National Survey of Family Growth

National Survey of Family Growth, Cycle I (1973)

Basic Information

  • Author: National Center for Health Statistics (U.S.). 
  • Fieldwork by: National Opinion Research Center (Chicago, IL). 
  • Distributed by: Springfield, VA: United States. National Technical Information Service, 1978. (No: PB 277 054). 
  • Data Prepared by: National Center for Health Statistics (U.S.). 
  • Universe: Women aged 15-44 who were ever married, or single with children of their own living in the household. 
  • Date of Survey: Midpoint September, 1973. 
  • Coverage: Coterminous United States (100% of 48 states). 
  • Sample Size: 9797 completed interviews. 
  • Record Weights: Product of the reciprocals of the probability of selection at each stage of the multi-stage sampling, adjusted for nonresponse. A post-stratification adjustment factor was used to make the weighted number of ever-married respondents conform to independent estimates of the population, classified by age and race, from the September, 1973, Current Population Survey. No post-stratification adjustment was made for single mothers, as no independent population estimate was available.

Additional Information

Sample

NCHS established a target sample size of 3600 black women and 6400 women who were white or of other races, in order to have a large enough sample of black women for analysis of subgroups. A four-stage stratified probability sampling method was used to identify 32,818 dwelling units; 3820 of these were either vacant or not dwelling units. Of the remainder, 26,028 (89.8%) completed household screeners. A fifth stage of the sampling process identified one eligible respondent from households that had more than one. Of the 10,879 eligible women thus selected, 9817 (90.2%) completed interviews. Twenty women were later eliminated from the sample because their ages fell outside the 15-44 age range.

Field Work

A few interviews were conducted in early 1973, but the bulk of the fieldwork was begun in July and completed by December.

Data Collected

The survey reports background information about the respondent and her husband, such as education, religion, ethnic origin, occupation, and earnings. Complete marital history, birth history and pregnancy history information are recorded. For pregnancies ending after January 1, 1970, a complete history of contraceptive methods used in the interval is available, including the reason the last method was stopped. The wantedness and timing of each pregnancy was ascertained. Finally, there are detailed questions about the woman's ideal family size, desired, intended and expected number of children. A monthly calendar of contraceptive use from January 1, 1970 until the date of the survey is provided; the information was recorded in the form of dates, and transcribed to the calendar by the interviewer.

Imputation of Missing Data

Items that had data missing for fewer than 15% of the responces (because the respondent didn't know the correct answer) had values imputed using a "hot deck" imputation method. Two different methods were used, depending on the percentage of responses that were missing. Some items were not imputed because there was no clear set of variables to use in the imputation. There is no indication in the data as to which responses were imputed at the individual level, although the codebook indicates for each variable the number of responses that were imputed.

Other References

The codebook for the data contains detailed information about the sampling design, the weighting procedure, estimation of variance and imputation of data.

Some other publications of interest are:

  1. Westoff, C.F. "Trends in Contraceptive Practice 1965-1973". Family Planning Perspectives, 8(2), pp. 54-57, March/April 1976. 
  2. National Center for Health Statistics. "Wanted and Unwanted Births Reported by Mothers 15-44 Years of Age: United States, 1973." Advance Data. No. 9. Washington, U.S. Government Printing Office, August 1977. 
  3. Vaughan, B., Trussell, J., Menken, J.A., and Jones, E.F. "Contraceptive Failure in the United States, 1970-1973." Family Planning Perspectives. 9:251-258. 1977.

Structure of the data

The data are in a rectangular file, with one record for each respondent. Repeating fields contain information for pregnancy and live birth intervals.

Location of Data and Documentation

You can click here for a file list.


National Survey of Family Growth, Cycle II (1976)

Basic Information

  • Author: National Center for Health Statistics (U.S.). 
  • Conducted by: Westat, Inc. (Rockville, MD) 
  • Distributed by: Springfield, VA: United States. National Technical Information Service, 1980. (No: PB 80-168206). 
  • Data Prepared by: National Center for Health Statistics (U.S.). 
  • Universe: Women aged 15-44 who were ever married, or single with children of their own living in the household. 
  • Date of Survey: Midpoint April, 1976. 
  • Coverage: Coterminous United States (100% of 48 states). 
  • Sample Size: 8611 completed interviews. 
  • Record Weights: Product of the reciprocals of the probability of selection at each stage of the multi-stage sampling, adjusted for nonresponse. A post-stratification adjustment factor was used to make the weighted number of ever-married respondents conform to independent estimates of the population, classified by age and race, from the May, 1976, Current Population Survey. No post-stratification adjustment was made for single mothers, as no independent population estimate was available.

Additional Information

Sample

NCHS established a target sample size of 4000 black women and 6000 women who were white or of other races, in order to have a large enough sample of black women for analysis of subgroups. A four-stage stratified probability sampling method was used to identify 32,652 dwelling units; 5490 of these were either vacant or not dwelling units. Of the remainder, 25,479 (93.8%) completed household screeners. A fifth stage of the sampling process identified one eligible respondent from households that had more than one. Of the 10,202 eligible women thus selected, 8611 (94.4%) completed interviews.

While the survey was in the field, Westat realized that the sample was falling short of the target. This was due to a larger than expected refusal rate, population shifts resulting in fewer than expected dwelling units in some strata, and a lower than expected proportion of white and other women in some strata. Westat increased the sampling ratio for some strata during the fieldwork to compensate for this. In spite of this, the sample of black women (3009) is 25% short of the target of 4000 and the sample of white women (5488) is 9% short of the target.

Field Work

The interviews were conducted by trained women interviewers over the course of six months centered on April, 1976. The interview took about an hour to complete.

Data Collected

The survey reports background information about the respondent and her husband, such as education, religion, ethnic origin, occupation, and earnings. Complete marital history, birth history and pregnancy history information are recorded. For pregnancies ending after January 1, 1973, a complete history of contraceptive methods used in the interval is available, including the reason the last method was stopped. The wantedness and timing of each pregnancy was ascertained. Finally, there are detailed questions about the woman's ideal family size, desired, intended and expected number of children. A monthly calendar of contraceptive use from January 1, 1973 until the survey is provided; the information was recorded in the form of dates, and transcribed to the calendar by the interviewer.

Imputation of Missing Data

Most missing data items were not imputed, but coded as missing (unlike the 1973 NSFG). A very few respondents had age or race imputed. If a date had a missing day of the month, it was imputed to be "15"; If the month of an event was unknown, but it was reported as "in the winter", it was imputed to be "January".

Other References

The codebook for the data contains detailed information about the sampling design, the weighting procedure, estimation of variance and imputation of data.

Structure of the data

The data are provided in two files. The first, the "respondent" file, contains background information about the woman, her husband, her fertility intentions and the open interval (the period since marriage or the last pregnancy), along with summary measures derived from the pregnancy histories. The second file, the "interval" file, contains one record for each pregnancy, containing the detailed pregnancy, birth, and contraceptive use history, along with important variables from the respondent file. A unique respondent ID number in columns 1-5 of both files allows the files to be matched.

Location of Data and Documentation

You can click here for a file list


National Survey of Family Growth, Cycle III (1982)

Basic Information

  • Author: National Center for Health Statistics (U.S.). 
  • Fieldwork by: Westat, Inc. (Rockville, MD) 
  • Distributed by: Springfield, VA: United States. National Technical Information Service, 1985. (No: PB 85-100022 ). 
  • Data Prepared by: National Center for Health Statistics (U.S.). 
  • Universe: All women aged 15-44. 
  • Date of Survey: Midpoint October, 1982 
  • Coverage: Coterminous United States (100% of 48 states). 
  • Sample Size: 7969 completed interviews. 
  • Record Weights: Product of the reciprocals of the probability of selection at each stage of the multi-stage sampling, adjusted for nonresponse. A post-stratification adjustment factor was used to make the weighted number of respondents conform to independent estimates of the population, classified by age and race, from the October, 1982, Current Population Survey.

Additional Information

Sample

This is the first nation-wide fertility survey to include childless never-married women. Black women and teenage women were over-sampled to produce numbers large enough to perform analyses for small subgroups. A special supplementary sample was drawn of women living in college dormitories and sororities. Permission of the respondent and a parent or guardian was required for never-married respondents aged 15-17. A four-stage stratified probability sampling method was used to identify 34,630 dwelling units; 3559 of these were either vacant or not dwelling units. Of the remainder, 28,817 (92.7%) completed household screeners. A fifth stage of the sampling process identified one eligible respondent from households that had more than one. Of the 9804 eligible women thus selected, 7969 (81.3%) completed interviews.

Data Collected

The survey reports background information about the respondent and her husband, such as education, religion, ethnic origin, occupation, and earnings. Complete marital history, birth history and pregnancy history information are recorded. For pregnancies ending after January 1, 1979, a complete history of contraceptive methods used in the interval is available, including the reason the last method was stopped. The wantedness and timing of each pregnancy was ascertained. There are questions about the woman's ideal family size, desired, intended and expected number of children. Women are asked their age at the first time they had intercourse. This survey has expanded questions about the respondent's use of health services, including PAP tests, pelvic exams, and tests for STD's. There are also detailed questions about child care. A calendar of contraceptive use, recorded at six-month intervals, is provided for the period from January 1st, 1979, until the date of the survey.

Imputation of Missing Data

An extensive effort was made to reconcile missing and inconsistent data using related information in the questionnaire. Missing days were imputed to be the 15th of the month and reponses like "in the winter" were imputed to be January, and so forth. Other than this, no data items had imputed values assigned if the responses were missing. However, for about 120 computer-generated "recode" variables, imputations were made using a hot-deck imputation procedure. Variables that are imputed are flagged in the data.

Other References

The codebook for the data contains detailed information about the sampling design, the weighting procedure, estimation of variance and the imputation procedures used for specific variables.

Structure of the data

The data are in a single hierarchical file, with the record for the respondent followed by the records for each of her pregnancies. The respondent's ID number appears in columns 1494-1498 of both the respondent and interval records.

Location of Data and Documentation

You can click here for a file list.


National Survey of Family Growth, Cycle IV (1988)

Basic Information

  • Author: National Center for Health Statistics (U.S.). 
  • Distributed by: Inter-University Consortium for Political and Social Research (Ann Arbor, MI), 1991. (No: 9473). 
  • Data Prepared by: National Center for Health Statistics (U.S.). 
  • Universe: All women aged 15-44. 
  • Date of Survey: January to August 1988 
  • Coverage: United States (50 states). 
  • Sample Size: 8450 completed interviews. 
  • Record Weights: Product of the reciprocals of the probability of selection,adjusted for nonresponse. Very large weights were trimmed to a maximum value. A post-stratification adjustment factor was used to make the weighted number of respondents conform to independent estimates of the population, classified by age, race, marital status and parity.

Additional Information

Sample

The National Center for Health Statistics (NCHS) selected eligible women from households in which a member had responded to a National Health Interview Survey (NHIS) between October, 1985 and March 1987. If more than one eligible woman was in a household, only one was selected for the National Survey of Family Growth (NSFG) interview. Women who had moved since the NHIS were tracked to their new addresses. Black women were over-sampled to produce numbers large enough to perform analyses for small subgroups.

The response rate for the NHIS, from which the NSFG sample was drawn, was 96%. Of the women selected for the NSFG sample, 80% completed interviews. In an intensive followup, NCHS did subsampling for nonresponse. Taking account of this subsampling, as NCHS does, produces a response rate of 82%. The response rate is thus the product of 96% (for the NHIS) and 82% (for the NSFG) or 79% overall.

Data Collected

The survey reports background information about the respondent and her husband, such as education, religion, ethnic origin, occupation, and earnings. Complete marital history, birth history and pregnancy history information are recorded. For pregnancies ending after January 1, 1982, a complete history of contraceptive methods used in the interval is available, including the reason the last method was stopped. The wantedness and timing of each pregnancy was ascertained. There are questions about the woman's ideal family size, desired, intended and expected number of children. Women are asked their age at the first time they had intercourse. This survey has expanded questions about the respondent's use of health services, including PAP tests, pelvic exams, and tests for STD's. There are more questions about precautions the respondent was taking to avoid AIDS and other STD's, although many of these responses are not included in the data because of concerns about confidentiality. There are also detailed questions about child care.

Imputation of Missing Data

For computer-generated "recode" variables, imputations were made using a hot-deck imputation procedure. Variables that are imputed are flagged in the data.

Other References

The codebook for the data contains summary information about the sampling design, the weighting procedure, estimation of variance and the imputation procedures used for specific variables. More detailed information is contained in the NCHS report National Survey of Family Growth, Cycle IV: Sample design, weighting, imputation and variance estimation. Individuals and institutions may obtain single copies of this and other publications free of charge from:

Scientific and Technical Information Branch 
National Center for Health Statistics 
3700 East-West Highway 
Hyattsville, MD 20782 

Structure of the data

The data are in a single hierarchical file, with the record for the respondent followed by the records for each of her pregnancies. The respondent's ID number appears in both the respondent and interval records.

Location of Data and Documentation

You can click here for a file list.


National Survey of Family Growth, Cycle IV: 1990 Telephone Reinterview

Basic Information

  • Author: National Center for Health Statistics (U.S.). 
  • Distributed by: Inter-University Consortium for Political and Social Research (Ann Arbor, MI). 
  • Data Prepared by: National Center for Health Statistics (U.S.). 
  • Universe: All women aged 15-44. 
  • Date of Survey: July-November 1990 
  • Coverage: United States (50 states). 
  • Sample Size:Of the 5,686 women interviewed in 1990, 5,359 were respondents who had been interviewed in 1988, and 327 were first-time interviewees aged 15-17 from the civilian, noninstitutionalized population. Black women were oversampled to yield reliable estimates by race.

Additional Information

The NSFG Cycle IV telephone reinterviews have been divided into two files. The Respondent File (Part 1) contains one record for each woman in the survey, while the Interval File (Part 2) contains one record for each completed pregnancy experienced by a woman in the survey. An interval can be defined as any of the following: the time between a first intercourse at last contact (in 1988) and a pregnancy that ended after last contact, or the time between a pregnancy that ended before last contact and one that was in progress at the time of the interview. Part 1 offers data on the respondent's marital history/update, education, family background, sex education, births and pregnancies, first sexual intercourse, sterilizing operations, contraceptive history/update, family planning services, infertility services, births intended and expected, adoption, sexually transmitted diseases/AIDS, religion, race/ethnicity, employment/occupation, income, and insurance. Part 2 supplies information on outcomes of pregnancies and other pregnancy-related information, use of birth control methods during intervals, and "wantedness" of pregnancies.

Location of Data and Documentation

You can click here for a file list.


National Survey of Family Growth, Cycle V, 1995

Basic Information

  • Author: National Center for Health Statistics (U.S.). 
  • Distributed by: Inter-University Consortium for Political and Social Research (Ann Arbor, MI). 
  • Data Prepared by: National Center for Health Statistics (U.S.). 
  • Universe: All women aged 15-44. 
  • Date of Survey: mid-January through October 1995 
  • Coverage: United States (50 states). 
  • Sample Size: A national probability sample of 14,000 women aged 15-44 was chosen from households that had participated in NATIONAL HEALTH INTERVIEW SURVEY, 1993 (ICPSR 6534). Black and Hispanic women were oversampled.

Basic Information

The NSFG Cycle V interviews have been divided into two files. The Respondent File (Part 1) contains one record for each woman in the survey, while the Interval File (Part 2) contains one record for each completed pregnancy experienced by a woman in the survey. An interval can be defined as one of the following: the time between a first intercourse at last contact (in 1988) and a pregnancy that ended after last contact, or the time between a pregnancy that ended before last contact and one that was in progress at the time of the interview. Part 1 offers data on respondents' marital histories, education, family background, sex education, births and pregnancies, first sexual intercourse, sterilizing operations, contraceptive histories, family planning services, infertility services, births -- intended and unexpected, adoption, sexually transmitted diseases/AIDS, religion, race/ethnicity, employment/occupation, income, and insurance. Part 2 supplies data on outcomes of pregnancies and other pregnancy-related information, use of birth control methods during intervals, and "wantedness" of pregnancies.

Location of Data and Documentation

You can click here for a file list.