BSNHCAN is a two-digit count variable.
03: Beginning in 2015, top code of 3 or more
21: Prior to 2015, top code of 21 or more
96: Not in Universe
98: Unknown-Not Ascertained
99: Unknown-Don't Know
For sample adults, BSNHCAN reports the number of the respondent's biological sons who ever had cancer of any kind.
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, adopted son, foster son, or son-in-law).
BSNHCAN is one of a series of related variables in the "Family History" section of the Cancer Module. 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 Manual provides a similar rationale, stating that the collection of this data "will allow analysts a greater understanding of how family history relates to cancer. For a full list of available cancer family history variables relating to biological sons, see the variable description for BSBLCAN, which reports whether the respondent's biological son ever had bladder cancer.
In addition to asking the number of the respondent's biological sons who ever had cancer of any kind, the "Family History" section of the Cancer Modules also asked for the number of the respondent's biological daughters (BDNHCAN), full brothers (FBNHCAN), and full sisters (FSNHCAN) who ever had cancer of any kind. For a full list of available cancer family history variables relating to biological daughters, see the variable description for BDBLCAN, for full brothers, see the variable description for FBBLCAN, and for full sisters, see the variable description for FSBLCAN.
Although BSNHCAN is substantively comparable across all years, users should note two changes in the recoding of values that may affect analyses of data from multiple cancer supplement years.
The first, and most recent, change affects the top code value for BSNHCAN. Prior to 2015, BSNHCAN was top coded at 21. Starting in 2015, BSNHCAN was top coded at 3. The second change, affecting how missing data values were treated for sample adults who completed only part of the cancer supplement, took place between the 2000 and 2005 cancer supplement. In 2000, persons who answered less than 50 percent of the questions in the supplement had a value of "not ascertained" automatically inserted in the appropriate fields of the Cancer Control Module file, whereas in 2005 and later years, persons who answered none of the questions in the supplement had a value of "not ascertained" automatically inserted in the appropriate fields of the Cancer Control Module file.
- 2000; 2005; 2010; 2015: Sample adults age 18+ who have one or more full sons.
- 2000, 2005, 2010, 2015
- 2000, 2005, 2010, 2015 : SAMPWEIGHT