was shown in the ECRHS study.12 Use of medications is also
more common than diagnosis of asthma. All of these factors
make it difficult to estimate what is the true prevalence of
asthma and if the prevalence is rising or declining.14 Previous
studies on Icelandic farmers frommore than two decades ago
found high prevalence rates of respiratory symptoms among
farmers in all age groups.10,11 Cough was found in 11%
compared to 5.8% in the current study and dyspnea in 7%
compared to 4.3%.