Table 1

Demographic information for the never, former, and current smokers

Never

Former

Current

n

21

31

52

Age

32.3 (10.7)

55.9 (14.7)

48.6 (15.2)

Pack years

34.0 (30.1)

34.5 (34.2)

Months since quitting

145.2 (162.82)

The mean and standard deviation (in parentheses) are reported. There is a significant age difference between the groups (P < 0.05 for all two-way group comparisons by t-test).

Beane et al. Genome Biology 2007 8:R201   doi:10.1186/gb-2007-8-9-r201