Codes and Frequencies
For sample adults whose biological mother ever had colorectal cancer (BMCLRCAN), BMACLRCAN reports whether the respondent's biological mother was under 50 years of age when first diagnosed with 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 may choose to recode the colon and rectal cancers variables BMACLCAN and BMARTCAN in 2000,
BMACLRCAN 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 mother is a mother related to the respondent by blood (i.e., not a stepmother, adoptive mother, foster mother, or mother-in-law).
- 2015: Sample adults aged 18 and older whose biological mother was ever diagnosed with colorectal cancer.
- 2015 : SAMPWEIGHT