Travel Distance to Nearest Lung Cancer Screening Center Differs by Race, Ethnic Makeup of Communities

A cross-sectional ecological study found that there are differences in travel distance to lung cancer screening (LCS) facilities by race and ethnicity, but those differences are only partially explained by rurality. According to the study authors, these findings could inform the placement of future imaging locations and mobile units for LCS to increase equitable access to LCS services. The results are published in Annals of Internal Medicine.

Researchers from Washington State University and Swedish Cancer Institute studied data from 71,691 U.S. census tracts (2,500-8,000 people) to examine race-, ethnicity-, and rurality-based differences in distance to the nearest LCS facility. The researchers focused on American Indian/Alaska Native (AI/AN) populations compared to non-Hispanic White (NHW) populations due to their high prevalence of smoking and status as the nation’s most rural-dwelling population. The outcome variable was road distance in miles from a census tract to the closest LCS facility. Independent variables measured were census tract racial and ethnic composition and rurality. The researchers defined a predominant racial/ethnic majority of a census tract as more than 50% of census tract residents identifying with one of the following racial or ethnic categories: AI/AN, Asian, Black, NHW, no single race, or Hispanic. No single race majority census tracts were defined as those in which none of the aforementioned racial populations comprised a majority of the population. Census tracts with Native Hawaiian/Pacific Islander majority were excluded due to small numbers. Census tract rurality was defined by rural-urban commuting area (RUCA) codes.

The researchers found that AI/AN-majority census tracts had the longest geometric mean distance to the nearest LCS facility at 49.6 miles compared to 4.4 to 6.9 miles in other majority census tracts. For Asian-, Black-, and Hispanic-majority tracts, distance to the nearest LCS were 16%, 39% and 7% shorter, respectively, than those in NHW-majority tracts. When adjusted for rurality, the mean distance in AI/AN-majority tracts was reduced, but still more than three times the distance in NHW-majority census tracts. Adjustment for rurality also reduced the observed advantage in Asian- and Black-majority census tracts compared to NHW tracts, whereas Hispanic census tracts changed from being slightly closer to slightly further away from the nearest LCS facility. The researchers note that the observed differences in access to LCS facilities for AI/AN people are concerning given that lung cancer is the leading cause of cancer deaths among AI/AN people.