Figure 4:
Changes in asthma prevalence among 13-14 year olds ranked by affluence and mean change per year




Key to Time Trends Chart

Top half represents high-income countries. Lower portion shows lower-and middle-countries.

Brackets contain the average prevalence of asthma in the country based on ISAAC Phase One and Phase Three data (1993–2003).

blue bar The blue bars indicate the
change in prevalence per year
between Phase One and Three.

Bars going to the right show an increase in prevalence and bars to the left show a decrease.

The length of the bar indicates the magnitude of the change.

Countries (AVERAGE PREVALENCE PHASE ONE AND PHASE THREE %)
MEAN CHANGE IN PREVALENCE PER YEAR (%)