From: (Christine Maggiore)


Changing the AIDS Definition Increases AIDS Survival Rates

This very insightful commentary was submitted by Rodney Richardson, a scientist in Denver, Colorado in response to our last emailer challenging the notion that AIDS drugs are the sole or significant cause of recent decreases in AIDS mortalities.

Thank you, Rodney.

I just finished reading the Alive & Well emailer (April 4, 2001) where Jason Nusbaum is quoted as stating:

"When you suddenly label large numbers of illness-free, symptom-free people HIV positives as 'AIDS patients,' this must result in increased survival in the overall AIDS patient population. This has to do with the

labeling, not with the effects of any treatment."

I recently stumbled onto a Italian study (Vella S, et al. JAMA 1994; 271:1197-9.), which actually quantifies this effect and have commented on it elsewhere as follows:

The NYTs article reports, "A study of the 394,705 Americans found to have AIDS from 1984 to 1997, ... showed that median survival times rose to 46

months from 11 months during the period." "Median survival time" basically refers to how long it takes for 50% of a given group to die. In other words, persons diagnosed with AIDS in 1997 were found to be dying four times slower than those diagnosed with AIDS in 1984. There are many possible reasons for this, one hypothesis is the availability of so called life-extending AIDS drugs.

However, an equally viable reason for the observed increased survival in AIDS patients today can be found hidden away in the ever changing definition of what "AIDS" is. AIDS is not the same thing today as it was in 1984. By definition, prior to 1993, 100% of AIDS patients had one or more life threatening diseases. After January 1993, a patient could be classified as an AIDS case even without a life threatening disease (less than 200 CD4 T cells/mm3). As a result of this redefinition, in 1997, only 39% of AIDS cases reported to the CDC had life threatening diseases. Obviously, if we were to compare survival rates between two groups, one where 100% of patients are deathly ill, and the other where only 39% are deathly ill, overall survival should be better in the later group. Since there are approximately only 40% as many sick people in the latter group, I would predict that they should die only 40% as fast! Or stated another way, survival should be 2.5 times (100%/40%) better in the later group.

Anticipating this potential, a group of researchers from the Istituto Superiore de Sanita, in Rome applied either the 1987 CDC definition, or the 1993 CDC definition, to the same patient population (3515 patients from 1987 to 1991) to see what effect the definition would have on median survival times. They discovered, "While the median survival of patients meeting the 1987 definition was 24 months, at the end of 57 months 53% of patients meeting the 1993 definition were still alive." (Vella S, et al. JAMA 1994; 271:1197-9.) In other words, by simply applying the 1993 definition to the same group of patients, median survival time went up 2.5 fold (damn close to my estimate above). It is also interesting to note that median survival time in this study (using the 1993 definition) is approximately 60 months, while the median survival time reported in the New York Times article (after the fourfold benefit of AIDS Drugs) is only 46 months. In other words, median survival time has dropped by over a year (14 months) since the introduction of protease inhibitors in 1996.

It is curious that the CDC stopped publishing how many new AIDS cases are due to non-illness at the end of 1997. As such, we will no longer know what percentage of AIDS is due to actual illness and therefore can no longer estimate how much "survival time" should increase simply due to the above phenomena. However, since those with illness are dying off much faster than those without illness, one could argue that the post 1993 AIDS pool will continue to be enriched with non-ill patients. As such, I would expect to see survival times continue their upward trends - at least until toxic drug effects (in those who can stay on them) make up the difference.

I hope you find this reference material useful, and I appreciate your efforts.

Rodney Richards.

Related Research:

Disclaimer: HiddenMysteries and/or the donor of this material may or may not agree with all the data or conclusions of this data. It is presented and reported here 'as is' for your benefit and research. Material for these pages are sent to HiddenMysteries from around the world. If by chance there is a copyrighted article posted which the author does not want read, email the webmaster and it will be removed. HiddenMysteries and/or the donor of this material does not offer or provide any medical opinion, medical endorsement and/or medical advice as would be defined in law, legal code, legal policy, administrative rules and regulations.