MPC teen preg prevention

MPC's high school program, delivered by trained health educators, aims to provide youth with information and tools to reduce their risk of Sexually Transmitted Infections (STIs), HIV, and pregnancy. It emphasizes that condoms can prevent pregnancy and STIs, and birth control can prevent pregnancy, if youth choose to have sex.

The study randomized 31 high school clusters in 4 US cities, with a combined sample of 2,138 students, to MPC vs control. Based on careful review, this was a high-quality RCT (e.g., good baseline balance, minimal attrition, appropriate analyses, MPC program delivered with fidelity).

6 months after program completion, the study found positive impacts on youths' knowledge and attitudes (about pregnancy, condoms, etc). However, these effects didn't translate into changes in sexual behavior or health (including pregnancy and STI rates).
The impacts on sexual behavior and health are shown below. Note that only 1 of 10 impacts was statistically significant (and the 1 could easily be a chance finding due measurement of many outcomes). Also, most effect sizes are very small - as I've highlighted in yellow.

The authors say the positive effects on knowledge/attitudes may yet lead to long-term behavior and health impacts. Although possible, prior RCTs in the area of teen pregnancy prevention haven't found this; behavior impacts tend to be largest shortly after program completion and if anything diminish over time.

Unfortunately the study abstract (below) portrays the results as unambiguously positive. That's concerning because busy readers often look to the abstract for key take-aways and could easily conclude (wrongly) that MPC was found effective.