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 Feasibility and Outcomes of Allogeneic HCT Compared to Chemotherapy in Older AML Patients (NCT01929408), a registered phase not stated study. The primary outcome is Percentage Analyzed Participants Receiving Hematopoietic Stem Cell Transplantation (HCT).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01929408 |
| Phase | Phase not stated |
| Condition | Acute Myeloid Leukemia (AML), Myelodysplastic Syndrome (MDS) |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 703 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Fred Hutchinson Cancer Center |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns older and medically infirm patients diagnosed with acute myeloid leukemia or high-risk myelodysplastic syndromes. The registry lists AML and MDS as conditions. It does not give further eligibility criteria or describe the characteristics of the participants included in the endpoint analysis.
Intervention
The treatment approach of interest is allogeneic hematopoietic cell transplantation (HCT). The registry describes a comparison of treatment methods and outcomes, but does not report detailed treatment protocols, selection criteria for HCT, or how treatment decisions were made.
Comparator
The title identifies conventional therapy, including chemotherapy in the study title, as the comparison with HCT. The registry does not give arm-level descriptions, treatment schedules, or results for the treatment groups. It also states that this is not a randomized comparison and that allocation is not stated.
Primary question
The primary endpoint asks what percentage of analyzed participants received HCT within 1 year after starting induction. This describes treatment receipt over a specified timeframe, rather than a direct comparison of survival, remission, or another clinical outcome. The endpoint result is not reported in the registry record.
In broad terms, the study asks how often HCT was delivered in this older or medically infirm population and compares treatment methods and outcomes. Because treatment was not randomly allocated, the intended comparison should be read as observational. Patients who received HCT and those who did not may have differed in ways that also relate to their outcomes. The registry does not report enough detail to assess those differences or determine whether the groups were adjusted to make them more comparable.
3. Trial Design
This is a prospective observational study of treatment methods and outcomes in patients diagnosed with AML or MDS. Its official title specifies older and medically infirm patients with AML or high-risk MDS. The registry lists Fred Hutchinson Cancer Center as the sponsor and reports an enrollment of 703. The study status is completed; the recorded start date is 2013-07-19 and the primary completion date is 2018-12-04.
The study is not described as randomized. The registry states that allocation is not stated and cautions that the arms are not a like-for-like control comparison. Thus, the treatment groups should not be interpreted as if assignment to HCT or conventional therapy had been determined by random allocation. Differences in health, eligibility, treatment selection, or other characteristics could influence both which therapy a participant received and subsequent outcomes. The registry does not describe how these potential differences were handled.
The registry lists two outcome measures. The primary measure is the percentage of analyzed participants receiving HCT within 1 year after starting induction. A secondary outcome is the percentage of analyzed participants without HCT who were deceased. The registry record does not provide arm-specific results for these measures, details of the analysis population, or a statistical analysis plan. It lists no statistical analyses.
Although the study is completed, completion status alone does not establish what the treatment outcomes were or how precisely they were estimated. Without reported endpoint values, uncertainty estimates, or analysis details, the record supports a description of the design and outcomes selected, but not a quantitative conclusion about differences between treatment approaches.
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.
Overall Study
| Stage | Acute Myeloid Leukemia (AML) & Myelodysplastic Syndrome (MDS) |
|---|---|
| STARTED | 703 |
| COMPLETED | 695 |
| NOT COMPLETED | 8 |
Reasons for not completing this period:
| Reason | Acute Myeloid Leukemia (AML) & Myelodysplastic Syndrome (MDS) |
|---|---|
| received HCT as initial treatment | 8 |
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.
| Characteristic | Unit | All Patients |
|---|---|---|
| Participants analysed | 703 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 436 |
| Age, Categorical: >=65 years | Participants | 267 |
| Age, Continuous | years | 62 (18 to 80) |
| Sex: Female, Male: Female | Participants | 304 |
| Sex: Female, Male: Male | Participants | 399 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 27 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 662 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 14 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 13 |
| Race (NIH/OMB): Asian | Participants | 23 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 9 |
| Race (NIH/OMB): Black or African American | Participants | 41 |
| Race (NIH/OMB): White | Participants | 608 |
| Race (NIH/OMB): More than one race | Participants | 3 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 6 |
| Region of Enrollment: United States | participants | 703 |
6. Primary Endpoint
The registry lists the primary outcome as Percentage Analyzed Participants Receiving Hematopoietic Stem Cell Transplantation (HCT), measured over 1 year after starting induction.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | % participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the percentage of analyzed participants who received hematopoietic stem cell transplantation within 1 year after starting induction. It measures receipt of HCT during a defined period, not whether HCT was successful or whether it improved a clinical outcome. The registry labels the measure as a percentage of participants and gives the timeframe as 1 year after starting induction.
As a general statistical concept, a treatment-receipt endpoint can describe whether a treatment was delivered in the study population. It may be relevant in an observational study focused on feasibility, because a treatment's use is a distinct question from its effects on survival or disease status. However, the endpoint alone does not explain why some participants did or did not receive HCT. Clinical suitability, patient preferences, access, disease course, and other factors could be relevant in general, but the registry record does not report how such factors operated in this study.
The endpoint's result, analysis denominator, and uncertainty are not reported in the registry record. The 695 participants listed as at risk in the adverse-event information are not identified as the denominator for this primary endpoint, so that count cannot be substituted for the endpoint population. Without the endpoint result and denominator, the percentage cannot be interpreted quantitatively.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies the study as a prospective observational comparison of treatment methods and outcomes, with HCT receipt within 1 year after starting induction as the primary endpoint. It does not report the endpoint percentage, a confidence interval, a p-value, or an adjusted comparison. Consequently, the posted record does not show how many analyzed participants received HCT or how precisely that percentage was estimated.
The record lists an enrollment of 703. That enrollment count should not automatically be treated as the denominator for the primary endpoint: the measure is defined for analyzed participants, and the analysis population and denominator are not reported. The adverse-event information separately lists 695 at risk for serious events and 695 at risk for other events. Those safety counts do not establish the primary endpoint denominator or the sizes of the treatment groups.
The registry's description of a nonrandomized comparison is important for interpretation. In an observational study, treatment groups may differ before treatment is received. For example, general factors related to health or treatment eligibility can influence both treatment selection and outcomes. A difference between groups, if reported, would therefore not by itself establish that the treatment caused the difference. The registry does not report the methods used to account for potential confounding, and it supplies no treatment-group outcome estimates for evaluating this issue.
The secondary outcome is the percentage of analyzed participants without HCT who were deceased. Its numerical result, timeframe, denominator, and uncertainty are not reported in the registry record. The record also does not provide survival estimates or other clinical outcome results. These omissions prevent assessment of the magnitude or precision of outcome differences.
No statistical analyses are listed in the registry record. In particular, there are no posted effect estimates, confidence intervals, or hypothesis-test results for the primary endpoint. A confidence interval generally describes the range of values compatible with a statistical estimate under the assumptions of the analysis; without a reported estimate and interval, the precision of the primary result cannot be judged. The completed status and selected outcomes describe the study record, but do not fill in the absent results.
Overall, the registry supports a limited interpretation: it documents the study's observational design, population of interest, and planned focus on HCT receipt and outcomes. It does not provide the quantitative results needed to describe the observed treatment-receipt rate, compare outcomes between treatment approaches, or assess the strength of statistical evidence.
9. Statistical Methods Explained
The registry record does not report a statistical analysis plan or any statistical analyses. The endpoint definitions and study design can still be explained using general statistical principles, but those principles should not be mistaken for methods confirmed to have been used in this study.
What does a percentage endpoint describe?
In general, a percentage endpoint expresses the share of a defined analysis population that meets an event definition. Here, the event is receiving HCT within 1 year after starting induction. To interpret such a percentage, readers need the numerator, the denominator, and a clear rule for who belongs in the analyzed population. The registry gives the event definition and timeframe, but does not report the endpoint percentage or denominator. It is therefore not possible to reconstruct or evaluate the estimate from the record.
The meaning of the percentage also depends on how participants who did not have complete follow-up were handled. A participant may not have a recorded treatment status for the full timeframe, or may leave follow-up before the endpoint can be assessed. General approaches include defining a complete-case population or using methods that account for time-to-event and censoring, but the registry does not state which approach, if any, was used. No particular handling of incomplete follow-up should be assumed.
Why does observational allocation matter?
In a randomized study, random assignment is intended to balance measured and unmeasured characteristics across treatment groups on average. This study is described as nonrandomized, and the registry says allocation is not stated. In observational comparisons, treatment choice can be related to participants' baseline characteristics or clinical circumstances. If those factors also relate to outcomes, a crude group comparison may mix treatment differences with pre-existing differences.
Statistical adjustment can sometimes address measured differences, using methods such as regression or weighting. These are general examples, not methods reported for this study. Adjustment cannot automatically remove bias from factors that were not measured or inadequately represented. The registry does not identify covariates, adjustment methods, or adjusted estimates, so the adequacy of any confounding control cannot be evaluated.
How should uncertainty be assessed?
As a general concept, an effect estimate describes the observed size and direction of a result, while a confidence interval conveys statistical uncertainty around that estimate under the model's assumptions. A p-value, when used, relates the observed data to a specified null hypothesis and model; it is not a measure of clinical importance or the probability that a hypothesis is true. The registry lists no such analysis results for the endpoint. There is therefore no basis to characterize statistical significance or precision.
Binary outcomes can also be affected by sparse events or unequal information across groups. More generally, over-dispersion occurs when observed variability exceeds that expected under a statistical model, which can make conventional uncertainty estimates too narrow if the model is not appropriate. These are general considerations only. The registry record does not report a model, event counts for the primary endpoint, or diagnostics with which to assess these issues.
What do planning calculations mean?
Sample-size planning calculations are hypothetical illustrations of how many participants might be needed under specified assumptions. The stated illustration assumptions are a two-sided significance level of 0.05, equal allocation between treatment groups, a normal approximation, and an effect defined as a stated fraction of the observed effect. Such calculations are not observed power and do not demonstrate that the completed study had a particular probability of detecting an effect. The registry does not report a trial-specific sample-size justification, and the planning illustrations should not be read as evidence that the study was designed around a documented target.
In general, a planning result depends on the assumed effect, variability, analysis method, and allocation. If an effect is defined relative to an observed estimate, the resulting illustration is especially dependent on that estimate and is not an independent confirmation of it. Since the primary endpoint result and statistical analysis are not reported in the registry record, the statistical evidence behind any such estimate cannot be examined from this record alone.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists two outcome measures: the primary percentage receiving HCT and the secondary percentage of analyzed participants without HCT who were deceased. It does not report how these outcomes were prioritized in the analysis, whether additional analyses were planned, or whether any adjustment was made for testing multiple outcomes. The number of outcomes alone does not establish how multiplicity was handled.
As a general statistical issue, testing multiple outcomes or conducting repeated subgroup and model analyses can increase the chance of finding a nominally unusual result by chance. Prespecified analysis plans and multiplicity procedures can help make the intended interpretation clear. The registry record does not provide enough information to determine whether such procedures were planned or used. No subgroup analyses or interim analyses should be inferred from the available record.
Missing-data handling is also not reported. The primary measure refers to analyzed participants, but the registry does not state who was included, whether all enrolled participants had endpoint information, or how missing treatment status or incomplete follow-up was addressed. The safety counts do not answer these questions for the endpoint. In general, excluding participants with incomplete data can affect an estimate if the reasons for missingness relate to treatment or outcomes; methods that address missing data also require assumptions that should be described.
The analysis populations, missing-data assumptions, and sensitivity analyses are not reported in the registry record. Without this information, readers cannot assess how robust the outcome estimates might be to alternative choices about eligibility, follow-up, or incomplete observations. No specific missing-data mechanism or method can be attributed to the study.
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 |
|---|---|---|---|
| All Patients | 0 | 695 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| All Patients | 309 of 695 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| All Patients | 0 of 695 |
The adverse-event information lists an All Patients group with 695 participants at risk for serious events and 0 affected. It also lists 695 at risk for other events and 0 affected. Deaths are recorded as 309. No leading serious-event terms are listed.
These figures should be read as separate registry entries, not as a complete description of comparative safety. The record does not provide treatment-group safety results, event definitions, follow-up details, or an explanation of how deaths relate to the event counts. The 695 at risk for each event category should not be assumed to represent the primary endpoint analysis population.
The absence of affected participants in the reported event fields does not establish that no adverse events occurred in every treatment group or throughout all follow-up. It describes what is recorded in these fields. Similarly, the death count does not identify causes, timing, treatment group, or an association with a particular therapy. Without those details, the safety information cannot support a comparative safety conclusion.
12. What the Result Does, and Does Not, Mean
The study is relevant to questions about treatment delivery and outcomes in older or medically infirm patients with AML or high-risk MDS. Its primary endpoint focuses on HCT receipt within 1 year after starting induction, and its secondary outcome concerns participants without HCT who were deceased. These endpoint definitions indicate the topics of interest, but they do not by themselves provide results.
The registry record does not report the primary endpoint percentage, the secondary outcome percentage, treatment-group comparisons, confidence intervals, or statistical tests. It therefore does not establish the observed frequency of HCT, the size of any outcome difference, or the precision of an estimate. Study completion and the recorded enrollment of 703 are not substitutes for those results.
Even if a numerical comparison were available, the observational design would require careful interpretation. The registry explicitly notes that the study was not randomized, allocation is not stated, and the arms are not a like-for-like control comparison. In general, differences in patient characteristics or treatment selection may complicate causal interpretation. The record does not describe adjustment methods that would allow readers to assess how those concerns were addressed.
The primary endpoint also concerns treatment receipt rather than a direct measure of survival or disease response. A receipt percentage can describe treatment delivery, but cannot on its own establish the benefits or harms of treatment. The registry does not report enough outcome detail to determine those effects. The safety entries likewise do not provide treatment-specific comparisons or context for the death count.
The defensible conclusion is therefore about the scope of the record: it identifies an observational study and its selected endpoint questions, but does not report quantitative results needed for a treatment comparison. It should not be interpreted as evidence for or against either treatment approach.
13. Why This Trial Matters Statistically
This study raises a statistically important distinction between describing treatment use and estimating treatment effects. Its primary endpoint measures HCT receipt within a defined timeframe. That can address a treatment-delivery question, but it is not interchangeable with a clinical outcome such as survival. Keeping those questions separate helps prevent an observed treatment-use measure from being interpreted as proof of benefit or harm.
The observational design also highlights why group comparability matters. When treatment allocation is not randomized, differences between groups may reflect patient selection as well as treatment. The registry expressly cautions that the arms are not a like-for-like control comparison. This makes the description of eligibility, baseline characteristics, follow-up, and adjustment methods especially important for interpreting any comparative result. Those details are not reported in this record.
Reporting uncertainty is equally important. An estimate without its analysis population and precision can be difficult to assess, while a completed study without posted endpoint values does not answer the quantitative question. Here, the registry records an enrollment of 703 and identifies the outcomes of interest, but it does not list statistical analyses or report the primary endpoint result. The record therefore illustrates how much interpretation depends on transparent outcome reporting, not merely on a study's status or enrollment.
These considerations matter beyond this study: clinical researchers and biostatisticians need to distinguish estimands, assess group comparability, and understand uncertainty before drawing conclusions from observational comparisons. In this case, the registry record establishes the study's purpose and design features, while leaving the central numerical results 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 does not report the primary endpoint result, the denominator used to calculate it, or its uncertainty. It also does not provide numerical results for the secondary outcome. This prevents direct assessment of the endpoint frequency and any comparison of outcomes.
Several design and analysis details are absent. The record does not describe participant eligibility in detail, baseline characteristics, arm sizes, treatment protocols, treatment-selection criteria, follow-up procedures, or the handling of incomplete endpoint information. It states that allocation is not stated and that the comparison is not a randomized, like-for-like comparison. Without analysis details, readers cannot assess whether or how confounding was addressed.
The registry lists no statistical analyses and does not report a statistical analysis plan, a trial-specific sample-size justification, or methods for multiplicity and missing data. It does not state whether there were interim analyses, and none should be assumed. The safety information lacks treatment-specific results, event definitions, and context for the deaths recorded.
These are limitations of what can be evaluated from the registry record; they do not establish that a particular method was or was not used outside the record. In particular, the absence of a posted result is not evidence that no result exists elsewhere. It means that the record alone is insufficient for a quantitative or causal interpretation of the treatment comparison.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Feasibility and Outcomes of Allogeneic HCT Compared to Chemotherapy in Older AML Patients — NCT01929408.
- Registry record last updated 2019-11-15; status last verified 2019-11.
- Results first posted 2019-11-15.
- 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
The registry identifies a completed prospective observational study sponsored by Fred Hutchinson Cancer Center, with an enrollment of 703. It concerns treatment methods and outcomes for older and medically infirm patients diagnosed with AML or high-risk MDS. The recorded start date is 2013-07-19, and the primary completion date is 2018-12-04.
The primary outcome is the percentage of analyzed participants receiving HCT within 1 year after starting induction. The secondary outcome concerns the percentage of analyzed participants without HCT who were deceased. The registry states that this was not a randomized comparison, that allocation is not stated, and that the arms are not a like-for-like control comparison.
The primary and secondary outcome results and statistical analyses are not reported in the registry record. The adverse-event information lists 695 at risk and 0 affected for serious events, 695 at risk and 0 affected for other events, and 309 deaths. The record does not provide the additional detail needed to interpret these safety figures comparatively.