NNT – Delusions of Benefit in the International Stroke Trial
NNT – Delusions of Benefit in the International Stroke Trial
The team at NNT (Number Needed to Treat) have looked at the International Stroke Trial 3 – the definitive trial on whether thrombolytics are useful in acute stroke and whether the time they are administered is important.
The NNT team say
“Results of the largest and arguably most important trial ever of thrombolytics (clot-busting drugs) for acute stroke were published last week in The Lancet, and the study’s conclusions are breathtaking. Not because of the study results, which are unsurprising, but because the authors’ conclusions suggest that they have gone stark, raving mad.”
The primary endpoints of death and disability showed no difference between the group who received thrombolytics and those who didn’t. This was consistent with nine of eleven previous trials.
However, the authors “describe a “secondary exploration” of their data using ordinal analysis. This uncommon method of measurement examined if thrombolytics may have ‘shifted’ some patients toward better categories of outcome, despite not shifting them toward being alive or independent.” And, lo and behold, they found a group who may have ‘shifted’.
NNT says:
“The authors blithely conclude that thrombolytics “improved functional outcome.” Worse, an accompanying editorial trumpets that “the role of stroke and emergency physicians is now not to identify patients who will be given rt-PA, but to identify the few who will not.”…
The primary outcome failed. We have a phrase for that: no benefit.”