Table 1. The baseline characteristics of study population.
Characteristics | Patients (n = 819) | Controls (n = 803) | P** |
Age (years) | 57.35 (10.51) | 57.04 (9.72) | 0.846 |
Sex (male) | 64.84% | 64.76% | 0.974 |
Smokers | 36.26% | 7.97% | <0.0005 |
Drinkers | 16.85% | 8.09% | <0.0005 |
COPD history | 14.53% | 4.73% | <0.0005 |
Family history of cancers | 11.36% | 10.83 | 0.738 |
Lung cancer subtypes | |||
Squamous cell cancer | 36.16% | −* | |
Adenocarcinoma | 31.75% | − | |
Small cell cancer | 19.79% | − | |
Others | 12.3% |
Abbreviations: COPD, chronic obstructive pulmonary disease. Data are expressed as mean (standard deviation or SD) or percentage as indicated.
data not available.
P values were calculated by using unpaired t-test for age, and by χ2 test for other categorical characteristics.