Willingness to Share Internet Use Data for Research on Early Disease Detection: Cross-Sectional Survey.

Background: Preliminary research has suggested that internet use data could offer digital signals of early disease and has the potential to facilitate early detection and improve patient outcomes. However, there are significant challenges in linking individual-level internet use data with health outcomes. One key aspect is that the public might not be willing to share data for research or that selective data sharing might create bias in datasets and increase inequalities. Objective: Our study aimed to investigate the willingness of the public to share their internet use data for medical research and to identify key criteria that affect willingness to share. Methods: We conducted a web-based, cross-sectional online survey with 2390 UK adults with and without a history of cancer, heart disease, and depression using quota sampling. Participants were randomly assigned to explore willingness to share different types of internet use data for 1 of 3 health conditions (cancer, heart disease, and depression) and for provision of a pictorial example of internet use data. Logistic regression analysis (α=.05) for each condition was used to determine key factors of willingness to share, including sociodemographics and attitudes toward sharing. Open-ended comments regarding facilitators of sharing and concerns were analyzed thematically. Results: Willingness to share internet use data was high across conditions (74%-77%, 95% CI 70.5%-80.3%), especially for health app data (73%-76%, 95% CI 69.8%-79.1%). The pictorial example of browsing history did not affect willingness to share. For all conditions, factors consistently associated with willingness to share were perceived benefits (odds ratios [ORs] 5.692-8.850; all P<.001) and concerns (ORs 0.343-0.432; all P<.001). Key concerns were data privacy, potential for misuse, and lack of relevance. Suggestions to increase willingness to share included contributing to society and research, data security assurances, clarification of research purposes, and monetary incentives. Familiarity with internet use data was related to lower willingness to share for heart disease detection (OR 0.740, 95% CI 0.561-0.976). Asian ethnicity was associated with lower willingness to share internet use for cancer detection (OR 0.234, 95% CI 0.076-0.723). Younger age (OR 0.975, 95% CI 0.951-0.999) and male gender (OR 2.615, 95% CI 1.511-4.526) were associated with higher willingness to share data for depression detection. Conclusions: This first large-scale assessment of public willingness to share internet use data for early disease detection adds novel insights by comparing conditions and examining sociodemographic factors alongside perceived benefits and risks. It highlights that understanding of internet data is limited yet willingness to share for research is high. Clear communication of benefits, strong privacy protections, and incentives may increase participation and reduce bias. The findings inform consent design, targeted outreach to underrepresented groups, and data governance for safe use of personal digital data. Future research should focus on improving public communication, particularly among less willing groups at risk of inequality.