What percentage of American homosexuals are HIV positive?

Answer 1

It is impossible to say what percentage of homosexuals are infected since it is not known how many people are homosexual. However, of the people who are infected with HIV the largest percentage are MSM (Men who have Sex with Men).

* ** *** **** Whoever posted this obviously doesn't understand the basics of statistics in research. To find an accurate % of male homosexuals in America that have HIV, all that is required is a large sample of men who identify themselves as such and have recently had an HIV test. Just divide the numerator (HIV infected men in the sample) by the denominator (sample size) to come up with the percentage. The exact number of gays in America is totally irrelevant. **** I don't think it's that simple. A large sample is not enough. It must be a REPRESENTATIVE sample (i.e., a sample of male homosexuals whose rate of infection is similar to that of all US male homosexuals). Taking a large sample isn't enough if the sample is sufficiently dissimilar to the population. Generally taking a large RANDOM sample will get you there, but that's very hard to do with homosexuals since there's no list of homosexuals to randomly sample from. You can't just go to random gay bars since gays who frequent random gay bars may not be representative of gays in general. And your suggestion of sampling homosexual males who have had recent HIV tests is a bigger problem still, since gays who get HIV tests are probably doing so because they are concerned that they be infected. Such a group is likely to have gays who engage in risky behavior over-represented in it, and gays who engage in risky behavior are (by definition) more likely to be HIV positive than are gays in general. All that said, I think the original answer was a Dodge since, while we don't know how many gays there are in the US, there are estimates, and that's all that's really being asked for.