Interim analysis
Encyclopedia
Clinical trial
s are unique in that enrollment of patients is a continual process staggered in time. This means that if a treatment is particularly beneficial or harmful compared to the concurrent placebo group while the study is on-going, the investigators are ethically obliged to assess that difference using the data at hand and to make a deliberate consideration of terminating the study earlier than planned.
for clinical trials. Sometimes interim analyses are equally spaced in terms of calendar time or the information available from the data, but this assumption can be relaxed to allow for unplanned or unequally spaced analyses, It is a tool used for statistical purpose.
(MADIT II) was conducted to help better identify patients with coronary heart disease who would benefit from an ICD. MADIT II is the latest in a series of trials involving the use of ICDs to improve management and clinical treatment of arrhythmia patients. The Antiarrhythmics versus Implantable Defibrillators (AVID) Trial compared ICDs with antiarrhythmic-drug therapy (amiodarone or sotalol, predominantly the former) in patients who had survived life-threatening ventricular arrhythmias. After inclusion of 1,232 patients, the MADIT II study was terminated when interim analysis showed significant (31%) reduction in all-cause death in patients assigned to ICD therapy.
Clinical trial
Clinical trials are a set of procedures in medical research and drug development that are conducted to allow safety and efficacy data to be collected for health interventions...
s are unique in that enrollment of patients is a continual process staggered in time. This means that if a treatment is particularly beneficial or harmful compared to the concurrent placebo group while the study is on-going, the investigators are ethically obliged to assess that difference using the data at hand and to make a deliberate consideration of terminating the study earlier than planned.
Statistical methods of interim analysis
The design of many clinical trials includes some strategy for early stopping if an interim analysis reveals large differences between treatment groups. In addition to saving time and resources, such a design feature can reduce study participants' exposure to the inferior treatment. However, when repeated significance testing on accumulating data is done, some adjustment of the usual hypothesis testing procedure must be made to maintain an overall significance level (Armitage, McPherson & Rowe, 1969; McPherson & Armitage, 1971). The methods described by Pocock (1977) and O'Brien & Fleming (1979), among others, are popular implementations of group sequential testingSequential analysis
In statistics, sequential analysis or sequential hypothesis testing is statistical analysis where the sample size is not fixed in advance. Instead data are evaluated as they are collected, and further sampling is stopped in accordance with a pre-defined stopping rule as soon as significant results...
for clinical trials. Sometimes interim analyses are equally spaced in terms of calendar time or the information available from the data, but this assumption can be relaxed to allow for unplanned or unequally spaced analyses, It is a tool used for statistical purpose.
Example for Interim analysis and early termination , MADIT II trial
The second Multicenter Automatic Defibrillator Implantation TrialMulticenter Automatic Defibrillator Implantation Trial
Multicenter Automatic Defibrillator Implantation Trial and MADIT II are implantable cardioverter defibrillator trials which investigate whether prophylactic ICD therapy in moderately high-risk coronary patients would significantly reduce death compared with patients treated with conventional...
(MADIT II) was conducted to help better identify patients with coronary heart disease who would benefit from an ICD. MADIT II is the latest in a series of trials involving the use of ICDs to improve management and clinical treatment of arrhythmia patients. The Antiarrhythmics versus Implantable Defibrillators (AVID) Trial compared ICDs with antiarrhythmic-drug therapy (amiodarone or sotalol, predominantly the former) in patients who had survived life-threatening ventricular arrhythmias. After inclusion of 1,232 patients, the MADIT II study was terminated when interim analysis showed significant (31%) reduction in all-cause death in patients assigned to ICD therapy.