Online Program

Effect of age-standardization on trends in US teen birth rates, 1981 - 2010

Tuesday, November 5, 2013 : 10:45 a.m. - 11:00 a.m.

Ronna Popkin, MS, Sociomedical Sciences, Mailman School of Public Health, Columbia University, New York, NY
John S. Santelli, MD, MPH, FSAHM, Heilbrunn Department of Population and Family Health, Columbia University, New York, NY
Background: Teen childbearing in the U.S. has generally declined over time; however, several unexplained periods of increase have occurred since 1981. Moreover, trends in teen births vary considerably among states and racial/ethnic groups. A possible explanation for these periods of increase is change in the age structure of 15-19 year olds. To explore this possibility, we examined the impact of age standardization on trends and disparities in teen childbearing. Methods: We calculated age-adjusted (by single year of age) and unadjusted teen birth rates stratified by race/ethnicity from 1981-2010. We then calculated and compared proportional changes in the adjusted and unadjusted rates over notable intervals of increase or decrease: 1986-1991, 1991-1996, 2005-2007, and 2007-2010. Finally, we estimated the percentage of the proportional changes in teen births over time that could be accounted for by changes in the age distribution. Results: From 1986-1996 and 2005-2007, fluctuations in the age structure inflated increases and decreases in teen birth rates, accounting for 8-35% of changes over time and varying considerably by racial/ethnic group. From 2007-2010, variations in the age distribution minimized decreases in rates of teen childbearing by 5-17%. Conclusion: Fluctuations in the population age distribution can account for sizeable proportions of increases or decreases in teen births over time. When examining trends in teen childbearing, researchers should consider using age-standardized rates so that changes are not inflated or masked by variations in the population age structure of teens.

Learning Areas:

Public health or related research
Social and behavioral sciences

Learning Objectives:
Identify notable periods of teen birth rate increases and decreases and racial/ethnic disparities in trends. Compare age-adjusted and unadjusted birth rates by race/ethnicity between 1981 and 2010, both in single years and over time. Explain how changes in the teen population age distribution might inflate or mask trends over time in teen childbearing.

Keyword(s): Reproductive Health Research, Teen Pregnancy

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I have training in demography, sociology, and public health and have been working and doing research on adolescent and young adult sexual and reproductive health for over 12 years.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.