Table 1.

Abstinence in studies testing pharmacological interventions, behavioral intervention, and combined (pharmacological and behavioral) interventions to reduce smoking rates among smokers not ready to quit.

Reference & Country	Sample Size	Eligibility Criteria	Control/Treatment conditions	Other Treatment Components	Follow-up (months)	Outcome	Smoking Abstinence Rates		Effect Size OR (95% CI)
							Treatment %(n/N)a	Control %(n/N)a
Pharmacological Interventions
Bolliger 2000; Switzerland	400	Smoke >15 CPD for ≥ 3 years Have an exhaled-air CO level for at least 10 ppm Failed at least 1 serious quit attempt in past 12 months Unwilling or unable to quit	Placebo Nicotine inhaler for 18 months	Counseling on reduction in 9 clinic visits	24	PP d	10.5% (21/200)	8.5% (17/200)	1.24 (0.63 – 2.41)
Wennike 2003; Denmark	411	Smoke ≥ 15 CPD for >=3 years Failed at least 1 serious quit attempt in past 2 years Have an exhaled-air CO level for at least 15 ppm Not intending to quit in next month	Placebo Nicotine gum for 12 months	Counseling on reduction in 9 clinic visits	24	PP	9% (19/205)	3% (7/206)	2.73 (1.17 – 6.35)
Etterb 2004; Switzerland	534c	Smoke ≥20 CPD Not intending to quit in next 6 months	No-intervention Placebo NRT (free choice; patch, inhaler, or gum) for 6 months	20-page booklets on reduction	26	PP	12% (32/265)	12% (29/269)	1.12 (0.66 – 1.90)e
Hatsukami 2004; USA	594	Smoke ≥20 CPD Not quit for >3 months in previous year Have at least 2 failed quit attempts including 1 with NRT	Placebo Bupropion for 26 weeks	Written materials Counseling on reduction in 3 telephone contacts	6	CA	7% (20/295)	5% (16/299)	1.29 (0.65 – 2.53)
Batra 2005; Germany	364	Smoke >20 CPD for ≥3 years Have an expired-air CO level of at least 15 ppm Have at least 1 failed quit attempt within 2 years but not within the previous 6 months Not intending to quit in next month	Placebo Nicotine gum for 12 months	Counseling on reduction in 9 clinic visits. Telephone support	13	PP d	12% (22/184)	5% (8/180)	2.69 (1.19 – 6.03)e
Rennard 2006; USA	429	Smoke ≥20 CPD for ≥ 3 years Failed at least 1 serious quit attempt in past 2 years Exhaled-air CO level for at least 15 ppm Not intending to quit in next month	Placebo Nicotine inhaler for 12 months	Counseling on reduction in 9 clinic visits	15	PP	8% (17/215)	2% (3/214)	5.64 (1.86–17.13)e
Behavioral Interventions
Glasgow 2009 USA	320	Smoke >10 CPD Not interested in quitting	Enhanced usual care Telephone counseling + tailored newsletters	--	12	PP	6.7% (11/164)	4.4% (7/156)	1.49 (0.57 – 3.93)
Combination of Behavioral and Pharmacological Interventions
Carpenter 2003 USA	67	Smoke >10 CPD Interest in quitting eventually but not in the next 30 days At least 1 previous quit attempt	Usual-care (i.e., brief advice to quit) + NRT (if participant decided to quit) Smoking reduction + free choice of NRT (gum or patches) for 6 months + brief advice to quit	--	6	PP	13%(3/35)	9%(4/32)	0.69 (0.14 – 3.28)e
Carpenter 2004b USA	419 c	Smoke ≥10 CPD No interest in quitting	No-intervention Motivational intervention (brief advice to quit + NRT if participant decided to quit) Smoking reduction + free choice of NRT (gum or patches) for 6 months + brief advice to quit	--	6	PP	18%(37/212)	4% (9/207)	4.01 (1.98 – 8.14)
Joseph 2008 USA	152	Smokers with cardiovascular disease Not interested in quitting in the next 30 days	Usual care (i.e., brief advice to quit) Rate reduction + nicotine gum for 18 months	--	18	PP	12% (9/78)	12% (9/74)	0.94 (0.36 – 2.52)e

Abbreviations: CA, Continuous Abstinence in the last 4 weeks; CO, Carbon monoxide; CPD, Cigarette(s) per day; NRT, Nicotine Replacement Therapy; PP Point-Prevalence Abstinence; ppm, parts per million

^aNumber of events/Number in group

^bThis study had a 3-arm design. For consistency with other studies, only 2 arms were included in the analysis

^cNumber of subjects in the two comparison groups

^dVerified by CO level

^eCalculated from the abstinence rate