Privacy policies for FDA-authorized or FDA-recognized digital therapeutics impose high digital health literacy demands: a cross-sectional analysis.

BACKGROUND: Although digital health literacy is often framed as an individual skill, participation in digitally mediated care is shaped by the demands built into system documents. Inaccessible privacy policies may represent a document-level pathway through which digital health systems contribute to digital exclusion and inequitable participation, particularly for underserved or disadvantaged populations. We examined the accessibility of privacy policies for US FDA-authorized or FDA-recognized digital therapeutics as system-level digital health literacy demands. METHODS: We conducted a cross-sectional document analysis of 36 publicly accessible privacy policies for digital therapeutics with FDA marketing authorization (510(k), De Novo, or Premarket Approval) or FDA provisional/discretionary recognition (e.g., enforcement discretion or Breakthrough Device Designation). Accessibility was assessed in two domains: (1) readability burden, summarized as a Composite Grade Mean derived from the Flesch-Kincaid Grade Level, SMOG Index, Gunning Fog Index, and Coleman-Liau Index; and (2) structural and design support, assessed using a prespecified 10-item rubric and summarized as the Structural and Design Support Score (SDSS) compliance rate. Findings were described relative to the prespecified grade 8 benchmark for readability burden and the prespecified 70% SDSS compliance benchmark. RESULTS: All 36 policies exceeded the grade-8 benchmark. The mean Composite Grade Mean was 16.40 ± 1.60 and the mean Structural and Design Support Score compliance rate was 48.89% ± 11.90%. Only 2 policies (5.6%) met or exceeded the prespecified 70% benchmark. Logical sequencing, descriptive headings, and typographic emphasis were common; internal navigation, key-information summaries, visual aids, and text-visual integration were uncommon. A two-axis mapping analysis showed that 34 of the 36 policies fell within the high readability burden/SDSS <70% quadrant. CONCLUSION: On average, privacy policies for FDA-authorized or FDA-recognized digital therapeutics were written above commonly cited public-facing reading-level benchmarks and provided limited structural and design support. These document-level characteristics may plausibly contribute to system-level digital health literacy demands. Improving document accessibility may therefore represent a modifiable target to support more informed participation in digital care and may be conceptually relevant to Sustainable Development Goals 3 (Good Health and Well-being) and 10 (Reduced Inequalities).