Codes and Frequencies
CYSTICFIYRC indicates whether the person had chronic cystic fibrosis 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 CYSTICFIYRC) created from the pre-1997 condition records, see the User Note on Condition Records and Condition Variables.
Defining Cystic Fibrosis Records and Identifying Persons with Cystic Fibrosis
For all available years, persons who were asked a direct question about cystic fibrosis and who have a chronic cystic fibrosis condition record are given a "Yes" code for CYSTICFIYRC. Persons who were asked a direct question about cystic fibrosis but do not have a chronic cystic fibrosis record are given a code of "No". Persons who were not asked a direct question about cystic fibrosis, 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 cystic fibrosis record.
Related Cystic Fibrosis Variables
The nearest equivalent of CYSTICFIYRC available for 1997 forward is CYSTICFIEV (Ever told had cystic fibrosis). However, researchers should use caution when comparing prevalence estimates derived from these two variables, as both the manner of collecting information about cystic fibrosis and the reference period differ greatly between the two. CYSTICFIYRC 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. CYSTICFIEV, by contrast, is based on a direct question about whether the person ever had the condition cystic fibrosis.
As with all of the person-level condition variables created by IHIS from condition records prior to 1997, the universe for CYSTICFIYRC 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 cystic fibrosis 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.
- 1973: All persons.
- 1978-1983: Persons living in 1/6 of households (who received Condition List 3).
- 1973, 1978-1983