Long term follow up on IST-3

16 Oct

I read this a few months back and forgot to post something on it. It’s not headline data the way IST 3 was but it’s worth knowing it’s out there. This is the long term (by which they mean 18 month) follow up on IST 3. The original trial has been written about and discussed fairly extensively on the FOAMed sites.

What they found:

  • they got around 2000 or so because only certain countries did follow up.
  • for those available they managed to follow up on the vast majority
  • the follow up was mainly phone and postal so not that great.
  • 30% knew which drug they got which they try to play down but given that the supposed benefit is so small then any recall may cause the difference
  • they do find about a 3.6% difference in alive and independent at 18 months favouring tPA (as pointed out by Brandon in the comments)
  • there’s a great Kaplan Meier curve showing early harm from TPA and then completely flat with placebo from then on. It’s behind the pay wall unfortunately but worth looking at
  • there was no difference in alive and independent at 18 months

“the unadjusted absolute difference in the number of patients alive and independent at 18 months was not significant”

So just to summarise that. A third of the patients knew which group they were in (nothing versus the fancy new drug) and ultimately there was no difference at 18 months.

Reference:

“Effect of Thrombolysis with Alteplase Within 6 H of Acute Ischaemic Stroke on Long-Term Outcomes (the Third International Stroke Trial [IST-3]): 18-Month Follow-Up of a Randomised Controlled Trial.” The Lancet Neurology (June 2013). PMID 23791822

2 Replies to “Long term follow up on IST-3

  1. tPA gives me as many headaches as anyone, but to show good faith, we really shouldn’t report results selectively. Cognitive biases thrive well enough without feeding them. Methodological weaknesses notwithstanding, the aforementioned study DID show a benefit in self-reported quality of life.

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