European heart journal vol:17 issue:9 pages:1444-7
In clinical practice, observational studies remain necessary for evaluating accepted and new treatments. The comparison of results remains difficult and often controversial, because of a wide variation in clinical characteristics. Survival analysis 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 three groups of patients, followed in two university centres: (i) patients treated with an implantable cardioverter defibrillator; (ii) patients under amiodarone treatment; and (iii) recipients of a heart transplant. There was no statistically significant difference in the cumulative survival from total mortality. The standardized mortality ratio revealed the different natural history of patients undergoing heart transplantation.