bemanian_beyer: Local Exposure and Isolation based on Bemanian & Beyer (2017)
In ndi: Neighborhood Deprivation Indices

bemanian_beyer

R Documentation

Local Exposure and Isolation based on Bemanian & Beyer (2017)

Description

Compute the aspatial Local Exposure and Isolation (Bemanian & Beyer) of a selected racial or ethnic subgroup(s) and U.S. geographies.

Usage

bemanian_beyer(
  geo_large = "county",
  geo_small = "tract",
  year = 2020,
  subgroup,
  subgroup_ixn,
  omit_NAs = TRUE,
  quiet = FALSE,
  ...
)

Arguments

`geo_large`	Character string specifying the larger geographical unit of the data. The default is counties `geo_large = 'county'`.
`geo_small`	Character string specifying the smaller geographical unit of the data. The default is census tracts `geo_small = 'tract'`.
`year`	Numeric. The year to compute the estimate. The default is 2020, and the years 2009 onward are currently available.
`subgroup`	Character string specifying the racial or ethnic subgroup(s). See Details for available choices.
`subgroup_ixn`	Character string specifying the racial or ethnic subgroup(s) as the interaction population. If the same as `subgroup`, will compute the simple isolation of the group. See Details for available choices.
`omit_NAs`	Logical. If FALSE, will compute index for a larger geographical unit only if all of its smaller geographical units have values. The default is TRUE.
`quiet`	Logical. If TRUE, will display messages about potential missing census information. The default is FALSE.
`...`	Arguments passed to `get_acs` to select state, county, and other arguments for census characteristics

Details

This function will compute the aspatial Local Exposure and Isolation (LEx/Is) of selected racial or ethnic subgroups and U.S. geographies for a specified geographical extent (e.g., the entire U.S. or a single state) based on Bemanian & Beyer (2017) \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1158/1055-9965.EPI-16-0926")}. This function provides the computation of LEx/Is for any of the U.S. Census Bureau race or ethnicity subgroups (including Hispanic and non-Hispanic individuals).

The function uses the get_acs function to obtain U.S. Census Bureau 5-year American Community Survey characteristics used for the aspatial computation. The yearly estimates are available for 2009 onward when ACS-5 data are available (2010 onward for geo_large = 'cbsa' and 2011 onward for geo_large = 'place', geo_large = 'csa', or geo_large = 'metro') but may be available from other U.S. Census Bureau surveys. The twenty racial or ethnic subgroups (U.S. Census Bureau definitions) are:

B03002_002: not Hispanic or Latino 'NHoL'
B03002_003: not Hispanic or Latino, white alone 'NHoLW'
B03002_004: not Hispanic or Latino, Black or African American alone 'NHoLB'
B03002_005: not Hispanic or Latino, American Indian and Alaska Native alone 'NHoLAIAN'
B03002_006: not Hispanic or Latino, Asian alone 'NHoLA'
B03002_007: not Hispanic or Latino, Native Hawaiian and Other Pacific Islander alone 'NHoLNHOPI'
B03002_008: not Hispanic or Latino, Some other race alone 'NHoLSOR'
B03002_009: not Hispanic or Latino, Two or more races 'NHoLTOMR'
B03002_010: not Hispanic or Latino, Two races including Some other race 'NHoLTRiSOR'
B03002_011: not Hispanic or Latino, Two races excluding Some other race, and three or more races 'NHoLTReSOR'
B03002_012: Hispanic or Latino 'HoL'
B03002_013: Hispanic or Latino, white alone 'HoLW'
B03002_014: Hispanic or Latino, Black or African American alone 'HoLB'
B03002_015: Hispanic or Latino, American Indian and Alaska Native alone 'HoLAIAN'
B03002_016: Hispanic or Latino, Asian alone 'HoLA'
B03002_017: Hispanic or Latino, Native Hawaiian and Other Pacific Islander alone 'HoLNHOPI'
B03002_018: Hispanic or Latino, Some other race alone 'HoLSOR'
B03002_019: Hispanic or Latino, Two or more races 'HoLTOMR'
B03002_020: Hispanic or Latino, Two races including Some other race 'HoLTRiSOR'
B03002_021: Hispanic or Latino, Two races excluding Some other race, and three or more races 'HoLTReSOR'

Use the internal state and county arguments within the get_acs function to specify geographic extent of the data output.

LEx/Is is a measure of the probability that two individuals living within a specific smaller geographical unit (e.g., census tract) of either different (i.e., exposure) or the same (i.e., isolation) racial or ethnic subgroup(s) will interact, assuming that individuals within a smaller geographical unit are randomly mixed. LEx/Is is standardized with a logit transformation and centered against an expected case that all races or ethnicities are evenly distributed across a larger geographical unit. (Note: will adjust data by 0.025 if probabilities are zero, one, or undefined. The output will include a warning if adjusted. See logit for additional details.)

LEx/Is can range from negative infinity to infinity. If LEx/Is is zero then the estimated probability of the interaction between two people of the given subgroup(s) within a smaller geographical unit is equal to the expected probability if the subgroup(s) were perfectly mixed in the larger geographical unit. If LEx/Is is greater than zero then the interaction is more likely to occur within the smaller geographical unit than in the larger geographical unit, and if LEx/Is is less than zero then the interaction is less likely to occur within the smaller geographical unit than in the larger geographical unit. Note: the exponentiation of each LEx/Is results in the odds ratio of the specific exposure or isolation of interest in a smaller geographical unit relative to the larger geographical unit.

Larger geographical units available include states geo_large = 'state', counties geo_large = 'county', census tracts geo_large = 'tract', census-designated places geo_large = 'place', core-based statistical areas geo_large = 'cbsa', combined statistical areas geo_large = 'csa', and metropolitan divisions geo_large = 'metro'. Smaller geographical units available include, counties geo_small = 'county', census tracts geo_small = 'tract', and census block groups geo_small = 'cbg'. If a larger geographical unit is comprised of only one smaller geographical unit (e.g., a U.S county contains only one census tract), then the LEx/Is value returned is NA. If the larger geographical unit is census-designated places geo_large = 'place', core-based statistical areas geo_large = 'cbsa', combined statistical areas geo_large = 'csa', or metropolitan divisions geo_large = 'metro', only the smaller geographical units completely within a larger geographical unit are considered in the LEx/Is computation (see internal st_within function for more information) and recommend specifying all states within which the interested larger geographical unit are located using the internal state argument to ensure all appropriate smaller geographical units are included in the LEx/Is computation.

Value

An object of class 'list'. This is a named list with the following components:

lexis: An object of class 'tbl' for the GEOID, name, and LEx/Is at specified smaller census geographies.
lexis_data: An object of class 'tbl' for the raw census values at specified smaller census geographies.
missing: An object of class 'tbl' of the count and proportion of missingness for each census variable used to compute LEx/Is.

References

Bemanian, A, & Beyer, KMM (2017) Measures Matter: The Local Exposure/Isolation (LEx/Is) Metrics and Relationships between Local-Level Segregation and Breast Cancer Survival. Cancer Epidemiology, Biomarkers & Prevention, 26(4):516-524. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1158/1055-9965.EPI-16-0926")}

Examples

## Not run: 
# Wrapped in \dontrun{} because these examples require a Census API key.

  # Local Exposure and Isolation 
  ## of non-Hispanic Black vs. non-Hispanic white populations
  ## in census tracts within counties of Georgia, U.S.A. (2020)
  bemanian_beyer(
    geo_large = 'county',
    geo_small = 'tract',
    state = 'GA',
    year = 2020,
    subgroup = 'NHoLB',
    subgroup_ixn = 'NHoLW'
   )


## End(Not run)

ndi documentation built on Sept. 9, 2025, 5:26 p.m.