WASHINGTON, April 18 (UPI) -- This new column will examine the facts behind recent statistical studies that have made the news but been misinterpreted, failed to make the news for some reason or are just plain weird.
The old killers are gone. Tuberculosis, leprosy and polio no longer afflict Westerners in great numbers. Anthrax and smallpox survive only as dread weapons of bioterror. Black deaths and plagues exist only in the history books. Even AIDS has failed to afflict the general population in the West, devastating though its effects have been in Africa and some Western sub-cultures. Accordingly, we are always wary, on the lookout for some new disease that might cut a swathe through Western society.
According to Newsweek's cover story on April 22, Hepatitis C is that next "killer virus." The magazine declared from its position on the nation's newsstands that "over 3 million Americans are infected with the STEALTH VIRUS. Most don't know it"(emphasis in the original.) Health-conscious Americans were no doubt shocked at the possibility that they might be struck down by a "stealthy disease" whose "insidious spread" had infected such celebrities as Pamela Anderson and Naomi Judd. The magazine warned us that "10,000 Americans are dying each year. By the end of the decade, that annual toll could reach 30,000 --- twice the toll that AIDS takes in America each year."
All very worrying, it would seem. Except that the numbers the story is based on are somewhat questionable. According to the latest figures from the Centers for Disease Control and Prevention, only 4,800 Americans died from all forms of Hepatitis in 1999. Moreover, the estimate of 3 million Americans infected comes from the National Health and Nutrition Examination Survey, which includes over-large samples of at-risk groups such as minorities and drug users. It is unclear whether the estimate has been adjusted to take account of the non-representative nature of the sample.
As the Newsweek article makes clear, the only way that you can catch Hepatitis C is if someone's infected blood enters your veins. That is why the vast majority of people who have it are injecting drug users. Some unfortunate people received the disease in transfusions in the '80s, but the blood supply has been safe from this risk for many years now. Calling this disease a "stealth virus" is a misnomer. No one ever knowingly catches a virus (except for those who infect themselves deliberately for experimental purposes), but the risk factors for this disease are well known. Stay away from injecting drugs and risky sexual behavior and you should be fine.
It looks like the doom merchants need to find a better candidate for the new plague.
Every week, the major medical journals are full of new studies. Some make news. Some don't, for no readily explicable reason. For instance, in the March 6 issue of the Journal of the American Medical Association, a team of researchers published the results of a long-term study into the effects that heavy cannabis use has on cognitive abilities. Given the current debate about the war on drugs and the advisability of using marijuana for medical purposes, you could have been forgiven for thinking that this study would have been a useful contribution to the debate. The study found that long-term, heavy use of cannabis significantly affected the memory. Even those people who've never touched a joint will find it hard to recall seeing this reported, however, because not one major news source in the U.S., apart from the San Francisco Chronicle, mentioned the study.
This was followed up by another study, this time by a Canadian researcher with the unfortunate surname of Fried, which discovered that heavy marijuana use lowered the IQ scores of his test subjects. Light marijuana use, on the other hand, seemed to help raise IQ scores, which convinced Fried enough that he called for the Canadian government to legalize the drug. That aspect made all the Canadian newspapers, but once again the negative element was not reported anywhere in the US media.
In a democracy, we can only be sure of taking the right decisions if we're properly informed of all sides in the case. We therefore need to know if drugs might be harmful before we decide whether or not they should be legalized. I hesitate to ask why the various health desks seem to have forgotten that.
Online polls are the most unreliable means of measuring public opinion I know of. They cannot guarantee a representative sample and are often used to push certain positions. I am grateful to Instapundit.com for drawing my attention to a particularly silly example organized by the Council on American Islamic Relations. They asked whether Israeli Prime Minister Ariel Sharon should be tried for war crimes. Pro-Israeli organizations found out about this, and spread the word, with the result that, after 11,951 votes had been cast, 94 percent were against the idea. CAIR took down the poll and complained of a "nefarious attempt" to manipulate it. They should have known that, whatever the result, it would be meaningless. Online polls need to be discredited. In a variation of the old saying, if you put garbage up, you may need to take the garbage down.
Iain Murray is director of research at STATS --- the Statistical Assessment Service, a Washington DC-based nonprofit, nonpartisan public policy organization dedicated to analyzing social, scientific and statistical research.