Abstainers (N=17) Whole sample (N=37)*   EC SB Mean difference (EC-SB) Sig (95%CI) EC SB Mean difference (EC-SB) Sig (95%CI)   Mean (SD)     Mean (SD)     MPSS score** 2.52 (0.76) 2.51 (0.68) 0.01 0.933 (-0.28-0.31) 2.37 (0.78) 2.46 (0.77) -0.09 0.149 (-0.27- 0.09) Urge to smoke 3.26 (0.71) 3.65 (1.14) -0.39 0.038 (-0.74- -0.02) 3.28 (0.89) 3.82 (1.68) -0.54 0.001 (-0.81- -0.27) Urge to smoke strength 3.18 (0.81) 3.59 (1.18) -0.41 0.052  (-0.82-0.01) 3.19 (0.91) 3.78 (1.21) -0.59 <0.001 (-0.87- -0.32) Urge to smoke frequency 3.35 (1.00) 3.71 (1.21) -0.36 0.109 (-0.80- 0.09) 3.38 (1.06) 3.86 (1.25) -0.48 0.015 (-0.84- -0.14)

Table 3: Rating of withdrawal symptoms and urges to smoke experienced over the day, *N=2 did not attend evening session and gave responses via telephone, **Mood and Physical Symptoms Scale: 5 items (depressed, irritable, restless, hungry, poor concentration) rated on 5-point scale, Urge to smoke: Frequency and strength rated on 6-point scale.