Codes and Frequencies
ENTCOLITYRC indicates whether the person had chronic enteritis or colitis 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 ENTCOLITYRC) created from the pre-1997 condition records, see the User Note on Condition Records and Condition Variables.
Defining Enteritis/Colitis Records and Identifying Persons with Enteritis or Colitis
For all available years, persons who were asked a direct question about enteritis or colitis and who have a chronic enteritis or colitis condition record are given a "Yes" code for ENTCOLITYRC. Persons who were asked a direct question about enteritis or colitis but do not have a chronic enteritis or colitis record are given a code of "No." Persons who were not asked a direct question about enteritis or colitis, 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 enteritis or colitis record.
For 1975 and 1978-1981, enteritis or colitis records were defined as those condition records with a code of "169" ("Gastroenteritis and colitis, except ulcerative, of noninfectious origin") or a code of "170" ("Chronic enteritis and ulcerative colitis") in the variable DIAGR1 in the original NHIS public use files. These condition code values come from NCHS's Diagnostic Recode #1: Diseases, Injuries, and Impairments, not from the International Classification of Diseases (ICD) codes. Additionally, to be considered "chronic," enteritis or colitis condition records must have a code of "1" ("Chronic") in the variable CACODE in the original NHIS public use files.
For 1982 to 1996, chronic enteritis or colitis records were defined as those condition records with a code of "311" ("Enteritis and colitis") 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.
For 1975, ENTCOLITYRC should be weighted with PERWEIGHT.
For 1978 to 1981, ENTCOLITYRC should be weighted with CONDWT1.
For 1982 to 1996, ENTCOLITYRC should be weighted with CONDWT3.
Related Enteritis/Colitis Variables
The nearest equivalent of ENTCOLITYRC available after 1996 is CROHNYR (Had Crohn's/ulcerative colitis symptoms, past 12 months). However, researchers should use caution when comparing prevalence estimates derived from these two variables, as the manner of collecting information about enteritis/colitis differs greatly between the two. ENTCOLITYRC 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 in the past year. CROHNYR, by contrast, is based on a direct question about whether the person had the condition Crohn's disease or ulcerative colitis.
As with all of the person-level condition variables created by IHIS from condition records prior to 1997, the universe for ENTCOLITYRC 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 enteritis or colitis in the past year. There is also a minor universe change between the sets of years 1978-1981 and 1982-1996. These changes require 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.
- 1975: All persons.
- 1978-1981: Persons living in 1/6 of households (who received Condition List 1).
- 1982-1996: Persons living in 1/6 of households (who received Condition List 3).
- 1975, 1978-1996