Codes and Frequencies
For sample adults and sample children who had surgery during the past 12 months (SURGERYR), SURGERYRNO reports the number of surgeries (either inpatient or outpatient) individuals had during that time period. Interviewers asked, "Including any time you may have already told be about, how many different times [have you/has sample adult/sample child] had surgery during the past 12 months?"
The 1997-1998 Field Representative's Manuals instructed interviewers to include as surgery "both major surgery and minor procedures such as setting bones or removing growths."
The Manuals for 1999 forward provided the following definition for surgery:
These definitions were not routinely shared with respondents. Indeed, the NHIS Codebooks for sample adults for 1999 forward acknowledge, "The data in this field may represent an undercount because the respondents may not have included all types of minor surgical procedures, such as setting bones or removal of growths, in their response." (See comparability section for further discussion.)
In 1997-2017, for sample children who had inpatient or outpatient surgery during the past 12 months (SURGERYR), information was collected on the number of outpatient surgeries they had during the past year (see SURGRYROUTNO).
Along with universe changes, differences in the survey instrument for the question associated with the filter variable SURGERYR (Had surgery in past 12 months) limit the comparability of SURGERYRNO across two time periods, namely, 1997-1998 and 1999 forward. Additionally, users should note changes to the top-code over time. In 1997-2015, number of surgeries per year was top-coded at 95. Beginning in 2016, this top-code was changed to 7 or more times for sample adults, though no sample children have more than 6 surgeries reported in 2016. In 2017, both sample adults and sample children are top-coded at 7 surgeries or more.
The question associated with SURGERYR asked, "During the past 12 months, [have you/has sample child] had surgery or other surgical procedures either as an inpatient or outpatient?" Beginning in 1999, interviewers were instructed to read, if necessary, "This includes both major and minor surgery such as setting bones or removing growths." (No guidance was given to interviewers on when such elaboration was "necessary").
Because the general public may not automatically equate "surgery" with minor procedures like the removal of a benign growth or the setting of a broken bone, the inclusion of the follow-up statement classifying these treatments as "surgery" probably increased completeness of reporting beginning in 1999. Thus, the pool of people giving responses in SURGERYRNO was probably more limited, and the definition of surgery they implicitly used was probably narrower, in 1997-1998 than in subsequent years. Analysts should therefore exercise caution in comparing results for 1997-1998 with those from later years. For further discussion of this point, see the variable description for SURGERYR.
- 1997-2003: Sample adults age 18+ who had surgery in the past 12 months.
- 2004-2011; 2015-2017 2018: Sample adults age 18+ and sample children under age 18 who had surgery in the past 12 months.
- 1997-2011, 2015-2018
- 1997-2011, 2015-2018 : SAMPWEIGHT