More than one-third of people with asthma are at risk of a potentially deadly attack, according to a new survey.

Data compiled by Asthma UK in conjunction with the regional branches of the charity – including Asthma UK Scotland – found 36% of people with the condition are at a high risk of an attack that could kill them.

The results of the survey of almost 25,000 sufferers, published today to mark World Asthma Day, show people with asthma are considerably underestimating their risk of having an attack.

Around 368,000 people in Scotland suffer from asthma, with three people across the UK suffering a fatal attack every day. At the same time, someone is admitted to hospital with a potentially fatal asthma attack every seven minutes in the UK.

The charity said such attacks and hospital admissions could be prevented if sufferers were better trained to spot and treat the early warning signs.

The Triple A Test, used to survey participants in the study, has been developed to help sufferers identify their risk of having an asthma attack and advise them what they can do to reduce it.

It asks simple questions about factors which have all been independently linked to an increased or highly increased risk of an asthma attack that could lead to a hospital admission – for example how often respondents use their blue inhaler, which relieves asthma symptoms.

Gordon Brown, Asthma UK's national director, said: "It's extremely worrying that many people with asthma do not realise their own risk of ending up in hospital.

"As up to 75% of emergency hospital admissions are preventable with better management and support it's vitally important people understand their asthma and crucial that they are supported by healthcare professionals who can help them to reduce their risk."

One of the respondents, Natalie Lussey, 22, from Livingston, West Lothian, said: "When I was in my teens, my asthma improved so I stopped taking my medication and I thought I was fine and that I'd grown out of it.

"But when I was finishing university it reared its ugly head again, so now I'm serious about taking my medication because I want to prevent attacks.

"Most of my attacks are at night ,which is really frightening because I wake up and can't breathe. There's no-one around to help me and it feels like the world is closing in around me. Every time it happens it upsets me for days afterwards and I feel very vulnerable."

Alex Kapranos, lead singer of Franz Ferdinand, who also did the test, said he was not surprised to learn he was in the high-risk category for an attack. He added: "I've had asthma all my life and understand the risks. A couple of things were surprising, though. I have a peanut allergy and knew it was connected in some way, but I didn't realise it was an indicator of risk. More surprising was the question about depression. I do get depressed, but never knew there was a connection."

The charity also spoke to people six weeks after they had taken the test. It found that 85% of respondents would recommend the test to others with asthma and more than half (54%) said it had made them think more seriously about their condition.

To take the Triple A (Avoid Asthma Attacks) test, visit asthma.org.uk/TripleA.