K. Kafadar et al., URBANICITY-RELATED TRENDS IN LUNG-CANCER MORTALITY IN US COUNTIES - WHITE FEMALES AND WHITE MALES, 1970-1987, International journal of epidemiology, 25(5), 1996, pp. 918-932
Background. The effect of urbanization on age-adjusted lung cancer mor
tality rates in US counties is investigated, The data come from Nation
al Cancer Institute, and urban trends are estimated in time periods 19
70-1979 and 1980-1987, for both white males and white females. To acco
unt for possibly different gradients in different parts of the country
, the 48 contiguous states are divided into seven regions. Methods. A
measure of urbanness, urbanicity, is defined and is used to stratify c
ounties. A multiplicative model is proposed that relates county mortal
ity rates to urbanicity. The residuals from this multiplicative model
serve as age- and urban-adjusted rates. Results. Urban-rural gradients
are significant for nearly all regions for both white males and white
females, diminishing slightly in the latter time period for white mal
es but becoming stronger for white females. Conclusions. The age- and
urban-adjusted rates may be used in mapping to investigate geographica
l patterns that remain after removal of the urban factor.