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
EAST-AFNET 4 was a randomized, parallel-design phase 4 prevention trial evaluating early standardized rhythm control in atrial fibrillation.
| Feature | EAST-AFNET 4 |
|---|---|
| NCT ID | NCT01288352 |
| Title | Early Treatment of Atrial Fibrillation for Stroke Prevention Trial |
| Status | COMPLETED |
| Lead sponsor | Atrial Fibrillation Network |
| Conditions | Atrial Fibrillation; Stroke |
| Allocation | Randomized |
| Masking | None |
| Primary purpose | Prevention |
2. Clinical Question
Population
Patients enrolled in a trial of atrial fibrillation and stroke prevention.
Intervention
Early standardized rhythm control.
Comparator
The registry identifies two randomized study arms.
Primary question
Does early standardized rhythm control affect the prespecified cardiovascular outcome composite and hospitalization burden?
3. Trial Design
Randomized, parallel assignment.
2 arms.
None.
Prevention.
4. Endpoints
| Endpoint | Definition | Time frame |
|---|---|---|
| Primary composite endpoint | A composite of cardiovascular death, stroke and hospitalization due to worsening of heart failure or due to acute coronary syndrome. | 8 years |
| Co-primary outcome | Nights spent in hospital per year. | 8 years |
5. Planned Analysis
The ClinicalTrials.gov record identifies the primary endpoints but does not report posted statistical analyses or outcome estimates.
For a time-to-first-event composite endpoint such as cardiovascular death, stroke, and hospitalization outcomes, a typical analysis evaluates time until the first qualifying event using survival-analysis methods such as Kaplan-Meier estimation, hazard ratios, and regression-based comparisons. Hospitalization burden measured as nights spent in hospital per year would typically require a method appropriate for repeated or count-like utilization data.
No formal statistical analyses were posted to ClinicalTrials.gov.
6. Statistical Methodology
Time-to-event analysis
The first primary outcome is defined as time to first occurrence of a composite clinical event. Time-to-event methods account for different follow-up durations and patients who do not experience the event during observation.
Composite endpoints
A composite endpoint combines multiple clinically meaningful events into one outcome. Interpretation requires understanding which components contribute most strongly and whether components have similar clinical importance.
Hospitalization outcomes
Nights spent in hospital per year represents a different statistical structure from a single first-event endpoint because patients may contribute repeated hospitalization experiences.
7. Statistical Methods Explained
Why use a composite endpoint?
A composite can increase statistical efficiency by counting several types of events, but the individual components remain important for interpretation.
What does a hazard ratio measure?
A hazard ratio compares estimated instantaneous event rates over time. It does not directly represent the percentage of patients experiencing an event.
Why is follow-up time important?
Time frames define the observation window over which endpoint events are assessed.
Why analyze hospital nights separately?
Hospitalization burden captures healthcare utilization and may require methods different from first-event survival analysis.
8. Limitations
- The registry does not report posted statistical analyses or endpoint estimates.
- Detailed analysis populations, missing-data methods, multiplicity procedures, and interim-analysis methods are not reported in the ClinicalTrials.gov record.
- Composite endpoints require interpretation of both the overall result and the individual clinical components.
9. Why This Trial Matters Statistically
| Concept | How it appears in EAST-AFNET 4 |
|---|---|
| Randomization | Randomized comparison of two study arms. |
| Parallel design | Participants were assigned in parallel groups. |
| Composite endpoints | Primary cardiovascular outcome combines multiple events. |
| Time-to-event analysis | Primary endpoint is defined by time to first occurrence. |
| Hospitalization analysis | Nights spent in hospital per year represents a utilization outcome. |