Table 2.

NRT use among subjects in the two groups.

Duration of NRT use	A1 (n = 284)	A2 (n = 278)
2 weeks or more	41.5*	53.6*
4 weeks or more	22.9	24.8
8 weeks or more	7.4	6.8

Note: all of those who were not available at followup were considered as nonusers.

*Significant difference between the two study groups (Chi-square = 0.54, df = 1, P = 0.004).