3%, of AYAs were female. Age at survey and interview was equally split (50.0%, 18–25 years; 50.0%, 26–39 years). Most were non-Hispanic White (79.1%). Half of the participants were single (50.0%) and 41.6% were married. School and employment changes due to cancer were common; only two (8.3%) individuals reported no change. Almost a third of participants had to quit work or school completely due to their cancer diagnosis (29.2%), while over half of the participants took time (paid or unpaid) off work or school (62.5%). Private health insurance was most common (87.5%); 45.8% reported their parent being the policyholder of their health insurance, 41.7% were their own policyholder, and 12.5% reported their spouse as the policyholder.
Sociodemographic Factors, Health Insurance Literacy, and Financial Toxicity of Adolescent and Young Adult Patients with Cancer (N = 24)
Missing 1.
Percentages add up to more than 100% as participants could select more than one option.
HILM: 21-item measure to assess health insurance and cost literacy. Score can range from 0 to 84, a higher score indicating higher literacy.
COST: 11-item measure to assess financial toxicity. Scores can range from 0 to 44 with a lower score indicating worse financial toxicity.
SD, standard deviation.
The most common sources of ongoing financial support were self-support (37.5%), personal savings (37.5%), spouse or partner support (33.3%), and parental support (37.5%). One-third of participants (33.3%) reported having less than $10,000 to cover living costs during the past year, and a majority (66.6%) reported having less than $40,000 to cover living expenses. The overall mean HILM score was 55.6 (standard deviation [SD]: 10.1, range: 31–75); for younger AYAs (18–25 years) the mean HILM score was 53.9 (SD, 11.1), and for older AYAs (26–39 years) the mean HILM score was 57.3 (SD, 9.1). The mean COST score was 22.7 (SD: 10.9, range: 4–38); for younger AYAs (18–25 years) the mean COST score was 27.0 (SD, 9.3), and for older AYAs (26–39 years) the mean COST score was 18.3 (SD, 11.0).
Four themes emerged regarding CoC conversations: (1) past experiences, (2) willingness, (3) usefulness, and (4) preferred provider. Supplemental quotes for each theme are shown in Table 2. We report on theme differences by age group as relevant.
Adolescent and Young Adult Patients with Cancer Preferences and Experiences with Cost-of-Care Conversations
Past experience with cost-of-care conversations
Nearly a quarter of AYAs reported having a previous CoC conversation. AYAs described CoC conversations occurring at different times including during diagnosis, during treatment, and after treatment concluded. AYAs often described CoC conversations as brief and incomplete (Table 2). For example, one participant said, “They’ve provided the nurse navigator and they’ve talked to us about finances a little bit, but it’s all been very superficial…’” Another participant said, “It’s just kind of like a, ‘You okay? Good.’” AYAs also mentioned that they were pointed to resources, with some being helpful and some not. For helpful resources, a participant said, “I just talked a little bit with [the AYA patient navigator] about different financial things. It has been good to hear about resources that are available.” In contrast, a different AYA said, “I brought [costs] up to my surgeon…and she was like…‘Talk to our financial aid team. We’ll help you.’ And I called their financial aid team and they didn’t really help at all, so I don’t know.” Most participants felt that from their previous experience, starting the CoC conversation was their responsibility as the patient. “I started [the CoC conversation], but it always felt pretty normal, it’s expensive, if like if it’s gonna be a continual pretty expensive thing, I would ask…”
Willingness to have cost-of-care conversations
While few AYAs had engaged in a prior CoC conversation, most participants expressed that they would be willing to talk about costs with someone on their cancer care team: “It’s definitely something I would do” and “Yeah I would. If it was something that I was like ‘This is a big-ticket item…’ you know?” Frequently AYAs expressed that they would be willing, in retrospect, because there were a lot of unknowns they experienced related to costs. However, AYAs did share that CoC conversations should occur in a way that is useful for them specifically. For example, AYAs would be willing to have such conversations if the cancer care team talked about cost in the context of their specific health insurance plan. Further AYAs expressed a need for reassurance that CoC conversations would not impact the quality of the cancer care they received.
For the minority of AYAs who were not willing to have CoC conversations, participants spoke about three distinct reasons. First, discussing costs can be uncomfortable or “hard to talk about.” Second, some preferred a caregiver to participate or lead in the CoC conversations, “My husband actually did it…[he’s] more up front. . . .” The third, as shown in Table 2, was because some participants “just want what works” for their cancer, no matter the cost of the treatment.
Usefulness of discussing costs-of-care with care team
Within the usefulness theme participants described whether a CoC conversation was helpful and/or could be helpful in the future (Table 2). Most AYAs thought CoC conversations would be useful because they felt their cancer care team understood treatment costs and health insurance better than they did. For example, when referring to costs one AYA said, “How much is this? This is gonna be a big deal. This is gonna cost us a lot and we didn’t really know.” Another AYA said, “[Cancer care team members] understand [insurance] really well. Quite often, they’re the ones who are putting the orders in and all that sort of stuff, so they can be very helpful.” One patient even mentioned that CoC conversations could be useful for the cancer care team too, “They want the best care possible for their patients, and they don’t want a patient that is financially strapped because of decisions that were made.”
Participants who questioned the usefulness of CoC conversations were typically not fully financially responsible for their cancer treatment costs and were often part of the younger AYA age group (18–25 years old). Several participants were covered through their parent’s health insurance plan or were young enough that they did not see costs and finances as their responsibility. One participant explained, “I would probably find [CoC conversations] interesting and enlightening but given my position as a child and student in high school, I couldn’t exactly do much about it. . . .”
Preferred provider for cost-of-care conversations
Most AYAs, when asked who they would feel most comfortable discussing costs with, mentioned specific members of their cancer care team who they connected with or trusted. Interview data (not shown in tables) revealed that preferred individuals to lead CoC conversations were often social workers (25.0%), nurses (20.8%), or oncologists (20.8%), while others wanted any provider knowledgeable in financial matters (20.8%). As an example, one participant said, “My surgeon was totally awesome…I wish she was in charge of it.” Most AYAs did not see a specific individual as the sole person to have a CoC conversation with. AYAs mentioned they would prefer to have a CoC conversation with a social worker, nurse, or their oncologist. Overall, AYAs generally just wanted to talk with someone who was knowledgeable about costs, finances, and health insurance (Table 2), just “Somebody who knows what they’re talking about.”
Discussion
With the AYA population being particularly vulnerable to financial toxicity, cancer-related CoC conversations with providers may be vital to addressing out-of-pocket medical costs and reducing the life-long impact of cancer on their finances. 28 To our knowledge, this study is one of the first to investigate the experiences and preferences of AYA patients and survivors having CoC conversations with their cancer care team. Within semistructured interviews, we found that most AYAs have not had these conversations with providers. Many do want CoC conversations, although younger AYAs are less interested due to their financial dependency on parents. AYA participants felt that their cancer care team understood health insurance concepts and procedures more than they themselves do. This understanding, if passed on in a CoC conversation, may help AYAs understand their out-of-pocket costs more readily.
To help cancer care teams develop strategies to support AYAs in discussing costs, we frame our discussion around four questions: why have CoC conversations, who should lead these conversations, what topics should be discussed, and ideas from literature on how to have CoC conversations (Fig. 1). The following paragraphs discuss our findings in relation to and complementing existing literature.

The Why, Who, Topics, and How of Cost-of-Care Conversations with AYAs.
Why have CoC conversations with AYAs?
Research shows that more than one-quarter of Americans have trouble paying for their medical bills, and unfortunately, this is even more common for those with a cancer diagnosis.29–31 Healthcare-related financial distress is associated with a poorer quality of life, lower adherence to treatment and medication, and earlier mortality.3,32–35 The American Society of Clinical Oncology (ASCO), in 2009, released a statement that acknowledged the critical role of oncologists to address out-of-pocket costs with their patients with cancer and that communication about cancer costs is essential in giving high-quality care.
The AYA population with cancer experiences higher material (i.e., debt, out-of-pocket costs, problems paying for care) and behavioral (i.e., difficulty paying for care or cost-related treatment nonadherence) financial hardship than older adults. 36 In our sample, during treatment almost one-third of AYAs reported having to quit either work or school completely, and 62.5% had to take paid or unpaid leave, potentially exacerbating their ability to make a livable income. Indeed, 66.6% of our sample reported having less than $40,000 per year to cover living costs. Our analyses also give us a glimpse of AYAs’ self-reported health insurance literacy (HILM) and their financial stress (COST). AYAs in our sample reported a lower than average HILM score (55.6, SD: 10.1; range: 0–84 with higher scores better) in comparison to the literature (63.5, SD: 12.3), but with a mean COST score (22.7, SD: 10.9; range: 0–44 lower scores better) similar to the COST score validation study (22.2, SD: 11.9).21,37 However, older AYAs in our sample had a mean COST score of 18.3 (SD, 11.0), denoting greater financial toxicity. Thus, as low health insurance literacy has been linked to higher financial burden in other studies, efforts to understand the role that CoC conversations could have in supporting insurance needs among AYAs across age is an important line of future work. 37
From the AYA HOPE Study, financial communication/advice is a commonly identified unmet need for AYAs, and AYAs reported awareness of their own low understanding of the health insurance system. 38 Thus, for providers, (1) having cost conversations with patients with cancer is considered best practice; (2) AYAs with cancer have a unique need for CoC conversations due to high financial burden and low health insurance literacy, and identify that support in this area is an unmet need; and (3) many AYAs are willing and want to have these conversations.
Who do patients want to have cost-of-care conversations with? Who should be included in the cost-of-care conversations?
Our results show that, from the AYA patient perspective, cost conversations do not always need to be between the primary oncologist and the patient. Some AYAs prefer a specific provider they felt close to while others felt that any cancer care team member knowledgeable about insurance and treatment costs would be helpful. 12 With this point of view in mind, it should be stressed that individuals who deliver cost information should have competency in oncology, financial advisement, and patient-centered care to engage in useful CoC conversations, and that different providers could play different CoC roles for patients. 39 For example, when deciding treatment avenues and costs, an AYA’s primary oncologist may need to be present so that high-quality care is prioritized along with consideration of the patient’s financial situation; however, discussions of other costs, such as oncofertility coverage, could be led by a financial or fertility navigator. 40
Throughout our findings, it was clear that most AYA participants believed that they, as the patients, needed to start the CoC conversation or that this topic would not be discussed at all. Participants were unclear about who to approach if they had financial questions. Rather than leave the onus on patients during a stressful time, Henrikson et al. suggested that cancer care teams should be proactive and establish clear team member roles and responsibilities for addressing CoC concerns. Patients should be told by their care teams up front who to contact when they have cost concerns. 41 Additionally, for younger AYAs, involving parents as part of these conversations should be considered due to financial and insurance circumstances.
What topics should be included in cost-of-care conversations?
One important aspect mentioned in our interviews and earlier research was the need for reassurance that having a CoC conversation with a cancer care team member would not affect the quality of their cancer care. 42 For example, among AYA participants hesitant to have cost conversations, many mentioned that they want the best care possible; certain patients may need assurance that their care will not be affected by affordability challenges. 42 Another common topic that emerged with our interviews was a desire to know the price of treatment in conjunction with their health insurance plans (i.e., wanting to know what the out-of-pocket prices will be). More specifically, some AYA participants in our study wanted to know their out-of-pocket costs for “big-ticket” items and/or what the costs of specific treatments would be at different clinical locations. For example, with their health insurance plan in mind, would treatment (e.g., chemotherapy, radiation) be less expensive at one hospital versus another hospital? However, knowing the costs of these types of conversations is a challenge. While there are federal price transparency rules, pricing information can be confusing for patients and providers due to inconsistent information on service, prices, and how payer type may affect costs.
Finally, multiple previous studies highlighted that when discussing costs, cancer care team members should bring age-appropriate resources to the conversation (e.g., scholarships, programs) and be able to focus on solutions to their patients’ financial concerns. This was echoed in our interviews, with some younger participants indicating less of an interest in CoC conversations due to their parents managing their insurance and bills.
How to have cost-of-care conversations?
Future research from the implementation science perspective is needed to ensure the success and scalability of CoC conversations in clinical settings. More proximally, institutional commitment is needed to support patients with their costs. The first step is identifying strategies to integrate CoC conversations into clinic workflow and ensure that patients feel supported and asked about their financial status throughout treatment and follow-up. Financial toxicity could be assessed with short and targeted CoC conversations, then providers can either act directly with cost-saving measures or act indirectly through referrals to financial counselors or patient navigators.12,43 If organizations practiced these “short, targeted” conversations with providers, CoC conversations could be more easily added into the clinic’s workflow. 43 Next steps could include (1) identifying staffing support and reviewing with providers what resources their organization already provides, (2) clearly delineating cancer care team responsibilities concerning CoC conversations, (3) obtaining access to cost and benefits data concerning the organization, and (4) start creating a culture that “welcomes patients’ cost questions and concerns and respects patients’ values and preferences.” 41
When having CoC conversations with AYAs, cancer care team members should consider unique life stages; some AYAs may be experiencing financial instability while finishing school, whereas others may feel similar instability when entering the workforce or when trying to care for a young family.28,40,44,45 Results from this study show that only 37.5% of participants supported themselves financially and 41.7% were their own health insurance policyholder, which highlights that CoC conversations with AYAs may need to include their caregiver (e.g., parent, spouse/partner). Further research should include how to discuss costs with patient-parent dyads or patient–partner dyads or families.
Lastly, there is a growing body of research where evidence-based tools have been created for cancer care team members to use when preparing to have CoC conversations, including a conversation guide from Sloan and Ubel that teaches seven highly effective habits when engaging in cost conversations, as well as a recent ASCO guide on initiating difficult conversations in AYA oncology.40,46 Thus, evaluations of these practices are needed, especially for special populations such as AYAs.
Limitations
Our study has certain limitations that should be considered. Our sample was small, well-educated, English-speaking, and dominantly non-Hispanic White from the Mountain West region of the United States, which limits these findings when considering AYAs from more diverse populations, cultures, and languages. It would be valuable for future research to investigate the experiences of CoC conversations for non-native English-speaking AYAs, as their experiences could be distinct. Only insured AYAs were included in this sample, as this study was a pilot for a larger health insurance education program for insured AYAs; thus, the perspectives of uninsured AYAs were not included. 16 To identify a holistic view of AYA CoC conversations, future research should include AYAs who have never been insured or who have experienced gaps in their coverage. Further, neither the HILM nor the COST are validated specifically with AYAs—highlighting a need for AYA-specific measure development. However, the financial toxicity reported by AYAs in our sample was close to the mean in the COST validation study, increasing the generalizability of our findings.20,21 We also conducted these interviews prior to the COVID-19 pandemic; due to the changing financial and employment repercussions of COVID-19, AYAs may have shifting priorities and needs regarding their desire to discuss costs during treatment.
Conclusions
In conclusion, AYAs with cancer can experience high financial toxicity and often have low health insurance literacy. Both factors increase the need for cancer care team members to engage in CoC conversations with AYAs. Most AYAs whom we interviewed were willing to have CoC conversations with their cancer care team and believed such conversations were and would be helpful; however, some younger patients feel less certain CoC conversations would be beneficial due to their parents’ financial and insurance support. Many had initiated CoC conversations themselves. For those who had experienced a CoC conversation, many felt they were not as thorough as they would have hoped. As a summary, future studies could include (1) recording, transcribing, and completing a content analysis to investigate how accepted and productive CoC conversations with AYAs are, especially for more diverse and uninsured AYA patient samples, (2) testing the best processes to include family-based CoC conversations in light of development age differences, and (3) implementation science studies to ensure success and scalability of CoC conversations.
Footnotes
Acknowledgments
The authors acknowledge the Huntsman Intermountain Adolescent and Young Adult (HIAYA) Cancer Care Program for their support in recruitment as well as the HIAYA Patient and Family Advisory Board who offered vital and insightful feedback on this study during each and every phase.
Authors’ Contributions
All authors contributed to project conceptualization and methodology. K.M.v.T.B., A.R.W., P.L.V.L., and A.C.K. were responsible for project administration. K.M.v.T.B., N.R., A.R.W., H.K., E.L.W., and A.C.K. were responsible for formal analysis and visualization. E.R.P. and A.C.K. provided supervision. K.M.v.T.B. was responsible for writing the original draft and A.R.W. and A.C.K. were key in the editing phases. All authors contributed to writing, review and editing.
Data Availability
Data may be available from the corresponding author upon reasonable request.
Author Disclosure Statement
The authors declare no potential or actual competing interests.
Funding Information
The research described in this article was supported by the
