Description

NEPHRITYRC indicates whether the person had chronic nephritis 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 NEPHRITYRC) created from the pre-1997 condition records, see the User Note on Condition Records and Condition Variables.

Defining Nephritis Records and Identifying Persons with Nephritis

For all available years, persons who were asked a direct question about nephritis and who have a chronic nephritis condition record are given a "Yes" code for NEPHRITISYRC. Persons who were asked a direct question about nephritis but do not have a chronic nephritis record are given a code of "No." Persons who were not asked a direct question about nephritis, 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 nephritis record.

For 1973 and 1978-1981, nephritis records were defined as those condition records with a code of "181" ("Nephritis (acute, chronic), [not elsewhere classified]") 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 International Classification of Diseases (ICD) codes. Additionally, to be considered chronic, nephritis condition records must have a code of "1" ("Chronic") in the variable CACODE in the original NHIS public use files.

For 1982-1996, nephritis records were defined as those condition records with any of the following codes in the variable DCICDCOD in the original NHIS public use files that correspond to the category "Nephritis, nephrotic syndrome and nephrosis":

• "5800" through "5839"

• "5845" through "5849"

• "5850" through "5859"

• "5870" through "5879"

These condition code values come from ICD Revision 9. As with earlier years, to be considered chronic, nephritis condition records must have a code of "1" ("Chronic") in the variable CACODE in the original NHIS public use files.

Comparability

As with all of the person-level condition variables created by IHIS from condition records prior to 1997, the universe for NEPHRITYRC 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 nephritis 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.

Universe

Availability

• 1973, 1978-1996

Weights

• 1973 : PERWEIGHT
• 1978-1981 : CONDWT3
• 1983-1996 : CONDWT4
• 1982 : CONDWT5