Letters sent to patients from ophthalmology services in the UK contain language and medical terminology that may be difficult for patients to understand, according to an analysis of more than 4 million letters published in BMJ Health & Care Informatics. The study, released on Aug. 4, found that most correspondence is written at a college reading level, which is not recommended for patient-directed content.
Researchers analyzed over 4.6 million outpatient clinic letters sent between 2013 and 2025 to nearly 805,000 patients across 17 subspecialty services at a UK hospital trust specializing in eye health. The average Flesch Reading Ease score was 51.1, indicating a college-level readability. Overall, the study found that 95% of the letters were less readable than recommended for patient communication.
The analysis revealed variation in readability across different subspecialties within ophthalmology. Letters from paediatrics, optometry, and orthoptics had the highest readability scores. Researchers suggest this may be due to correspondence in children's eye services being directed at parents or caregivers and the use of structured templates in optometry and orthoptics.
The proportion of letters addressed directly to patients showed a slight increase over time but remained low overall at just over two percent. Use of personal pronouns such as 'you' was also limited throughout the study period.
Researchers noted several limitations to their findings, including an inability to assess differences between individual clinicians' writing styles and a focus on linguistic complexity rather than communication aspects most important to patients or those with greatest impact on healthcare outcomes. They also acknowledged potential effects from changes in clinical practice or institutional policies during the study period.
"It demonstrates that poor readability is pervasive, has worsened over time, and varies substantially between services, revealing system-level patterns that were previously unquantified," researchers wrote. They concluded, "These findings highlight a persistent gap between national recommendations and real-world practice, which underscores the need for targeted interventions and innovative approaches to support clear and patient-centred communication."
