Codes and Frequencies
For sample adults aged 18 and older whose biological father ever had cancer of any kind (BFHCAN), BFCLRCAN reports if the person's biological father ever had colorectal cancer.
In 2015, due to low frequencies among family members, separate variables for colon and rectal cancers were suppressed in the NHIS public use data file to maintain respondent confidentiality. Instead, a series of "colorectal cancer" variables that combine information about colon and rectal cancers into the same variables was created. Researchers may choose to recode the colon and rectal cancers variables BFCLCAN and BFRTCAN in 2000, 2005 and 2010 to mimic the "colorectal cancer" variables in 2015.
BFCLRCAN is one of a series of related variables in the "Family History" section of the Cancer Modules. This section begins with the general comment:
According to the 2000 and 2005 Field Representative's Manuals, the purpose of this and other family cancer history questions is to "determine the prevalence of cancer in families in the population" to "allow a greater understanding of how data obtained from genetics clinics can be applied to the general population." The 2010 and later Manuals provide a similar rationale, stating that the collection of these data "will allow analysts a greater understanding of how family history relates to cancer.
The Manuals for all years define "biological" relatives as people related by blood. Thus, a respondent's biological father is a father related to the respondent by blood (i.e., not a stepfather, adoptive father, foster father, or father-in-law).
- 2015: Sample adults aged 18 and older whose biological father ever had cancer.
- 2015 : SAMPWEIGHT