We conducted a pilot randomized controlled trial of the MAPS intervention, described in more detail below, among 52 female HL survivors between 2019 and 2020. Females diagnosed with HL before 2011, treated with mantle or chest radiation, and with an attained age of at least 18 years at the time of recruitment were eligible. Participants were required to be English-speaking, mentally/physically competent to complete a questionnaire and provide consent, and willing to learn mobile device technology. HL survivors who were hearing or visually impaired in a way that would prevent them from using a mobile application and those who were diagnosed with breast cancer or were previously seen in the cancer survivorship clinic at the University of Minnesota where they would have already received counseling and specific recommendations on screening were excluded from participation. This study was approved by the University of Minnesota Institutional Review Board (IRB #: 1610S97201), and all participants provided written informed consent prior to study participation.

Potentially eligible participants were identified based on a review of electronic medical records and a database of cancer survivors at the University of Minnesota. Initial invitation letters were mailed and followed by a telephone call from the study coordinator to assess interest and confirm eligibility. For those not interested (active decline) or unresponsive to the invitation and two subsequent outreach attempts (passive decline), no further contact was made. Following written consent and completion of the baseline survey, participants were randomized 1:1 to the intervention or control arm. SAS 9.4 was used to generate random sequence numbers based on block randomization. The allocations were placed in opaque, sealed envelopes and opened sequentially by the study coordinator to randomize participants.

The app modules were developed and tested by a multi-disciplinary team based on the Fogg Behavioral Model of Mobile Persuasion [31], and using input from focus groups of HL survivors. Focus groups were conducted in June 2017 among 10 HL survivors (1) with secondary complications of breast cancer or cardiovascular disease or (2) at risk for secondary complications. During the focus groups, patient experience, awareness of potential late effects and screening, barriers to screening, and preferences for receiving information were assessed. Key findings included (1) a general awareness that additional screening may be indicated with a gap in knowledge on what to do and (2) that most preferred to receive information about recommended health screening digitally. Potential barriers to screening included conflicting information, low confidence that they are receiving the correct information, financial concerns/lack of insurance coverage, or avoidance/rejection of information (i.e., “I feel good so why should I do additional testing?”).

Five educational online modules were created, incorporating the focus group findings, and utilizing videos and graphics to enhance messaging (Fig. 1). These tailored and interactive modules were provided to participants in the intervention group, spread out over 5 days. Each daily module took approximately 5 min to complete. The modules prompted participants to interact and respond to questions, but the educational information was delivered to all participants. Prompted daily topics included (1) the importance of cancer survivorship care plans, (2) treatment-related cardiovascular complications and secondary cancers, (3) individual risk factors based on prior therapies, (4) screening guidelines, and (5) communication strategies, healthy lifestyle, selfcare, and follow-up. Participant access to MAPS was password protected. Study coordinators were able to monitor if the modules were completed in entirety or not with website metrics; but for those with only partial completion, we did not capture the percent completed nor which modules were partially vs fully completed.

Screenshot of Mobile Applications for Survivorship Care (MAPS) online learning module

Participants in the control group electronically received a 5-page handout tailored to the study population and an educational handout from the American Society of Clinical Oncology (ASCO) for cancer survivors, i.e., these handouts described referenced published literature around survivorship care plans, second cancer, and cardiovascular screening, and information regarding healthy lifestyle following cancer treatment [32]. The handouts included the same topics as the intervention group. At the completion of the study, participants in the control group were given access to the online modules.

After providing written consent, study participants were asked to complete an online baseline survey via REDCap electronic data capture tool hosted at the University of Minnesota. Following completion of the baseline survey and randomization, those randomized to the intervention group were instructed to download the MAPS application and view all materials. Both groups were electronically sent the educational handouts. A final REDCap survey was sent to all participants 3 months after baseline.

The surveys were adapted from previously developed and utilized surveys in previous studies, results of focus group, and with collaboration with the Office of Measurement Services at the University of Minnesota [33,34,35]. The primary outcome was usability, defined as the feasibility, measured by completion rate (the proportion of individuals randomized to the intervention group who completed all study-related procedures), and acceptability, measured by satisfaction with the app-based intervention. Six items were developed for the study to identify satisfaction with attributes of the intervention, similar to questions we had previously used to assess a previous mobile app intervention (Table 2) [36]. Acceptability of printed materials was not measured in the control group. We were interested in several secondary outcomes: (1) HL survivors’ knowledge of risk of secondary cancers, adverse cardiovascular outcomes, and of screening guidelines. This knowledge was assessed both at baseline and in the post-intervention survey. Questionnaire items are depicted in Table 3. (2) Adherence to recommended screening guidelines (mammogram alone, mammogram and breast MRI or MRI alone) or intention to screen. Additionally, self-reported demographic and clinical information such as age, education, rural/urban location defined by ZIP-code-based Rural Urban Commuting Area (RUCA) codes, and annual household income were collected. Cancer- and treatment characteristics including age at diagnosis and treatments received for HL (surgery, chemotherapy, and radiation) were abstracted from medical records.

The planned sample size of 60 participants for this pilot study was primarily a function of feasibility and to provide preliminary estimates of the acceptability and effectiveness of the intervention. Based on previous experience, we anticipated approximately 60% of those recruited to the study would complete the 3-month follow-up survey, and therefore a final sample size of 34 participants with complete data was expected. For analysis of knowledge scores, a sample size of 34 (17 in each arm) achieves 80% power to detect an effect size of 1.0 using a two-sided, two-sample t-test with a significance level of 0.05. Recruitment was stopped for this study at 52 participants due to significant disruptions to research implementation due to the COVID-19 pandemic.

Descriptive analyses were conducted to compare demographic and clinical characteristics between the randomized groups. Frequencies of correct answers to the knowledge questions regarding potential complications from prior HL treatment and breast cancer and cardiovascular screening guidelines were compared between the intervention and control groups at baseline and post-intervention using Chi-squared and Fisher’s exact tests. The primary analysis was intention-to-treat, analyzing participants in the group they were randomized to regardless of intervention engagement. A secondary analysis was completed, including only those who completed the MAPS learning modules in the intervention group. SAS 9.4 was used for all statistical analyses, and P values < 0.05 were considered statistically significant.