Supplementary material
Please note: supplementary material is not edited by the Editorial Office, and is put online as it has been supplied by the author.
Files in this Data Supplement:
- Table S1 -
GOLD percentages in the overall sample by gender, age, smoking habit and asthma
- Table S2 -
Results of multinomial logistic regression (relative risk ratio and 95% confidence interval) (stage GOLD)
