Risks: Absolute or relative?
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* Christine Rivet

I think you have done your readers and their patients a disservice by publishing the results of the Women's Health Initiative study in terms of relative rather than absolute risk.1 Not including the denominator makes it difficult for anyone to assess the meaning of these results. Instead of discussing a 41% increase in strokes, a 26% increase in breast cancer, a 37% reduction in colorectal cancer and a 33% reduction in hip fractures, as was done in the *CMAJ* piece,1 why not present the results in terms of absolute excess risk or absolute risk reduction? The abstract of the *JAMA* article summarizing the results of the original study2 does just that, stating that there is an absolute risk of 8 more strokes, 8 more invasive breast cancers, 6 fewer colorectal cancers and 5 fewer hip fractures per 10 000 person-years. 

## References

1.  1. Sibbald B. US estrogen plus progestin HRT trial stopped due to increased risk of breast cancer, stroke and heart attack. CMAJ 2002;167(3):294.
    
    [FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiRlVMTCI7czoxMToiam91cm5hbENvZGUiO3M6NDoiY21haiI7czo1OiJyZXNpZCI7czo5OiIxNjcvMy8yOTQiO3M6NDoiYXRvbSI7czoyMjoiL2NtYWovMTY3LzkvOTg5LjEuYXRvbSI7fXM6ODoiZnJhZ21lbnQiO3M6MDoiIjt9) 

2.  2. Writing Group for the Women's Health Initiative Investigators. Risks and benefits of estrogen plus progestin in healthy postmenopausal women: principal results from the Women's Health Initiative randomized controlled trial. JAMA 2002;288:321-33.
    
    [CrossRef](http://www.cmaj.ca/lookup/external-ref?access_num=10.1001/jama.288.3.321&link_type=DOI) 
    
    [PubMed](http://www.cmaj.ca/lookup/external-ref?access_num=12117397&link_type=MED&atom=%2Fcmaj%2F167%2F9%2F989.1.atom) 
    
    [Web of Science](http://www.cmaj.ca/lookup/external-ref?access_num=000176807000024&link_type=ISI)