Posted on February 26th, 2009 1 comment
When is it best to start antiretroviral treatment?
The issue of when it is best for asymptomatic HIV infected people with more than 350 CD4 cells to start treatment with antiretroviral drugs has received renewed attention lately. Reports at recent conferences and discussions of these reports on several websites all seem to favour an earlier start than at a CD4 count of 350. There is absolutely no reliable evidence to support this recommendation. The evidence that is presented derives mostly from retrospective observations. Such retrospective studies cannot provide reliable evidence that improved clinical outcomes in those starting treatment earlier are actually caused by the antiretroviral drugs. That this is so can only be an hypothesis, a theory to be tested by prospective studies. Such a prospective study would essentially follow people who are randomly assigned to start treatment immediately or to defer it.
Some of the problems associated with interpreting retrospective observations are outlined at the end of this post1.
The “when to start” issue of course only applies to infected persons who are not symptomatic and have a CD4 count above 200. For those with fewer CD4 cells there is no doubt at all that such individuals should be on therapy.
If the antiviral drugs were completely harmless, with no toxicity, we would have no problem at all, apart, of course from the financial toxicity. However the drugs are not without problems, particularly if we are dealing with taking the medicines for a life time. The newer drugs are touted as being less toxic. However it takes years for some toxicities to become manifest. How many years were people taking Zerit, (D4T,stavudine) before we knew about its effects on fat distribution? Another example of toxic effects only becoming apparent after years of use is thinning of bones caused by some antiviral drugs.
When potent antiretroviral agents were introduced in the 1990s their impact on reducing mortality was unequivocally demonstrated in persons with more advanced disease. This immediately left us with a question regarding the effect of starting these drugs in individuals with less advanced disease.
Rather than admitting that the answer to this question was unknown, and required to be studied in a prospective fashion, the Department of Health and Human Services issued a set of guidelines. It is understandable that issuing guidelines, in the face of uncertainty is reasonable, but they must be regarded as interim, pending the outcome of studies.
In 1997 I wrote a letter in response to the publication of these guidelines; it was received by the Guidelines Committee, but I was sent absolutely no response. The letter can be seen here: http://aidsperspective.net/articles/guidelines1.pdf
Despite attempts to rely on retrospective observations to resolve clinical uncertainty, – such as uncertainty about when to start antiviral treatment, prospective randomized trials remain the best way to achieve this. They minimize bias, and thus misinterpretation, and are therefore the most reliable way to resolve uncertainty. There is no getting over this. Such trials may be expensive, and last a long time, but in the end, probably more time and money is lost by repeating inconclusive and conflicting retrospective studies.
As always, you can’t beat the truth. Regarding the “when to start” question, the truth was and still is that the answer to the question is unknown. Again, if the drugs were harmless there would be no problem. But it is quite possible that a person starting treatment at say 700 CD4 cells, even 500 CD4 cells, who may be a slow progressor may well have his or her life shortened by long exposure to the medications.
If, for whatever reason one presumes to favour a particular answer one can always select snippets of data to support one’s bias. Many would like to believe that it is better to start early. I have even read on one web site, that a New York physician stated that he would start any infected person on treatment no matter what the CD4 count was. I suppose this physician, and those who share this view are happy to practice with only their unsupported beliefs as a guide. This is as reliable as using a crystal ball and sick people deserve more from their health care advisers. In this respect the writers reporting such nonsense generally make no comment on the danger of views based only on belief, thereby adding credibility to these statements of faith. The practice of medicine is not a faith based activity.
The scientists who attach unwarranted importance to retrospective studies are also doing a disservice to clinical research. Some at the recent CROI meeting did admit that a prospective randomized trial was the best way to obtain reliable evidence on the issue of when to start. But as reported on one web site:
“Professor Doug Richman of the University of California San Diego questioned whether a ‘when to start’ trial was worth the expense. “Rather than spend millions on a trial, given that most people aren’t diagnosed until much later, why not use all that money to identify people who have the higher risk?” he asked”.
“He [Bartlett] also believes that the field is not willing to wait the 5 to 10 years necessary to generate an answer on when to start therapy.”
Discovering what is in the best interests of the infected person is not worth the expense? Waiting 5 to 10 years to find out is unacceptable?
So if we dispense with the truth to inform our actions, what could it be that guides us? Whatever it is, it is certainly no more reliable than consulting a palm reader.
Interpretations of associations found in retrospective studies presented as reliable indicators of a cause and effect relationship, rather than possibly suggestive of such a relationship, have as much meaning as the interpretations of an astrologer. Of course such data may be useful in suggesting hypotheses.
At a recent ICAAC meeting Dr Kitahata presented an analysis of a large retrospective study comparing outcomes among people starting at a higher as compared to a lower CD4 count. There was little meaningful criticism of the interpretation that the improved outcome in those starting treatment earlier was actually due to medications taken. Dr Kitahata felt that it was possible by some statistical magic for retrospective observations to mimic a randomized prospective study.
Here is an illustration of the interpretive pitfalls in such studies; it is a comment I sent to the web site reporting the results and conclusions of retrospective studies. I used the name James Mello, and pointed out that, as an example people who started treatment earlier were more likely to be under medical care than those who started later, and this might have contributed to their better survival. Another possibility is that most of the mortality might have occurred in those with the lowest CD4 counts; the examples I gave in my comment were a CD4 count of 1 compared to 349, when in fact the study concentrated on individuals with counts above 350. There are other possible explanations. There was one comment that suggested the possibility that people who choose to start treatment early are more likely to be concerned with their health in general and thus more prudent, and presumably more cautious in risk taking.
This is the comment of James Mello:
Another retrospective study actually showed no survival benefit in people with CD4 counts above 450. Here is a report of this study and that of Dr Kitahata:
Surely we need to know, and not guess when it is best to start treatment.
There are those who favour an earlier start and may have reasonable ideas to support these views. But they remain views – not proven ways to proceed that are in the patient’s best interests.
Let us find out if it is a fact that there is a benefit to starting earlier. All of us – HIV infected people and their advocates should be calling for appropriate prospective studies to guide us. We need to know the truth about when it is best to start.
Even if we were to conduct an appropriate large randomized prospective study we would only know if in asymptomatic HIV infected people with greater than 350 CD4 cells, it is on average better or worse to start treatment early or to defer it or if it makes no difference, of course apart from the expense.
The causative interpretations of retrospective observations are made difficult by what are called confounding factors and some are impossible to overcome. For example we don’t know why people choose or agree to start treatment early or defer it. The different decisions may reflect the possibilities that those choosing an earlier start may have better access to medical care, and receive better care in general, or may be more likely to be people concerned with their overall health.
Here is another example of something that might make interpretation of retrospective observations difficult. A retrospective study comparing mortality in people starting treatment above and below 500 CD4 cells finds that those who start treatment at higher CD4 numbers have a lower risk of risk of death. If, in those who delayed treatment and died, we are not told what the median CD4 count was at the time treatment was started the overall conclusion that antiretroviral drugs improve survival if started above 500 CD4 cells, would be unwarranted. It might well be that those most who died delayed treatment until a CD4 count of 100 or less. Had`they started at 450, 350, or 300 – numbers of course`all below 500, the outcome might have been very different.
The importance of individualized treatment.
Posted on February 25th, 2009 1 comment
February 24th 2009
AIDS and Minorities
In the US, African Americans constitute 12% of the population, yet almost half of the total number of AIDS cases in the country occurs among them. This disaster is only now being generally recognized, with the leadership of the Federal AIDS response finally turning their attention to this tragedy, at least publicly.
This is a tragedy that has been developing in full view for more than twenty years. One only has to look at statistics provided by the Centers for Disease Control (CDC) since the epidemic started to know, as early as 1987 that without intervention a preventable disease was inexorably moving into African American communities.
Firstly, take a look at the situation in 2006 (data from the Kaiser family Foundation).
Now take a look at this picture that clearly tells a horrible story that words cannot match.
In the light of this devastating evidence how is one to understand the comments of Dr Fauci, who can be regarded as the head of the Federal scientific and medical response to AIDS?
He noted that these “shocking statistics would be tragic anywhere but are particularly inexcusable in a wealthy country such as the United States.”
His complete statement can be seen here: http://www3.niaid.nih.gov/about/directors/news/BAAID_09.htm
Look at the above picture again. Cases in African Americans started to exceed those in white Americans in 1994, but the trends were quite evident long before this. We knew in 1988-1989 what was coming. So, one must wonder why it took all of twenty years to announce only in 2009, that these statistics are shocking.
A preventable tragedy was taking shape in full view of the Federal AIDS leadership, who rather than fund a vigorous prevention education campaign directed towards those most in danger, instead chose to support a wasteful, vacuous untargeted prevention education program in the form of “America Responds to AIDS”.
It is not only the federal AIDS leadership that failed to respond to warning signals flashing brightly right in front of them. In the early days of the epidemic there was a vigorous and exemplary community activist response. This was a terrific example of people dealing with a deadly disease taking action on their own behalf, fighting for the best medical and scientific response and against the all too frequent shameful stigmatization of HIV infected individuals.
The flowering of AIDS activism in the late 1980s and early 1990s achieved a great deal. All people dealing with serious illness have benefitted from the precedent that was set. Yet, in recognizing this achievement, we must also wonder why many of these experienced advocates, who no doubt were aware of the demographic trends shown above, seemed generally less willing to at least try to avert the disaster threatening their fellow citizens? Of course some tried, and maybe were overwhelmed by massive indifference.
Whatever the reasons, the advocacy of US activists abroad, particularly in Southern Africa, proved to be more effective than anything they were able to achieve in their own country for their fellow African American citizens. There are also other groups where AIDS has been, and continues to be a growing problem, but have been relatively neglected.
Not for profit organizations, that raise funds to help and advocate for people with AIDS were also aware of what was developing, but if there were any efforts devoted to preventing a calamity visibly descending on the largest community at greatest risk, these clearly were of little benefit.
What is almost, but not quite, as shocking as the neglect of a disaster developing in front of our eyes, is the complete absence of any sense of contrition, let alone a simple acknowledgment of failure, on the part of those who might have helped to prevent it.
If justice includes the notion of equity then prevention resources should be distributed in proportion to the needs of different communities. This clearly has not happened and it might be helpful to give some thought as to why this has been the case.
We need to know and admit what it is that we did unsuccessfully, or failed to do, to stop a preventable disaster, so that we can get it right in the future.
Instead we have a wringing of hands by those who could have done something, but did nothing, to stop this.
A similar article was posted on a health related web site in December of last year. There was no response to the issue I raised.
This post can be seen here.
Take yet another look at the picture showing the changes in the proportion of AIDS cases according to racial/ethnic group over the past 20 years. It tells the whole story; no comment is really needed.
Posted on February 4th, 2009 1 comment
Why another AIDS blog?
In order to just get started on this blog, the various reasons for creating it will be described on my web site: aidsperspective.net One of these reasons, which I suppose is self evident, is to bring some attention to the web site, where I am attempting to create a record of various AIDS related activities I have been involved with since the epidemic was first recognized in 1981. I have more or less learned how to construct a web site – at least to the extent that I am able to post legible material, and I am gradually adding to its content.
Another reason for creating this blog is to provide an opportunity for comment on contemporary HIV/AIDS related events.
With that I can start with the first post on this blog.