Table 3

Smoking and clinical stage: Stockholm workshop scale

Smoking	Stage 0–1 Minimal symptoms	Stage II Moderate symptoms	Stage III Severe symptoms
Non-smoker	86	85	113	284
Smoker	74	134	109	317
Total	160	219	222	601
Smokers (%)	46.3	61.2	49.1	52.8

p=0.007 by χ² teat.