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
THRACE evaluated intra-arterial thrombectomy as a treatment strategy for patients with acute ischemic stroke. The randomized trial compared alteplase alone with alteplase combined with mechanical thrombectomy.
| Feature | THRACE |
|---|---|
| Condition | Cerebral Stroke; Cerebrovascular Accident |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Single |
| Primary purpose | Treatment |
| Lead sponsor | Central Hospital, Nancy, France |
2. Clinical Question
Population
Patients with acute ischemic stroke.
Intervention
Alteplase (rt-PA)/Actilyse combined with mechanical thrombectomy using MERCI, PENUMBRA, CATCH, or SOLITAIRE devices.
Comparator
Alteplase (rt-PA)/Actilyse.
Primary question
Does adding intra-arterial thrombectomy improve functional outcome compared with alteplase alone?
3. Trial Design
Randomize
412 participants
Arm 1
Alteplase
Arm 2
Alteplase + thrombectomy
Assess
Modified Rankin Score
Time point
3 months
4. Treatment Arms
Control
Alteplase (rt-PA)/Actilyse drug treatment.
Intervention
Alteplase (rt-PA)/Actilyse plus mechanical thrombectomy using MERCI, PENUMBRA, CATCH, or SOLITAIRE.
5. Endpoints
| Endpoint | Time frame |
|---|---|
| Modified Rankin Score (mRs) | 3 months after treatment |
6. Planned Analysis
The registry identifies Modified Rankin Score at 3 months after treatment as the primary endpoint. No posted statistical analyses or outcome results are available in the ClinicalTrials.gov record.
For a functional outcome scale such as the Modified Rankin Score, analysis commonly depends on how the score is modeled in the statistical analysis plan. Approaches may include ordinal analysis across the full disability scale, dichotomized functional independence comparisons, or other prespecified methods. The appropriate method depends on the protocol-defined analysis population and statistical plan.
7. Statistical Methodology
Randomized treatment comparison
Randomization creates the framework for comparing treatment groups while reducing the influence of measured and unmeasured baseline differences. The analysis question is whether outcomes differ between groups assigned to the competing treatment strategies.
Functional outcome analysis
The Modified Rankin Score is an ordered disability scale. Statistical interpretation must account for the fact that categories have a natural ordering but the distance between categories is not necessarily equal.
The choice of statistical model determines how information contained in the outcome scale is represented.
8. Statistical Methods Explained
Why is the Modified Rankin Score suitable for stroke trials?
The Modified Rankin Score measures global disability and functional dependence after stroke. It captures clinically meaningful differences in recovery.
Why does the analysis method matter for an ordinal endpoint?
Ordinal outcomes contain ranking information. Treating categories as simple numerical measurements may not reflect their statistical structure.
What does randomization accomplish?
Randomization balances treatment assignment at the population level, allowing outcome differences to be interpreted as comparisons between assigned strategies.
Why is the three-month time point important?
The registry defines the primary endpoint assessment at three months after treatment, providing a prespecified outcome window.
Why are confidence intervals important?
Confidence intervals describe uncertainty around an estimated treatment effect and provide information beyond whether a statistical test crosses a significance threshold.
9. Limitations
- The ClinicalTrials.gov record does not report posted statistical analyses or outcome estimates.
- The registry does not report baseline characteristics, subgroup analyses, safety comparisons, or detailed statistical analysis plan elements.
- Functional outcome analyses depend on prespecified modeling choices that are not described in the registry information available here.
10. Why This Trial Matters Statistically
| Concept | Application in THRACE |
|---|---|
| Randomization | Comparison of two treatment strategies |
| Ordinal outcomes | Modified Rankin Score as a functional endpoint |
| Time-defined endpoint | Assessment at 3 months after treatment |
| Clinical trial methodology | Parallel randomized design |