National Health Statistics Reports, Number 104, June 22, 2017

Methods 

Data source 

This report is focused on combined 

NSFG data from 2011–2013 and 

2013–2015, resulting in a data file of 4 

years of interviews spanning 2011–2015. 

These two datasets together contain a 

total of 20,621 interviews: 11,300 with 

women and 9,321 with men, all aged 

15–44. These interviews include 4,134 

with teenagers: 2,047 females and 2,087 

males aged 15–19. NSFG is administered 

through face-to-face interviews and 

represents men and women aged 15–44 

in the household population of the United 

States, including persons temporarily 

living away from the household in a 

college dormitory, sorority, or fraternity 

(14). Further details on the sample 

design, variance estimation, and 

fieldwork procedures for the most recent 

NSFG surveys were published previously 

(14–16). Earlier NSFG surveys presented 

here include the 1988, 1995, and 2002 

periodic surveys and the 2006–2010 

continuous survey (17). Also presented 

are statistics from the 1988 and 1995 

NSAM, a national panel survey of never-

married male teenagers conducted by the 

Urban Institute that is administered face-

to-face and designed to yield information 

parallel to that for female teenagers 

from NSFG (18). The earliest surveys 

align approximately with the beginning 

of the decline in teen pregnancy rates. 

Because the teen pregnancy rate peaked 

in 1990, after which it fell 50% through 

2010 (5), it is informative to examine 

national trends in both sexual activity 

and contraceptive use among teenagers 

during a time period starting as close to 

the peak as possible. For both NSFG and 

NSAM, 1988 is the survey point closest 

to the peak in teen pregnancy rates. 

Presenting data from the 2002 

and 2006–2010 surveys in addition to 

2011–2015 allows for examination of 

more recent trends (through the 2000s) 

in sexual activity and contraceptive use. 

Monitoring changes in these measures is 

important for gauging whether progress is 

being made toward the goals of reduction 

in pregnancy and STI risk behaviors.

In addition, changes in the overall 

use of contraceptive methods and the use 

of specific methods are influenced by 

frequent changes in the development and 

discontinuation of specific contraceptive 

methods and their accessibility. 

All respondents were given written 

and oral information about the survey 

and informed that participation was 

voluntary. Adult respondents aged 18–44 

were asked to sign a consent form but 

were not required to do so. For minors 

aged 15–17, signed consent was required 

first from a parent or guardian, and 

then signed assent was required from 

the minor: If either the parent or the 

minor declined to give written consent 

or assent, the minor did not participate 

in the survey. The overall response rate 

for the 2011–2015 NSFG was 71.0%. 

The response rate was 73.0% for female 

teenagers and 72.5% for male teenagers.