Survival analysis in patients at risk for sudden death: a comparative observational study in two centers

In clinical practice, observational studies remain necessary for evaluation and acceptance of new treatments. Thecomparison of results remains difficult and often controversial, because of a wide variation in clinical characteristics. Survival analyxis and calculation of the standardized mortality ratio offer the possibility to compare outcomes in different study groups. We have applied these techniques to an observational comparison of outcomes in two groups of patients, followed intwo university nters: (i) patients treated with an implantable cardioverter defibrillator (ICD), (II) patients under amiodarone treatment. There was no statistically signifcant difference in the cumulative survival total as compared to total mortality.