BSNCLRCAN is a two-digit count variable.
00: Not in Universe
03: Top code of 3 or more
98: Unknown-Not Ascertained
99: Unknown-Don't Know
For sample adults with at least one biological son (BSNUM) who ever had colorectal cancer, BSNCLRCAN reports the number of the respondent's biological sons diagnosed with head and neck 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 may choose to recode the colon and rectal cancers variables BSNCLCAN and BSNRTCAN in 2000, 2005 and 2010 to mimic the "colorectal cancer" variables in 2015.
BSNCLRCAN 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 "biological" relatives as people related by blood. Thus, a respondent's biological son is a son related to the respondent by blood (i.e., not a stepson, adoptive son, foster son, or son-in-law).
- 2015: Sample adults aged 18 and older whose son(s) were ever diagnosed with colorectal cancer.
- 2015 : SAMPWEIGHT