Codes and Frequencies
For sample adults with at least one biological daughter (BDNUM) who ever had cancer of any kind (BDNHCAN), BDCLRCAN reports whether the respondent had at least one biological daughter who ever had colorectal cancer.
In 2015, due to low frequencies among family members, cancers of the colon and rectum were removed from the NHIS public use file to maintain respondent confidentiality. To maintain continuity of data analyses using these cancers the "colorectal cancer" variable was created. Researchers may choose to recode the component cancers variables (BDCLCAN and BDRTCAN in 2000, 2005 and 2010 to mimic the "colorectal cancer" variables in 2015.
BDCLRCAN is one of a series of related variables in the "Family History" section of the Cancer Module. 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 subsequent 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 daughter is a daughter related to the respondent by blood (i.e., not a stepdaughter, adopted daughter, foster daughter, or daughter-in-law).
Beginning in 2015, details about colon and rectum cancer (and several other cancer types) were suppressed because of low frequencies of these types of cancer among family members and are instead offered in the combined variable, BDCLRCAN. Prior to 2015, details about colon (BDCLCAN) and rectum (BDRTCAN) cancers are available in separate variables.
- 2015: Sample adults aged 18 and older whose biological daughter(s) were ever diagnosed with cancer.
- 2015 : SAMPWEIGHT