1.
PRISMA flow diagram of the included studies.
2.
Rate of uncontrolled asthma assessed using the GINA symptom control.
Regression plot of rate of uncontrolled asthma against smoking.
Rate of well-controlled asthma assessed using the GINA symptom control.
Rate of partly controlled asthma assessed using the GINA symptom control.
The rate of well-controlled asthma assessed using the Asthma Control Test (ACT).
The rate of uncontrolled asthma assessed using the Asthma Control Test (ACT).