Table 2.

Associations between distance from time zone meridian and HCC incidence (SEER 2000–2014)

Distance from time zone meridian (per 5 degree increase)aCases (N)Basicb IRR (95% CI)PFully adjustedc IRR (95% CI)P
Main analyses56,3471.10 (1.02–1.18)0.011.07 (1.01–1.14)0.03
Stratified analyses
 Age (years)<0.01
  <6533,7671.11 (1.04–1.20)
  ≥6522,5801.01 (0.94–1.10)
  Non-Hispanic white27,8081.11 (1.04–1.17)
  Non-Hispanic black7,6231.47 (1.07–2.02)
  Non-Hispanic Asian, Pacific Islander, American Indian, or Alaskan Native9,8121.50 (1.02–2.22)
  Hispanic11,1040.75 (0.68–0.84)
  • aPer 5 degrees in longitude moving east to west within a time zone.

  • bModels are adjusted for individual-level age at diagnosis, sex, race/ethnicity, year of diagnosis, and SEER registry.

  • cModels are additionally adjusted for the following county-level variables: alcohol consumption; smoking; obesity; diabetes; shift work occupation; median household income; bachelor's degree or higher; unemployed; poverty; foreign born; urbanicity; outdoor light at night; UV.