Life-saving or life-prolonging? Interpreting trial data and survival curves for patients with congestive heart failure.
Chronic heart failure is responsible for considerable suffering and mortality throughout the world. Clinical trials have consistently demonstrated the benefits of pharmacological therapies such as angiotensin-converting enzyme inhibitors and beta-adrenoceptor blockers. These drugs are often quoted as reducing mortality from heart failure, yet all patients with heart failure deteriorate and most will die because of their disease. Therapies in heart failure are not truly life saving; they modify the natural history of the disease and delay the time to deterioration. The time benefit in survival is not usually reported in clinical trials, which are conducted over fixed time points and report risk reductions during this period only. In this paper, we discuss the use of prolongation of life statistics as an outcome measure in clinical trials and review simple techniques for calculating the lifetime benefit of pharmacological intervention in heart failure using data from a number of major studies
Malkin
C J
CJ
Department of Cardiology, Royal Hallamshire Hospital, Sheffield Teaching Hospitals, Sheffield, UK.
Channer
K S
KS
D002986:Clinical Trials as Topic; D003627:Data Interpretation, Statistical; D006333:Heart Failure / Q000188:drug therapy* / Q000401:mortality*; D006801:Humans; D018570:Risk Assessment; D016019:Survival Analysis; D015996:Survival Rate