FAIR USE NOTICE.  This document contains copyrighted material 
whose use has not been specifically authorized by the copyright owner.
The CHANCE project is making this material available as part of our
mission to promote critical thinking about statistical issues.
We believe that this constitutes a `fair use' of the copyrighted
material as provided for in section 107 of the US Copyright Law.
If you wish to use this copyrighted material for purposes of your own
that go beyond `fair use', you must obtain permission from the
copyright owner.

                  Copyright 1986 The  New York Times  Company                    
                              The  New York Times                               
               March 27, 1986, Thursday, Late City Final Edition                
SECTION: Section A; Page 26, Column 4;  Editorial  Desk                         
LENGTH: 394 words                                                               
   To the Editor:                                                               
   Even William F. Buckley Jr.'s much-admired supercilious tone cannot hide his 
failure to explore in depth the basic facts of AIDS transmission. In ''Crucial  
Steps in Combating the AIDS Epidemic: Identify All the Carriers'' (Op-Ed, March 
18), Mr. Buckley's political positions regarding testing for acquired immune    
deficiency syndrome are rendered meaningless by his apparent unfamiliarity with 
viral transmission, seroconversion and antibody testing. Readers should be aware
of these facts, ignored or obfuscated by Mr. Buckley:                           
   * There is a distinction between ''having AIDS'' and ''carrying AIDS.'' It   
may be helpful to regard ''infection'' with the AIDS virus (HTLV III/LAV) as a  
continuum ranging from having the virus in one's bloodstream and/or             
seroconverting, testing positive in either the Elisa antibody test or the more  
refined  Western blot  test, to having AIDS-related complex or a full-scale case
of AIDS, as defined by the Centers for Disease Control. It should not be assumed
that those having AIDS-related complex or full-blown AIDS are more likely to    
transmit the virus than those who test antibody positive.                       
   * Mr. Buckley raises the issue of an AIDS testing requirement for a marriage 
license. There is a significant problem with AIDS virus transmission in utero,  
or during or shortly after birth. Mr. Buckley seems to believe the problem stems
from men with AIDS transmitting the virus to their wives. In fact, 48 percent of
pediatric AIDS patients are born to mothers who are intravenous-drug abusers,   
according to the Dec. 6, 1985, issue of Morbidity and Mortality Weekly Report,  
issued by the Department of Health and Human Services.                          
   Mr. Buckley quotes The Economist, ''If AIDS were to spread to the general    
population, it would become a catastrophe.'' It goes without saying that many   
thoughtful people already view the AIDS epidemic as a catastrophe. Fortunately, 
from this catastrophic epidemic, scientists have been able to learn much about  
the nature of this disease. Men and women trained as physicians, nurses,        

                 Copyright 1986 The  New York Times  Company                    
                              The  New York Times                               
                April 5, 1986, Saturday, Late City Final Edition                
SECTION: Section 1; Page 26, Column 5;  Editorial  Desk                         
LENGTH: 421 words                                                               
WHAT A POSITIVE MEANS                                                           
   To the Editor:                                                               
   William F. Buckley Jr.'s cry for an AIDS tattoo adds nothing of value to an  
increasingly complicated and difficult health crisis.                           
   Where then should our efforts be? Unquestionably, the first crucial step is  
education. Neither Government nor industry has seen fit to mount the type of    
scientific and educational programs necessary to understand, curtail or control 
this devastating illness. At the very least, misinformation should not be part                                                                                  
of the debate. For example, Mr. Buckley states, ''Two million soldiers will be  
given the blood test, and those who have AIDS will be discreetly discharged.''  
The blood tests that Mr. Buckley is referring to are the Elisa test             
(enzyme-linked immunosorbent assay) and the  Western Blot  test.                
   The critical point is that these are not tests for AIDS. The tests are       
methods to determine whether specific antibodies are being produced by a        
person's body at some period, usually from weeks to six months, after exposure  
to the AIDS virus. Even when used, the tests do not identify those ''who have   
AIDS,'' but rather provide responsible medical personnel with possibilities.    
According to ''AIDS, Employer Rights and Responsibilities,'' page 25 (Commerce  
Clearing House Inc., 1985):                                                     
   ''(1) a positive result is a mistake or a false positive - created by some   
technical error or because the test has reacted to some other substance in the  
blood; (2) a positive test could mean that the body has successfully fought off 
previous exposure to the AIDS virus, but the antibodies produced by the white   
blood cells still remain; (3) a positive test may mean that the person has      
antibodies, and the live AIDS virus is present in the body, but does not have   
the disease and will never develop the disease; (4) a positive test may mean    
that the person is infected with the virus and will develop AIDS; however, the  
majority of affected adults will not acquire medically apparent AIDS in the     

                  Copyright 1987 The  New York Times  Company                    
                              The  New York Times                               
                 May 5, 1987, Tuesday, Late City Final Edition                  
SECTION: Section A; Page 34, Column 4;  Editorial  Desk                         
LENGTH: 720 words                                                               
HEADLINE: AIDS Test Is, Unfortunately, Still Ambiguous                          
   To the Editor:                                                               
   Although few would quarrel with Willard Gaylin's position that those at risk 
for acquired immune deficiency syndrome have a moral duty to avoid infecting    
others (''On AIDS and Moral Duty,'' Op-Ed, April 24), he is quite wrong about   
the efficacy, accuracy and meaning of tests for exposure to the human           
immunodeficiency virus (HIV) that appears to cause AIDS.                        
   ''We now have tests for the presence of the virus,'' Mr. Gaylin states, that 
are ''efficient and reliable,'' and he adds, the tests are ''considered 100                                                                                    
percent certain by experts.'' Apparently referring to the Right Rev. Paul Moore 
Jr., Mr. Gaylin continues: ''To state that the test for AIDS is 'ambiguous,' as 
a clergyman recently said in public, is a misstatement and an immoral act.'' The
misstatements and misinformed acts are those, I fear, of Mr. Gaylin, and not of 
a clergyman who has perhaps done more than any other New Yorker to care for     
people with AIDS. The most widely used and least expensive screening test for   
antibodies to HIV is the enzyme-linked immunosorbent assay (known as Elisa).    
When used to test individuals who are in groups with high prevalence of exposure
to HIV, such as sexually active homosexual men, the test is quite accurate. When
used to test groups with a low prevalence of HIV exposure, the Elisa test is    
documented as having a very high rate of ''false positives'' - that is, blood   
samples that test positive for HIV antibodies but actually do not contain the   
   Estimates of the number of false positives range from a majority of samples  
with positive Elisa reactions (Journal of the American Medical Association,     
volume 253, pages 221-225, Jan. 11, 1985; volume 257, pp. 1,357-66, March 13,   
1987) to as high as 90 percent of all samples testing positive on the Elisa test
(study of New York Blood Center, cited by Nan Hunter, ''AIDS Prevention and     
Civil Liberties,'' American Civil Liberties Union, 1987). There are now         
confirmatory tests, such as the  Western blot  test, which are much more        
accurate than the Elisa test in detecting HIV antibodies. These tests,          
however, can be prohibitively expensive to administer to large populations and  
are unlicensed and unregulated by the Food and Drug Administration.             
   Further, even though a ''true positive'' reaction in an HIV antibody test    
indicates exposure to HIV, it does not indicate in all cases active infection   
with HIV or the ability to transmit HIV to others, according to our present     
medical knowledge (Journal of the American Medical Association, volume 253, page
225; volume 257, p. 1,359). Antibody screening tests are therefore, contrary to 
what Mr. Gaylin claims, quite ''ambiguous'' in their meaning and significance.  
   Again, Mr. Gaylin is surely correct that those who are at risk for AIDS or   
who have tested positive on an antibody test should behave, and have a duty to  
behave, as if they were active carriers of HIV. But with state legislatures and 
White House policy councils now debating proposals for mandatory HIV screenings 
and consequent restrictions on privacy, it behooves all of us, including Mr.    
Gaylin, to note with care and exactitude the limits and fallibilities of these  
antibody tests.                                                                 
   Indeed, what is most disturbing about Mr. Gaylin's article is its tone, the  
fervor and insistence he expresses, before which accuracy collapses.            

                 Copyright 1987 The  New York Times  Company                    
                              The  New York Times                               
                May 23, 1987, Saturday, Late City Final Edition                 
SECTION: Section 1; Page 26, Column 4;  Editorial  Desk                         
LENGTH: 533 words                                                               
HEADLINE: Second AIDS Tests Increase Accuracy Dramatically                      
   To the Editor:                                                               
   Your May 5 letter from Mark Barnes, ''AIDS Test Is, Unfortunately, Still     
Ambiguous,'' gave the misleading impression that current blood tests for        
antibodies to HIV, the human immunodeficiency virus that causes acquired immune 
deficiency syndrome, are inaccurate. In that this idea could discourage testing,
it might have lethal consequences.                                              
   Mr. Barnes stated that the enzyme-linked immunosorbent assay, or Elisa, which
is used to detect antibodies that signify exposure to HIV, is inaccurate when   
applied to populations with low rates of HIV infection. In this he is correct.  
Even an accurate test that produces a low rate of ''false positives'' will be   
inaccurate when applied to populations containing few ''true positives.''       
Suppose, for example, that the Elisa has a false positive rate of .18 percent.  
Then, if 10,000 New York City adults were tested whose only risk for AIDS was   
heterosexual sex, and 10 were truly infected with HIV, the false positive rate  
of .18 percent would have to be applied to 9,990 uninfected persons.            
   As a result, 18 of these uninfected people (.0018 times 9,990) would be      
declared antibody-positive, or infected. Only 10 out of 28 total positives (10  
true positives, plus 18 false positives), or 36 percent of the positives, truly 
would be infected. A positive result thus could not be given much credence.     
   However, all responsible testing laboratories are using a second,            
confirmatory test whenever a positive result occurs on the Elisa. By retesting  
positive samples with the  Western blot  test or some other confirmatory test,  
almost all false positive results are eliminated, while true positives are      
   The accuracy of the two combined tests is very close to 100 percent, even in 
a low-prevalence population, even though either test used alone would be        
inaccurate in such a population.                                                
   In high-prevalence populations, such as homosexual men or intravenous drug   
users in New York City, the Elisa alone would be quite accurate. The technique  
of stringing two tests together, known as serial testing, is a well-known device
commonly used in public health to address the problem of testing low-prevalence 
   The expense of  Western blot  testing is not, as Mr. Barnes stated,          
prohibitive, because the test is used only on samples that are positive on the  
   The HIV antibody tests and education concerning how the virus is spread are  
the only tools we have right now to contain the AIDS epidemic. People who are   
positive on blood testing must be assumed to be capable of infecting others.    
People who take the test and find they are infected can take precautions to     
avoid infecting their partners in sex or drug abuse, and to avoid bearing       
infected offspring. Individual test results can personalize moral               
responsibilities during the AIDS epidemic in ways that mass education cannot.   
   Incorrect information on the accuracy of HIV blood testing is potentially    
damaging to public health. The ultimate toll extracted by AIDS will be increased
by statements that incorrectly discourage use of the HIV blood tests.       

              Copyright 1987 The  New York Times  Company                    
                              The  New York Times                               
              September 5, 1987, Saturday, Late City Final Edition              
SECTION: Section 1; Page 22, Column 1;  Editorial  Desk                         
LENGTH: 587 words                                                               
HEADLINE: When AIDS Tests Are Wrong                                             
   What should an enlightened society do about a health test that can do as much
harm as good? The blood tests now used to screen for exposure to the AIDS virus 
are highly accurate. But in any widespread testing program, the tests are likely
to give as many false positives as true.                                        
   No senior policy maker in the Administration seems to understand that        
paradox, or the terrible price of pressing ahead with widespread testing. For   
every true case detected, as many other people may be falsely branded, exposing 
them to discrimination and loss of jobs and housing.                            
   AIDS tests have proved very effective so far, especially in screening blood  
donations and keeping the blood supply free of virus. But when even a highly    
accurate test is applied to a population at low risk for AIDS, the number of    
true positives is so small that it doesn't differ much from the number of false 
positives. The false positives can thus amount to a significant, even           
overwhelming, share of the total number found.                                  
   AIDS testing is now done in two stages. The first test, called ELISA, can    
give up to 7 percent false positives. To compensate for errors or sloppiness,   
this test is usually done twice. But false positives can still occur. The blood 
contains proteins that happen to mimic the antibodies to the AIDS virus or      
otherwise confuse the test reagents.                                            
   A blood sample that still tests positive is then retested with the  Western  
 blot  test. The chance of it giving false positive readings on both tests is   
very much less. The Army, which tests thousands of recruits each year with      
carefully standardized equipment, has probably lowered the joint false positive 
rate to 0.005 percent, or 1 in 20,000. By the standards of most medical tests,  
that's a fine achievement. For screening high-risk populations like gay men or  
addicts, the false positives are a tiny fraction of the true positives          
identified by the test.                                                         
   But consider what happens when the Army's test is applied to a population at 
low risk. Assume, as is typical of women blood donors, that only 1 in 10,000    
carries the AIDS virus. Thus among 100,000 women, 10 have the virus and 99,990  
don't. The Army's AIDS test procedure, assuming it is perfectly sensitive, will 
pick up all 10 virus carriers. But among the 99,990 uninfected women, the       
1-in-20,000 false positive rate will indicate 5 are carriers. Thus of a total of
15 positive results, a third will be false.                                     
   These estimates, published recently in the New England Journal of Medicine,  
were developed by Klemens Meyer and Stephen Pauker of the New England Medical   
Center. They note that in any test procedure less accurate than the Army's, the 
ratio of false to true positives rises alarmingly. If the joint false positive  
rate rises to only 1 in 1,000, 10 people will be wrongly identified as AIDS     
carriers for every one true infection found.                                    
   These figures must give serious pause to people who advocate AIDS testing    
among low-risk populations, like marriage license applicants or hospital        
patients in low-risk areas. Such a policy puts government in the position of    
urging or compelling citizens to be tested, then wrongly informing many who test
positive that they are infected. The certain harm thus done outweighs the       
uncertain benefit of identifying a few more AIDS carriers.                      

                 Copyright 1987 The  New York Times  Company                    
                              The  New York Times                               
               November 30, 1987, Monday, Late City Final Edition               
SECTION: Section A; Page 18, Column 1; National Desk                            
LENGTH: 632 words                                                               
HEADLINE: A Treacherous Paradox: AIDS Tests                                     
   Present tests for the AIDS virus antibody are highly accurate. Yet if applied
to the population at large, they could falsely brand nine people infected for   
every true case identified. The President's AIDS commission had better be sure  
it understands this treacherous paradox if it intends to recommend the          
widespread testing favored by some Administration officials.                    
   Applied to groups at high risk for AIDS, like gay men and drug abusers, the  
tests are highly reliable, and the minute number of false positives is dwarfed  
by the large number of true positives. The testing of prostitutes, as suggested 
last week by Stephen Joseph, New York City's health commissioner, is worth      
  onsidering because 20 to 60 percent may be addicts, and the proportion of false
positives would probably be minute.                                             
   But that's not true of groups at low risk, among whom the very small number  
of true positives can easily be less than the number of false positives. If a   
low-risk group - like blood donors in Peoria, for instance - were screened for  
AIDS by the Elisa test, with its positive results confirmed by the  Western     
 blot  test, 89 people out of 100,000 would be labeled as carrying the virus.   
But the real incidence of AIDS infection among this group probably is 10 per    
100,000. The tests would miss one of the 10, catch the other nine and falsely   
describe 80 other people as carriers of the virus, according to new estimates by
Lawrence Miike of the Congressional Office of Technology Assessment.            
   Such screening programs can easily do more harm than good, needlessly        
devastating dozens of lives for every case of infection detected.               
   The Army has been testing military recruits, a low-risk group, for two years.
Its chief tester, Col. Donald Burke, believes that the rate of false positives  
is less than one in 100,000 people tested. At a recent Congressional hearing,   
Colonel Burke urged mass screening to identify almost every infected person in  
America. But the Army is able to insist on unusually rigorous standards from its
testing laboratories. States and local authorities setting up mass screening    
 programs would reap many more false positives. Not only is the  Western blot    
test for AIDS antibodies very difficult to perform, but there is not yet a      
generally agreed way to interpret its results. The slightest inaccuracy or      
sloppiness - a notorious problem with medical laboratories - quickly leads to   
more false diagnoses than true.                                                 
   Commercial laboratories recently given negative samples to test by the       
College of American Pathologists reported nearly 2 percent as positive by the   
Elisa test and 5 percent as positive by the  Western blot.  This joint error    
rate, according to the Office of Technology Assessment, means that in screening 
a low-risk population, up to 90 percent of people confirmed by the two tests as 
infected will not be.                                                           
   People infected with the AIDS virus risk loss of jobs, insurance and housing.
What responsible government could assume the burden of falsely telling nine     
people they were infected for each true infection identified? The cost of       
screening low-risk populations could be over $50,000 for each true positive     
detected. In states that seek to reach infected individuals for counseling,     
there is an innocuous and cheaper alternative - tracing the sexual and needle   
contacts of those already diagnosed.                                            

                 Copyright 1987 The  New York Times  Company                    
                              The  New York Times                               
               December 14, 1987, Monday, Late City Final Edition               
SECTION: Section A; Page 22, Column 4;  Editorial  Desk                         
LENGTH: 448 words                                                               
HEADLINE: The News on AIDS Testing From Minnesota                               
   To the Editor:                                                               
   I'm sure you were well-intentioned in ''A Treacherous Paradox: Aids Tests'' (
 editorial,  Nov. 30). But why estimate about false positive acquired immune    
deficiency syndrome tests in Peoria, Ill., when actual tests of more than       
250,000 low-risk people have shown not one false positive in Minnesota!         
   Dr. Michael Osterholm, Minnesota's state epidemiologist, and Dr. Brooks      
Jackson of the St. Paul Red Cross will soon publish these results. They have    
tested what you must concede is a low-risk population - voluntary blood                                                                                    
donors! Of the 250,000-plus donors, there were 15 positives after repetitive    
Elisa (enzyme-linked immunosorbent assay) tests and confirmatory  Western blot  
   The actual AIDS virus was cultured from the blood of all 13 patients who came
in to date for testing. The 14th donor was already symptomatic with AIDS; the   
15th also admitted to being in the high-risk category. Indeed, all 15 positives 
admitted to high risk. And there was not one false positive in more than 250,000
real people.                                                                    
   Yet, your  editorial  quotes new estimates made by Lawrence Miike of the     
Congressional Office of Technology Assessment, in which he theorized that if a  
low-risk group - like blood donors in Peoria, for instance -were screened for   
AIDS by the Elisa test, with its positive results confirmed by the  Western     
 blot  test, then 80 people out of 100,000 would be falsely described as        
carriers of the virus!                                                          
   This prompted a lengthy telephone conversation with Dr. Miike:               
   ''What about labs like Minnesota? Can't Peoria do it if the Twin Cities      

   Dr. Miike explained that they had omitted all the good ''reference'' labs.   
''We weren't worried about the good labs, so they weren't part of the study,''  
he said.                                                                        
   Then he had additional interesting information: The Army contracted its AIDS 
tests out to a commercial laboratory. It sent 40 dummy known serum samples each 
month mixed in with the others to test the lab's accuracy. If the lab made      
mistakes, it wasn't paid for that month. The cost was $4 a person, and this     
included repetitive Elisa tests and the  Western blot  confirmatory test.       
   In your  editorial,  I was erroneously accused of urging the members of the  
American Medical Association, of which I am a member, to test all their         
patients. Make that all patients who are high risk, who have had blood          
transfusions or consider themselves at slight risk for reasons best kept to     
themselves. In Indiana, incidentally, we keep people with AIDS in their jobs for
as long as they are able to work.                                               
CORY SERVAAS, M.D.                                                              
Indianapolis, Dec. 3, 1987                                                      
  The writer, a member of the Presidential AIDS Commission, is editor of The    
Saturday Evening Post.