Codes and Frequencies
ANEMIAYRC indicates whether the person had chronic anemia 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 ANEMIAYRC) created from the pre-1997 condition records, see the User Note on Condition Records and Condition Variables.
Defining Anemia Records and Identifying Persons with Anemia
For all available years, persons who were asked a direct question about having anemia and who have a chronic anemia condition record are given a "Yes" code for ANEMIAYRC. Persons who were asked a direct question about having anemia but do not have a chronic anemia record are given a code of "No." Persons who were not asked a direct question about anemia, 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 anemia record.
For 1973 and for 1978 to 1981, chronic anemia records were defined as those condition records with a code of "8" ("Anemias, 3 months+") in the variable DIAGR3 in the original NHIS public use files. This condition code value comes from NCHS's Diagnostic Recode C: Chronic Diseases and Impairments, not from the International Classification of Diseases (ICD) codes.
For 1982 to 1996, chronic anemia records were defined as those condition records with a code of "404" ("Anemias") 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 1973, ANEMIAYRC should be weighted with PERWEIGHT.
For 1978 to 1981, ANEMIAYRC should be weighted with CONDWT3.
For 1982 to 1996, ANEMIAYRC should be weighted with CONDWT4.
Related Anemia Variables
The nearest equivalent of ANEMIAYRC available for 1997 forward is ANEMIAYR (Had anemia, past 12 months). However, researchers should use caution when comparing prevalence estimates derived from these two variables, as the manner of collecting information about anemia differs greatly between the two. ANEMIAYRC 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. ANEMIAYR, by contrast, is based on a direct question about whether the person had the condition anemia.
As with all of the person-level condition variables created by IHIS from condition records prior to 1997, the universe for ANEMIAYRC 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 anemia 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.
- 1973: All persons.
- 1978-1981: Persons living in 1/6 of households (who received Condition List 3).
- 1982-1996: Persons living in 1/6 of households (who received Condition List 4).
- 1973, 1978-1996