Census Block Group 2010

Field Length:  1

Description

This field is provided for coding the block group of patient’s residence at time of diagnosis, as defined by the 2010 Census.

Rationale

A block group is a subdivision of a census tract designed to have an average of 1500 people, versus a census tract's average of 4500 people. All land area in the United States is described by a census block group in the 2010 Census. The Census Bureau publishes detailed population and socioeconomic data at this level. Block groups thus offer a high level of specificity for geographical and socioeconomic analyses.

A block group has no meaning in the absence of a census tract. Refer to Census Tract Certainty 2010 to ascertain basis of assignment of Census Block Group 2010.

Comment
Numerous registries find the distinction between “attempted, could not be determined” (zero) and “not coded” (blank) to be useful for geocoding planning purposes.

Note: The values 1 through 9 are nominal, with no hierarchy of values. This number determines the first digit of all the blocks which comprise the block group; for instance, census block group 3 would contain blocks numbered 3000 to 3999.