This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record.
1. Trial at a Glance
WISDOM was a randomized phase 4 parallel-group trial evaluating withdrawal versus continuation of amiodarone therapy in successfully treated patients with persistent atrial fibrillation.
| Feature | WISDOM |
|---|---|
| Condition | Persistent Atrial Fibrillation |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None |
| Primary purpose | Treatment |
| Lead sponsor | University Medical Center Groningen |
| Study period | 2000-08 to 2009-06 primary completion |
2. Clinical Question
Population
Successfully treated patients with persistent atrial fibrillation.
Intervention
Withdrawal of amiodarone therapy.
Comparator
Continuation of amiodarone therapy.
Primary question
Does withdrawal versus continuation of amiodarone affect the occurrence of late relapse of persistent atrial fibrillation over 2 years?
3. Trial Design
37 patients
Two groups
Withdrawal or continuation
2-year endpoint
4. Endpoints
| Endpoint | Definition | Time frame |
|---|---|---|
| Occurrence of late relapse of persistent atrial fibrillation | Registered primary endpoint | 2 years |
5. Planned Analysis
The registry identifies the primary endpoint as the occurrence of late relapse of persistent atrial fibrillation over 2 years. No statistical analyses or numerical results were posted to ClinicalTrials.gov.
For a randomized comparison of time until relapse, a typical analysis would examine time-to-event outcomes using methods such as Kaplan-Meier estimation and comparisons between randomized groups using appropriate survival-analysis techniques. The choice of analysis depends on the prespecified statistical analysis plan, including definitions of relapse, censoring rules, and analysis populations.
6. Statistical Methodology
Randomization
Randomization creates treatment groups intended to be comparable at baseline. The purpose of the randomized comparison is to reduce bias from measured and unmeasured differences between groups.
Time-to-event analysis
Because the primary endpoint concerns occurrence of relapse over a defined follow-up period, the statistical framework commonly used for such outcomes accounts for both whether an event occurs and when it occurs.
Time-to-event methods allow participants with incomplete follow-up to contribute available information until censoring.
7. Statistical Methods Explained
Why does randomization matter?
Randomization supports an unbiased comparison of treatment strategies by assigning participants to groups without investigators selecting who receives each intervention.
Why analyze relapse over time rather than only relapse percentages?
Time-to-event methods incorporate when relapse occurs, not only whether relapse occurred by the end of follow-up.
What does censoring mean?
Censoring occurs when the event has not been observed for a participant during available follow-up. Statistical methods use the observed follow-up information without assuming the exact future outcome.
Why are confidence intervals important?
Confidence intervals describe uncertainty around an estimated treatment effect. They provide information about precision beyond a single point estimate.
8. Limitations
- The registry does not report posted statistical analyses or numerical outcome results.
- The sample size was 37 participants, which affects the precision achievable for estimated treatment effects.
- The registry does not report subgroup analyses, safety results by arm, missing-data methods, or multiplicity procedures.
- The registry does not report whether proportional-hazards assumptions, interim analyses, or alternative statistical models were used.
9. Why This Trial Matters Statistically
| Concept | How it appears in WISDOM |
|---|---|
| Randomized trial design | Participants were allocated randomly to two treatment strategies. |
| Parallel design | Two groups were compared concurrently. |
| Time-to-event endpoint | The primary endpoint evaluates occurrence of relapse over 2 years. |
| Clinical endpoint definition | Statistical interpretation depends on the registry-defined relapse endpoint. |
10. Important Interpretation Points
A randomized comparison can estimate differences between treatment strategies, but the strength and precision of conclusions depend on the observed events, analysis method, and uncertainty around estimates.
The primary endpoint focuses on late relapse of persistent atrial fibrillation. The registry record does not report outcome estimates or treatment-group comparisons.
11. Related Tutorials
12. Related Calculators
13. Sources
- ClinicalTrials.gov: WISDOM (NCT00845780)