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
EDEN was a completed randomized phase 3 parallel-group trial evaluating two enteral feeding strategies in adults with acute lung injury or acute respiratory distress syndrome.
| Feature | EDEN |
|---|---|
| Condition | Respiratory Distress Syndrome, Adult |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None |
| Primary purpose | Treatment |
| Sponsor | National Heart, Lung, and Blood Institute (NHLBI) |
| Primary completion date | 2011-03 |
2. Clinical Question
Population
People with acute lung injury or acute respiratory distress syndrome.
Intervention
Minimal (trophic) feeding.
Comparator
Full feeding.
Primary question
How do two enteral feeding strategies compare for prespecified clinical outcomes?
3. Trial Design
Patients were allocated randomly.
Two-arm parallel-group treatment comparison.
Minimal (Trophic) Feeding
- Behavioral intervention
Full Feeding
- Behavioral intervention
4. Endpoints
| Endpoint | Time frame |
|---|---|
| Number of ventilator-free days (VFD) | Measured at Day 28 |
| Mortality before hospital discharge, with unassisted breathing | Measured at Days 60 and 90 |
5. Planned Analysis
The registry lists the primary endpoints but does not report posted statistical analyses or endpoint estimates. No formal statistical analyses were posted to ClinicalTrials.gov.
For ventilator-free days, an analysis would typically compare the distribution of ventilator-free time between randomized groups because this endpoint combines survival and duration of mechanical ventilation. The appropriate method depends on the prespecified statistical analysis plan, including how deaths and ventilation duration are handled.
For mortality before hospital discharge with unassisted breathing, analysis would typically use methods for binary or time-to-event outcomes depending on the prespecified definition. Common approaches include comparison of event proportions, survival methods, or regression models adjusted for design features.
6. Statistical Methodology
Randomized treatment comparison
Randomization is the foundation of the treatment comparison. By assigning participants to feeding strategies rather than allowing treatment choice, the trial design aims to balance measured and unmeasured baseline factors on average.
Ventilator-free days as a composite endpoint
Ventilator-free days incorporate more than one clinical experience: survival and liberation from mechanical ventilation. Interpretation requires understanding the endpoint definition because patients who die and patients who remain ventilated contribute differently than patients who achieve sustained ventilator independence.
Mortality endpoints
Mortality outcomes are commonly analyzed using methods designed for binary outcomes or time-to-event data. The statistical interpretation depends on the exact analysis population, event definition, and censoring rules specified in the analysis plan.
7. Statistical Methods Explained
Why use randomization?
Randomization reduces systematic differences between treatment groups and allows differences in outcomes to be interpreted as treatment comparisons rather than simple associations.
Why are ventilator-free days statistically challenging?
Ventilator-free days combine multiple possible outcomes. A patient may survive without prolonged ventilation, remain ventilated, or die. The chosen statistical method must reflect how these outcomes are ranked and analyzed.
Why are mortality outcomes analyzed differently from continuous measurements?
Mortality is an event outcome rather than a simple numeric measurement. Statistical methods account for whether and when events occur.
What does a confidence interval show?
A confidence interval describes uncertainty around an estimated treatment effect. It does not describe the range of outcomes experienced by individual patients.
Why does the analysis population matter?
The interpretation of a randomized trial depends on whether participants are analyzed according to randomized assignment or according to treatment received.
8. Limitations
- The ClinicalTrials.gov record does not report posted statistical analyses or numerical results for the primary endpoints.
- The registry does not report subgroup analyses, safety results by arm, or detailed analysis-population definitions.
- The interpretation of ventilator-free days depends on prespecified handling of death and ventilation duration.
- Mortality comparisons depend on endpoint definitions, follow-up rules, and analytic methods.
9. Why This Trial Matters Statistically
EDEN illustrates several important clinical-trial concepts:
| Concept | Application |
|---|---|
| Randomization | Comparison of two feeding strategies |
| Parallel design | Separate randomized treatment groups |
| Composite endpoints | Ventilator-free days combine clinically meaningful outcomes |
| Time-based outcomes | Mortality measured at defined follow-up points |
10. Related Tutorials
No related tutorial cards are available for this trial.
11. Related Calculators
No related calculator cards are available for this trial.
12. Sources
- ClinicalTrials.gov: NCT00883948
- PubMed record
- PubMed record