presents age-adjusted incidence rates and population distribution for the first and last years of observation by gender, area-socioeconomic position, and race-ethnicity, as well as the percent change from 1992 to 2004. To give an overall picture of changes in the incidence of lung cancer, shows the trends in the age-adjusted incidence of lung cancer, by gender, for social groups characterized by area-socioeconomic position (left panel) and race-ethnicity (right panel). Among males, incidence generally declined for all area-socioeconomic and race-ethnic groups, but among females the picture was more mixed, with rates decreasing among some groups (e.g., Hispanics, those living in counties with 15–19 percent of the population in poverty) and increasing among others (e.g., non-Hispanic Blacks, those living in counties with >20 percent poverty). For both females and males, there is considerably more variation in incidence by race-ethnicity than by area-socioeconomic position.
Age-adjusted (year 2000 standard) incidence of lung cancer and population distribution among those aged 45 years or more according to area-socioeconomic position and race-ethnicity, by gender, United States, 1992–2004
FIGURE 1 Age-adjusted (year 2000 standard) incidence of lung cancer in those aged 45 years or more among socioeconomic (left) and race-ethnic (right) groups, by gender, United States, 1992–2004. Top panels, females; bottom panels, males. NH, non-Hispanic; (more ...)
Change in area-socioeconomic disparity
shows the change in absolute and relative disparity among area-socioeconomic groups from 1992 to 2004, and displays disparity trends across the entire period. Generally speaking, all of the measures of disparity suggest that area-socioeconomic disparities in lung cancer incidence are increasing among females. However, the magnitude of the increase differed widely across disparity measures, ranging from a 52.9 percent increase in the relative concentration index to a 348.7 percent increase in the mean log deviation (changes in the Theil index, not shown, were virtually identical to the mean log deviation). In addition, the two measures that are sensitive to the direction of the gradient (relative concentration index and absolute concentration index) are the only measures for which the 95 percent confidence interval includes 0. The estimated increases in disparity are smaller for these measures because, while rates among the 20 percent poverty group increased most, rates among the 15–19 percent poverty group, which is considerably larger, declined most (). Among males, the picture was less consistent, with some measures indicating that area-socioeconomic disparities have increased and some suggesting a decrease. For example, in terms of relative disparity, the index of disparity showed a statistically significant increase in area-socioeconomic disparity of 46.6 percent, while the relative concentration index decreased by 116.3 percent, suggesting that lung cancer incidence has become less concentrated among those in poor areas. In terms of absolute disparity, the rate difference and between-group variance suggest that area-socioeconomic disparity decreased by 20 percent or less, but the absolute concentration index suggests a much larger decrease of 112.1 percent.
Change in relative and absolute area-socioeconomic disparity in lung cancer incidence, United States, 1992–2004
FIGURE 2 Percent change since 1992 in the US absolute concentration index (ACI), between-group variance (BGV), and rate difference (RD) as measures of absolute area-socioeconomic disparity (left), as well as the index of disparity (IDisp), relative concentration (more ...)
Change in race-ethnic disparity
shows the change in absolute and relative disparity among race-ethnic groups from 1992 to 2004, and shows disparity trends. Among females, all of the measures of disparity suggest that race-ethnic disparity in lung cancer incidence has increased, but again the magnitude of change differed across measures. For example, the rate ratio increased by a nonsignificant 36.2 percent, while the Theil index and mean log deviation increased significantly by roughly 50 percent. also shows a lack of agreement among measures of relative disparity that differ with respect to population weighting. Among females, for example, from 1994 to 1998, the unweighted index of disparity declined while the population-weighted Theil index and mean log deviation increased, but from 2003 to 2004, the index of disparity increased and the Theil index and mean log deviation decreased sharply. Among males, the measures of relative race-ethnic disparity suggested that disparity has either increased by as little as 1.7 percent (rate ratio) or by as much as 36.0 percent (index of disparity), while the measures of absolute disparity all indicated statistically significant declines in race-ethnic disparity ().
Change in relative and absolute race-ethnic disparity in lung cancer incidence, United States, 1992–2004
FIGURE 3 Percent change since 1992 in the US between-group variance (BGV) and rate difference (RD) as measures of absolute race-ethnic disparity (left), as well as the index of disparity (IDisp), mean log deviation (MLD), Theil index (TI), and rate ratio (RR) (more ...)