Reply to the Editor

Related article
Osnabrugge RLJ, Head SJ, Kappetein AP
Methodologic issues regarding background mortality in observational studies
J Thorac Cardiovasc Surg, 142: 1289-1290, 2011

We acknowledge that the method suggested by Osnabrugge and colleagues should be applied in studies with extended long-term follow-up, because of a strong correlation between age and length of follow-up, to avoid underestimation of the general population survival.

(SINTESI)