Asthma together with allergic diseases are among the great diseases of our time and constitute the largest disease group among children and adults up to middle age. It is estimated that 300-400 million people worldwide have asthma. The prevalence of asthma has increased significantly in many parts of the world. For the dimension of care, it is important to know about how the prevalence of major diseases such as asthma changes over time. Changed environmental exposure and lifestyle can be important for incidence, disease progression, remission and relapse.
The overall purpose of the study is an epidemiological update on the prevalence, incidence, remission and relapse of asthma as well as the factors that correlate with these. Both cross-sectional data and longitudinal data are used.
The research project was started in 2008 and has resulted in nearly 100 scientific publications over the years. Many different researchers from different disciplines have been involved.
Among our recent results, we have been able to show that the prevalence of asthma has increased slightly in 2008-2016 and is now just over 11%, the largest increase seen in the 16-25 age group. The prevalence of respiratory symptoms also increased in Västra Götaland during this time period. The occurrence of allergic rhinitis was the most common symptom and it also showed the greatest increase. Preliminary data show that the incidence of asthma remains at approximately 2/1000 / year and co-varies with female sex and prevalence of allergic rhinitis.
As the publications are numerous, here follows a brief summary of previous results:
Although a five-fold increase in the use of asthma medicine has taken place since the early 1990s, and that the use of inhaled steroids has increased from 1.5 to 7.7% in the population, the adherence to asthma medication has been shown to be low. There is potential for improvement in asthma care in order to improve the adherence of asthmatics in general and thereby achieve asthma control.
By using a few questions in the 2008 postal survey, a group of asthmatics with multiple symptoms despite use asthma medication could be identified; these made up 2% of the population and 25% of all asthmatics. The definition was associated with clinical signs of more severe disease and not dependent on inferior adherence. By defining symptoms indicative of severe asthma and examining these phenotypic signs, we were able to show that at least 1/3 of all people with asthma have at least one sign of severe disease and the variation is great. The prevalence of the phenotype with asthma-COPD overlap accounted for 3% of the population, and these have poorer lung function and more clinical symptoms than those with only asthma or COPD.
Smoking has a negative impact on the respiratory tract already after a few years, which is especially evident among young women who not only smoke more than young men, they also have an earlier smoking debut and a higher incidence of bronchitis symptoms. In collaboration with the OLIN studies, we have shown that the use of e-cigarettes is most common among smokers, and those who use both regular cigarettes and e-cigarettes have a higher incidence of respiratory symptoms.
Regarding rhinitis, we have been able to show that the protective effect of growing up on a farm on the occurrence of rhinitis, previously shown in studies in children, remains throughout life. In the case of allergic sensitization, in particular, pollen sensitization has increased, as has multisensitization, where the latter is strongly correlated with asthma. Food hypersensitivity shows a rising trend among adults, however, the correlation with specific IgE, which would indicate allergy, is generally low. WSAS has many uses and selected groups of participants have been included in mechanistic studies and the random selection has served as a control material for studies of a Swedish normal equation for lung function, scoliosis, esophageal atresia and as well as severe wheezes in childhood.
Group members currently working on the project