Table of Contents

Component Description

The Mobile Examination Center (MEC) Interview questionnaire on sexual behavior (variable name prefix SXQ) provides information on lifetime and current sexual behavior for both males and females. Items covered in this section include: sexual identity, age of first sexual encounter, number of sexual partners, circumcision status (male), and history of sexually transmitted infections.

Eligible Sample

Survey participants aged 14-69 years were eligible. Questions in this section are age-specific and gender-specific. Questions were limited to survey participants who were able to understand English or Spanish. Only data from youth aged 14-17 years are included in this data file; data for adults 18 to 69 years is located, separately, in SXQ_L_R. Both data files are accessed through the NCHS Research Data Center.

Interview Setting and Mode of Administration

The sexual behavior questions were self-administered in a private room at the MEC, during the MEC Interview, using the Audio Computer-Assisted Self Interview (ACASI) system. No proxy respondents or interpreters were used in situations when the respondents could not self-report for themselves in English or Spanish. 

Due to MEC time constraints in NHANES August 2021-August 2023, the two questions on sexual identity (one for males and one for females) were moved back to ACASI. These questions had been administered using the Computer Assisted Personal Interview (CAPI) system beginning in 2017 to be consistent with their administration mode in the National Health Interview Survey. The questions were specifically placed at the beginning of the ACASI to separate them from the sexual behavior questions asked later. This helps avoid the potential context effect with other behavioral questions, which may make the participant more likely to interpret the sexual orientation question from a behavioral as opposed to a social identity perspective.

Quality Assurance & Quality Control

The ACASI system is programmed with built-in consistency checks to reduce data entry errors. The system also uses online help screens to assist in defining key terms used in the questionnaire. All data were reviewed by the NHANES staff for accuracy and completeness.

Data Processing and Editing

The variable SXD021 (Ever had vaginal, anal, or oral sex) was derived from whether the respondent reported having any of the specific types of sex. For example, if a male answered “yes” to having had any of the following types of sex: SXQ800 (Ever had vaginal sex with a woman), SXQ803 (Ever performed oral sex on a woman), SXQ806 (Ever had anal sex with a woman), or SXQ809 (Ever had any sex with a man; anal, oral); he would be coded as a “1” or “yes” in SXD021. The value of SXD021 was set to missing if the respondent missed or responded “don’t know” or “refuse” to at least one of the questions that were part of the algorithm for deriving SXD021 and had “no” responses for the other questions in the algorithm. 

Edits were made, when necessary, to address data disclosure concerns. For example, responses to age first of first sexual encounter that were 12 years or less were grouped and coded as “12 years or younger.” Responses to questions on number of partners were grouped and coded as “100 or more”. 

In general, if a respondent was not asked a question, the response to the question is shown as “missing.” It is up to the analysts to recode the response to zero as they see fit. For example, if a respondent reported that they had zero lifetime male sex partners, they wouldn't be asked the number of male sex partners in the past 12 months. Since the respondent does not receive the question about partners in the past 12 months, the data will be coded as missing for this variable. Analysts may want to recode this to “0” for their analyses.

For questions that ascertain total number of partners for all types of sex (i.e., SXD171, SXD510, SXD101 and SXD450), if the respondent had reported never having any type of sex, the responses were coded as “0.”

Analytic Notes

Several questions were dropped in NHANES August 2021-August 2023 and are not included in this data file: SXQ618, SXQ824, SXQ827, SXQ636, SXQ841, SXQ853, SXQ864, SXQ827, SXQ845, SXQ610, SXQ251, SXQ724, SXQ741.

In the ACASI system, if participants did not answer the question and instead pressed “next” to move forward, they get a screen asking them to indicate: “I really meant to answer,” “I’d rather not answer,” or “I don’t know the answer.” If they chose “I really meant to answer,” they were taken back to the question so they could respond. If they selected “I’d rather not answer,” their response was coded as “refuse.” The selection of “I don’t know the answer” was coded as “don’t know.”

Although the ACASI has many advantages over interviewer-administered questionnaires for sensitive information, inconsistent responses can occur. Since the questions were self-administered, unlikely answers or confusing questions generally were not clarified by the interviewer. Although the questionnaire was programmed to alert respondents of potential data entry errors or inconsistencies, not every possible consistency check was added. To minimize potential respondent frustration and confusion, the interview was not interrupted each time an inconsistent answer occurred in terms of the number of sexual partners for different periods of recall and/or for different types of sexual behavior.

Analysis by subgroup characteristics should be conducted carefully. The sample size for the non-heterosexual subgroups is limited and may not meet the minimum sample size requirements for statistical reliability as noted in the NHANES analytic guidelines. Additionally, the high rate of selecting a non-specific answer to the questions should be considered (Miller et. al., 2011). That is, selecting “don’t know,” “refused,” “not sure,” or “something else” as a response. Respondents select these answers for a variety of reasons that are well summarized in Table 2 of the NCHS report “Design, Development and Testing of the NHIS Sexual Identity Question” (Miller et. al., 2011). For example, respondents from the lesbian, gay, bisexual, and transgender (LGBT) community may select “something else” when they use a different sexual identity label than those presented in the response options. However, the same option may also be selected by others because they are not familiar with the terms presented. 

References

Codebook and Frequencies

SEQN - Respondent sequence number

Variable Name:
SEQN
SAS Label:
Respondent sequence number
English Text:
Respondent sequence number.
Target:
Both males and females 14 YEARS - 17 YEARS

SXD021 - Ever had vaginal, anal, or oral sex (B)

Variable Name:
SXD021
SAS Label:
Ever had vaginal, anal, or oral sex (B)
English Text:
Ever had vaginal, anal, or oral sex.
English Instructions:
DERIVED FROM SXQ615, SXQ800, SXQ803, SXQ806, SXQ809 FOR MALES, AND SXQ615, SXQ700, SXQ703, SXQ706, SXQ709 FOR FEMALES.
Target:
Both males and females 14 YEARS - 17 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 114 114
2 No 388 502
7 Refused 0 502
9 Don't know 0 502
. Missing 55 557

SXD001C - CHECK ITEM

Variable Name:
SXD001C
English Instructions:
CHECK ITEM SXD001C: IF FEMALE, GO TO SXQ700. IF MALE, CONTINUE TO SXQ800.
Target:
Both males and females 14 YEARS - 17 YEARS

SXQ800 - Ever had vaginal sex with a woman (M)

Variable Name:
SXQ800
SAS Label:
Ever had vaginal sex with a woman (M)
English Text:
Have you ever had vaginal sex, also called sexual intercourse, with a woman? This means your penis in a woman's vagina.
Target:
Males only 14 YEARS - 17 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 40 40
2 No 18 58
7 Refused 0 58
9 Don't know 0 58
. Missing 499 557

SXQ803 - Ever performed oral sex on a woman (M)

Variable Name:
SXQ803
SAS Label:
Ever performed oral sex on a woman (M)
English Text:
Have you ever performed oral sex on a woman? This means putting your mouth on a woman's vagina or genitals.
Target:
Males only 14 YEARS - 17 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 37 37
2 No 21 58
7 Refused 0 58
9 Don't know 0 58
. Missing 499 557

SXQ806 - Ever had anal sex with a woman (M)

Variable Name:
SXQ806
SAS Label:
Ever had anal sex with a woman (M)
English Text:
Have you ever had anal sex with a woman? Anal sex means contact between your penis and a woman's anus or butt.
Target:
Males only 14 YEARS - 17 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 5 5
2 No 53 58
7 Refused 0 58
9 Don't know 0 58
. Missing 499 557

SXQ809 - Ever had any kind of sex w/man (M)

Variable Name:
SXQ809
SAS Label:
Ever had any kind of sex w/man (M)
English Text:
Have you ever had any kind of sex with a man, including oral or anal?
Target:
Males only 14 YEARS - 17 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 9 9
2 No 49 58
7 Refused 0 58
9 Don't know 0 58
. Missing 499 557

SXQ700 - Ever had vaginal sex with a man (F)

Variable Name:
SXQ700
SAS Label:
Ever had vaginal sex with a man (F)
English Text:
Have you ever had vaginal sex, also called sexual intercourse, with a man? This means a man's penis in your vagina.
Target:
Females only 14 YEARS - 17 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 44 44
2 No 13 57
7 Refused 0 57
9 Don't know 0 57
. Missing 500 557

SXQ703 - Ever performed oral sex on a man (F)

Variable Name:
SXQ703
SAS Label:
Ever performed oral sex on a man (F)
English Text:
Have you ever performed oral sex on a man? This means putting your mouth on a man's penis or genitals.
Target:
Females only 14 YEARS - 17 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 40 40
2 No 17 57
7 Refused 0 57
9 Don't know 0 57
. Missing 500 557

SXQ706 - Ever had anal sex with a man (F)

Variable Name:
SXQ706
SAS Label:
Ever had anal sex with a man (F)
English Text:
Have you ever had anal sex? This means contact between a man's penis and your anus or butt.
Target:
Females only 14 YEARS - 17 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 6 6
2 No 51 57
7 Refused 0 57
9 Don't know 0 57
. Missing 500 557

SXQ709 - Ever had any kind of sex w/woman (F)

Variable Name:
SXQ709
SAS Label:
Ever had any kind of sex w/woman (F)
English Text:
Have you ever had any kind of sex with a woman? By sex, we mean sexual contact with another woman's vagina or genitals.
Target:
Females only 14 YEARS - 17 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 15 15 SXQ648
2 No 42 57 SXQ648
7 Refused 0 57 SXQ648
9 Don't know 0 57 SXQ648
. Missing 500 557

SXD171 - # female sex partners/lifetime (M)

Variable Name:
SXD171
SAS Label:
# female sex partners/lifetime (M)
English Text:
In your lifetime, with how many women have you had any kind of sex?
Target:
Males only 14 YEARS - 17 YEARS
Hard Edits:
0 to 99
Code or Value Value Description Count Cumulative Skip to Item
0 to 20 Range of Values 259 259
100 100 or more 0 259
77777 Refused 0 259
99999 Don't know 0 259
. Missing 298 557

SXD510 - # female sex partners/year (M)

Variable Name:
SXD510
SAS Label:
# female sex partners/year (M)
English Text:
In the past 12 months, with how many women have you had any kind of sex?
Target:
Males only 14 YEARS - 17 YEARS
Hard Edits:
0 to 99
Code or Value Value Description Count Cumulative Skip to Item
0 to 12 Range of Values 259 259
100 100 or more 0 259
77777 Refused 0 259
99999 Don't know 0 259
. Missing 298 557

SXQ410 - # male sex partners/lifetime(M)

Variable Name:
SXQ410
SAS Label:
# male sex partners/lifetime(M)
English Text:
In your lifetime, with how many men have you had anal or oral sex?
Target:
Males only 14 YEARS - 17 YEARS
Hard Edits:
1 to 99
Code or Value Value Description Count Cumulative Skip to Item
1 to 3 Range of Values 9 9
100 100 or more 0 9
77777 Refused 0 9
99999 Don't know 0 9
. Missing 548 557

SXQ550 - # male sex partners/year (M)

Variable Name:
SXQ550
SAS Label:
# male sex partners/year (M)
English Text:
In the past 12 months, with how many men have you had anal or oral sex?
Target:
Males only 14 YEARS - 17 YEARS
Hard Edits:
0 to 99
Code or Value Value Description Count Cumulative Skip to Item
0 to 3 Range of Values 9 9
100 100 or more 0 9
77777 Refused 0 9
99999 Don't know 0 9
. Missing 548 557

SXQ648 - Had sex with a new partner past 12mos(B)

Variable Name:
SXQ648
SAS Label:
Had sex with a new partner past 12mos(B)
English Text:
In the past 12 months, did you have any kind of sex with a person that you never had sex with before?
English Instructions:
THE ITEM INCLUDES SEX WITH BOTH MALE AND FEMALE PARTNERS.
Target:
Both males and females 14 YEARS - 17 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 65 65
2 No 28 93
7 Refused 0 93
9 Don't know 0 93
. Missing 464 557

SXD003C - CHECK ITEM

Variable Name:
SXD003C
English Instructions:
CHECK ITEM SXD003C: IF MALE, GO TO SXQ260. IF FEMALE, CONTINUE TO SXD101.
Target:
Both males and females 14 YEARS - 17 YEARS

SXD101 - # male sex partners/lifetime (F)

Variable Name:
SXD101
SAS Label:
# male sex partners/lifetime (F)
English Text:
In your lifetime, with how many men have you had any kind of sex?
Target:
Females only 14 YEARS - 17 YEARS
Hard Edits:
0 to 99
Code or Value Value Description Count Cumulative Skip to Item
0 to 5 Range of Values 243 243
100 100 or more 0 243
77777 Refused 0 243
99999 Don't know 0 243
. Missing 314 557

SXD450 - # male sex partners/year (F)

Variable Name:
SXD450
SAS Label:
# male sex partners/year (F)
English Text:
In the past 12 months, with how many men have you had any kind of sex?
Target:
Females only 14 YEARS - 17 YEARS
Hard Edits:
0 to 99
Code or Value Value Description Count Cumulative Skip to Item
0 to 4 Range of Values 243 243
100 100 or more 0 243
77777 Refused 0 243
99999 Don't know 0 243
. Missing 314 557

SXQ130 - # female sex partners/lifetime (F)

Variable Name:
SXQ130
SAS Label:
# female sex partners/lifetime (F)
English Text:
In your lifetime with how many women have you had sex? By sex, we mean sexual contact with another woman's vagina or genitals.
Target:
Females only 14 YEARS - 17 YEARS
Hard Edits:
1 to 99
Code or Value Value Description Count Cumulative Skip to Item
1 to 9 Range of Values 15 15
100 100 or more 0 15
77777 Refused 0 15
99999 Don't know 0 15
. Missing 542 557

SXQ490 - # female sex partners/year (F)

Variable Name:
SXQ490
SAS Label:
# female sex partners/year (F)
English Text:
In the past 12 months, with how many women have you had sex? By sex, we mean sexual contact with another woman's vagina or genitals.
Target:
Females only 14 YEARS - 17 YEARS
Hard Edits:
0 to 99
Code or Value Value Description Count Cumulative Skip to Item
0 to 2 Range of Values 15 15
100 100 or more 0 15
77777 Refused 0 15
99999 Don't know 0 15
. Missing 542 557

SXQ260 - Ever told that you had genital herpes(B)

Variable Name:
SXQ260
SAS Label:
Ever told that you had genital herpes(B)
English Text:
Has a doctor or other health care professional ever told you that you had genital herpes?
Target:
Both males and females 14 YEARS - 17 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 0 0
2 No 114 114
7 Refused 0 114
9 Don't know 0 114
. Missing 443 557

SXQ265 - Ever told that you had genital warts (B)

Variable Name:
SXQ265
SAS Label:
Ever told that you had genital warts (B)
English Text:
Has a doctor or other health care professional ever told you that you had genital warts?
Target:
Both males and females 14 YEARS - 17 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 0 0
2 No 114 114
7 Refused 0 114
9 Don't know 0 114
. Missing 443 557