West Sweden Asthma Study: Prevalence trends over the last 18 years argues no recent increase in asthma

Jan Lötvall,Erik P Rönmark,Linda Ekerljung,Kjell Torén,Anders Lindén,Göran Wennergren,Eva Rönmark,Bo Lundbäck

doi:10.1186/1465-9921-10-94

Abstract

Asthma prevalence has increased over the last fifty years, but the more recent changes have not been conclusively determined. Studies in children indicate that a plateau in the prevalence of asthma may have been reached, but this has not yet been confirmed in adults. Epidemiological studies have suggested that the prevalence of asthma in adults is approximately 7-10% in different parts of the western world.We have now performed a large-scale epidemiological evaluation of the prevalence of asthma and respiratory symptoms in adults between the ages of 16-75 in West Sweden. Thirty thousand randomly chosen individuals were sent a detailed questionnaire focusing on asthma and respiratory symptoms, as well possible risk factors. Sixty-two percent of the contacted individuals responded to the questionnaire. Asthma prevalence, defined as asthma diagnosed by a physician, was 8.3%. Moreover, the prevalence of respiratory symptoms was lower compared to previous studies. The most common respiratory symptom was any wheeze (16.6%) followed by sputum production (13.3%). In comparison with studies performed 18 years ago, the prevalence of asthma has not increased, and the prevalence of most respiratory symptoms has decreased. Therefore, our data argues that the continued increase in asthma prevalence that has been observed over the last half century is over.

Highlights

In terms of prevalence and morbidity, asthma has increased in most parts of the world during the second half of the past century [1,2,3]
The increase was first recognised in Australia, New Zealand and in areas of the United Kingdom (UK) and the USA, countries in which the mortality in asthma increased at the time [1,4,5]
This study presents the most updated information on the current prevalence of asthma and respiratory symptoms in northern Europe

Summary

Introduction

In terms of prevalence and morbidity, asthma has increased in most parts of the world during the second half of the past century [1,2,3]. Less change in the prevalence, morbidity and mortality was seen in Continental [6,7] and Eastern Europe [8]. Recent studies, including the ISAAC III [14], suggest that the increase in asthma among children and adolescents has leveled off in several westernized countries [15,16,17]. There are no recent published studies of the change of prevalence in adult asthma and symptoms common in asthma

Methods

Results

Conclusion