thuan@garnet.Berkeley.EDU@ (Thuan Nguyen) (07/20/90)
A Response to Arthur Hu's article on Asians and AIDS. Arthur Hu's article on Asians and AIDS is a textbook example of the most common blunders in sampling and interpreting statistics. His presentation is so muddy that his point is completely lost in all the racist diatribe against other minorities. Mr. Hu claims that the incidence of AIDS in Asians is lower than for other races because Asian-Americans have sex less often than other races. His claim is nonsense. People get infected with the AIDS virus because of what they do, not how often they do it. As he himself pointed out, the only reliable way to be infected with the AIDS virus is to share needles with another person who has the AIDS virus or to have unsafe sex with that person. Whether someone shares needles 12 times a year or 12 times a week, he or she will eventually be infected. Similarly, whether someone has unsafe sex 12 times a year or 12 times a week with a person who has the AIDS virus, he or she will eventually be infected. The chance of getting infected depends on what you do, not on your ethnic background. A heterosexual Asian-American teenager who has unsafe sex with a person who has the AIDS virus is just as likely to get infected as a white or black or Latino teenager who has unsafe sex with a person who has the AIDS virus. Do Asian-American teenagers have less sex than other American teens as Mr. Hu says? His claim is, once again, nonsense. He bases his arguments on information he gleaned from a study on teenagers in Japan and on his unreliable phone survey of 13 Asian students and 15 white students at MIT. First, teenagers in Japan are a different group of people from Asian-American teenagers; thus, the comparison between these two groups is invalid. The behavior of teenagers in another country has no direct relation to the behavior of Asian-American teens. Second, his phone survey of students at MIT about their sexual behavior is imprecise because there are too few people in the sample. In addition, these results are biased because the Asians at MIT are a select minority within the Asian community, and because some Asians at MIT are not Americans: they are foreign students who are here only to study and who plan to leave the US when they graduate. Their values cannot be taken as representative of those held by Asian-Americans. Furthermore, people of any race will sometimes lie when asked about their sexual behavior, so the results of any survey on sexual behavior will contain some false information which adds to the existing bias. Where does one get true information? Mr. Hu himself has courteously provided evidence that Asian-American teenagers do have sex. He states that the teen pregnancy rates for Asians [in the U.S] are comparable to that of whites. Pregnancy is a sure sign that a teenage girl had unsafe sex; thus it's likely that Asian-American teenagers are infecting each other with the AIDS virus at the same rate as white teenagers, through unsafe sex. Mr. Hu concedes that Asian-Americans are getting infected with the AIDS virus faster than any other ethnic group in the US, and yet he dismisses the seriousness of this fact. He seems to believe that the percentage of AIDS cases in the Asian-American community has gone "from nothing to almost nothing". By claiming that the percentage of AIDS cases is "nothing" he dismisses the trauma of AIDS on Asian-American people with AIDS and their families. He also blinds himself to the eventuality that thousands of Asian-Americans will suffer and die from AIDS if our people continue to get infected with AIDS faster than any other ethnic group. Furthermore, Arthur Hu's belief that the percentage of AIDS cases in the Asian-American community amounts to "nothing" is based on faulty methodology. He chose to list the percentage of AIDS cases and the rate per total population for each ethnic group. The problem with his method is that it does not tell who is truly at risk of getting infected with AIDS. The entire population is not at risk for getting infected with AIDS. We must remember that people most commonly get infected with AIDS because they had unsafe sex or shared needles with someone who is already infected with AIDS. Therefore, we need to know what percentage of the people in each ethnic group performs these high-risk activities before making any estimate of the risk of getting infected with AIDS for any group. To illustrate my point, I will use a hypothetical example involving the rate of prostatic cancer. My hypothetical example consists of two populations, one of 400 white Americans and one of 400 Asian-Americans. There are both men and women in each population, but only the men are at risk of getting prostatic cancer. Thus the rate of prostatic cancer depends on the number of men, but not on the total number of people. A person who is estimating the rate of getting prostatic cancer must first know how many men are in each population. In this hypothetical example, you are told that 30 of the whites and 20 of the Asian-Americans have prostatic cancer? By Mr. Hu's flawed method, the rate per total population is 30/400 = 7.5% for the whites and 20/400 = 5% for the Asian-Americans. Thus, at first glance, it would seem that the rate of prostatic cancer in Asians is lower than that in whites; the rate for Asians seems to be 2/3 that of whites. But is this true? No. What you have not been told is the actual number of men in each population. The white population consisted of 300 men and 100 women while the Asian-American population consisted of 200 men and 200 women. What is the real rate of prostatic cancer in this example? The real rate is equal to the number of cases of prostatic cancer divided by the number of people at risk of getting prostatic cancer. For whites, it's 30/300 = 10% and for Asians, it's 20/200 = 10% . The real rates of prostatic cancer are exactly the same for both populations. Mr. Hu's assessment of the risk of getting AIDS suffers from exactly the same type of error as above. He estimated the rate of infection with the AIDS virus without knowing the percentages of people who are at risk in each population, that is, people who had unsafe sex or who shared needles sometime between 1977 and the present. In the past, gay men were at risk; today, IV drug users are increasingly at risk. In his assessment, Mr. Hu used data collected from regions of the US with disproportionately large numbers of gay men and IV drug users. San Francisco, Los Angeles, and New York City are gay meccas. Gay people from all over the US migrated to these places because of their tolerance of gays & lesbians. Since most people in the US are white, most of the migrants are also white. Thus, there is a disproportionately large number of gay white men in the populations of San Francisco, Los Angeles, and New York City. The same holds true to a lesser extent for the cities of Seattle and San Mateo and for the state of Massachusetts. The case of IV drug users is similar. Each of the above places are predominantly urban areas with significant numbers of poor minorities, some of whom succumb to drug addiction as a result of their downtrodden situation. Before making any sort of estimate of the rate of infection with AIDS, Arthur Hu should have gotten accurate numbers for the percentage of gay men and IV drug users in each population. But he did not have reliable percentages for any population. Mr. Hu was well aware of the flaws in his method and he attempted to compensate by guessing the number of gay white and Asian-American men in San Francisco by quickly scanning the personals page of the Guardian, a non-gay newspaper. The personals page of any newspaper is a poor indicator of the percentage of Asian gay men, much less a non-gay newspaper. What Mr. Hu seems to have missed is that, in the future, one of the groups at high risk for getting infected with AIDS will be sexually active teenagers of all ethnic groups. We must teach these young people about safe sex because we cannot prevent all of them from having sex. There are thousands of Asian-American kids who will become sexually active teenagers in a few years. We already know that they are having unsafe sex because Asian-American teenaged girls are getting pregnant. Should they and their children be condemned to suffer from AIDS because Arthur Hu said in 1990 that Asians are the least likely to get infected with AIDS? No! ------------------------------------------------------------------------------ Thuan Nguyen thuan@garnet.berkeley.edu University of California, San Francisco/Berkeley Bioengineering Graduate Group ------------------------------------------------------------------------------