1. The manufacturer of the drug sponsored all the trials and
the reviewers found evidence of publication and reporting biases. With so much
at stake I was surprised that there had been no prospective, placebo-controlled
trials conducted that were funded by an independent source. Industry trials can
be well conducted, but there are many situations where a lack of independence
has had an influence on the way the study was designed and the results that are
released. At the very least, it is worth noting that they were probably
designed to have the best chance of showing benefit. And that the reviewers had
concerned about whether all the information was released. In addition the
experts found evidence of reporting bias. According to Tom Jefferson, one of
the authors of the Cochrane study: 60% of randomized data from the Tamiflu
treatment trials (i.e. in people with influenza-like-illness symptoms) have
never been published including the biggest trial ever conducted (which was done
in the US, so it’s of great relevance to you).”
2. The studies did not show that Tamiflu reduced the risk of
hospitalization. One of the reasons people might take an antiviral is to
prevent the illness progressing to the point where they would need to be
hospitalized. Unfortunately there was no evidence that the drug produced that
benefit.
3. The studies were inadequate to determine the effect of
Tamiflu on complications. Even though the drug did not reduce hospitalizations,
some people may think it would prevent less severe complications.
Unfortunately, the reviewers found that limitations in the design of the
trials, their conduct, and the way they were reported precluded any conclusions
about the effect of the drug on complications. To expect that Tamiflu can
reduce complications would be a leap of faith currently unsupported by the
available evidence. You should also know that the FDA requires Roche to print
on the label: “Tamiflu has not been shown to prevent such complications
[serious bacterial infections].”
4. The studies were inadequate to determine if Tamiflu
reduced transmission of the virus. Same story. Some people might prescribe the
drug to prevent the spread of the virus. The expert reviewers simply said that
with what information they had available; they could not assess the effect of
the drug on transmission. I asked Peter Doshi, one of the authors of the
Cochrane report about this issue of transmission and here is what he wrote me:
“Roche’s prophylaxis trials were not designed to answer the question of
transmission. The prophylaxis trials – and FDA approval of Tamiflu for
prophylaxis – is based on its proven ability to reduce the chances of
symptomatic influenza. (But since we don’t know anything about asymptomatic
influenza infections, we cannot say anything about whether or not Tamiflu
reduces actual transmission of virus.)”
5. The use of Tamiflu did reduce the duration of symptoms by
about a day. The reviewers found 5 studies that assessed the effect of Tamiflu
on the duration of symptoms. They were fairly consistent in their findings –
though the duration of the symptoms varied quite a lot across the studies. (Más)
BMJ editor urges Roche to fulfil promise to release Tamiflu trial data.
Roche esconde.../podría no curar sino matar
Entradas
No hay comentarios:
Publicar un comentario