1.
Standardized path coefficients for Belgian and French (in parentheses) residents for handwashing ( N = 3744).
2.
3.
4.
5.
6.
Standardized path coefficients for Belgian and French (in parentheses) residents for limitation of social contacts ( N = 3744).
Daily new confirmed COVID-19 cases per million people in Belgium and France.
Daily new confirmed COVID-19 deaths per million people in Belgium and France.
COVID-19 government response stringency on lockdown in Belgium and France.
PRISMA flow diagram of the included studies.
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.