Sometimes you just need to turn to the church when you want to get sex education right. The Our Whole Lives (OWL) curriculum taught at many Unitarian Universalist churches is a model of what great comprehensive sex education, not to mention great health education in general, can be. It gives kids the information and skills they need to make good healthy choices throughout their lives, and I'm thrilled to know several people who teach it and talk about it on a regular basis. But I got distracted from the actual purpose of this blog post, which was supposed to be congratulating Washington State for setting curriculum guidelines that promote comprehensive sex education in their schools.

New York City just suspended the use of a quick oral HIV test because of too many false positive results. I'm not terribly surprised about the problem, since when the oral test was first introduced it was designed to be used in very high prevalence settings, where false positives are less of an issue. To understand why, you need to understand how the positive predictive value of an STD test is affected by prevalence. The less common a disease is, the more the positive predictive value of a test is affected by the specificity of the test - how good it is at ruling out people who have HIV. Unfortunately, the specificity of the oral test is somewhat lower than for traditional HIV testing, which is why second tests are always supposed to be done for these individuals. Discordant results shouldn't actually be surprising, which suggests to me that some of the individuals doing the testing may need a bit of an update on the theory involved... not that I necessarily disagree with the decision to suspend use of the test.

• When Two Tests Give Two Different Answers
• Understanding Positive Predictive Value
• HIV Testing Hub
• Specificity
• Sensitivity