Tobacco Price Increase and Successful Smoking Cessation for Two or More Years in Japan.

Introduction: Assessing long-term smoking cessation after tobacco price increases is more valuable than short-term cessation as smokers often relapse after temporary cessation. We investigated whether tobacco price increases were associated with long-term smoking cessation and whether the association differed according to demographic, socioeconomic, and behavioral factors, using a national longitudinal survey of middle-aged individual-level data from 10 waves, every November from 2005 to 2014.

Methods: Temporary and long-term at least 1 year (1y+) or 2 years (2y+) quitters were defined by smoking in any one wave and quitting in the subsequent two or three waves in a discrete-time design. November 2006 (after July 11% increase) and November 2010 (after October 37% increase) were used as proxy variables for price increases. Generalized estimating equation models adjusted for demographic, socioeconomic, and behavioral covariates, and analyses stratified by these covariates were performed to estimate the association between price increases and smoking cessation.

Results: Of 43 630 smokers aged 50-65, 7.7%, 5.6%, and 5.2% of smokers quit temporarily, for at least 1 year and at least 2 years, respectively. 2y+ quitters significantly increased in November 2005-November 2008 (adjusted odds ratio = 1.23, 95% confidence interval: 1.06-1.43) and November 2009-November 2012 (adjusted odds ratio = 1.85, 95% confidence interval = 1.57-2.16). In stratified analyses, higher prices were associated with 2y+ quitters in all subgroups with some exceptions, including participants who smoked 21-30 cigarettes per day and those aged 60-65.

Conclusions: Increasing tobacco prices may be effective in promoting long-term smoking cessation in various subgroups among middle-aged Japanese adults.

Implications: Few longitudinal studies have examined the effect of a tobacco price increase on long-term smoking cessation. In a national longitudinal survey of middle-aged Japanese from 10 waves, the 37% tobacco price increase was found to be a trigger for successful smoking cessation for two or more years. Price increases were significantly associated with 2y+ smoking cessation in most demographic, behavioral, and socioeconomic subgroups. Results indicate that higher tobacco prices may be effective for long-term smoking cessation in almost all subgroups. Raising tobacco taxes and prices may be one of the most effective strategies for promoting long-term smoking cessation.