Rurality and other determinants of early colorectal cancer diagnosis in Nebraska: a 6-year cancer registry study, 1998-2003.

BACKGROUND: There are no studies of rurality, and other determinants of colorectal cancer (CRC) stage at diagnosis with population-based data from the Midwest.
METHODS: This retrospective study identified, incident CRC patients, aged 19 years and older, from 1998-2003 Nebraska Cancer Registry (NCR) data. Using federal Office of Management and Budget classifications, we grouped patients by residence in metropolitan, micropolitan nonmetropolitan, or rural nonmetropolitan counties (non-core based statistical areas). In univariate and multivariate logistic regression analyses, we examined the association of the county classification and of other determinants with early (in situ/local) versus late (regional/distant) stage at CRC diagnosis.
RESULTS: Of the 6,561 CRC patients identified, 45% were from metropolitan counties, 24% from micropolitan nonmetropolitan counties and 31% from rural nonmetropolitan counties, with 32%, 38%, and 33%, respectively, being diagnosed at an early stage. Multivariate analysis showed micropolitan nonmetropolitan residents were significantly more likely than rural nonmetropolitan residents to be diagnosed at an early stage (adjusted OR, 1.22; 95% CI: 1.05-1.42, P < .05). However, rural nonmetropolitan and metropolitan residents did not significantly differ in the likelihood of early diagnosis. Residents with Medicare rather than those with private insurance (P < .0001), married rather than unmarried residents (P < .01), and residents with rectal cancer rather than those with colon cancer (P < .0001) were more likely to be diagnosed at an early stage.
CONCLUSIONS: Early CRC diagnosis needs to be increased in rural (non-core) non-metropolitan residents, unmarried residents, and those with private insurance.