Discussion
skin cancer, melanoma, sunburn, sunburns
MELANOMA, RECRUITMENT, SECONDARY, SKIN CANCER, OF SKIN CANCER
Contrary to our hypotheses, we found no differences in self-reported sun protection behaviors, UVR exposure, or sunburns following the 12-week intervention, including no behavioral differences in subgroup analyses. We further found no long-term behavioral differences with the one exception of slightly fewer participants in the intervention group reporting spending at least 2 hours outside on weekends at 64 weeks. Below we discuss possible reasons for our overall null findings and lessons learned for future research in this area.We chose a previously validated summary measure of self-reported sun protection behaviors as the primary outcome for this study to enable comparisons with other similar intervention studies [A key secondary outcome for this study was self-report of at least one red or painful sunburn during the intervention period. 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 [We chose an attention-control group over no intervention so that we could objectively measure UVR exposure in both groups and increase engagement in the control group over the 12-week intervention. A 2021 study that used the Shade device and control mobile application found that unintentional tanning and time spent outside decreased among children (aged 8–17) who wore the device for a two-week period; however, no changes in UVR exposure or sunburn were observed [Some of the Shade device features may have contributed to our null findings. Although Shade is highly sensitive and accurate, defects in the hardware resulted in many participants needing device repair or replacement during the study. Further, the Shade built-in algorithm, which reported SPF-reduced UVR exposure to participants after sunscreen use, is potentially problematic and misleading, as evidenced by our exploratory finding that those who reported using sunscreen compared with those who did not had higher objective UVR exposure. The goal of using sunscreen is to reduce sunburn, but can mislead sunscreen users to believe they can prolong their direct sun exposure without additional protective measures. Because of this and the general lack of proper use of sunscreen (amount and reapplication), the World Health Organization recommends that other protection methods such as clothing and shade be prioritized over sunscreen for primary prevention of skin cancer [The underlying idea of the intervention was that making people aware of their UVR exposure in real-time would motivate them to reduce that exposure. While unintentional UVR exposure more frequently leads to sunburn than intentional tanning, it is possible that promoting awareness is not sufficient to change action. Barriers to sun behavior changes may be higher in Northern climates where summers are short—for example, in Minnesota, where the study was conducted. Minnesota is second only to Utah in sunburn prevalence [Finally, behavior change is difficult. Two other studies have aimed to improve sun protection behaviors (in addition to skin self-examination) among melanoma survivors, with varying levels of success. After an interactive online intervention, Manne et al. detected small improvements in sun-protective behaviors at 24 weeks [Strengths of the current study include a strong study design with rigorous implementation (blinded randomized clinical trial), successful participant recruitment despite study implementation during the COVID-19 pandemic, high participant retention, and collection of objective UVR data. Beyond the already described flaws of the device, including the need to back-transform data, limitations included the use of self-report outcome measures, which may be prone to social desirability bias in this study population. Further, with melanoma survivors as the participants, we acknowledge that their prior melanoma diagnosis and knowledge of the risk factors may affect their sun exposure behaviors and these results may have been different among participants without a history of skin cancer. While the study was conducted remotely, allowing it to proceed largely unimpeded through the COVID-19 pandemic, it is not clear how or to what extent people’s sun exposure may have been affected by the pandemic. We have no a priori reason to think that such effects would have been differential between the study arms, but this may limit generalizability of our findings in a post-pandemic era.