4.37 Sexual Activity & Contraception

Sexual Activity: In 1983, 1984, and 1985 NLSY79 respondents were asked about their sexual activity. Once the respondent answered the questions, he or she was not asked the series in subsequent surveys. Out of a total of 12,686 respondents, 310 did not answer any of the questions in these three years.

The first activity question asked respondents whether they had ever had sexual intercourse. This question was skipped if the respondent had previously reported either being a parent or being pregnant. Out of the 11,797 respondents, 889 or 7.5 percent stated that they had never had sexual intercourse. Researchers should note that the youngest respondents answered this question when they were 18. The validity of these items is evaluated in Mott (1985). These data should be used cautiously because inconsistencies in reports of first intercourse with subsequent fertility events can sometimes occur. Respondents who had ever engaged in sex were then asked at what age they first had intercourse. Table 4.37.1 includes frequencies broken down by race and gender, as well as a total for the whole cohort.

Table 4.37.1 Reported Age at which Respondents First Had Sex by Race and Gender

Questions in this section also ask NLSY79 respondents if they have had sex in the past month. In 1983, respondents provided a yes/no answer. However, in 1984 and 1985 they were asked the number of times they had sex in the last month. The data contain some outlying entries; users should carefully decide how to interpret outlying data points in these distributions. Additionally, there is evidence of a significant number of youth who changed their “ever had sex” status from yes to no between 1983 and subsequent survey years.

In 1984, the survey also asked if respondents had taken a sex education course. If so, they were asked at what date they took the course. Respondents also stated whether the first course they took covered:

• The female menstrual cycle
• Contraception methods
• Where to obtain contraception
• Effects of contraception
• Sexual diseases

To test reproductive knowledge, respondents were also asked when pregnancy is most likely to occur during the female monthly menstrual cycle. Answers in 1984 show a substantial portion of respondents did not choose the medically correct answer of about two weeks after the period. Approximately 25 percent of men and 12 percent of women stated they did not know the answer.

Table 4.37.2 Knowledge of When Pregnancy Most Likely to Occur

Contraception: Since 1982, NLSY79 respondents have regularly been asked about their use of contraception. These contraception questions appear in the “Fertility” section of the questionnaire. The questions were asked annually from 1982 to 1986. After 1986 the questions were asked only in even years corresponding with the child supplements (i.e. 1988, 1990, 1992, etc.). After 1994, the surveys became biennial and the questions were included in each survey.

When conducting the survey in person, the standard sequence for these questions is to first show respondents a hand card listing a variety of birth control methods. The respondents are then asked if they use birth control. If they state that they do, the second question asks the frequency of these methods using a three-point scale of “always,” “sometimes,” or “almost never.” Finally, respondents are asked to state all the methods they have used in the past month from the following list:

Over time the list has been expanded and now includes three additional choices:

• Abstinence
• Norplant
• Cervical Cap

Beginning in 2002 a specific individual question was added asking respondents if they have been surgically sterilized. If they have been sterilized they will not be asked this series of birth control questions again. Previously, sterilization was an option among a list of birth control options (see list above), but it was not a separate question.

In most years, at the end of this three-question series, the interviewer fills in a question that states if anyone else was present during this part of the questioning. Small children under three years old are not counted by interviewers when filling in their response.

In addition to these questions, female respondents who are pregnant or who have given birth since the last survey year are asked about their contraception methods before conceiving. Respondents are asked if before becoming pregnant they used one of the birth control methods listed, or if they stopped all birth control methods before becoming pregnant. Finally, they were asked if the reason they stopped using birth control was because they wanted to become pregnant.

Survey Instruments: The questions on sexual activity and contraception can be found in the “Fertility” section of each questionnaire. In 1983, the fertility section was fielded as a separate supplement for those respondents who were not interviewed in 1982.

Data Files: The variables described above can be found within the “Birth Record” and BIRTHRECXX areas of interest.

Comparison to Other NLS Cohorts: NLSY79 young adults have been asked about both sex and birth control methods in the "Confidential" section of each survey. In NLSY97 rounds 1 and 2, data on sexual activity were obtained from respondents who were at least 14 years old; all respondents were eligible in later rounds. These respondents are first asked if they have ever had sexual intercourse and if they have had intercourse since the last interview (later rounds). If a respondent reports ever having sexual intercourse, questions are asked about the first occurrence (e.g., the respondent’s age, whether the respondent and the partner used birth control). For more precise details about this topic, users should consult the NLSY97 User’s Guide.

Reference

Mott, Frank L. "Evaluation of Fertility Data and Preliminary Analytical Results from the 1983 (Round 5) Survey of the National Longitudinal Surveys of Work Experience of Youth." Columbus, OH: CHRR, The Ohio State University, 1985.