This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Double Cord Blood Transplant for Patients With Malignant and Non-malignant Disorders (NCT00801931), a non-randomized phase 1, phase 2 study. The primary outcome is Graft Failure Rate.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00801931 |
| Phase | Phase 1, Phase 2 |
| Condition | Leukemia, Lymphoma, Neuroblastoma |
| Allocation | Non-Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 1 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Columbia University |
| Results posted | Yes |
2. Clinical Question
Population
Patients with selected malignant or non-malignant disorders. The listed conditions include leukemia, lymphoma, neuroblastoma, immunodeficiencies, and anemia. The registry does not report a sufficiently enrolled population for outcome analysis.
Intervention
Double umbilical cord blood transplantation, with conditioning approaches described as full intensity with TBI, full intensity without TBI, moderate intensity, reduced intensity, a Fanconi's anemia regimen, and a regimen for non-malignant diseases.
Comparator
No randomized or like-for-like control comparison is reported. The study is non-randomized, and the registry cautions that its arms are not a like-for-like control comparison.
Primary question
The stated primary measure is the number of patients experiencing graft failure, followed for up to 2 years. The registry says there were not enough subjects for data analysis.
The study's stated purpose combines feasibility and safety questions with an assessment of donor chimerism after transplantation. Specifically, the brief summary describes an aim to determine safety, toxicity, and feasibility, and to quantify the percentage and donor sources of mixed donor chimerism. These are study aims, not reported findings: the registry record contains no analysis results for those aims.
The study includes several conditioning regimens rather than one uniform treatment description. This makes the research question broader than a simple comparison of one intervention with one control. The listed arm descriptions identify different regimen categories, but the record does not establish a comparative treatment effect between them. Its non-randomized allocation and lack of masking also mean that the design does not support interpreting the groups as randomized equivalents.
The registry lists enrollment as 1 and identifies only the moderate-intensity group in the adverse-event record. It does not report enough subjects for analysis of the primary endpoint. Consequently, the central question can be stated from the protocol aims, but an answer about graft failure or the other intended outcomes is not available in the posted results.
3. Trial Design
This is a Phase 1 and Phase 2 study with non-randomized allocation, no masking, and a parallel model. Columbia University is listed as the sponsor. The record gives a start date of 2007-09-06 and a primary completion date of 2009-05-05; its current status is terminated. The reason for termination is not reported in the registry record.
The design describes six regimen categories: full intensity with TBI, full intensity without TBI, moderate intensity, reduced intensity, a regimen for Fanconi's anemia, and a regimen for non-malignant diseases. Their descriptions outline distinct conditioning approaches and include double cord blood infusion. The listed interventions include alemtuzumab, total body irradiation, melphalan, busulfan, phenytoin, fludarabine, cyclophosphamide, and horse antithymocyte globulin. The regimen descriptions are not all complete in the registry record, so they do not support a fully detailed account of every treatment component.
Because allocation was not randomized, assignment to regimen groups cannot be treated as if it were determined by chance. The registry specifically warns that the arms are not a like-for-like control comparison. No masking was used, and no separate control arm or randomized comparator is described. These design features matter when considering whether observed differences, if reported, could be attributed to the regimen rather than to differences between the groups.
Although the record describes several regimens, the enrollment listing is 1, and the primary outcome population statement says there were not enough subjects for data analysis. The adverse-event listing identifies the moderate-intensity group. The record does not provide an analyzed comparison across the regimen categories or a complete account of enrollment by group. Sample-size justification, planned interim analyses, and a detailed statistical analysis plan are not reported in the registry record.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Before assignment: There was only 1 subjected enrolled. The 1 subject was enrolled into Arm - Experimental: C: Moderate Intensity.
Overall Study
| Stage | Experimental: C: Moderate Intensity |
|---|---|
| STARTED | 1 |
| COMPLETED | 1 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: Not enough subjects were enrolled for data analysis.
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
Population: There was only 1 subjected enrolled. The 1 subject was enrolled into Arm - Experimental: C: Moderate Intensity.
| Characteristic | Unit | Experimental: C: Moderate Intensity |
|---|---|---|
| Participants analysed | 1 | |
| Age, Categorical: <=18 years | Participants | 1 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 |
| Age, Categorical: >=65 years | Participants | 0 |
| Sex: Female, Male: Female | Participants | 1 |
| Sex: Female, Male: Male | Participants | 0 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 1 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 1 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 0 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Graft Failure Rate, measured over Up to 2 years.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the graft failure rate, described operationally as the number of patients who experience graft failure. The stated timeframe is up to 2 years. This endpoint concerns whether the transplanted graft fails, making it a direct outcome for a study evaluating the feasibility and safety of transplantation.
In general, a clearly defined endpoint gives a study a specific outcome to assess and helps distinguish the primary question from other outcomes. The registry's wording identifies the event of interest and a follow-up period, but does not provide a numerical graft failure result, a rate estimate, or a description of how graft failure was defined or confirmed. Those details are not reported in the registry record.
The registry also states that not enough subjects were enrolled for data analysis. Therefore, the endpoint definition should not be mistaken for an observed result. No number of graft failures, uncertainty interval, or inferential comparison is reported. Although the study summary describes intended assessment of donor chimerism and safety, those aims do not substitute for a result on the primary endpoint.
In general, follow-up duration is relevant to interpreting an event outcome because events may occur at different times. Here, the stated timeframe is up to 2 years, but the record does not give participant-level follow-up, timing of events, or an analysis accounting for follow-up time. A quantitative interpretation of graft failure is therefore not possible from this record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry's primary endpoint is graft failure, measured as the number of patients experiencing the event up to 2 years. However, the population statement for that outcome explicitly says that not enough subjects were enrolled for data analysis. There is no posted graft failure count, rate estimate, confidence interval, or hypothesis-test result. The record therefore describes an intended outcome without providing an analyzable result for it.
The enrollment entry is 1. That listing does not establish an adequate basis for estimating an outcome across the study's regimen categories. The adverse-event information is limited to the experimental moderate-intensity group, with one listed at risk for serious adverse events, one affected by serious adverse events, no listed participants affected by other adverse events, and one listed death. These counts describe the registry's safety record; they do not supply a comparative estimate or establish the cause of an event.
The study has non-randomized allocation and no masking. The registry also cautions that the arms are not like-for-like control comparisons. In general, a non-randomized group difference may reflect differences in who received each regimen, in addition to any effect of the regimen itself. With no reported analysis results and no adequate primary-outcome analysis, that concern is not something the available record can resolve.
The brief summary describes aims involving safety, toxicity, feasibility, and mixed donor chimerism, including its percentage and donor sources. Those aims are not accompanied by reported results in the record. The status is terminated, but the reason for termination is not reported. Neither termination nor the stated enrollment alone identifies why the study ended or what happened clinically.
No inferential analyses are listed. The record does not report p-values or confidence intervals for the primary endpoint, adjustment for covariates, an analysis population, or procedures for handling incomplete outcome data. Since there are no outcome estimates to assess, precision cannot be quantified. In general, a confidence interval describes the range of values compatible with an estimate under an analysis model; no such range is available for graft failure in this record.
The sample-size framework described for planning is explicitly an illustration based on an observed effect, not the trial's own design. Such planning figures, where presented, are not evidence of observed power and do not replace the missing outcome analysis. The record's assumptions include a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the intended effect is a stated fraction of the observed effect. Time-to-event illustrations use total events under the Schoenfeld approach, while other illustrations use participants per arm. These assumptions do not establish that the trial enrolled, randomized, or analyzed participants according to that framework.
Overall, the record supports a description of the study's aims, design, and limited safety entries, but not an estimate of graft failure or a conclusion comparing regimens. Any claim about benefit, harm relative to another regimen, or the frequency of graft failure would go beyond the reported analysis.
9. Statistical Methods Explained
The study is described as parallel and non-randomized, with no masking. In a parallel design, participants are assigned to a regimen group and followed in that group rather than switching between regimens as part of a crossover comparison. This is a general description of the design type; the registry record does not report enough information to reconstruct how participants were assigned or what criteria governed assignment.
What does non-randomized allocation imply?
In general, random allocation aims to make treatment groups comparable, on average, with respect to both measured and unmeasured characteristics. Non-randomized assignment does not provide that protection. Differences between groups may reflect baseline characteristics, clinical decisions, or other factors as well as the treatment regimen. This matters especially when comparing outcomes across groups. The registry explicitly cautions that its arms are not a like-for-like control comparison, so between-group contrasts should not be interpreted as randomized treatment effects.
No masking was used. In general, masking can limit the influence of knowledge about treatment assignment on some aspects of care, assessment, or reporting. Its absence does not by itself establish that an outcome is biased, but it is relevant context for interpretation. The record does not describe outcome-assessor masking or any other procedures that might have limited such influence.
What can the primary endpoint tell readers?
The primary outcome is the number of patients experiencing graft failure, with a timeframe of up to 2 years. A count is a direct description of observed events, while a rate generally relates events to a population or period of observation. The registry labels the endpoint a rate but describes the measure as a number of patients. It does not report a graft failure count or a more detailed calculation method. This prevents interpretation of the endpoint as a quantified rate from the posted record.
In general, estimates from small amounts of data tend to be imprecise, and sparse data may not support stable comparisons or complex models. The registry says there were not enough subjects enrolled for data analysis. It reports enrollment as 1, but the outcome section does not provide an estimate or explain a model that could overcome the lack of analyzable data. No standard error, confidence interval, or p-value is reported for graft failure.
How should uncertainty be understood?
In general, a confidence interval communicates uncertainty around an estimated quantity under a stated statistical method and its assumptions. It does not measure every possible source of bias, and a wide interval can reflect limited information. Since no confidence interval is reported for the primary endpoint, the precision of any graft failure estimate cannot be assessed. No estimate is available to distinguish a precise null result from an imprecise or unavailable result.
Similarly, a hypothesis test evaluates data against a specified null hypothesis under a statistical model. The registry lists zero analyses and does not report a p-value or the analysis plan used for testing. That absence should not be read as evidence that an effect is absent. It means that an inferential result is not reported in the registry record.
What are the planning assumptions?
The stated sample-size approach is a planning illustration based on the observed effect, not the trial's own design. It assumes a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect expressed as a stated fraction of the observed effect. In general, such assumptions help translate a target effect and error-rate choices into a planning requirement. They do not show what power the completed study achieved. Sample-size illustrations are planning calculations, never observed power.
For time-to-event outcomes, the stated illustration uses the total number of events under the Schoenfeld approach. For other outcomes, it expresses planning requirements as participants per arm. These are different units because time-to-event planning is commonly driven by the number of events, while other designs may be expressed in terms of group size. The record does not report a trial-specific sample-size justification or a statistical plan establishing that these illustrative assumptions were used prospectively.
Over-dispersion is a general concern when count outcomes vary more than a simple statistical model expects; if present, a model that assumes less variability can understate uncertainty. The registry does not report a count model or dispersion assessment, and the primary outcome is not presented as an analyzed count series. This concept therefore explains a general issue rather than describing an analysis performed in this study.
For adverse events, the registry reports at-risk and affected counts for the identified group, along with a listed serious-event term and deaths. These are descriptive safety entries. In general, such counts do not by themselves provide a comparative risk estimate, particularly without a suitable control group, sufficient follow-up detail, and an analysis plan. The record does not report adjusted safety comparisons or uncertainty intervals.
10. Multiplicity, Missing Data and Analysis Populations
The study describes several objectives, including safety, toxicity, feasibility, mixed donor chimerism, and graft failure. When a study evaluates multiple endpoints or repeated statistical tests, multiplicity can increase the chance of an apparently notable result arising by chance. In general, a prespecified testing hierarchy or multiplicity adjustment can address this issue. The registry does not report whether any such approach was planned or used.
The record lists zero analyses and does not provide outcome estimates for the primary endpoint. It therefore does not offer a set of reported tests for which readers could assess multiplicity adjustments. A statistical analysis plan, including any rules for prioritizing endpoints, is not reported in the registry record.
The primary outcome population statement says there were not enough subjects enrolled for data analysis. The record does not describe a full analysis population, an intention-to-treat approach, a per-protocol population, or criteria for including participants in outcome analyses. The enrollment listing is 1, but it does not provide details about eligibility, treatment received, or analysis inclusion.
Missing outcome data and follow-up completeness are also not described. The record does not state whether any outcomes were missing, how missing measurements were handled, or whether participants were censored for time-to-event analyses. This is not evidence that data were complete; the relevant information is not reported in the registry record.
Without a reported analysis population, missing-data method, or multiplicity plan, readers cannot determine how the intended outcomes would have been analyzed or how selective availability of results might affect interpretation. These are reporting gaps, not findings about the data.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Experimental: C: Moderate Intensity | 1 | 1 | 100.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Experimental: C: Moderate Intensity | 1 of 1 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Experimental: C: Moderate Intensity | 0 of 1 |
Most frequent serious adverse event terms
| Event term | Organ system | Experimental: C: Moderate Intensity |
|---|---|---|
| Respiratory Failure with Cardiac Tamponade | Respiratory, thoracic and mediastinal disorders | 1 of 1 |
Serious events with the highest arm-level rate: respiratory failure with cardiac tamponade (100.0%).
The adverse-event record identifies the experimental moderate-intensity group. It lists 1 at risk for serious adverse events and 1 affected by serious adverse events. For other adverse events, it lists 1 at risk and 0 affected. The record also lists 1 death. These entries are descriptive counts in the registry; they do not establish that a regimen caused an event or death.
The leading listed serious adverse-event term is “Respiratory Failure with Cardiac Tamponade,” shown at 100.0%. The registry record does not provide enough context to interpret that percentage's denominator beyond the displayed adverse-event listing. It should not be treated as a rate applicable to a broader population.
In general, safety counts need context such as the number and characteristics of participants exposed, duration and completeness of follow-up, event definitions, and whether events are considered treatment-related. The registry does not report those details sufficiently for comparative interpretation. Since allocation was non-randomized and no like-for-like control comparison is identified, the counts cannot establish a difference in safety between regimens.
The listed death should be read as a reported count, not as proof of treatment causation. The record does not report a causal assessment, a detailed event narrative, or a comparison group safety analysis.
12. What the Result Does, and Does Not, Mean
This record documents a study intended to evaluate double umbilical cord blood transplantation across selected malignant and non-malignant disorders using several conditioning approaches. It identifies graft failure as the primary endpoint and describes additional aims related to safety, toxicity, feasibility, and mixed donor chimerism. It also records a limited set of adverse-event information for the moderate-intensity group.
It does not provide a result for the primary endpoint. The registry states that too few subjects were enrolled for data analysis, and the analysis count is zero. No graft failure estimate, uncertainty interval, or statistical comparison is reported. Thus, the record does not establish how often graft failure occurred or how outcomes differed across regimen categories.
The safety entries likewise do not establish a treatment effect or causal relationship. They are descriptive counts without a reported comparative analysis. The death listing does not establish that transplantation or a particular regimen caused the death. The listed serious-event term and its displayed percentage should be understood within the limited registry record, not generalized to other patients or settings.
The study's terminated status is a registry fact, but the reason for termination is not reported. It should not be used to infer an adverse result, a safety concern, or a decision about treatment. The record also does not report a complete statistical analysis plan, the analysis population, or missing-data procedures.
In general, a trial can be informative through a well-supported estimate or through transparent evidence that an intended analysis could not be completed. Here, the record supports the latter interpretation: the research aims and design are described, but the primary outcome is not analyzed. It cannot establish that a regimen works, does not work, is safe, or is unsafe relative to another option.
13. Why This Trial Matters Statistically
Statistically, this record illustrates the difference between registering an outcome and reporting an estimate for it. Graft failure is identified as the primary endpoint, with a stated timeframe of up to 2 years, but the registry says the enrolled population was insufficient for data analysis. Without an observed endpoint result, there is no estimate whose precision or comparative meaning can be evaluated.
The design context is also important. The study is non-randomized, unmasked, and parallel, and the registry warns that the arms are not a like-for-like control comparison. These features limit what could be inferred from any unadjusted difference between regimen groups. In general, design limitations and statistical uncertainty are related but distinct: more detailed analysis cannot automatically remove confounding inherent in non-randomized assignment.
The limited safety entries emphasize why denominators and follow-up matter. Counts can describe what was recorded for a group, but they do not alone establish comparative risk or causation. The record gives at-risk and affected counts for the listed group, yet does not provide a comprehensive comparative safety analysis or detailed follow-up context.
Finally, the sample-size framework is explicitly a planning illustration rather than the study's own design or observed power. This distinction is essential: a planning calculation does not substitute for completed enrollment, collected outcomes, or an analysis. The record is therefore a useful example of how a registry can convey intended questions and design characteristics while leaving the statistical evidence needed to answer those questions unavailable.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The registry record is limited by the stated inability to analyze the primary outcome because not enough subjects were enrolled. Enrollment is listed as 1, while no graft failure count or estimate is reported. This prevents assessment of the outcome's magnitude and precision.
The study includes multiple regimen categories and is non-randomized. The registry explicitly cautions that the arms are not a like-for-like control comparison. The record does not provide an adjusted comparison, baseline characteristics by regimen, or sufficient information to assess confounding. No causal interpretation of between-group differences is supported.
The registry does not report the reason for termination, a detailed analysis plan, an analysis population, missing-data procedures, outcome-assessment methods, or results for the stated chimerism objectives. Several regimen descriptions are incomplete in the record, limiting the detail available for reconstructing the treatment approaches. The primary endpoint is described as a rate but operationalized as a number of patients, without a reported calculation method or observed value.
Safety interpretation is constrained by the limited adverse-event entry, which identifies the moderate-intensity group but does not provide a comparative analysis or detailed follow-up context. The displayed serious-event term and death count should not be generalized beyond the record. The record also does not report a causal assessment linking the death or serious event to treatment.
These limitations mean that the record is informative about study intent and design, but does not supply a basis for estimating graft failure or comparing the safety or effectiveness of regimens.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Double Cord Blood Transplant for Patients With Malignant and Non-malignant Disorders — NCT00801931.
- Registry record last updated 2019-03-27; status last verified 2019-03.
- Results first posted 2019-03-27.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT00801931 is a Phase 1 and Phase 2, non-randomized, unmasked, parallel study sponsored by Columbia University. Its title concerns double cord blood transplantation for patients with malignant and non-malignant disorders. The registry lists leukemia, lymphoma, neuroblastoma, immunodeficiencies, and anemia among the conditions.
The record describes six conditioning regimen categories and identifies graft failure as the primary outcome, measured as the number of patients experiencing it up to 2 years. It states that there were not enough subjects for data analysis, lists enrollment as 1, and reports zero analyses. The study status is terminated; the reason is not reported in the registry record.
A limited adverse-event entry concerns the moderate-intensity group. The registry cautions that the non-randomized arms are not a like-for-like control comparison. No analyzable primary outcome result or comparative treatment estimate is reported.