Absolute risk reduction a must
==============================

* Robert Y. Shaw

After reading the article by Wells and colleagues on cardiac resynchronization therapy,1 I was not sure that the article had come from *CMAJ*; it sounded like a salesperson had just dropped by and “detailed” me on the merits of putting a pacemaker/implantable cardioverter defibrillator into every patient with NYHA (New York Heart Association) class II disease.

To quote the authors, there was “no need for further clinical trials” because “the cumulative evidence is now conclusive” that there is “an unequivocal benefit … in reducing all-cause mortality.” Nowhere in the article is the absolute risk reduction mentioned. One would have to refer to Figures 2 and 3 to calculate it.

What happened to the peer review process at *CMAJ*? And where was the *CMAJ* editor? How can an article be published without the most relevant information in a trial — the absolute risk reduction?

I thought this was just an oversight, and I proceeded to the next excellent article in that issue by Eisenberg and associates.2 Again, no absolute risk reduction! How can I counsel patients on the hazards of cardiac imaging without this crucial information?

I humbly request that *CMAJ* include absolute risk reduction and/or increase in every research article published.

## References

1.  Wells G, Parkash R, Healey JS, et al. Cardiac resynchronization therapy: a meta-analysis of randomized controlled trials. CMAJ 2011;183:421–9.
    
    [Abstract/FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6NDoiY21haiI7czo1OiJyZXNpZCI7czo5OiIxODMvNC80MjEiO3M6NDoiYXRvbSI7czoyNDoiL2NtYWovMTgzLzEzLzE1MTcuNC5hdG9tIjt9czo4OiJmcmFnbWVudCI7czowOiIiO30=) 

2.  Eisenberg MJ, Afilalo J, Lawler PR, et al. Cancer risk related to low-dose ionizing radiation from cardiac imaging in patients after acute myocardial infarction. CMAJ 2011;183:430–6.
    
    [Abstract/FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6NDoiY21haiI7czo1OiJyZXNpZCI7czo5OiIxODMvNC80MzAiO3M6NDoiYXRvbSI7czoyNDoiL2NtYWovMTgzLzEzLzE1MTcuNC5hdG9tIjt9czo4OiJmcmFnbWVudCI7czowOiIiO30=)