Description

For sample persons under age 6 or 7, and all children 19 to 35 months old, with any information transcribed from a shot record and with at least four polio vaccinations indicated on record, IMRPOLMO4 reports the month of fourth polio vaccine.

Please use the IPUMS NHIS drop down menu and search functions for related variables.

Comparability

Apart from changes in the universe, this variable is mostly comparable over time. While the variable meaning is comparable for all available years, the NHIS underwent a major sample redesign in 1997; users should use caution when combining variables across these years.

Universe

Availability

• 1991-2003

Weights

• 1991 : SAMPWEIGHT
• 1992-2003 : SUPP1WT