There is a continued movement toward health data transparency, accelerated by the 21st Century CURES Act, which mandated the automatic and immediate release of clinical notes, often termed “open notes.” Differences in utilization among different patient demographics and disproportionately affected populations within the emergency department (ED) are not yet known.

This was an observational study of 10 EDs and 3 urgent care centers across a single health system over a 13-week period from February 1, 2021 to May 2, 2021. Primary outcomes included the proportion of patients with patient portal access to open notes at the time of encounter, the proportion of patients with access who opened the clinical note, and time from clinical note signing to patient read.

Among 98,725 patient visits, less than half (48.9%) had patient portal access, of which 13.7% read an open note. Access was less likely in patients who were under age 18 (odds ratio 0.10, 95% confidence interval 0.08 to 0.11), older than 65 (0.82, 0.73 to 0.93), Black non-Hispanic (0.66, 0.61 to 0.73), non-English speakers, and on public insurance. Patients were less likely to read open notes if they identified as Black non-Hispanic (0.61, 0.57 to 0.66), spoke Spanish (0.70, 0.60 to 0.81), or were on public insurance.

We identified substantial differences in digital access to clinical notes as well as patient utilization of open notes in a large, diverse sample. Health transparency initiatives must address not only technology adoption broadly but also the unique barriers faced by populations experiencing disadvantage to facilitate equitable access to and awareness about digital health tools without the unintended consequence of expanding disparities.