EMR usability and patient safety: a national survey of physicians.

Despite widespread adoption of electronic medical records (EMRs), concerns persist regarding their usability and implications for patient safety. This national cross-sectional survey assessed physicians' perceptions of EMR usability across safety-relevant domains. Among 1933 respondents from diverse care settings, 56% reported that their EMR did not enhance patient safety, and 50% perceived their system as inefficient. Usability ratings averaged 52% of the maximum score. Statistically significant differences were observed between EMRs in outpatient (η² = 0.13) and hospital (η² = 0.37) settings. Multilevel modeling attributed 38% of the variance in usability ratings to differences between EMRs, 51% to hospital-level variation within EMRs, and 11% to physician-level differences. Canonical discriminant analysis identified key differentiating usability features, including system response times, excessive alerts, prevention of data entry errors, and support for collaboration. These findings underscore substantial limitations in current EMR systems and reinforce the value of comparative usability assessments to inform targeted improvements in digital health infrastructure.