Codes and Frequencies
For sample persons under age 18, OPOUTPATNO reports the total number of outpatient operations ever performed on the person. Please see Comparability tab for information on a contradiction in the sample universe.
The original NHIS data includes 50 persons with ages of over 18 in this variable; this contradicts the universe of sample persons ages 18 and under. However, these persons appear to have legitimate values regarding their sample child status and are included in other Child Health Supplement variables such as BIRTHORDERR (birth order of child: recode). The IPUMS NHIS variable OPOUTPATNO retains these cases. Data users may wish to restrict this variable to persons ages 18 and under to ensure that they are only including cases with verifiable in-universe status. This variable has no additional comparability issues.
- 1981: Sample persons under age 18.
- 1981 : SAMPWEIGHT