Description

CANSCRYRC indicates whether the person had cancer of the stomach, colon, or rectum (SCR) in the past year. This variable is created with supplemental programming by the IPUMS NHIS staff from the pre-1997 condition records. For general information about IHIS variables (such as CANSCRYRC) created from the pre-1997 condition records, see the User Note on Condition Records and Condition Variables.

Defining SCR Cancer Records and Identifying Persons with SCR Cancer

For all available years, persons who were asked a direct question about having stomach, colon, or rectal cancer and who have a chronic SCR cancer condition record are given a "Yes" code for CANSCRYRC. Persons who were asked a direct question about having SCR cancer but do not have a chronic SCR cancer record are given a code of "No." Persons who were not asked a direct question about SCR cancer, or for whom it is unknown whether they were asked such a question, are given a code of "NIU" (not in universe), regardless of whether they have a chronic SCR cancer record.

For 1975 and for 1978 to 1981, chronic SCR cancer records were defined as those condition records with a code of "43" ("malignant neoplasm of stomach") or "44" ("malignant neoplasm of intestines, any part") in the variable DIAGR1 in the original NHIS public use files. This condition code value comes from NCHS's Diagnostic Recode #1: Diseases, Injuries, and Impairments, not from the International Classification of Diseases (ICD) codes.

For 1982 to 1996, chronic SCR cancer records were defined as those condition records with a code of "316" ("malignant neoplasms of stomach, intestines, colon, and rectum") in the variable C1CONDRC in the original NHIS public use files. This condition code value comes from NCHS's Diagnostic Recode C: Chronic Conditions and Impairments.

Weights
For 1975, CANSCRYRC should be weighted with PERWEIGHT.

For 1978 to 1981, CANSCRYRC should be weighted with CONDWT1.

For 1982 to 1996, CANSCRYRC should be weighted with CONDWT3.

Related SCR Cancer Variables
The nearest equivalents of CANSCRYRC for 1997 forward are CNSTOM (Ever had cancer: Stomach), CNCOLN (Ever had cancer: Colon), and CNRECT (Ever had cancer: Rectal). However, researchers should use caution when comparing prevalence estimates derived from these two sets of variables, as the manner of collecting information about SCR cancer differs greatly between the two. CANSCRYRC was created by recoding condition records that were generated in response to several different survey questions about health problems underlying disability, sick days, or contacts with health care practitioners. CNSTOM, CNCOLN, and CNRECT, by contrast, are based on direct questions about whether the person had stomach, colon, or rectal cancer. Additionally, the reference period differs between the two sets of variables. CANSCRYC refers to cancer in the past year, whereas CNSTOM, CNCOLN, and CNRECT refer to having ever had SCR cancer.

Comparability

As with all of the person-level condition variables created by IHIS from condition records prior to 1997, the universe for CANSCRYRC is substantially different for 1978 forward than it is for years prior to 1978. Beginning in 1978, only persons living in 1/6 of households, rather than all persons, were asked a direct question about having stomach, colon, or rectal cancer in the past year. This change requires that different weight variables be used depending on which years of data are analyzed. See the "Description" tab for details.

Additionally, there is a change in the way "Yes" responses are coded over time. See the User Note on Condition Records and Condition Variables for details about the composite coding scheme employed by IHIS.

Universe

Availability

• 1975, 1978-1996

Weights

• 1975 : PERWEIGHT
• 1978-1981 : CONDWT1
• 1982-1996 : CONDWT3