Characteristics of the studies included in the systematic review
| Study | Country | N | Gene tested | Female (%) | Mean age | Cigs/day | Methodological quality* | Statistical quality† | Reliability and validity‡ |
| I. Studies examining effectiveness of genetic testing | |||||||||
| Hishida et al (2010)25 | Japan | 533 | L-myc | 6.2 | NA | NA | 5 | 2 | 1 |
| Ito et al (2006)26 | Japan | 697 | L-myc | 415 | 46.5 | 22.2 | 5 | 3 | 1 |
| Lerman et al (1997); Audrain et al (1997)29 30 | USA | 426 | CYP2D6 | 38.6 | 43.6 | 22.7 | 6 | 5 | 2 |
| McBride et al (2002)27 | USA | 557 | GSTM1 | 60 | 44.5 | 15.5 | 6 | 3 | 2 |
| Sanderson et al (2008)28 | UK | 61 | GSTM1 | 62 | 49 | 19 | 8 | 4 | 1 |
| II. Studies examining smokers' interest in genetic testing | |||||||||
| Ostroff et al (1999)31 | USA | 148 | GSTM1 | 43 | 39.2 | 17 | 5 | 3 | 2 |
| Sanderson et al (2010)32 | USA | 116 | GSTM1 | 53.4 | NA | NA | 7 | 3 | 2 |
| Tercyak et al (2006)33 | USA | 211 | NA | 16.4 | 69 | NA | 5 | 3 | 1 |