The effect of cigarette price increases on smoking cessation in California.

We investigated whether smoking cessation increased in California after a cigarette manufacturer's retail price increase and an increase in the state cigarette excise tax. The sample for this study was drawn from the 1996 and 1999 California Tobacco Surveys. The rate of unsuccessful and successful quit attempts and the rate of abstinence were calculated for each month of the 14-month period preceding each survey administration. We combined the monthly rates for both surveys and used multiple regression modeling to test whether the proportion of smokers reporting a quit attempt and the proportion of smokers reporting abstinence increased during the period following the price increases. We included several covariates in our models to control for factors other than the price increases that could account for any increases observed in quit attempts and abstinence. Because smokers recall quits occurring closer to the date of the survey better than quits occurring further back in time, we included a term in the models representing the number of months elapsed between the survey administration and the reported quit. We also included terms in the models representing the months before and after the over-the-counter (OTC) availability of the nicotine patch and nicotine gum in 1996 to control for the increase in smoking cessation observed following the availability of OTC nicotine replacement therapy (NRT). Lastly, in order to control for increased quits made in January as a result of New Year's resolutions, we included a term in our models for quit attempts and successful quits (abstinence) made during this month. Results of the regression analyses indicated a significantly greater proportion of smokers reported quit attempts (p < 0.05) in the months immediately following the cigarette price increases (after November 1998); however, a significant increase in abstinence was only observed from December 1998 through March 1999 (p < 0.05) relative to abstinence occurring before the price increases.