Table shows current smoking prevalence among adults aged 18 years and older by state for men and women for the 1992-93, 1998-99, and 2006-07 surveys. During the 2006-07 survey, the highest smoking prevalence was recorded in Kentucky for men and in Kentucky and West Virginia for women. Seven of the top ten states for smoking prevalence in men and five of the top ten states in women are located in the Southern region (Figure ). In contrast, Utah showed the lowest smoking prevalence for men and Utah and California for women during the corresponding time interval.
Current smoking prevalence among adults (aged 18 years or older) by sex and state, according to data from Current Population Survey, 1992-1993, 1998-1999, and 2006-2007
Smoking prevalence by sex and state, 2006-2007. Source: Current Population Survey, 2006/07
Adult smoking prevalence decreased from 1992-93 to 2006-07 in both men and women in all states but Wyoming (Table ). States with the largest percentage reduction among men were Virginia (38.6%), Idaho (35.7%), Washington DC (34.8%), Utah (32.7%), and Florida/California (both 32.3%) (Table , Figure ). Those with the largest percentage reduction among women were New Jersey (43.9%), Nevada (43.4%), California (42.2%), Maryland (41.7%) and Massachusetts (38.1%). States with the smallest percentage reduction among men were Wyoming (0%), Missouri (5.6%), Kansas (8.3%), Oklahoma (12.5%) and Iowa (12.9%), and among women they were Wyoming (6.9%), Iowa (7.0%), Ohio (9.8%), Indiana (10.1%) and West Virginia (10.7%).
Relative change in smoking prevalence between 1992-1993 and 2006-2007 by state. Source: Current Population Survey, 1992/93 and 2006-07
Regionally, the percentage reductions in smoking from 1992-93 to 2006-07 among men and women respectively were the largest in the West (average decrease of 28.5% and 33.3%) and the smallest in the Midwest (18.6% and 20.3%) (Additional File 1
, Table S1). Within region, the decreases by state were not statistically significant in 8 of 12 mid-western states and 9 of 17 southern states for at least one sex. Seven mid-western states (North Dakota, Nebraska, Iowa, Kansas, Missouri, Indiana, and Ohio) were in the bottom 10 states for reductions in male and/or female smoking (Figure ).
Considerable heterogeneity in the trends was observed in certain regions, especially in the Mountain States and Midwest (Additional File 1
, Table S1 and Figure ). Whereas Wyoming had the smallest percentage decrease in both sexes, the bordering state of Idaho had the second largest percentage decrease in men (35.7%) and was in the top quintile for women (36.2%). South Dakota had greater reductions in male and female smoking (by 21.5%, 20.5%) respectively than the neighboring states of either North Dakota (13.9%, 14.6%) or Nebraska (13.4%, 14.0%). Similarly, the reductions in male and/or female smoking, respectively, were much smaller in Missouri (5.6%, 14.5%), Iowa (12.9%, 7.0%), and Kansas (8.3%, 23.8%) than in Michigan (28.2%, 29.4%), and Minnesota (20.3%, 33.5%).
The decrease in smoking prevalence by state was not strongly correlated with the 1992-93 baseline smoking prevalence in either women (r = 0.29, p = 0.04) or men (r = 0.10, p = 0.47). For example, the relative percentage reduction in women's smoking prevalence was as large in California (42.2%) as in Nevada (43.4%), even though the initial smoking prevalence was nearly half as high among women in California. Further, the relative percentage decrease in smoking prevalence was generally greater in women (median = 23.4%) than in men (median = 21.5%), while the relative prevalence of smoking was higher in men than women in all states except Rhode Island (22.0%, 24.2%) and Montana (23.0%, 24.1%) at the start of the study.
The relative change in smoking prevalence by state was significantly correlated with the state's IOI score in both women (r = -0.49, p < 0.001) and men (r = -0.31, p = 0.03) and with state's SOTC index in women (r = -0.30, p = 0.03), but not in men (r = -0.21, P = 0.14) (Figure ). The correlation coefficients remained unchanged when we adjusted for percent federal poverty level and/or percent black in the population. They were not also affected by exclusion of states with extreme values or outliers, including Arizona and California for the highest IOI, Alaska for the highest SOTC, and Wyoming and Nevada for the lowest and highest relative changes, respectively. However, the associations became weaker or non-existent when we restricted the analysis to non-Hispanic whites (r = -0.2 to r = 0.01, p > 0.1), except for IOI among women (r = -0.54, p < 0.0001).
Relationship between changes in smoking prevalence and indices of state tobacco control policies and activities (IOI) and tobacco control resources and capacity (SOTC).
In contrast to the 1992-93 to 2006-07 period where smoking prevalence statistically decreased in 35 states in men and 31 states in women, smoking prevalence from 1998-99 to 2006-07 significantly decreased in 14 states in men and 19 states in women, with 5 of these states in men and 4 in women located in the North East (Additional File 2
, Table S2). Overall the decreases in the smoking prevalence from 1998-99-2006-07 by state were not statistically significantly correlated with changes in the price of cigarettes (men, r = -0.1, p = 0.5; women, r = -0.2, p = 0.13), nor with changes in percent of indoor workers with smoke-free work place (men, r = -0.2, p = 0.18; women, r = 0.0, p = 0.8) over the corresponding time interval.