One in six people in the UK struggle with literacy. ¹ The Leitch Review found that more than five million adults lack functional literacy, the level needed to get by in life and at work. ^{Reference Leitch2} This is particularly important as approximately 70% of adults with a self-reported mental health problem are either functionally illiterate or marginally literate. Furthermore, adults with mental illness who are literate read three to five grade levels below that expected by their level of education. ^{Reference Christensen and Grace3}

The involvement of patients, carers and the public in health decision-making is at the heart of the modernisation of the National Health Service (NHS). Hence, in the good practice guideline, Copying Letters to Patients, ⁴ the Department of Health stressed the importance of using ‘plain English’ when sending copies of letters between healthcare professionals to patients.

We conducted an audit to assess whether clinicians were sending copies of letters to patients written in plain English. The secondary outcome was to see the differences between letters from doctors and nurses.

We used the Simple Measure of Gobbledygook (SMOG) to check for use of plain English. This measure of ‘readability’ estimates the years of education needed to completely understand a piece of writing. It is the outcome of research commissioned by the National Institute of Adult Continuing Education.

The data were collected retrospectively in April-May 2010 from letters sent by clinicians working in older people mental health services, 2gether NHS Foundation Trust.

We found that only 59% of letters in the sample were copied to patients. The average SMOG readability index was 17.2, with little difference between doctors and nurses. The sentence length varied, with a few examples of sentences with more than 40 words. Also, passive sentences and noun and adjectives in large clusters were frequently used.

The SMOG value of 14 corresponds to GCSE levels A-C, and to Adult Literacy Standard level 2. The SMOG values for editorials of the commonly read tabloids The Sun and The Daily Express are less than 14 and 16 respectively. ⁵

It was painful to note that not a single letter in the audit sample had a SMOG value of 14 or less. This may mean that many of our patients may not be able to understand our letters.

We suggest that all letters sent by clinicians should be copied to patients unless there is a valid reason documented in notes not to do so. We should ponder on the layout and presentation of the letter, avoid long sentences, passive sense, and polysyllabic words.