What is severe asthma? 0:07 – 1:34
Severe asthma is actually a problem for only a small proportion of all people who have asthma. If you look particularly in the western environments where asthma prevalence is very well understood and measured, severe asthma probably accounts for only around 5% of all the people who have asthma. The important thing about this, is that we used to say severe asthma was if you had a severe attack and you ended up in hospital or even had to have something like an intervention such as intensive care or ventilation. We now know that many people who might have presented like that don’t have severe asthma at all, they simply didn’t take medication for their asthma. So we now define severe asthma as asthma symptoms and abnormal lung function that persist despite optimal medication, both adherence and prescribing of appropriate medication and when you know for certain that the patient is adherent and they’re receiving the best possible medications on offer, and they’re pursuing a healthy lifestyle, but they still have symptoms, abnormal lung function and exacerbations, then they have severe asthma.
Who does asthma affect? 1:35 – 2:54
People with severe asthma can be of any age, they can be from as young as five or six years old through to 96 years old. Anyone can have severe asthma. There are particular features about severe asthma that tend to mean that it more often affects people in their young adult life and through to their middle adult life. More typically severe asthma will occur in someone who has had lifelong asthma since childhood, it very rarely affects somebody who had very trivial or mild asthma in childhood suddenly in their later life getting severe is not the usual pattern of events, it’s much more normally something that declares itself in childhood or adolescence as an aspect that means they are never completely symptom free. Their treatments are never completely controlling their events, in terms of exacerbations and so they’ve never had a prolonged symptom for an interval, where as many people with asthma who are well treated achieve very prolonged periods without any symptoms, as long as they’re taking their medication.
What happens to a person who is suffering from an asthma attack? 2:55 – 4:26
Somebody who has a severe asthma attack can have either very sudden onset of very extreme breathlessness where they can’t breathe, they would often describe themselves wheezing and not getting relief from their inhalers, particularly their reliever medication, where they step up very quickly when they become much more breathless; these events can be brought on by a huge range of different triggers, things like a viral respiratory infection, is a very common trigger. On the other hand, sudden exposures to things they might be allergic to, things like cats and dogs or severe reactions to moulds or house dust, if the burden is big enough. But for some people, it’s just an evolution that never has a complete answer, you can never entirely say what brought it on, but their asthma gets out of control. Lots more symptoms, very breathless, coughing, wheezing, can’t really do their usual things, don’t get relief from their reliever medication and when that happens they need a lot more anti-inflammatory, they need oral medications as well as inhaled and they may well need very frequently do hospital admission and occasionally intensive care admission and assisted ventilation. So a severe episode can be life threatening.
What is the prevalence of asthma in the Asia-Pacific and around the world? 4:27 – 5:53
The prevalence of severe asthma in Asia is really not fully documented. There are some countries that have attempted asthma epidemiologic studies, but the prevalence of asthma in Asia is lower than it is in many Anglo-Saxon western countries. So in Australia for instance, the prevalence of asthma in adults is around 12%, in children around 18-20%. In Asia, it’s about half that and as I mentioned to you, there is also only a small proportion of people with asthma who have severe asthma. So we have to presume that in Asia, it’s probably, being around 10% of the whole asthma population, the prevalence of severe asthma is probably only 0.5-1%. Yes, the prevalence of asthma and severe asthma is much higher in Australia, New Zealand, the UK, Canada, some parts of Europe, but in fact, we do have a high burden of asthma in our part of the world here in Australia and New Zealand and many of the leading clinical research papers have come out of Australia and New Zealand for that very reason.
Why is the prevalence of asthma higher in countries like Australia? 5:54 – 7:17
We don’t know why there is more asthma in Australia and New Zealand, for instance or in the UK or Canada. Obviously we do have better epidemiologic records and so there may well be some underreporting, underdiagnosing in Asia of course, because access to medical services is not as good as it is in many other parts of the world. On the other hand, even when you do really rigours epidemiologic studies in Asia, the prevalence rates for asthma appear to be significantly lower than they are in, for instance, Australia, New Zealand and the UK. So it may be our Anglo-Saxon inheritance is really important, certainly most of us, strongly believe asthma is a consequence of genes and environment, you need both and so although we have a relatively clean environment, we have one that is very allergen rich, we have a temperate environment and fungi and mites and moulds and pollens, they all love our environment, so those sorts of exposures are one of the things that causes the inflammation of asthma – so, a range of different range of reasons, but we definitely do see lower prevalence’s in Asia than in Australia and New Zealand.
Why is Australia and the broader Asia-Pacific region important for running clinical trials? 7:18 – 9:22
Australia is a really stand out country, in terms of asthma clinical trials, clinical knowledge, expertise and strong methodology around asthma. Australia made asthma a national health priority back around 2000; we’ve built really good education into primary care settings, so primary care doctors are very aware of asthma as a problem. Although we don’t measure lung function nearly as often it should be measured to make the diagnosis, the clinical care of asthma is good and so we have that and on top of that we have really excellent academics; we have academic researcher’s in respiratory disease, in asthma and COPD who are leaders internationally and who’ve done really innovative, independent investigator studies as well as participated in many, very large, national and global randomised control trials. So we have experience, expertise, we have people who have the disease and who are willing to participate and we can conduct really good studies with reliable data. Asia is important because it’s untapped and it’s an opportunity and there is still a very significant proportion of the population who have asthma who don’t receive good medication and good quality care. So there’s a real opportunity to conduct clinical trials there and we at the George have basis in Asia, which enables us to do those trials really well to a very high professional standard and with the unique contribution that we have from the scientists in the George and the clinicians in the George along with our clinical operations capacity, we can really deliver very strongly in asthma and COPD studies.
Is the future bright for sufferers or those at risk of suffering severe asthma? 9:23 – 10:40
I think the future is bright for people with severe asthma, though it really depends how long they have had it. If you’ve had severe asthma all your life and you are now in your sixties or seventies you have probably lost a lot of lung function and as yet we don’t have any drugs that can turn that around. What we do have is medications that really significantly reduce symptoms and also exacerbation episodes were people land in hospital or they have to take a lot of additional medication. So I think the future is much brighter than it was but it is most bright for younger people who have severe asthma, because they are going to start treatments that are going to intervene in the disease much earlier and are then going to prevent the loss of lung function that happens of over time. If you have asthma that’s not well controlled despite optimal inhaled medications, then progressively you lose lung function and so getting a very good treatment late in your life is nothing like as good as getting a very good treatment early in your life and that’s what offers the really bright hope for people with severe asthma now.