Thursday, November 01, 2007

Contraception, continued: A graph

Blogging on Peer-Reviewed ResearchContinuing from my previous blog entry, Does the Pill encourage teenage sex? No., here is the graph showing the cumulative age at first coitus for students that had received and had not received comprehensive sex ed and contraception

The original graph is in black and white and my annotations are in color. If I'm reading this graph correctly, the median age for the entry into sexual activity is about 14.5 for the group without the program, and lightly over 15 for the group with the program. So we can conclude that the program caused about an 0.8 year delay in becoming sexually active.

Furthermore, at the median age for sexual activity for the non-program group (where 50% of them had begun sexual activity), only 35% of the program group was having sex. So we can see that exposure to sexual education and the availability of contraception clearly causes a delay in sexual activity in teenagers.

The Zabin study is from 1986, probably before AIDS prevention programs and condom awareness were in full swing. So the contraception methods uses were probably primarily the pill. In fact, the study goes on to look at pill usage specifically. They also found that, even though girls were likely to postpone sexual activity to a later age, they were more likely to be using the pill when they did start sexual activity.

Dr. Fig was kind enough to send me a big, honking list of references from PubMed. I'll try to go through some of those soon.


  • Zabin, L. S., M. B. Hirsch, E. A. Smith, R. Streett, and J. B. Hardy. "Evaluation of a Pregnancy Prevention Program for Urban Teenagers." Family Planning Perspectives 18. 119 (1986).

1 comment:

Fig said...

Mauldon J and Luker K. The Effects of Contraceptive Education On Method Use at First Intercourse Family Planning Perspectives, 28:19–24 & 41, 1996

That's the article I recommended to. It's a decade later than the one you cite and the PDF is available from the Guttmacher site. It has this great table that clearly shows that teens who get contraceptive education start having sex later. Without sex ed, the age of first intercourse is 15.6, with sex ed it's 17.2.

Not being my field of expertise, I don't know how the samples differed between those two studies or what the national average for age of onset of penetrative intercourse is currently.

Strong work, Narc!