The demographic characteristics of asthma patients in Japan, stratified by age, sex and prefecture

Abstract

Background:
The demographic characteristics of asthma patients in Japan are not known in detail. The investigation of regional differences in prevalence of asthma is useful to identify factors that might predispose individuals to asthma.
Methods:
We examined data from the Ministry of Health, Labour and Welfare “Vital Statistics” and “Patient Survey” reports of 1999, 2002, and 2005.
The number of patients with asthma per 1000 population stratified by age, sex and prefecture was analyzed.
Results:
Although the total number of patients with asthma reported in 1999, 2002, and 2005 did not significantly differ, there was a significant increase over time in the number of asthmatic boys aged 0 to 14 years and the number of asthmatic girls aged 0 to 4 years. There were also significant differences in asthma prevalence by prefecture: prevalence was higher in Hokkaido and in the area adjacent to the Sea of Japan in the Tohoku region, and lower in Okinawa prefecture and the Kinki region in 1999, 2002, and 2005.
Conclusion:
In Hokkaido, the prevalence of asthma was consistently high, and consecutively increased, from 1999 through 2005.