EUGLOREH project




5.9. Asthma and allergic rhinitis

5.9.3. Data description and analysis

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5.9.3. Data description and analysis


Incidence and natural history


With respect to its natural history, asthma presents two different forms: early- and late-onset asthma.


The first one occurs in the very first childhood, affects mainly males and has a good prognosis; the second one, in general, occurs after puberty, in particular in females, and is characterized by a poor prognosis.


Different studies have pointed out that people with early-onset asthma have a greater percentage of remission than people with late-onset asthma and the minority of the patients with early-onset asthma represents about 35% of prevalent cases of the young adult population (20-44 years of age) (de Marco, 2000).


Previous studies described the history of asthma in childhood and in adulthood separately, observing that the possibilities of remission are high in children and low in adults; nevertheless, such a clean division between early- and late-onset asthma has not been noticed before for the limited age range considered in the surveys. These first results can be compared with those obtained in another study (de Marco et al, 2002), aimed at assessing the incidence and remission of asthma from birth to the age of 44 by using data from 18,873 subjects involved in a large, nationally representative, cross-sectional study carried out in Italy from 1998 through 2000. The average annual incidence rate for the 1953 to 2000 period was 2.56/1000 people per year. Incidence peaked in boys aged less than 10 years (4.38/1000 people per year) and in women aged 30 or more (3.1/1000 people per year) and showed a generational increase (incident rate ratio = 2.63 and 95% CI = 2.20-3.12 for 1974-1979 vs 1953-1958 birth cohort). The overall remission rate was 45.8% (41.6% in women and 49.5% in men, P <.001). Asthmatic patients in remission had an earlier age at onset (7.8 vs 15.9 years, P <.001) and a shorter duration of the disease (5.6 vs 16.1 years, P <.001) than patients with current asthma. The probability of remission was strongly (P <.001) and inversely related to the age at onset (62.8% and 15.0% in the <10- and > or =20- age-at-onset groups, respectively). Further studies are necessary to achieve a deeper knowledge of the natural history of asthma, from birth to adulthood, and, consequently, a better understanding of its aetiological causes and its epidemiological features.




Prevalence rates


ISAAC showed a more than 20 fold difference in prevalence data between the different centres, varying from from 3.7% in Greece  to 32.2% in UK. The existence of a significant correlation (P<0.0001) between the prevalence of asthma and rhinitis symptoms was also shown. In fact, countries with a low prevalence of asthma, such as Greece, presented also a low prevalence of rhinitis, while in other countries (such as the UK), where asthma prevalence was higher than 30%, allergic rhinitis prevalence also resulted to be higher than 15%. In Italy, the prevalence in tha same age range varied from 2.5% to 3.5% in the different centres where the data were collected.


The results of the European Community Respiratory Health Survey (ECRHS) (Burney et al, 2004) have shown once again that the prevalence of asthma varies widely, whilst the geographical pattern reflects the distributions of atopy and bronchial hyperresponsiveness. The prevalence data were compared with the results from the ISAAC: the estimates in ECRHS were lower; however, there was a good correlation between asthma (74% of country level and 36% of centre level variation explained), hay fever (61 and 73%) and eczema (41 and 50%) in the ECRHS and the corresponding data in the ISAAC. These findings can be supported by the different pattern in the prevalence of allergic symptoms provided in adulthood and childhood.


Figure 5.9.1. Wheeze in last 12 months in ECHRS and ISAAC phase I by country


Figure 5.9.2. Asthma ever in ECHRS phase II and ISAAC phase I by country.


Figure 5.9.3. Asthma by age 14 years in ECHRS and ISAAC phase I by country


Figure 5.9.4. Hay fever in ECHRS and ISAAC phase I by country.


The AIRE study (Asthma Insights & Reality in Europe) (Blanc et al, 2002) identified a total population prevalence of current asthma of 2.7% for the seven AIRE countries (Sweden, France, Italy, Spain, United Kingdom, Netherlands and Germany). The epidemiological results were globally similar among the seven countries included in the survey; however, the mean age at diagnosis (9.6 years) and the predominance of males among asthmatic patients were most remarkable in German children (p < 0,05)


The survey by Compalati et al, 2007 reported that the highest prevalence rates of asthmatic symptoms in European countries were registered in the UK - which reported 19% prevalence in adults and 35% in children - while the lowest was in Iceland - which reported 2%; in the middle of this scale. The other countries considered were: Portugal (the most recent data available indicate a 12.9% of prevalence in children, 14.7% in adolescents, while in 1992 an estimate of 4.4% among adults was recorded), Bulgaria (9% in the total population), Latvia (8.2%), Czech Rep.(8% of the general population: 11.2% in children of 6-7 years of age and 16.9% in children of 13.14 years of age), Romania (7%), Switzerland (9.1% in children and 6.8% in adults), Spain (6.3%), Croatia (6%), Serbia (6%), Greece (5.6%), Poland (5.4%), Germany (2.5%), Hungary (4%), Macedonia (3.3%) and Italy (3.2%).


Allergic rhinitis is a very common disease. As far as AR prevalence is concerned, the highest rates have been declared by Portugal, which has reported an increase in prevalence during the last three years, from 24% to 26% in the age group 15 years and older, while adolescents 13 to 14 years old presented a 37.1% prevalence. The other countries presented the following prevalence data: Greece 27.5%, Macedonia 20.8%, Bulgaria 18.3%, Latvia and Hungary 17%, Romania 15%, Switzerland 14.2% in adults and 17% in children, Czech Rep. 12.5%, Croatia 12.1%, Serbia 11.6%, Iceland 11%, Spain 10.6% and Poland 8.5% and Germany 3%. These results show that there are considerable differences among European countries.


Actually, these data are likely to underestimate the disease because many people do not undergo any medical evaluation. In the nine centres participating to the Italian Study on Asthma in Young Adults (ISAYA) (Bugiani et al, 2005), the prevalence of allergic rhinitis varied between 13.5% and 23.6% (median 18.9%) in 19982000. The AllergyNet of the May 2007 issue of Allergy (Mantovani et al, 2007), reported that in 2003 the prevalence of allergic rhinitis in Italy amounted to 4.5% since the end of 1990s, based on the national database of general practitioners. As acknowledged by the Authors themselves, this figure is much lower than the prevalence estimates recorded by questionnaire-based surveys. Indeed, in people from Northern Italy aged 2045, the prevalence of allergic rhinitis was 15.9% according to the European Community Respiratory Health Survey (ECRHS) in 199193 and had increased to 18.3% by the end of the 1990s.


Trends in prevalence rates

A substantial increase in asthma prevalence has been emphasized in several reports since the early 60s. The review by von Hertzen and Haahtela (tables 5.9.1 to 5.9.3) identified that in 13 of the 20 studies reviewed, a decreasing or stable trend for asthma or current wheeze at any time during the study period was reported. It has been emphasized in several EU countries (such as England, Italy), and elsewhere (Australia, USA), that the rising trends in asthma prevalence among adults may have reached a plateau or may even be decreasing, after having increased for decades. Data on children are more contradictory: many studies have shown stable trends in childhood asthma since the late 90s (Greece, United Kingdom), while others have shown a steadily rising asthma prevalence (East Germany, Australia).


Table 5.9.1. Summary of data on stable or decreasing trends in prevalence of asthma


Table 5.9.2. Summary of data on continuously increasing trends in prevalence of asthma


Table 5.9.3. Summary of studies showing disparities in trends for asthma and allergic rhinitis


Most centres involved in the different phases of the ISAAC studies showed an increasing prevalence of 1 or more standard error for at least one disorder, more commonly in the 67 years of age-group than in the 1314 years of age-group: for the 67 years of age-group, two of the 64 centres recorded reductions in all three disorders, 16 recorded increases, and 45 mixed changes (one centre actually reported no changes); for the 1314 years of age-group, 11 of 105 centres registered decreases in all three disorders, 20 showed increases, and 74 showed mixed changes. For both age-groups, more centres showed increases in all three disorders more often than showing decreases, but most centres had mixed changes; on the contrary, asthma symptoms were less common in the older age-group at high prevalence. There was a particularly marked reduction in current asthma symptoms prevalence in English language countries. These data provide a basis for a better understanding of these pathologies, since this epidemiological pattern seems to be related to environmental and socio-economic factors.


Mortality data


Although mortality is low, most asthma deaths result from acute exacerbations and are generally thought to be avoidable. Death from asthma may thus be considered a sentinel health event of the access to and the quality of outpatient health care.


Deaths due to asthma are estimated to be 250,000 per year worldwide. EU mortality due to asthma (death defined by ICD-10 J45-J46) is low and Standardized Death Rates (per 100,000 people) in all EU Countries are significantly decreasing over time, but for the Netherlands, no decrease in mortality has been observed since 1994(Figure 5.9.5.)


Figure 5.9.5. Trends in mortality due to asthma in selected EGLOUREH countries


The costs of health care


Data provided by the National Asthma Campaign (UK) concerning asthma primary care serving a population of 330000 people suggest that: 665.000 people with wheezing are visited in a year of observation, 44900 had asthma diagnosis, 25100 received treatment from general practitioner, 493 were the emergency admissions, 8 patients died. (Lung Health in Europe, 2003 ERJ)


According to the “European Allergy White Paper” (Allergic diseases as a public health problem in Europe, The UCB Institute of Allergy, 1997), health care providers and authorities are becoming progressively aware that allergic disorders represent a major and increasing factor in public health costs. Although they can be calculated with difficulty because of the lack of adequate data, they are estimated - in terms of health care and absenteeism, for example - at 45 billion euros a year. Allergies impair the quality of life over a long period, resulting in a continuous drain on public health resources and loss of workdays. For a better evaluation of the effective socio-economic costs, different factors must be considered, such as direct and indirect costs. A more sophisticated approach is needed: it would be useful if costs related to allergic asthma and rhinitis were included in all statistics from health providers. Antiallergic drugs should be evaluated in terms of both short- and long-term benefits on symptoms and also with respect to the improvement of the individual quality of life and long-term reduction of direct and indirect costs.


At the moment, in Europe allergic patients are underestimated, improperly diagnosed and undertreated. Major efforts are needed to redress this situation: at first by generating additional expenditure for health care systems but then reducing the cost of the allergenic care to society as a whole.


The total cost of care for asthma amounts to €17.7 billion . As a chronic disease which is often difficult to control, asthma is responsible for significant work impairment and more than a half of the cost imposed by the disease on society is represented by lost work days (indirect costs amounting to €9.8 billion) (Lung Health in Europe Facts & Figures, 2003 ERJ). The burden of asthma care in Europe is consistent and the direct costs are related to outpatient and ambulatory care (€ 3.8 billion), drugs (€ 3.6 billion) and inpatient care (€ 0.5 billion) (Lung Health in Europe, 2003).


In a review of nine studies carried out in different countries, Barnes et al, (Barnes et al, 1996) provided an estimation of the proportion of direct costs of asthma care. The average physician costs were 22% (of which 75% related to general practitioner consultations and 25% to specialist visits). Drug costs make up 37% of the total direct cost of asthma; hospital costs were 20-25%: inpatient cost were the major component (70-85%), whilst emergency room treatment was 14-18%. Nevertheless, in different Countries, such as in the Czech Republic, the number of hospitalizations for asthma symptoms seems to have decreased from 1995 until 2005 (-52%) (Tuberkulóza a respirační nemoci 2005; All these data underline the importance of nowadays available medical tools (educational programs, environmental prophylaxis, maintenance therapy etc.) for preventing heavier socio-economical costs in the future.


A study on burden of COPD and asthma was performed in the city of Dubrovnik during 2002-2006. Asthma patients (4121) were treated in hospital for 1 192 days during a five-year period. Total cost was 90 771 Euro. Average length of stay in hospital was 9.85 days and the cost of treatment per patient was 750.18 Euro (Vrbica, 2007). It was found that all analysed parameters (number of patients, length of stay, cost of treatment) was higher for COPD than for asthma.