Insights, attitudes, and perceptions about asthma and its treatment: a multinational survey of patients from Europe and Canada
© Sastre et al. 2016
Received: 30 December 2015
Accepted: 14 March 2016
Published: 4 May 2016
Asthma surveys completed within the past 10 years in the Americas and the Asia-Pacific region have shown significant underassessment of asthma severity in addition to undertreatment of asthma and have suggested the need to improve long-term asthma management. In this study, we examined the frequency of asthma symptoms and severe episodes, patients’ perceived asthma control, and use of asthma medications in Europe and Canada.
The Asthma Insight and Management survey (54 questions) was conducted in Europe (Germany, Italy, Spain and the United Kingdom) and Canada from June 14 through July 28, 2010. Telephone interviews were conducted with randomly screened patients or parents of adolescents (aged 12–17 years) with asthma; patients younger than 12 years of age were excluded from the survey. Responses were reported separately for each country and in total for all five countries.
Seventy-five thousand three hundered thirty-five households were screened, and 2003 patients were interviewed. The survey respondents represented a wide range of severity. Overall, 26 % of patients reported symptoms daily or most days over the past 4 weeks, but most patients (81 %) perceived their asthma to be well or completely controlled. Over the past year, 41 % of patients had episodes of frequent/severe symptoms, and 50 % reported acute treatment (e.g. hospitalization, emergency visit, unscheduled physician visit) for asthma. Across countries, 52 % of patients reported taking controller medication every day over the past year, 27 % reported not taking any controller medication, and 14 % reported stopping controller treatment for 3 months or longer the last time they stopped. Many patients considered asthma well controlled if each year they had only two urgent doctor visits (50 %), three or four exacerbations (60 %), and/or one emergency room visit (41 %).
This is the largest survey of patients with asthma in Europe and Canada in more than a decade.
In 2010, many surveyed patients in Europe and Canada reported features indicating uncontrolled asthma, yet the majority believed they were well controlled, indicating that they had low expectations of long-term asthma management. Use of controller medications was substantially less than recommended in treatment guidelines.
Asthma is a global public health problem affecting an estimated 235 million people . Poorly controlled asthma results in symptoms that are burdensome and that may precede clinically significant exacerbations. The National Review of Asthma Deaths (NRAD) reported that asthma mortality in the United Kingdom was among the highest in Europe and reviewed information on 195 patients who died from asthma between February 2012 and January 2013 . Only 23 % of these patients had been provided personal asthma action plans to identify factors that trigger or exacerbate asthma. The NRAD also found evidence that reliever medication was overused and preventer medication was underused in the United Kingdom . Patient surveys reported in the previous two decades have indicated an inadequate level of asthma control based on symptoms, activity limitations and acute treatment (e.g. hospitalization) [3–13]. The 1996 European Community Respiratory Health Survey (ECRHS) found a high rate of asthma attacks and asthma medication use among asthmatic adults aged 20 to 44 years to be particularly high in western Europe, the United Kingdom, Sweden, Australia, New Zealand and the United States; this contrasts with particularly low rates in Estonia, Greece and Spain . A survey using the same sampling strategy and instruments as the ECRHS was conducted in 1993 to 1994 at six sites across Canada, and it evaluated the sex-specific prevalence of asthma attacks and asthma medication use. This survey found the prevalence of asthma attacks and asthma medication use to be higher among women than men in all sites, except for a higher rate of asthma attacks among men in Vancouver . The International Study of Asthma and Allergies in Childhood (ISAAC; 1998) reported asthma-symptom prevalence rates for 13- to 14-year-old children in 56 countries that ranged from 1.6 % (Indonesia) to 36.8 % (UK) In addition, up to approximately 30 % of Canadian children in the ISAAC survey reported asthma symptoms over the past 12 months . In the 1999 Asthma Insights and Reality in Europe (AIRE) study of adults and children with asthma (N = 2803) in seven European countries, only 5 % of patients met all of the criteria for asthma control, and 7 % of patients had overnight hospitalization in the previous year . A later analysis of AIRE study data found overall that >50 % of children and >40 % of adults with severe asthma perceived their asthma to be well controlled and that disparities between patient perceptions and actual control were substantial although variable among the seven countries . In a 1996 telephone survey of Canadian patients >16 years of age with physician-diagnosed asthma (N = 829), 43 % reported frequent or very frequent symptoms of asthma. Furthermore, 26 % reported use of urgent care services in the past year, and 21 % reported an asthma flare-up (i.e. exacerbation) or need for urgent treatment within the past 6 months . Additional survey results have corroborated a lack of control considered adequate at the time by expert practitioners [10, 15].
The main goal of this Europe and Canada (EUCAN) Asthma Insight and Management (AIM) survey was to re-examine patient-reported beliefs concerning their asthma and its management and to analyze whether these beliefs have changed since previous surveys. In particular, the purpose of the study was to explore and document asthma-related patient perceptions, behaviors, and presentation patterns. Another goal of this survey was to gain a better understanding of the tools and techniques physicians currently use to assess and manage their patients’ asthma and to gauge the extent to which physicians are following Global Initiative for Asthma (GINA) guidelines  with regard to asthma assessment and management techniques.
The EUCAN AIM survey was conducted in Germany, Italy, Spain, the United Kingdom, France, and Canada from June 14 through July 28, 2010. All questions were originally drafted in English and translated to local languages. The translated questions were back-translated to English and compared for meaning against the original English version. Findings from France are not included here owing to inaccurate translation of the questionnaire, which was identified before completion of the survey in France. Households were sampled by random-digit dialing and systematically screened to determine whether there were any household members with current physician-diagnosed asthma, and if so, whether they (or their child) had used any prescription medicine for control, prevention, maintenance, or regular treatment of asthma in the past year.
This survey was restricted to adults and adolescents with current asthma, so households with no current patients with asthma or only patients younger than 12 years with pediatric asthma screened out of the survey. Patient consent was obtained before the interview began, and the respondent could refuse to cooperate at any point in the interview.
The survey was developed by the public opinion research organization Abt SRBI, Inc. (New York, NY, USA) with input from the steering committee and from prior published AIM surveys. Telephone interviews lasting approximately 40 min were conducted with patients or parents of adolescents (aged 12–17 years) with asthma. Interviewers with survey organizations based in each target country read a standard text to introduce the study and ask the survey questions. The data were not collected by doctors or other health professionals.
All patients had physician-diagnosed asthma and used asthma medication or had asthma symptoms in the past year. The survey had 54 questions (Additional file 1), and responses were reported separately for each country as well as total estimates for all five countries.
Understanding of asthma exacerbations was explored using several terms (asthma flare-ups, asthma exacerbations, asthma attacks, and asthma worsening). The frequency and duration of exacerbations or asthma worsening was documented. Respondents were provided several scenarios of exacerbations and urgent doctor visits and asked whether these indicated well-controlled asthma. Details of asthma assessment and management by the patient and their healthcare provider, use of oral corticosteroids, frequency of use of a reliever inhaler, and use of controller medications were ascertained.
Sample size and statistical analysis
The maximum margin of error for a sample size of 400 (individual country samples) is ±4.9 percentage points at the 95 % confidence level. Descriptive comparison of response rates among countries is provided, but no statistical analysis of the results was performed.
Demographic characteristic of patients
Adults and parents of adolescents (age 12–17 years) with asthma (physician diagnosed and past year medication or asthma symptoms)
Telephone screening of national random digit dialing sample of households
Mean: 37.9 min
Households screened, n
Asthmatics interviewed, n
Mean age, years
Mean age at Diagnosis, years
In addition to the reported occurrence of frequent/severe asthma episodes and exacerbations, the EUCAN AIM survey demonstrates the significant impact of asthma on patients’ day-to-day lives. Overall, 19 % of adults and adolescents reported that their asthma caused them to miss work or school in the past year, with a median of 7 days missed (Table 3), 31 % of patients reported that they had episodes of sufficient severity to be short of breath while sitting still, 23 % reported that they had severe episodes limiting their speech to only a few words at a time, and 28 % reported that they had been awakened frequently at night by asthma symptoms.
More than half of patients reported that they had taken prescription controller medicines for their asthma in the past 4 weeks. The proportion of patients with asthma using prescription controller medicines in the past 4 weeks was 49 % in Italy, 58 % in the United Kingdom, 59 % in Canada, 60 % in Spain, and 61 % in Germany.
EUCAN AIM survey responses
(N = 2003)
(n = 401)
(n = 402)
(n = 400)
(n = 400)
(n = 400)
Control classification based on 2009 GINA, %
▪ Well controlled
▪ Partly controlled
Had episodes in the past 12 months when asthma symptoms were more frequent or more severe than normal, %
▪ Median number of episodes, n
Have ever had an asthma episode perceived as life threatening, %
Have in the past year had an asthma episode perceived as life threatening, %
Missed work or school in the past year due to asthma, %
▪ Median number of days missed, n
Used quick relief medication for asthma in past 4 weeks, %
Used inhaler for quick relief of asthma symptoms at least once a week over the past year, %
Used an oral steroid (pill or liquid) to manage asthma symptoms in the past year, %
▪ Median number of times an oral steroid was used for 3 days or longer in the past year, n
How the doctor usually assesses asthma, %
▪ Has the patient fill out a questionnaire
▪ Gives the patient a breathing test or spirometry
Has a doctor-developed written action plan for asthma treatment, %
Agree with the following statements, %
▪ Maintenance medicines should be taken every day
▪ Maintenance medicines are not necessary when asthma symptoms are not experienced regularly
▪ Rescue medicines can be used every day if needed
▪ Fear of asthma exacerbations keeps me from doing the things I want to
▪ I worry about using oral steroids, like prednisone
Nearly seven of 10 patients with asthma in Europe and Canada reported that they had taken prescription quick-relief or rescue medicines for their asthma in the past 4 weeks (Table 3). This means that about 30 % had not used an inhaler in the last 4 weeks, emphasizing that many had mild or intermittent disease where one would not expect regular controller treatment to be mandatory. Forty-six percent of all subjects (range 34 % in Italy to 56 % in UK) had used an inhaler for quick relief of asthma symptoms at least once a week over the last year, indicating the presence of persistent asthma. Among patients who reported having symptoms every day, 23 % did not use rescue medications in the past year, although 66 % of these patients used controller medication every day (Table 4). Overall, however, at least 19 % of patients with daily symptoms had not used any inhaled medication in the past year. The proportion of EUCAN AIM respondents who reported taking an oral steroid (pill or liquid) to manage their asthma symptoms in the past 12 months ranged from 21 % in the United Kingdom to 50 % in Italy. On average, patients took oral steroids for 3 days or longer twice in the past year (Table 3).
In a further analysis, 19 % of patients who experienced symptoms every day did not take a controller medicine in the past year, and 11 % took it less than once a week. In contrast, among patients who experienced symptoms less frequently than once a week, 33 % did not take any controller medication in the past year (Table 4).
Attitudes about asthma
When survey respondents were asked how their doctor usually assesses asthma, 2 to 13 % of asthma patients reported that their doctor had them fill out a questionnaire. About one-quarter of patients with asthma in Canada and Italy, as well as at least half of asthma patients in the United Kingdom, Germany, and Spain said that their doctor usually assessed their asthma with a breathing test or spirometry. Many patients may have simply had peak flow monitoring rather than full spirometry. The proportion of patients reporting that they had a doctor-developed written action plan for asthma treatment was one-quarter or less in Germany, Canada, and the United Kingdom, in contrast to over one-third in Italy and Spain.
Overall, two-thirds of patients with asthma agreed that maintenance medicines should be taken every day. However, more than half of patients in Spain, Canada, and Germany also agree that maintenance medicines are not necessary when asthma symptoms are not experienced regularly. Another negative finding is that two-thirds of patients with asthma agreed with the statement that rescue medicines can be used every day if needed. Moreover, about one-third of patients with asthma in the European countries reported that they worry about using oral steroids. Patients’ attitudes and beliefs about treatment are important because they may affect asthma management and control.
The EUCAN AIM is the largest survey of patients with asthma in Europe and Canada in more than a decade. The survey was conducted by telephone interview (median time, 39.7 min) in 2420 adults or parents/guardians of adolescents (aged 12–17 years) with current diagnosed asthma. Based on national probability samples of approximately 400 persons aged 12 years and older with current asthma, the study showed significant unmet needs in asthma care in Europe and Canada, with persistence of significant asthma symptoms and exacerbations, low expectations, and marked undertreatment. Up to 19 % of those taking controller medication reported gaps in treatment of 3 months or longer. The study is limited, however, in that between-country results were not analyzed statistically and self-selection bias may preclude the generalizability of study findings to the general population. Another study limitation is that thorough data on correlations between asthma severity and medication usage were not obtained in the survey. About half of patients were very infrequent users of reliever treatment, which means almost certainly that they had mild or intermittent disease and were unlikely to be prescribed maintenance medication. The finding of low reliever use among some patients suggests they had very mild disease or were among those who reported using controller medications every day and so did not feel the need for rescue medication. However, nearly one in four patients reported that they used rescue medication every day but had daytime symptoms less than once a week. Given that assessment of asthma severity determines the medications that are required, it is not reasonable to anticipate that patients with different degrees of asthma severity would require the same controller or rescue therapy.
Patients in this survey experienced relatively frequent asthma symptoms and approximately 40 % reported symptoms to be moderately to extremely bothersome. Some patients with troublesome asthma who reported frequent bronchodilator use were not prescribed controller therapy. Findings from the National Review of Asthma Deaths (NRAD) indicate that 14 % (n = 27) patients who died from asthma in the United Kingdom were prescribed a single-component quick-relief medication around the time of death. At least 3 % (n = 5) patients were on reliever monotherapy without controller treatment . In EUCAN AIM, nearly half of patients who reported episodes of symptom worsening also reported that they needed hospitalization, emergency room care, or other unscheduled medical visits for asthma episodes or exacerbations over the past year. Over the past year, nearly one-third of patients had required a course of oral steroids, and nearly 10 % of patients reported having an episode as being sufficiently grave that they felt their life was in danger.
While our findings showed similarities across countries in patient-perceived level of asthma control, they also revealed that asthma is far from being well controlled. Our survey revealed a huge discrepancy between the proportion of asthma patients agreeing with the statement that their asthma is well or completely controlled (80 %) and the proportion who would be classified as having controlled asthma according to GINA guidelines (18 %) . The patients with asthma who were surveyed had low expectations about what constitutes well-controlled asthma given their reported symptom frequency, exacerbations, use of quick-relief medicine, and emergency room visits or other urgent care. This indicates that patients are satisfied with what clinicians consider to be an unacceptable burden of disease.
The untoward consequences of uncontrolled asthma and its impact on costs and exacerbation risk have been reported in several epidemiologic studies [17–19]. In addition, the burden of asthma identified in previous surveys of the region [4, 6–8, 14] continues to exist, even though effective controller medications are available and treatment guidelines have been widely disseminated.
Patient-reported activity limitations, missed school/work days, number of emergency visits, and number of hospitalizations in the present survey suggest a lack of improvements in asthma control in Europe and Canada over the past decade, and reveal significant unmet needs with regard to the current state of asthma care in these countries. Although most survey respondents recognized that maintenance medication for asthma should be used every day, many reported that they did not take prescription controller medicines daily. Other patients discontinued controller medicines altogether for a week or longer in the past year, and still other asthma patients had not taken asthma maintenance medicines in the past year. These findings are consistent with parallel AIM surveys conducted in the United States [20, 21], the Asia-Pacific region , and Latin America .
Daytime symptom frequency and use of rescue and controller medication among EUCAN patients
Frequency of daytime symptoms
Frequency of rescue medication use, n (%)a
Frequency of controller medication use, n (%)a
Not used in past year
1–6 / week
Not used in past year
(n = 303,a 288b)
(n = 226,a 213b)
(n = 240,a 248b)
(n = 132,a 133b)
Less than once/week
(n = 1162,a 1120b)
(n = 2063,a 2002b)
Similarities and differences between EUCAN and US AIM survey results
Proportions of patients (%)
Had well-controlled asthma based on guidelines
Had severe asthma episodes in the past year
Ever had an asthma exacerbation perceived as life-threatening
Missed work or school in the past year due to asthma
Had overnight hospitalization for asthma in the past year
Agreed with the statement that:
• maintenance medication should be taken every day
• maintenance medication is not necessary when asthma symptoms are not experienced regularly
• rescue medication can be used every day if neededd
Used prescribed controller medication in the past 4 weeks
Used quick-relief inhaled medication at least once a week over the past year
Used an oral steroid (pill or liquid) to manage asthma symptoms in the past year
Worry about using oral steroids, like prednisone
Had a doctor-developed written action plan for asthma treatment
The reporting of regular, as needed quick-relief inhaler use by two-thirds of patients in the EUCAN AIM survey is consistent with the findings of a survey involving 1022 patients with asthma in five European countries, in which 64 % of patients reported that treatment with immediate results (ie, quick relief) gave them a reason for regular use of that treatment .
In 2010, many patients in Europe and Canada had low expectations of long-term asthma management and unacceptable levels of asthma control, despite the availability of effective medications. Furthermore, their reported use of controller medications did not reflect guideline recommendations for uninterrupted daily use. Although more than half of those surveyed reporting taking controller medication every day, discontinuation of this medication was common. The survey findings yield a number of important insights about asthma and the current state of asthma management. Many patients believe that their symptoms are well controlled, despite reporting substantial symptoms and morbidity. Patients with asthma have very low expectations for controlling their disease, with 60 % considering their asthma to be well controlled if they have only three or four exacerbations a year.
Patient acceptance of asthma burden, as well as the apparent lack of conviction on treatment recommendations and goals, are persistent problems which need to be addressed by improved implementation of asthma guidelines and patient education.
Editorial assistance was provided by Ken Kauffman and Patricia Abramo, Adelphi Communications, New York, NY. This assistance was funded by Merck & Co., Inc.
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- World Health Organization. Asthma: fact sheet No. 307. Available at: http://www.who.int/mediacentre/factsheets/fs307/en/. Accessed September 18, 2015.
- Royal College of Physicians. Why asthma still kills: the National Review of Asthma Deaths (NRAD) Confidential Enquiry report. London: RCP, 2014. Available at: http://www.rcplondon.ac.uk/sites/default/files/why-asthma-still-kills-full-report.pdf. Accessed September 18, 2015.
- European Community Respiratory Health Survey. Variations in the prevalence of respiratory symptoms, self-reported asthma attacks, and use of asthma medication in the European Community Respiratory Health Survey (ECRHS). Eur Respir J. 1996;9(4):68795.Google Scholar
- Manfreda J, Becklake MR, Sears MR, Chan-Yeung M, Dimich-Ward H, Siersted HC, et al. Prevalence of asthma symptoms among adults aged 20–44 years in Canada. CMAJ. 2001;164(7):995–1001.PubMedPubMed CentralGoogle Scholar
- The International Study of Asthma and Allergies in Childhood (ISAAC) Steering Committee. Worldwide variation in prevalence of symptoms of asthma, allergic rhinoconjunctivitis, and atopic eczema: ISAAC. Lancet. 1998;351(9111):1225–32.View ArticleGoogle Scholar
- Rabe KF, Vermeire PA, Soriano JB, Maier WC. Clinical management of asthma in 1999: the Asthma Insights and Reality in Europe (AIRE) study. Eur Respir J. 2000;16(5):802–7.View ArticlePubMedGoogle Scholar
- Vermeire PA, Rabe KF, Soriano JB, Maier WC. Asthma control and differences in management practices across seven European countries. Respir Med. 2002;96(3):142–9.View ArticlePubMedGoogle Scholar
- Bellamy D, Harris T. Poor perceptions and expectations of asthma control: results of the International Control of Asthma Symptoms (ICAS) survey of patients and general practitioners. Prim Care Respir J. 2005;14(5):252–8.View ArticlePubMedGoogle Scholar
- Canonica GW, Baena-Cagnani CE, Blaiss MS, Dahl R, Kaliner MA, Valovirta EJ, for The GAPP Survey Working Group. Unmet needs in asthma: Global Asthma Physician and Patient (GAPP) Survey: global adult findings. Allergy. 2007;62(6):668–74.Google Scholar
- Cazzoletti L, Marcon A, Janson C, Corsico A, Jarvis D, Pin I, for the Therapy and Health Economics Group of the European Community Respiratory Health Survey. Asthma control in Europe: a real-world evaluation based on an international population-based study. J Allergy Clin Immunol. 2007;120(6):1360–7.View ArticlePubMedGoogle Scholar
- Accordini S, Corsico A, Cerveri I, Gislason D, Gulsvik A, Janson C, for the Therapy and Health Economics Group of the European Community Respiratory Health Survey II. The socio-economic burden of asthma is substantial in Europe. Allergy. 2008;63(1):116–24.View ArticlePubMedGoogle Scholar
- Demoly P, Gueron B, Annunziata K, Adamek L, Walters RD. Update on asthma control in five European countries: results of a 2008 survey. Eur Respir Rev. 2010;19(116):150–7.View ArticlePubMedGoogle Scholar
- Partridge MR, Dal Negro RW, Olivieri D. Understanding patients with asthma and COPD: insights from a European study. Prim Care Respir J. 2011;20(3):315–23.View ArticlePubMedGoogle Scholar
- Joyce DP, McIvor RA. Use of inhaled medications and urgent care services: study of Canadian asthma patients. Can Fam Physician. 1999;45:1707–13.PubMedPubMed CentralGoogle Scholar
- Demoly P, Annunziata K, Gubba E, Adamek L. Repeated cross-sectional survey of patient-reported asthma control in Europe in the past 5 years. Eur Respir Rev. 2012;21(123):66–74.View ArticlePubMedGoogle Scholar
- Global Strategy for Asthma Management and Prevention. Global Initiative for Asthma. 2007 Revision. 2007.Google Scholar
- Barnett SBL, Nurmagambetov TA. Costs of asthma in the United States: 2002-2007. J Allergy Clin Immunol. 2011;127(1):145–52.View ArticlePubMedGoogle Scholar
- Sullivan SD, Wenzel SE, Bresnahan BW, Zheng B, Lee JH, Pritchard M, for the TENOR Study Group. Association of control and risk of severe asthma-related events in severe or difficult-to-treat asthma patients. Allergy. 2007;62(6):655–60.View ArticlePubMedGoogle Scholar
- Haselkorn T, Fish JE, Zeiger RS, Szefler SJ, Miller DP, Chipps BE, for the TENOR Study Group. Consistently very poorly controlled asthma, as defined by the impairment domain of the Expert Panel Report 3 guidelines, increases risk for future severe asthma exacerbations in The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study. J Allergy Clin Immunol. 2009;124(5):895–902. e4.View ArticlePubMedGoogle Scholar
- Meltzer EO, Blaiss MS, Nathan RA, Doherty DE, Murphy KR, Stoloff SW. Asthma burden in the United States: results of the 2009 Asthma Insight and Management survey. Allergy Asthma Proc. 2012;33(1):36–46.PubMedGoogle Scholar
- Murphy KR, Meltzer EO, Blaiss MS, Nathan RA, Stoloff SW, Doherty DE. Asthma management and control in the United States: results of the 2009 Asthma Insight and Management survey. Allergy Asthma Proc. 2012;33(1):54–64.PubMedGoogle Scholar
- Thompson PJ, Salvi S, Lin J, Cho YJ, Eng P, Abdul Manap R, et al. Insights, attitudes and perceptions about asthma and its treatment: findings from a multinational survey of patients from 8 Asia-Pacific countries and Hong Kong. Respirology. 2013;18(6):957–67.View ArticlePubMedGoogle Scholar
- Maspero JF, Jardim JR, Aranda A, Tassirini CP, Gonzalez-Diaz SN, Sansores RH, et al. Insights, attitudes, and perceptions about asthma and its treatment: findings from a multinational survey of patients from Latin America. World Allergy Organ J. 2013;6:19.View ArticlePubMedPubMed CentralGoogle Scholar
- Partridge MR, van der Molen T, Myrseth S-E, Busse WW. Attitudes and actions of asthma patients on regular maintenance therapy: the INSPIRE study. BMC Pulm Med. 2006;6:13.View ArticlePubMedPubMed CentralGoogle Scholar
- Nathan RA, Sorkness CA, Kosinski M, Schatz M, Li JT, Marcus P, et al. Development of the Asthma Control Test: a survey for assessing asthma control. J Allergy Clin Immunol. 2004;113:59–65.View ArticlePubMedGoogle Scholar