Explanation for the choice of comparators {6b}
The control group will also be given the UVR-sensor-enabled device to wear (details below); however, they will be provided a version of the mobile app that only collects the UVR exposure and does not provide notifications as they reach daily limits or summary information about exposure. The attention-control group was chosen over no intervention for three reasons: one, we can objectively measure UVR exposure in both groups; two, providing the device to the control group will help with recruitment, engagement, and retention; and three, the intervention is low risk.
Intervention description {11a}
We are adopting the Health Belief Model as our theoretical guide for this intervention given its emphasis on several constructs important for promoting behavior change, including individual perceptions—such as perceived susceptibility, perceived severity, perceived benefits, perceived barriers, and self-efficacy—and cues to action, or factors in the environment that can trigger action [16, 17]. Distinct intervention components, described below, will enable us to address individual perceptions and provide cues to action to prompt engagement in optimal sun protection behaviors and reduce sunburns.
We will provide a commercially available UVR-sensor-enabled wrist wearable device to all participants, Shade, 2nd generation, which was developed in collaboration with the National Health Institutes (National Cancer Institute). Shade reported significantly more accurate UVR measurements than similar devices [18], and melanoma survivors have previously reported that the first version of the device was easy to use [19]. In addition to accurately measuring UVR exposure in a manner that does not rely on self-report and memory, Shade includes a mobile app that helps users set daily limits that take into account UVR intensity, time of exposure, and sunscreen application. Importantly, the app and device provide prompts when approaching the daily limit, with the goal of serving as a cue to action. The device will alert participants once they reach 20% of their daily limit (and every 20% after that) via a notification on the participant’s phone. Participants are asked to wear the devices and sync it with the mobile app every day for 12 weeks, regardless of planned outdoor activities.
For participants in the intervention group, we also developed a brochure that provides information about the importance of UVR avoidance and protection among individuals with a history of melanoma and tips for making these behaviors routine and sustainable, with the goal of addressing perceptions to promote sun protection behaviors. The brochure will be provided to those in the intervention group as a printed brochure at baseline and via a website after completing each subsequent survey. The brochure was pretested among five individuals with a history of melanoma.
Criteria for discontinuing or modifying allocated interventions {11b}
Participants will not be terminated from this study unless they request it. They will not be removed due to new melanoma diagnosed or recurrence unless requested. All participants, regardless of their device use, will be followed unless they drop out of the study. Switching between the intervention and control groups is not permitted. Those in the intervention group are not able to alter or turn off receipt of UV exposure notifications.
Strategies to improve adherence to interventions {11c}
The study coordinator will view the data of all participants (both intervention and control) consistently to monitor device use and will contact participants who do not use their device or sync the app data more than 3 days in any given week to determine barriers and encourage use. In addition, a lottery-based incentive will be used to promote adherence. This incentive structure will indirectly support behavior change by incentivizing the use of the devices rather than directly incentivizing sun protection behavior. Participants will be entered into weekly lotteries for $100 gift cards for the duration of the intervention period. The weekly winners will be randomly drawn from all participants. The randomly selected winners will only be eligible for the prize if they wore the device at least 5 days during that week. We will email the study group every week indicating that the lottery was drawn, a winner was chosen, and the number of draws required to obtain a participant who was eligible to win.
Relevant concomitant care permitted or prohibited during the trial {11d}
Participation in this study will not affect clinical care.
Provisions for post-trial care {30}
There are no processes in place to provide post-trial care due to the minimal risks associated with this study and the return of the devices following the intervention period.
Outcomes {12}
The primary outcome is a composite measure of healthy sun protection behaviors at the end of the intervention period (12-week survey) [14]. A total score for each individual will be created by taking the average of 6 protective behaviors (wearing a shirt with sleeves, wearing sunglasses, staying in the shade, using sunscreen, limiting time in the sun, and wearing a hat) on a 4-point ordinal scale ranging from 1 = rarely or never to 4 = always. This composite measure has been used previously in similar intervention studies [14]. We will not focus on change from baseline, as the baseline may be obscured by the time of year; further, we expect the baseline measures would be balanced between the two randomized groups, but we will take any differences into account in the analysis. As a self-reported outcome, social desirability may affect reported measures. It is possible that we will have misclassification of these measures; however, we do not anticipate misclassification rates to be differential by treatment group. While assessing the maintenance of behavior change is beyond the scope of the proposed study, we have added a short follow-up survey 1 year post study completion (64 weeks: the end of each following summer) to obtain preliminary estimates of durability.
A key secondary outcome for this study is a self-reported measure of at least one red or painful sunburn in the past 3 months at the completion of the intervention period (12-week survey) [20]. The National Institutes of Health has deemed sunburns following an intervention to be a clinically relevant endpoint and suitable outcome for trials aiming to prevent skin cancer [21]. We will calculate the proportions of individuals with at least one sunburn. We will additionally calculate the proportions of participants engaging in each sun protection behavior separately used in the calculation of the primary outcome and the number of hours outside per day between 10 am and 4 pm in the summer separately for weekdays and weekend days (week 12). For the purposes of this analysis and ease of interpretation, all measures were dichotomized into “optimal” and “suboptimal” categories. The following will be considered optimal: weekday sun exposure in the summer of 1 hour or less, weekend day sun exposure in the summer of 1 hour or less, and reporting often or always using sunscreen, often or always wearing a shirt with sleeves, often or always wearing a hat, often or always staying in the shade, and rarely or never intentionally tanning. The Shade device will provide objective measures of daily UVR exposure (continuous) and will be summarized as a total accumulation during the study period. Lastly, we will calculate a total sun protection knowledge score, which will be measured using six items created by the study team which address particular concerns related to sun protection following melanoma. We will create a total score by summing the number of correct answers (range 0 to 6), focusing on both the week 12 measure and change from baseline.
We will also measure physical activity, depression, and anxiety to examine any potential unintended negative consequences of the intervention. A number of potential harms of promoting sun protection have been suggested in the literature, including reduced physical activity and increased anxiety. A study of prospective cohorts found increased leisure-time physical activity was associated with risk of melanoma [22]. This finding is in accordance with recent cross-sectional data suggesting sunburn was greater among those who were highly physically active and that physical activity frequently occurs outdoors [23]. Increasing anxiety is another concern; one study found a higher proportion of participants in the intervention group reported greater rates of worrying about developing melanoma compared to control participants, although this difference was not statistically significant [24]. Conversely, it is possible that promoting sun protection behaviors may, in fact, improve emotional health by educating survivors about how to protect themselves when they are outside. Some survivors, at least initially, attempt to completely avoid the sun or be outside due to fear [25], and therefore empowering them to safely enjoy their activities may result in lower anxiety and depression. Physical activity will be measured using the Godin Leisure-Time Exercise Questionnaire [26] which asks about times per week of engaging in strenuous (vigorous), moderate, and mild physical activity on average of the preceding month, as well as minutes per week engaging in each type. We will calculate a total weekly leisure activity score: (9 × strenuous) + (5 × moderate) + (3 × light) and focus on total scores at week 12 and change from baseline. Depression and anxiety will be measured using the Hospital Anxiety and Depression Scale (HADS) instrument which includes 14 items designed to screen for potentially clinically relevant anxiety and depression [27]. Each item is scored from 0 to 3. We will calculate subscale anxiety and depression scale scores and the proportions of individuals with potentially clinically meaningful depression and anxiety using an established cut-off of 8 for each scale. We will focus on proportions with potentially clinically meaningful depression and/or anxiety at week 12 and changes in subscale scores between week 12 and baseline.
We will measure satisfaction and usability of the device at week 12 using the System Usability Scale [28]. The scale includes 10 items with Likert scale responses (strongly agree to strongly disagree). Total scores will be created by summing items and multiplying by 2.5 to obtain a range of 0–100.
Last, we will examine a number of metrics regarding study implementation, including recruitment, compliance/engagement, and retention. The implementation metrics will be examined after Wave 1 (Summer 2020) is completed to identify areas of opportunity to improve recruitment, compliance/engagement and retention that can be implemented prior to starting Wave 2 (Summer 2021). While we will keep the intervention consistent across waves, we will consider alternative methods of recruitment, incentives, reminders, and other actions to maximize engagement and retention.
Participant timeline {13}
Following screening and consent, participants will complete the baseline survey and be randomized to condition. Participants will then be mailed their device and appropriate training materials and mobile app access within 1 week of randomization. Participants will be asked to wear the device and sync it with the mobile app every day for 12 weeks, regardless of planned physical or outdoor activities. Self-administered questionnaire data during the intervention period will be collected at week 4, week 8 and week 12 (end of intervention), and week 64 (1 year after the end of the intervention; the end of the following summer). Participants will be asked to return the device after their 12-week intervention period is complete (Fig. 1).
Sample size {14}
The sample size was calculated to maximize power for the primary outcome (self-reported overall sun protection score) while also achieving moderate power for a key secondary outcome, experience of a sunburn during the intervention period. A sample size of 368 randomized (314 completed by assuming a 85% completion rate) will achieve 95% power to detect an effect size of 0.40 between intervention and control groups using a two-sided two-sample t-test assuming a significance level of 0.05. This effect size is similar to that found in an intervention to promote sun protection behaviors in high-risk individuals with the same primary outcome [14]. Importantly, it will also achieve 70% power to compare report of sunburn during the intervention period between the two groups (detect 20% of the control participants reporting a sunburn, as seen in our preliminary data [29], and 10% of the intervention participants reporting a sunburn) as statistically significant at 0.05 significance level. We assumed that 85% of those randomized would complete the 12-week follow-up survey, which resulted in a total planned sample size of 368 (184 per group).
Recruitment {15}
HealthPartners Institute Center for Evaluation and Survey Research will recruit potential participants. Screening and recruitment will follow a two-step process. First, HealthPartners medical claims data will be queried to identify patients or members diagnosed with invasive cutaneous melanoma during the recruitment eligibility period (2010 to present). Recruitment will occur in the spring of each year with the study intervention running during the summer to account for seasonality. We will send potential participants a letter on HealthPartners letterhead introducing the general nature of the study and the elements of informed consent, and notifying the potential participant that a study interviewer will call them. The letter will state that the information obtained is confidential and that participation is voluntary. Next, within 2 weeks of sending each letter, an interviewer trained specifically on this study protocol will phone the potential participant to ask if they are willing to participate in the study, if they have not already opted out. For those interested in participating, the interviewer will obtain permission to share their contact information (name, address, phone number) with members of the University of Minnesota research staff. The University of Minnesota staff will then send an introductory email, which includes a link to complete online consent and HIPAA forms, and then leads directly to the online baseline survey to finalize the study registration process. In light of the COVID-19 pandemic, all study procedures were designed to be conducted remotely with no in-person contact with participants.