Prevalence, risk factors and underdiagnosis of asthma in the general population aged over 60 years

Introduction
Bronchial asthma is one of the frequent chronic diseases in elderly persons. Global data show that 6.5–17% of the elderly suffer from asthma. However, there are no Polish data available on asthma prevalence in this group.

Aim
This article is a retrospective analysis of the Polish Multicentre Study of Epidemiology of Allergic Diseases (PMSEAD) results aimed at assessing prevalence and clinical characteristics in the elderly.

Material and methods
The study was conducted in 1998–1999 in 11 research centres in Poland, including the Lodz centre. The study included randomly selected subjects of both sexes. Demographics and prevalence were assessed among adults (aged 16–80 years) based on the nationwide database and the detailed clinical analysis was based on the Lodz centre database.

Results
Nationwide data were obtained from 12 970 adults, including 1057 respondents in the Lodz Province; 20.3% of respondents in Poland and 23.6% in the Lodz Province were over 60 years of age. In both groups, elderly participants significantly more frequently suffered from asthma (asthma prevalence in this group was 6.7% for Poland and 12.0% for the Lodz Province). The multivariate analysis demonstrated that age over 60 years (OR = 2.08), residence in the city centre (OR = 3.30), and occurrence of seasonal allergic rhinitis (OR = 3.11) were significant risk factors for asthma occurrence among the residents of the Lodz Province. Among the elderly in Lodz, almost 50% of patients with asthma had not had a proper diagnosis made despite reporting clinical symptoms.

Conclusions
In Poland asthma is a common and frequently underdiagnosed disease in the elderly.