Table 1.
Characteristics of participants in included studies
| Author (year) | No in study* | No of continuous smokers† | No of quitters† | Continuous smokers (%)‡ | Men (%) | Squamous cell tumour (%) | Small cell lung cancer (%) | Stage 1-3a/limited (%) | Grade 1-2 (%) |
|---|---|---|---|---|---|---|---|---|---|
| Non-small cell lung cancer studies | |||||||||
| Baser (2006)16 | 93 | 47 | 46 | 51 | 49 | NR | 0 | 90 | NR |
| Kawaguchi (2006)22 | 62 | 16 | 19 | 46 | 81 | 48 | 0 | 100 | NR |
| Nia (2005)17 | 311 | 169 | 35 | 83 | 86 | 47 | 0 | 92.1 | NR |
| Saito-Nakaya (2006)24 | 238 | 6 | 92 | 6 | 60.9 | 21 | 0 | 81 | NR |
| Shiba (2000)25 | 156 | 8 | 61 | 12 | 72 | 59 | 0 | 100 | 72 |
| Small cell lung cancer studies | |||||||||
| Johnston-Early (1980)21 | 112 | 57 | 35 | 62 | NR | 0 | 100 | 29 | NR |
| Kawahara (1998)23 | 70 | 33 | 31 | 52 | 60 | 0 | 100 | 100 | NR |
| Tucker (1997)26 | 611 | 214 | 181 | 54 | 55 | 0 | 100 | 79 | NR |
| Videtic (2003)27 | 215 | 79 | 107 | 42 | 60 | 0 | 100 | 100 | NR |
| Yoshida (1996)28 | 61 | 26 | 33 | 44 | 80.3 | 0 | 100 | 85 | NR |
NR=not reported.
*Some studies also included former smokers and non-smokers, whose data were not included in meta-analyses presented here; characteristics of each study are for whole study population.
†See text for definition of smoking categories.
‡Continuous smokers/(continuous smokers+quitters)×100.