Originally Posted by cwill
Actually, the study only includes randomized clinical trials that met the high quality standard described in the Cochrane Review you cited (that was one of the criteria for inclusion). It's possible to read the full article on JAMA if you register (for free) for their reader.
It did not say that - at least not in the article.
Perhaps it said so in the full article - do you have a quote?
The numbers are small - we are talking 95 and 151 here.
I find the numbers odd. There is a 4.7 cardiac event rate in the non-vax group and a 2.9 in the vaxxed group…so a difference of 1.8%. The flu vaccine only prevents about 2% of people (at best!) from getting the flu. The vaccine is about 50% effective overall, and far less effective in the elderly (around 10% and the average age of those in the study was 67)- so the numbers are not adding up.
I found this critique on CIDRAP which I thought was good read. They raised a number of concerns that are valid. They were particularly concerned with findings in subgroups. In the subgroup of those who had a recent cardiac event, the risk of having a cardiac event if unvaccinated was 12 or 13% higher. That makes no sense - it is far higher than the flu attack rate.
"In an accompanying JAMA editorial, Kathleen M. Neuzil, MD, MPH, welcomed the findings but raised questions about the big risk reduction in those with recent cardiovascular events.
Referring to the reported reduction in absolute risk, she wrote, "The estimate of 12.9 major cardiovascular events prevented for every 100 persons vaccinated would require a high attack rate, high vaccine efficacy, and nearly every episode of clinical influenza leading to a major cardiovascular event. This scenario seems unlikely, and suggests possible design flaws and residual bias in at least some" of the studies included in the meta-analysis"
Edited by kathymuggle - 11/13/13 at 7:24am