Pages 1 through 11 in the Results section show the outcomes from the model when subject to status quo as well as California and Kentucky’s initiation and cessation rates.
Status quo initiation rate was taken to be 25 percent, consistent with the prevalence for the 18–24 age group observed in 2003 (CDC 2005). Cessation rates for the status quo scenario were taken to be the ones estimated by Mendez and colleagues (1998): 0.21 percent for the 18–30 age group; 2.15 percent for the 31–50 age group; and 5.97 percent for individuals aged 51 and older. By using these age group-specific cessation rates we obtained an estimated 2.59 percent overall cessation rate in 2005 for the United States.
California and Kentucky rates were estimated with data from the Behavioral Risk Factor Surveillance System (BRFSS) from recent years (2000–2003). California’s initiation rate was estimated to be 20 percent, an average of the 18–24 age group prevalence from 2000 to 2003. Kentucky’s smoking initiation rate was estimated to be 39 percent.
Cessation rates for California and Kentucky were estimated in the following way: first, we obtained from BRFSS adult smoking prevalence by age group for each state from 2000 to 2003. We also obtained, from the Statistical Abstract of the United States, population size by age for each of the two states for the year 2000. We aged the population from 2000 to 2003 according to age-specific death rates and, for every year, computed the adult smoking prevalence assuming a single cessation rate for the population. We estimated the single cessation rate as the value that matched the calculated overall adult smoking prevalence with the prevalence reported from BRFSS for a specific year. These years, 2001 for Kentucky and 2002 for California, were chosen to highlight the high cessation in California and the low cessation in Kentucky. This procedure yielded an estimated cessation rate of 3.33 percent for California and 1.00 percent for Kentucky. We should note that this is a crude estimation procedure that ignores the effect of migration into and out of the states. The procedure is aimed to produce a rough estimate of the cessation rates in the states.
To obtain national age-specific cessation rates consistent with the aggregate quit rates obtained for California and Kentucky, we multiplied the status quo age-specific cessation rates by the ratio of the estimated cessation rates for California and Kentucky to the overall U.S. cessation rate: that is, 3.33/2.59 for California and 1.00/2.59 for Kentucky.
Page 1 in Results presents the status quo scenario. Pages 2 through 11 show scenarios in which the United States attains California and Kentucky rates at different times: almost instantaneously (in 2006) and gradually (linearly), by 2010, 2015, and 2020.
Pages 12 through 26 in Results describe different scenarios in which the country will move from a current adult smoking prevalence of 20.6 percent in 2005 to a 10 percent adult smoking prevalence in 2025. These scenarios describe necessary changes in initiation and/or cessation rates to achieve the 2025 10 percent target prevalence. These changes in initiation and cessation rates are assumed to happen instantaneously by 2006 or gradually (linearly) by 2010, 2015, and 2020. Once target cessation and initiation rates are reached, they are kept constant at the target levels for the remainder of the analysis period.
Finally, pages 27 through 38 present the percentage decrease in adult smoking prevalence (from the status quo) due to a 10 percent increase in cessation for each of the age groups reported in the analysis.