Patient letters from UK hospital eye health services likely too difficult to understand

They are largely college level readability, which isn’t recommended for patient content
Communication quality may influence clinical outcomes, but dual purpose makes improvement challenging, say researchers

Letters to patients from ophthalmology services—-the highest volume outpatient specialty in UK healthcare—include too much complex language and medical terminology which patients are likely to find hard to understand, reveals an analysis of more than 4 million letters from one large hospital trust, published in the open access journal BMJ Health & Care Informatics.

Their readability is mostly college level, the analysis—the first of its kind–shows. This isn’t recommended for content designed to be read by patients, say the researchers, who add that while communication quality may influence clinical outcomes, the dual purpose clinical letters serve makes improvement challenging.

Unlike many other health systems, there is a well established practice in the UK of sending letters to patients following an outpatient clinic appointment. These letters used to be copies of those sent to the patient’s family doctor (GP), but the emphasis has shifted to making them clearer and more patient centred, note the researchers.

Academy of Medical Royal Colleges (AoMRC) guidance in 2018 encouraged clinicians to write directly to patients rather than about them, and NHS England has since reinforced the importance of clear and timely communication with patients as essential for efficient and effective outpatient services, they add.

But it’s not clear to what extent clinical letters meet recommended readability standards. To find out and set a quality benchmark, the researchers focused on the highest volume outpatient specialty in UK healthcare—-ophthalmology.

They measured the readability and linguistic complexity of over 4.6 million outpatient clinic letters sent to 804,986 patients between 2013 and 2025 attending 17 subspecialty services at a UK hospital trust, specialising in various aspects of eye health.

Their analysis shows that the average readability score (Flesch Reading Ease) of the letters was 51.1, indicating college-level understanding. This means the correspondence was more complex and less accessible than recommended for content designed to be read by patients. Overall, 95% of the letters were less readable than recommended.

Readability varied across the 17 subspecialties, however, suggesting that communication quality may reflect service-level culture and documentation requirements, say the researchers.

The highest readability was observed for letters from paediatrics, optometry, and orthoptics services.

In children’s eye services, correspondence was often directed to parents or caregivers, which may encourage use of simpler language, suggest the researchers. And in optometry and orthoptics structured templates were often used, likely facilitating more consistent readability, they add.

There was a slight upward trend over the study period in the likelihood of letters being addressed directly to patients over the study period, but the proportion doing so remained very low, overall, at just over 2%, while use of the personal pronoun ‘you’ was also very low.

The researchers highlight several limitations to their findings, including the inability to assess variations in the readability of individual clinicians’ letters. The analysis also focused on readability and linguistic complexity rather than measuring which aspects of communication matter most to patients or had the greatest impact on healthcare outcomes.

The methods used to classify the intended audience may not fully reflect how correspondence is ultimately used or interpreted, while shifts in clinical practice, record keeping, or institutional policies may also have introduced effects not accounted for in the analysis, the researchers add.

But the study is the first long term population-scale evaluation of outpatient clinic letter readability over more than a decade, and exposes a gap between policy recommendations and routine practice, they point out.

“It demonstrates that poor readability is pervasive, has worsened over time, and varies substantially between services, revealing system-level patterns that were previously unquantified,” they write.

Clinician letters must simultaneously work as a medical record and provide key information for other healthcare professionals as well as for patients, making it hard to simplify the linguistic content—a challenge that is further compounded by time pressures—they explain.

But they conclude: “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.”

04/08/2026

Notes for editors
Research: How well do we write for patients? Longitudinal analysis of the readability and complexity of 4.6 million ophthalmic clinical letters Doi: 10.1136/bmjhci-2026-102086
Journal: BMJ Health & Care Informatics

About the journal
BMJ Health & Care Informatics is one of 75 journals published by BMJ Group. The title is an official publication of BCS, the Chartered Institute for IT
https://informatics.bmj.com

External funding: National Institute for Health Research (NIHR); Moorfields Eye Charity with The Rubin Foundation Charitable Trust, and Alcon Research Institute

Link to Academy of Medical Science press release labelling system: http://press.psprings.co.uk/AMSlabels.pdf

Externally peer reviewed? Yes
Evidence type: Observational
Subjects: People