What’s the down side to these HIV home testing kits that are being discussed (and have been discussed for some time albeit the kits may be changing)? Are there any countries using them?
Also, I assume somebody who comes up HIV+ on the test might just administer themselves one, or more, additional trials of the same test from the shock. What would this do to reliability. I vaguely recall something about retesting from some decision making course I took long ago…
There is only one home HIV test that is FDA approved and legal in the U.S., manufactured by Home Access. It requires sending a blood sample through the mail for analysis. The FDA says tests providing immediate results are less accurate because the sample is not analyzed under controlled laboratory conditions.
There is a home test with immediate results, made by MiraTes, that’s legal and approved in the Netherlands.
Once upon a time, one of the downsides was that HIV was considered a death sentence, so the concern was that without proper counseling the results might increase the suicide rate. I don’t know how much that is still a concern, and IIRC they included counseling in the results.
As for sending blood samples through the mail, I assume it would need to be labelled as biohazardous, but not sure.
Yeah, there’s a bugaboo in this whole debate that makes it hard to figure out what the real deal is: the FDA only approves the one that requires “counseling” (the Home Access test), and the marketers of the other ones say that that is the only reason that the FDA won’t approve the other tests.
The problem is that we don’t know if the marketer’s claim is true or not, and don’t really have a way to find out. On ther other hand, perhaps FDA approval isn’t the end-all be-all of whether a test is good or not. The Netherlands and other countries seem to trust the results of the other tests.
Blood is sent through the mail/fedex all the time. I personally had 14 tubes of blood drawn at a lab in DC to be sent to a lab in MN when they thought that I might be a match for someone who needed a bone marrow transplant. The blood can be in vials and must be packed for safe transport (like the black box on an ariplane). With the home HIV test, the blood sample is one where you prick your finger and let a drop of blood fall onto an absorbant gause (sp?) strip. The sheet of paper with the strip is sealed in a special envelope and sent to the company. The sample is no more thick than a few sheets of paper so any risk of infection to someone else is very small–especially since the people on the other end should know what to expect in the packet.
I assume the blood that is sent for the HIV test is not drawn at home (talk about death rates!) but just pin prick amounts? I assume the kit provides the right kind of mailer.
I think the objections came not from reliability end but more from HIV activists. Why do they oppose this? Do they still?
Does anyone have the figures for the reliability and specificity of the various tests? It seems to me that you’d want both to be awfully high, for something like an HIV test. Suppose that both figures are 95%, which is pretty good for a home test. That means that one out of every twenty negative users is going to test positive, and one out of every twenty positive users is going to test negative. Is either of those something that we really want happening? The occasional wrong answer is acceptable for something like a pregnancy test (besides, the mother-to-be will find out for sure soon enough, anyway), but for an HIV test, it would be downright dangerous.
Then too, what’s the point? A person who, for whatever reason, is unwilling or unable to go to a completely anonymous clinic for testing is not likely to go for treatment, either. And what good does it do to know that you’re positive, if you’re not going to be treated?
As for false results, you’d want your test to err on the side of false positives rather than false negatives (generally, it can be hard to minimize both and there’s some tradeoff as to which you can minimize the most, to the best of my understanding), as those are traumatic but not dangerous per se.* I’m suspecting - but have no idea at all - that this is how the tests work, and that the one that requires counseling might push people to see their doctor for a more formal test. And one would hope that you submit enough for two samples, and they run the test twice.
Regarding the second paragraph, the point of finding out that you’re positive is that at the very least you will hopefully not act in such a way that would put other people at risk of getting infected (no unprotected sex, no needle sharing, etc.). Quite possibly, it might also shock the person into deciding that now that they know for sure, they should probably do something about it.
*I do sympathize with people who get false positive results, but they’re better than false negatives in this respect. I even dealt with one myself. Before starting my current job at a medical center, I had to be tested for tuberculosis. I passed the first test, but on the second one, the nurse looked at the slightly swollen spot on my arm (I’d had the test only 2 days before, and it really hurt when they stuffed that under my skin), and immediately started asking me, “Have you had a positive TB test before? Where were you born?” and so forth, going into all these questions and generally freaking me out. Suddenly I went from relief over finally getting a job after being out of work for so long, to panic over somehow being exposed to a rather contagious disease that would disqualify me from my new job and could be chronic. Then she left the room and I stewed in those thoughts a while, until she returned with another nurse. The other nurse felt my arm, pointed out a couple differences in the swollen area from a normal positive result, and told me I was fine. :smack:
However, a false negative might encourage people to have unprotected sex. Worse, a negative may be “correct” only because time has not passed for you to develop antigens or what not to the HIV in you, and maybe you could still pass it on. I’m probably wrong on that, but for the old test, you would technically have to get a person test twice, several months apart, before you would absolutely know the test was saying negative. I guess activists might disapprove of the kits becuase they fear it will increase people having unsafe sex on the notion that they are “tested clean”. I guess the trade off is losing out on the people who have HI V and don’t know it, but may not ever come in for testing, but would use a kit…whatever number that might be…
A test which gets the right answer 95% of the time (meaning that 5% of all positives are actually negaive and 5% of all negatives are actually positive) is statistically too unreliable to be useful as a test.
This exact example (95% correct) was explained to me once by someone who had just taken their statistics exam at Northwestern’s Kellog school so I believe them. Perhaps someone who know statistics better than me can confirm my statement above and explain it.
Typically, tests like this will have a very very low false negative rate, but a higher false positive rate. That’s one reason why counseling is needed - to explain that a follow-up test will be needed.
Slight hijack…"Blood is sent through the mail/fedex all the time. "
My dad worked for the AVMA’s insurance company for years. He told me of an incident where the head of a suspected rabid dog was being bussed to a lab for testing. The bus crashed and all the fluids from the head were all over the place. People were sued, but I don’t recall the outcome. I’m not sure if the animal was found to actually be rabid or not.