Tag: low-risk populations

Don’t Try This at Home: The Mathematics of HIV Testing in Low-Risk Populations

This post considers potential pitfalls of home HIV testing. It provides an excuse to write a slightly less nerdy column on the mathematics of screening tests.

My friend and co-author A. David Paltiel flew in from Yale to speak with my University of Chicago students. David is a national authority on medical cost-effectiveness, particularly in matters connected with HIV. For example, this beautiful New England Journal of Medicine piece showed that population HIV screening is surprisingly cost-effective, even in relatively low-risk populations. In significant measure due to this analysis, the Centers for Disease Control and Prevention modified national guidelines to promote much more aggressive HIV screening in a variety of settings. So if your primary care doctor or emergency department nurse asks you whether you’d like an HIV test–blame Paltiel.

David and I have published related work on issues surrounding home HIV tests, now under FDA review. (See a great earlier commentary by Walensky and Paltiel here.) To simplify things, the idea here is that you could go to your local Walgreen’s and buy a test kit for about $40. You swab the thing around your mouth. In about 20 minutes, with impressive “accuracy” (in a minute I’ll explain why the commonsense word “accuracy” is a slippery way to describe screening tests), the test will say whether you are HIV-infected.

One natural group of customers might be romantically-involved University of Chicago students: They go out on a date. It goes well. They buy a pair of test kits (maybe romantically sharing one) for a quick HIV test. If the tests come out well…. whatever one cares to happen can now proceed.

Is this test a good idea? In some ways, yes. This normalizes testing. Some people will get tested who would not otherwise obtain care. But there are a variety of reasons to worry. One issue concerns the ability of ordinary people not to mess the test up. A second issue concerns whether home HIV tests will lead people to avoid other medical and public health systems that could provide better counseling and (if needed) stronger post-test linkages to care.

Continue reading…