Understanding
severe & uncontrolled asthma
Executive summary
• Asthma is a common disease, with 315 million individuals worldwide currently suffering from the disease.1
• The number of patients suffering from asthma continues to grow globally and by 2020 will likely affect as many
as 400 million people.2
• Established therapies have their limitations in severe asthma control.3 More than 40% of severe asthma is
uncontrolled.4
• Patients with uncontrolled, severe asthma experience symptoms every day, which can impact their quality
of life (QoL).5
• Eosinophils can play an important role in the inflammatory response, and reducing eosinophils may be beneficial
across the range of asthma outcomes, including lung function, symptoms, exacerbations and hospitalisations.6,7
Understanding severe asthma
Asthma is one of the most common chronic diseases in the world.8 It is a
long-term condition of the airways that makes breathing difficult.8 Currently 315
million individuals suffer from asthma worldwide, including an estimated 30 million
people in Europe and 17.7 million adults in the US.1,9,10
Asthma prevalence continues to increase, and it is estimated that by 2020 asthma
will likely affect as many as 400 million people.2
Most people with asthma can manage their symptoms. However, up to 10% of asthma cases are severe, of which
approximately 40% are uncontrolled.3,4
The burden of uncontrolled asthma
Asthma is a complex and potentially life-threatening disease for those patients who remain uncontrolled.3 Patients
with uncontrolled asthma are significantly more likely to suffer from poor outcomes and medical emergencies.9
Severe, uncontrolled asthma is associated with frequent exacerbations and an eight times higher risk of death than
severe asthma.3,9 The number of hospital stays per year is about 10 times higher for individuals with uncontrolled
asthma than those with controlled disease.9
Uncontrolled asthma also has a significant impact on the
everyday lives of patients.8 Uncontrolled asthma results in
a significant increase in debilitating symptoms, including
night-time symptoms and impact on everyday activities
due to shortness of breath, which could require patients
to plan when and where they can travel.5 Normal daily
activities are affected more than once per week for 91%
of uncontrolled versus 0% of controlled asthma patients.9
Daily activities affected more than once a week for...9
Uncontrolled asthma patients:
91%
Controlled asthma patients:
0%
Additionally, patients with uncontrolled asthma require considerably more medication, including rescue inhaler and
oral corticosteroids.9 A 2014 report found that 63% of patients with uncontrolled asthma used oral corticosteroids
more than once per week within the past year, compared to 23% of patients whose asthma was controlled.9 The
higher doses of medication also result in more side effects, such as depression, sleep disruption, weight gain and
skin conditions. These side effects increase the already substantial burden of severe, uncontrolled asthma and its
impact on QoL.11
Growing economic burden
There is a significant physical and socio-economic burden with asthma related health costs. Asthma results in an
estimated 346,000 deaths and 22 million disability-adjusted life years lost each year worldwide.12 Adults and
children with uncontrolled asthma, as well as adults who are caregivers of children with uncontrolled asthma, lose
a considerable amount of time at work and in education, with twice as many days off than controlled asthma.13
The economic burden of asthma is high, with annual direct costs in the US estimated to be approximately $50
billion, mostly related to medication, office-based visits and hospitalisation.14 In Europe, the cost of asthma care is
estimated to be £18 billion per year, with lost productivity accounting for almost £10 billion of this cost.9
Patients with the poorest control account for the greatest burden of disease.15 Patients with uncontrolled asthma
are 27% more likely to use emergency services and 20% more likely to be hospitalised than those with less severe
disease.9 Consequently, while severe asthma accounts for 10 percent of patients; severe, uncontrolled asthma
accounts for 50% of the economic burden.15
The role of eosinophils in asthma
An important measure of lung function is FEV1, the volume of air
that can be forced out in one second after taking a deep breath.
There is a strong association between greater reductions in
eosinophil levels and improvements in FEV1.7
Change in sputum eosinophils (%)
Eosinophils have long been recognised as strongly associated with asthma and poor outcomes in a significant
proportion of patients.16 Eosinophils are white blood cells that
drive airway inflammation and hyper-responsiveness, which
Correlation between changes in
respond to stimulus by allergens or pollutants in the airway.17
sputum eosinophil and lung function7
Eosinophils can play an important role in the inflammatory
70
response, and reducing eosinophils may be beneficial across the
60
50
range of asthma outcomes, including lung function, symptoms,
40
6,7
exacerbations and hospitalisations. The greater the control of
30
eosinophils, the greater the potential benefit, making eosinophils
20
10
an important therapeutic target.16,18
0
-10
0
10
20
30
40
50
60
Change in FEV1 (%)
Adapted from Di Franco A, Bartoli ML, Carnevali s, et al,2003
1. To T, Stanojevic S, Moores G, et al. Global asthma prevalence in adults: ndings from cross-sectional world health survey. BioMed Central Public Health. 2012: 12(204) 2. Chanez
P, Humbert M. European respiratory review: Asthma: still a promising future? European Respiratory Review. 2014, 23 (134) 405-407 3. Fernandes AG, Souza-Machado C, Coelho
RC et al. Risk factors for death in patients with severe asthma. J Bras Pneumol. 2014; 40(4): 364-372 4. Adelphi Real World Respiratory Disease Specific Programme. 2012-2014.
[Asthma patient data file], Bollington, UK. Unpublished raw data, cited with permission. 5. Asthma UK. https://www.asthma.org.uk/globalassets/health-advice/living-with-asthma/
Fighting-for-breath.pdf. Accessed August 2016 6. Green RH, Brightling CE, McKenna S, et al. Asthma exacerbations and sputum eosinophil counts: a randomised controlled trial.
Lancet. 2002 Nov 30;360(9347):1715-21. 7. Di Franco A, Bartoli ML, Carnevali s, et al. Analysis of sputum cell counts during spontaneous moderate exacerbations of asthma in
comparison to the stable phase. J Asthma 2003; 40(2) 155-162. 8. World Health Organization. “Asthma” Available from: http://www.who.int/mediacentre/factsheets/fs307/en/.
Last accessed August 2016. 9. Price D, Fletcher M, van der Molen T. Asthma control and management in 8,000 European patients: the REcognise Asthma and LInk to Symptoms
and Experience (REALISE) survey. NPJ Prim Care Respir Med 2014; 12; 24: 14009. 10. Centers for Disease, Control and Prevention (CDC). Respiratory & Allergies. Available from:
http://www.cdc.gov/nchs/fastats/asthma.htm Last accessed August 2016. 11. Hyland ME, Whalley B, Jones RC, et al. A qualitative study of the impact of severe asthma and its
treatment showing that treatment burden is neglected in existing asthma assessment scales. Quality of Life Research. 2015: 24 (3) 631-619. 12. The Global Asthma Network.
“Global Asthma Report” Available from: http://www.globalasthmareport.org/resources/Global_Asthma_Report_2014.pdf Last accessed August 2016. 13. Dean BB, Calimlim BM,
Kindermann SL, et al. The Impact of Uncontrolled Asthma on Absenteeism and Health-Related Quality of Life. J Asthma. 2009; 46(9): 861-866. 14. Barnett SBL, Nurmagambetov
TA. Costs of asthma in the United States: 2002-2007. 15. World Allergy Organization. The management of severe asthma: economic analysis of the cost of treatments for severe
asthma. Available from: http://www.worldallergy.org/educational_programs/world_allergy_forum/anaheim2005/blaiss.php. Last accessed August 2016. 16. Garcia G, Taille C,
Laveneziana P, et al. Anti-interleukin-5 therapy in severe asthma. Eur Respir Rev. 2013 Sep 1;22(129):251-7. 17. Possa SS, Leick EA, Prado CM et al. Eosinophilic inflammation in
allergic asthma. Front Pharmacol. 2013 Apr 17;4:46. 18. Griffin E et al. J Allergy Clin Immunol 1991; 87(2): 548-557.
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Global ATLAS ID: 1,006,744.011; Date of preparation: September 2016; Date of expiration: September 2017