One in six people in the UK have a literacy level below that expected of an 11-year old.
This is alarming enough in terms of the ability to manage day-to-day activities, but problems may be even more widespread if we consider health literacy, which is an individual's ability to read, understand and use healthcare information to make decisions and follow instructions for treatment.
Literacy difficulties may stem from a variety of factors including conditions such as dyslexia, health problems, disrupted schooling or stresses acting as barriers to learning in childhood.
Unfortunately, stigma still surrounds adults who struggle to read and they are often too embarrassed to disclose any literacy difficulties, even in the confidential setting of a doctor's consulting room.
Patients with reading difficulties may have developed effective strategies to conceal problems and minimise any impact on their lives, such as avoiding form filling and declining to read aloud when in company.
They may have excellent verbal communication skills, and it is therefore not always easy for anyone - doctors and other healthcare professionals included - to detect there is a problem that could have an adverse effect on the patient's health.Potentially toxic
Understanding medication instructions can be particularly hazardous.For instance, a very commonly prescribed painkiller such as paracetamol can be bought over the counter in pharmacies and supermarkets.
Whilst safe in the recommended dose, it may quickly become toxic if the correct timing of the dose or number of tablets is exceeded, and those with literacy problems may be unaware of this if they assume it is only a mild painkiller and cannot easily read the instructions.
Some more powerful drugs such as methotrexate, used for rheumatoid conditions, have unusual dose instructions, such as "take once per week", which again may lead to confusion and potentially severe consequences if inadvertently taken daily.
Of course, doctors can only make allowances for literacy difficulties if they know they exist, but there are signs for them to look out for such as a patient having difficulty completing forms in surgery, having unexpected problems responding to recall letters or struggling to follow written advice.
There is currently a wealth of health information available to the public in the form of leaflets, posters and websites, and these are often recommended by health professionals either to encourage healthy lifestyle advice or to teach patients more about their medical conditions.
While this is welcomed in terms of making the public more 'health aware', over-reliance on the written word may be dangerous to those who struggle with reading, and the increasing use of email advice brings further risks.
Patients should request that information is provided in the way they feel most comfortable with and understand.
Doctors, in return, should work in partnership with patients, for example, by ensuring that information is given verbally as well as in writing.
For patients, if you have such difficulties, please report them to your doctor or other health professional so that they can give you information in a format that is easy to understand and you get the best possible care. They may be able to help you access information on support such as adult literacy courses, and you can also seek help from family or friends.
And for all those working to provide health care, it is important to remain vigilant at all times to detect problems, and perhaps ask specifically about such difficulties more often.
Information leaflets should be kept simple and as easy to read as possible, avoiding medical jargon and including diagrams where possible. They are best used as an addition and not an alternative to verbal communication.