Effectiveness of stop-smoking medications: findings from the International Tobacco Control (ITC) Four Country Survey.
OBJECTIVE
To evaluate the population effectiveness of stop-smoking medications while accounting for potential recall bias by controlling for quit attempt recency.


METHODS
Prospective cohort survey.


METHODS
United Kingdom, Canada, Australia and the United States.


METHODS
A total of 7436 adult smokers (18+ years) selected via random digit dialling and interviewed as part of the International Tobacco Control Four Country Survey (ITC-4) between 2002 and 2009. Primary analyses utilized the subset of respondents who participated in 2006 or later (n = 2550).


METHODS
Continuous abstinence from smoking for 1 month/6 months.


RESULTS
Among participants who recalled making a quit attempt within 1 month of interview, those who reported using varenicline, bupropion or nicotine patch were more likely to maintain 6-month continuous abstinence from smoking compared to those who attempted to quit without medication [adjusted odds ratio (OR) 5.84, 95% confidence interval (CI) (2.12-16.12), 3.94 (0.87-17.80), 4.09 (1.72-9.74), respectively]; there were no clear effects for oral NRT use. Those who did not use any medication when attempting to quit tended to be younger, to be racial/ethnic minorities, to have lower incomes and to believe that medications do not make quitting easier.


CONCLUSIONS
Consistent with evidence from randomized controlled trials, smokers in the United Kingdom, Canada, Australia and the United States are more likely to succeed in quit attempts if they use varenicline, bupropion or nicotine patch. Previous population studies that failed to find an effect failed to control adequately for important sources of bias.
Division of Cancer Prevention and Population Sciences, Roswell Park Cancer Institute, Buffalo, NY 14263, USA. karin.kasza@roswellpark.org
Karin A
KA
Kasza
Andrew J
AJ
Hyland
Ron
R
Borland
Ann D
AD
McNeill
Maansi
M
Bansal-Travers
Brian V
BV
Fix
David
D
Hammond
Geoffrey T
GT
Fong
K Michael
KM
Cummings
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D001315:Australia; D001552:Benzazepines / Q000627:therapeutic use*; D016642:Bupropion / Q000627:therapeutic use*; D002170:Canada; D018765:Dopamine Uptake Inhibitors / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018722:Nicotinic Agonists / Q000627:therapeutic use*; D011446:Prospective Studies; D011810:Quinoxalines / Q000627:therapeutic use*; D012008:Recurrence; D017678:Sex Distribution; D012907:Smoking / Q000523:psychology; D016540:Smoking Cessation / Q000379:methods*; D000074606:Smoking Prevention; D061485:Tobacco Use Cessation Devices; D016896:Treatment Outcome; D006113:United Kingdom; D014481:United States; D000068580:Varenicline; D055815:Young Adult
D001552:Benzazepines; D018765:Dopamine Uptake Inhibitors; D018722:Nicotinic Agonists; D011810:Quinoxalines; D016642:Bupropion; D000068580:Varenicline