Codes and Frequencies
For sample adults with at least one full brother (FBNUM) who ever had cancer of any kind (FBNHCAN), FBCLRCAN reports whether the respondent had at least one full brother who ever had colorectal cancer.
In 2015, due to low frequencies among family members, colon and rectal cancers were removed from the NHIS public use file to maintain respondent confidentiality. Therefore, from 2015 NHIS does not provide colon and rectal cancer variables separately, and instead a series of "colorectal cancer" variables was created. Researchers could recode the colon and rectal cancers variables FBCLCAN and FBRTCAN in 2000, 2005 and 2010 to make it comparable to the "colorectal cancer" variables in 2015.
FBCLRCAN is one of a series of related variables in the "Family History" section of the 2000 and later Cancer Modules. In all years, 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 "full siblings" as people who have "the same biological father and mother." Thus, a respondent's full brother is a brother who has the same biological father and mother as the respondent (i.e., not half-brothers, stepbrothers, adopted brothers, foster brothers, or brothers-in-law).
- 2015: Sample adults aged 18 and older whose biological brother(s) were ever diagnosed with cancer.
- 2015 : SAMPWEIGHT