Study to probe why patients disregard medical advice
A £1.24m UK study has begun to examine why so many patients fail to follow medical advice or stick with treatment.
Psychologists and dermatologists at Guy's Hospital in London will question 400 patients with the rare genetic condition xeroderma pigmentosum (XP).
They have to protect themselves from the effects of daylight, as their skin cannot repair itself in the normal way.
Research suggests a third to a half of all medicines for long-term conditions are not taken as recommended.
Examples include children not using asthma inhalers to prevent an attack, and even transplant patients not taking medicine that stops their body rejecting the new organ.
Psychologist Prof John Weinman, from King's College London, told BBC News: "Medicine is waking up to this but it's a massive worldwide problem.
"Some doctors just assume a good diagnosis is enough, and treatment will be followed.
"They might not check to see how much the patient understands the condition.
"Certainly, there are major communication challenges."
Ben Fowler, 55, from Brighton, has a less harmful variant of XP - but he still needs to put on strong sunscreen and cover up, even on a cloudy day.
He has had many skin lesions removed - and had skin cancer on multiple occasions.
Specialist doctors monitor him three times a year.
Mr Fowler, who runs a furniture design business, told BBC News: "It took me a long time to recognise the importance of UV.
"I thought the doctors meant I shouldn't go sunbathing on the beach.
"Then, I noticed that some photographic paper had gone black even though I kept it in a drawer in my studio.
"This brought it home to me that UV is there all the time - and it's damaging the cells in my skin.
"I also got a letter from the doctors, expressing concern that I wasn't doing enough to protect myself.
"A doctor can tell you what's wrong with you in layman's terms - but you don't always understand the science behind it.
"Once I realised I had to avoid UV or be really careful, I recognised I needed to alter my behaviour profoundly - and I did."
Funded by the National Institute for Health Research, the study will question patients from Europe, Tunisia, Japan and the US.
A consultant dermatologist at Guy's Hospital, Dr Bob Sarkany, runs the NHS service for the UK's 100 XP patients.
Many of them put protective film over their windows to block invisible ultra-violet (UV) light, which causes permanent damage to their cells, from entering their homes.
Some children with XP have to wear visors to protect the face and neck.
The average life expectancy of an XP patient is just 32.
Dr Sarkany said: "XP is important, but a much more common problem is people without the condition who have had life-threatening skin cancers.
"A lot of those people have problems protecting their skin from the Sun after cancer - we don't understand why.
"We hope our research with XP will allow us to help these other patients."