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 Stroke With Transfusions Changing to Hydroxyurea (NCT00122980), a randomized phase 3 study. The primary outcome is Occurrence of an Adjudicated Secondary Stroke During the 30-month Treatment Period.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00122980 |
| Phase | Phase 3 |
| Condition | Hemochromatosis, Cerebrovascular Accident, Anemia, Sickle Cell |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 134 |
| Arms in the primary outcome | n/a |
| Lead sponsor | St. Jude Children's Research Hospital |
| Results posted | Yes |
2. Clinical Question
Population
Children with sickle cell anemia were the population of interest. The registry describes the primary endpoint as recurrent secondary stroke during treatment. Its intent-to-treat population included randomized subjects who received any on-study treatment. The record does not give further eligibility criteria or describe the participants’ clinical histories in enough detail to characterize them beyond these registry entries.
Intervention
The alternative strategy paired hydroxyurea with phlebotomy. The registry identifies hydroxyurea as a drug and phlebotomy as a procedure. The stated purpose was to compare this strategy with standard therapy for secondary-stroke prevention and management of iron overload.
Comparator
The comparison strategy paired red cell transfusions with iron chelation. The registry lists both as procedures. Further details about how either strategy was delivered, including doses, schedules, treatment adjustments, or adherence, are not reported in the registry record.
Primary question
The primary endpoint concerned the number of participants with an adjudicated secondary stroke during the treatment period, described as lasting up to 30 months because the study ended early. A stroke was defined as a clinical event with brain injury due to vascular disease, and neurological events underwent formal stroke adjudication. The registry identifies this as the first component of a composite primary endpoint. A result comparing the strategies for this outcome is not reported in the registry record.
3. Trial Design
NCT00122980, titled Stroke With Transfusions Changing to Hydroxyurea, was registered as a Phase 3, randomized, parallel-group study with no masking. The registry lists enrollment as 134. That is the recorded enrollment figure; the record does not establish from this fact alone how many participants were randomized, received treatment, completed follow-up, or contributed data to each outcome.
The two described strategies were hydroxyurea and phlebotomy, and transfusion and chelation. The registry’s study summary frames the comparison around secondary-stroke prevention and iron-overload management in children with sickle cell anemia. The listed conditions also include hemochromatosis, cerebrovascular accident, and hematologic diseases. The sponsor was St. Jude Children's Research Hospital.
The recorded study start was 2006-10, and primary completion was 2010-06. The status is terminated. The endpoint timeframe specifically notes early termination and defines observation from the beginning of treatment until treatment ended, up to 30 Months. The reason for termination, the timing of the termination decision, and the treatment and follow-up exposure for individual participants are not reported in the registry record.
Random assignment is intended, in general, to support a fair comparison by reducing systematic differences between treatment groups at the point of assignment. No masking means the study was not blinded, according to the registry entry. The record does not describe allocation procedures, concealment, treatment adherence, crossover, or any methods used to account for departures from assigned treatment. It also does not report a statistical analysis plan, so the planned handling of these design features cannot be assessed.
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: Participant qualification was initially evaluated by medical chart review and interview. Subsequent to subject consent, subjects were further screened to confirm eligibility. Screening included, in part, expert verification of initial stroke and of liver biopsy results prior to randomization.
Overall Study
| Stage | Hydroxyurea/Phlebotomy | Transfusion/Chelation |
|---|---|---|
| STARTED | 67 | 66 |
| COMPLETED | 24 | 26 |
| NOT COMPLETED | 43 | 40 |
Reasons for not completing this period:
| Reason | Hydroxyurea/Phlebotomy | Transfusion/Chelation |
|---|---|---|
| Death | 0 | 1 |
| Physician Decision | 2 | 0 |
| Protocol Violation | 5 | 1 |
| Withdrawal by Subject | 2 | 3 |
| Adjudicated stroke (study endpoint) | 7 | 0 |
| Study termination | 27 | 35 |
Analysis population for the primary outcome, as defined in the registry: The Intent-to-Treat population included all subjects who were randomized and who received any on-study treatment.
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 | Hydroxyurea/Phlebotomy | Transfusion/Chelation | Total |
|---|---|---|---|---|
| Participants analysed | 67 | 66 | 133 | |
| Age, Categorical: <=18 years | Participants | 60 | 60 | 120 |
| Age, Categorical: Between 18 and 65 years | Participants | 7 | 6 | 13 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Age Continuous | years | 13.0 (SD 4.05) | 13.3 (SD 3.76) | 13.1 (SD 3.89) |
| Sex: Female, Male: Female | Participants | 26 | 35 | 61 |
| Sex: Female, Male: Male | Participants | 41 | 31 | 72 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 4 | 2 | 6 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 63 | 64 | 127 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 62 | 64 | 126 |
| Race (NIH/OMB): White | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): More than one race | Participants | 1 | 0 | 1 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 4 | 2 | 6 |
| Region of Enrollment: United States | participants | 67 | 66 | 133 |
| History of splenomegaly: Yes | Participants | 22 | 16 | 38 |
| History of splenomegaly: No | Participants | 45 | 50 | 95 |
| Age at index stroke | years | 5.6 (SD 2.97) | 6.2 (SD 2.75) | 5.9 (SD 2.87) |
| Duration of Transfusion | years | 7.4 (SD 3.85) | 7.0 (SD 3.61) | 7.2 (SD 3.72) |
| Prior use of Desferal (deferoxamine mesylate): Yes | participants | 47 | 44 | 91 |
| Prior use of Desferal (deferoxamine mesylate): No | participants | 19 | 19 | 38 |
| Prior use of Desferal (deferoxamine mesylate): Missing | participants | 1 | 3 | 4 |
| Prior use of Exjade (deferasirox): Yes | participants | 57 | 55 | 112 |
| Prior use of Exjade (deferasirox): No | participants | 9 | 8 | 17 |
| Prior use of Exjade (deferasirox): Missing | participants | 1 | 3 | 4 |
| Prior use of hydroxyruea: Yes | participants | 5 | 3 | 8 |
| Prior use of hydroxyruea: No | participants | 62 | 63 | 125 |
| Liver iron concentration | mg ferritin/gram dry weight liver | 14.5 (9.5 to 23.3) | 13.9 (8.7 to 22.9) | 14.5 (9.0 to 23.0) |
| History of recurrent stroke: Yes | participants | 10 | 4 | 14 |
| History of recurrent stroke: No | participants | 57 | 62 | 119 |
6. Primary Endpoint
The registry lists the primary outcome as Occurrence of an Adjudicated Secondary Stroke During the 30-month Treatment Period, measured over Because the study was terminated early, time frame is from beginning of treatment until end of treatment (up to 30 Months).
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary outcome is the occurrence of an adjudicated secondary stroke during treatment. It is expressed as the number of participants with a recurrent secondary stroke, rather than as a measure of stroke severity or a count of all neurological events. The registry defines stroke as a clinical event involving brain injury due to vascular disease and says neurological events underwent formal stroke adjudication. Adjudication is a process for applying outcome definitions to events; in general, it can help ensure that endpoint classification follows consistent criteria.
The timeframe is from the beginning of treatment until the end of treatment, up to 30 Months, because the study was terminated early. Therefore, the registry does not describe an identical fixed follow-up period for every participant. It calls this outcome the first component of a composite primary endpoint. The other components and how the composite was evaluated are not reported in the registry record.
A participant-based event outcome can be useful for asking whether a clinically defined event occurred during the specified observation period. It does not, by itself, describe when an event occurred, how many events an individual experienced, or the full course of neurological health. Those details would require other reported measures. The registry record does not give the primary endpoint counts, an effect estimate, a confidence interval, or a statistical test comparing the treatment strategies. Thus the endpoint definition can be described, but its comparative result cannot be interpreted from this record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a randomized comparison of hydroxyurea and phlebotomy against transfusion and chelation, with secondary stroke as the first component of the composite primary endpoint. It does not report a single primary endpoint comparison. The posted results therefore do not establish the number of participants with an adjudicated secondary stroke in either strategy or the magnitude and precision of any difference between them.
The registry explains why the endpoint observation period may vary: the study was terminated early, and the timeframe runs from treatment start to treatment end, up to 30 Months. Without participant-level follow-up information or an analysis that accounts for differing observation time, the endpoint description alone cannot show how much observation contributed to the comparison. The reason for termination and its consequences for the planned analysis are not reported in the registry record.
For a comparative treatment result, the event counts would need to be considered alongside the analysis population, the observation period, and the statistical method. In general, an estimate describes the direction and magnitude of a contrast, while a confidence interval indicates the range of values compatible with the data and model. Neither an estimate nor a confidence interval for the primary comparison is reported in the registry record. A p-value or other test result for that comparison is also not reported.
The registry reports an enrollment figure of 134 and defines an intent-to-treat population as subjects who were randomized and received any on-study treatment. It does not report the number included in that population or the number contributing to the primary endpoint. Enrollment should not be treated as interchangeable with an analyzed population or as proof that every enrolled participant had complete endpoint follow-up.
Other outcomes listed include parent- and child-reported Pediatric Quality of Life changes, Barthel Index change, cognitive and achievement measures, and changes in height and weight. The record lists nine outcome measures and nine analyses, but does not provide results for these measures in the registry record for this analysis. Their presence in the registration does not substitute for the missing primary endpoint comparison.
The appropriate reading is consequently descriptive rather than comparative: the record documents the trial question, design, outcome definition, early termination, and selected safety counts, but it does not supply enough primary efficacy information to quantify the observed result. No conclusion about the relative effect of the treatment strategies on secondary stroke can be drawn from the endpoint information recorded.
9. Statistical Methods Explained
Statistical methods are described only where the registry record gives enough information to do so. The record identifies randomization, a parallel-group design, no masking, an intent-to-treat population definition, and a participant-count primary outcome. It does not report the statistical analysis method for the primary endpoint, an analysis plan, or an effect estimate. Those omissions limit what can be inferred about how the primary comparison was conducted.
What does randomization contribute?
In general, randomization assigns participants to treatment groups using a chance-based process. Its purpose is to reduce systematic differences between groups at assignment, including differences that may not be measured. It does not guarantee that groups will be identical, particularly in a trial with limited enrollment, and it does not eliminate bias arising after assignment. The record says the study was randomized but does not report the sequence-generation or allocation-concealment procedures. Their implementation therefore cannot be assessed from the registry entry.
What does the parallel design mean?
In a parallel-group trial, participants are assigned to a strategy and followed within that group, rather than switching through a sequence of strategies as part of the design. This general description is consistent with the registry’s listed model. The entry does not report whether participants crossed over, stopped assigned treatment, or received other therapies during follow-up. It also does not specify the analysis used to address any such events.
How should the endpoint count be understood?
The primary endpoint is a count of participants with an adjudicated secondary stroke during treatment. In general, a count is a direct summary of how many participants meet the event definition, but a count alone does not express the comparison relative to the number observed in each group or account for differences in follow-up. The registry’s outcome description gives the event definition and timeframe, but no group-specific primary endpoint counts. It also identifies the outcome as the first part of a composite primary endpoint without reporting the other parts or the composite analysis details.
Why does the observation period matter?
The recorded endpoint period ends when treatment ends and can extend up to 30 Months. The registry states that the study was terminated early. In general, when participants have different durations of observation, a simple event count may not convey the same information as an analysis that incorporates time at risk. Time-to-event methods can account for the timing of events and censoring under specified assumptions. However, the record does not report whether such a method was used, how censoring was handled, or whether the endpoint was analyzed only as a participant count. It would be inappropriate to assume a particular method.
What is an intent-to-treat population?
The registry defines its intent-to-treat population as all subjects who were randomized and received any on-study treatment. In general, an intent-to-treat analysis seeks to preserve the comparison created by random assignment, although the exact population and handling rules must be specified. The definition recorded includes a treatment-receipt condition; it is not enough to assume that every randomized participant was included. The number in this population, reasons for exclusions, and the extent of missing endpoint information are not reported in the registry record.
What can a confidence interval or p-value tell a reader?
In general, a confidence interval describes the uncertainty around an estimated effect under the chosen statistical model and assumptions. A p-value summarizes how incompatible the observed data are with a specified null hypothesis under a statistical model; it is not a measure of clinical importance or the probability that a treatment strategy is effective. Neither a confidence interval nor a p-value for the primary endpoint comparison is reported in the registry record. Without an estimate and its uncertainty, the comparative magnitude and precision cannot be evaluated.
What is not known about the statistical plan?
The registry record does not report the primary endpoint test, model, covariate adjustment, treatment of repeated events, handling of missing data, or planned subgroup analyses. It does not give a multiplicity procedure for the composite endpoint and secondary measures. These are not minor details that can be safely filled in from common practice: different reasonable methods can answer different questions or rely on different assumptions. The methods and results cannot be reconstructed from the outcome names and design labels alone.
The registry includes a general sample-size planning description based on an observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. It describes planning illustrations for specified fractions of an observed effect, not the trial’s original design justification. No calculated planning values are available in the record details considered for this explanation. Such illustrations are not observed power and do not replace a reported analysis. The trial’s own sample-size rationale and any assumptions used to design it are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists nine outcome measures and nine analyses. The primary endpoint is described as the first component of a composite endpoint, and the listed secondary outcomes cover quality of life, functional status, cognitive and achievement measures, height, and weight. The record does not report how the composite was defined beyond identifying the secondary-stroke component, how the remaining components contributed, or how the primary outcome was tested as a composite.
When several outcomes or analyses are considered, there can be more opportunities for apparently notable results to occur by chance. In general, multiplicity methods can control or describe this issue, but the appropriate approach depends on the questions and analysis plan. No multiplicity adjustment, hierarchy among endpoints, prespecified testing sequence, or interpretation rule is reported in the registry record. The nine listed measures and analyses should not be treated as evidence that any particular correction was or was not applied.
The registry defines an intent-to-treat population as randomized subjects who received any on-study treatment. It does not report the number analyzed for the primary endpoint, the number with observed endpoint data, or reasons for missing data. The amount and pattern of missing outcome data, the handling of missing values, and any sensitivity analyses are not reported in the registry record.
Early termination is stated, but its reason and the decision process are not reported. Information about interim analyses, stopping boundaries, or changes to planned endpoints is also not reported in the registry record. These unknowns matter because early stopping and incomplete follow-up can affect the amount of information available and the interpretation of estimates. Without a reported analysis plan and results, the consequences cannot be assessed.
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 |
|---|---|---|---|
| Hydroxyurea/Phlebotomy | 29 | 67 | 43.3% |
| Transfusion/Chelation | 14 | 66 | 21.2% |
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 |
|---|---|
| Hydroxyurea/Phlebotomy | 65 of 67 |
| Transfusion/Chelation | 65 of 66 |
Most frequent serious adverse event terms
| Event term | Organ system | Hydroxyurea/Phlebotomy | Transfusion/Chelation |
|---|---|---|---|
| Sickle cell anaemia with crisis | Congenital, familial and genetic disorders | 16 of 67 | 5 of 66 |
| Pyrexia | General disorders | 4 of 67 | 2 of 66 |
| Cerebrovascular accident | Nervous system disorders | 6 of 67 | 0 of 66 |
| Acute chest syndrome | Blood and lymphatic system disorders | 1 of 67 | 3 of 66 |
| Pancreatitis | Gastrointestinal disorders | 2 of 67 | 1 of 66 |
| Cholecystitis | Hepatobiliary disorders | 2 of 67 | 1 of 66 |
| Cholelithiasis | Hepatobiliary disorders | 1 of 67 | 1 of 66 |
| Pyelonephritis | Infections and infestations | 2 of 67 | 0 of 66 |
| Right ventricular failure | Cardiac disorders | 0 of 67 | 1 of 66 |
| Abdominal pain | Gastrointestinal disorders | 1 of 67 | 0 of 66 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Hydroxyurea/Phlebotomy | Transfusion/Chelation |
|---|---|---|---|
| Sickle cell anaemia with crisis | Congenital, familial and genetic disorders | 35 of 67 | 29 of 66 |
| Pyrexia | General disorders | 21 of 67 | 20 of 66 |
| Headache | Nervous system disorders | 18 of 67 | 22 of 66 |
| Alanine aminotransferase increased | Investigations | 15 of 67 | 14 of 66 |
| Hyperbilirubinaemia | Hepatobiliary disorders | 9 of 67 | 18 of 66 |
| Reticulocytopenia | Blood and lymphatic system disorders | 21 of 67 | 3 of 66 |
| Aspartate aminotransferase increased | Investigations | 14 of 67 | 10 of 66 |
| Anaemia | Blood and lymphatic system disorders | 20 of 67 | 3 of 66 |
| Vomiting | Gastrointestinal disorders | 12 of 67 | 11 of 66 |
| Transfusion reaction | Injury, poisoning and procedural complications | 4 of 67 | 10 of 66 |
Serious events with the highest arm-level rate: sickle cell anaemia with crisis (23.9%), cerebrovascular accident (9.0%), pyrexia (6.0%), acute chest syndrome (4.5%), pancreatitis (3.0%).
The registry reports serious adverse event figures for both treatment groups. For Hydroxyurea/Phlebotomy, the record lists 67 at risk and 29 affected by serious adverse events. For Transfusion/Chelation, it lists 66 at risk and 14 affected. These are reported counts; they are not a primary endpoint comparison, and the registry entries do not provide an inferential analysis of the difference.
Other adverse event figures are also listed: 65 at risk and 65 affected in the Hydroxyurea/Phlebotomy group, and 66 at risk and 65 affected in the Transfusion/Chelation group. The record does not provide a narrative definition of the distinction between these event categories or further details about severity, timing, recurrence, or attribution. No deaths are reported in the available safety details; the record does not give a death count.
The registry lists serious adverse event terms and percentages: Sickle cell anaemia with crisis, 23.9%; Cerebrovascular accident, 9.0%; Pyrexia, 6.0%; Acute chest syndrome, 4.5%; Pancreatitis, 3.0%; and Cholecystitis, 3.0%. The denominator and the basis for these percentages are not reported in the registry record, so they should be read as listed rather than converted into participant counts or compared across groups. The record does not establish that these terms are exhaustive or attributable to a particular treatment strategy.
12. What the Result Does, and Does Not, Mean
The registry record documents a randomized Phase 3 comparison addressing secondary-stroke prevention and iron-overload management in children with sickle cell anemia. It specifies hydroxyurea with phlebotomy as one strategy and transfusion with chelation as the other. It also supplies a definition of adjudicated secondary stroke and states that the study was terminated early, with treatment observation lasting from its start to its end, up to 30 Months.
These registry entries explain the clinical question and parts of the design; they do not establish the result. The primary endpoint counts by group, the comparative effect estimate, its uncertainty, and a test result are not reported in the registry record. Without them, the direction, magnitude, and precision of the primary comparison cannot be described. The absence of a reported result should not be interpreted as evidence that the strategies had equal outcomes, nor as evidence favoring either strategy.
The record’s enrollment figure is not a substitute for the number analyzed for the endpoint. Likewise, the stated intent-to-treat definition does not reveal how many participants met that definition or how missing observations were handled. Since early termination is recorded but its cause and implications are not, the available information cannot establish why observation ended or how that affected the analysis.
The adverse-event figures are descriptive counts, and the listed serious-event terms and percentages provide additional safety information as recorded. They do not, on their own, establish comparative risk, causation, or whether events were more likely under one strategy. The percentage denominators and detailed safety-analysis methods are not reported.
In general, treatment decisions require evidence interpreted in the context of the full clinical record and an individual's circumstances. The statistical information recorded for this trial is insufficient to characterize the primary comparative result. It can support an account of the study question, endpoint definition, design labels, termination status, and certain safety observations, but not a conclusion about which strategy had better outcomes.
13. Why This Trial Matters Statistically
This trial is statistically notable because its registration connects an important clinical question with a clearly described event definition: adjudicated secondary stroke during treatment. It also shows why endpoint definition alone is not enough for interpretation. A reader needs the group-specific results, the analysis method, and an account of follow-up and missing data to understand the comparative evidence. Those primary analysis details are not reported in the registry record.
The early-termination note makes the time basis especially relevant. The endpoint period runs from treatment start until treatment end, up to 30 Months, rather than being stated as a completed fixed period for all participants. In general, unequal observation time can influence how event counts should be interpreted. The record does not describe an analysis addressing time at risk, so the statistical handling of this feature remains unknown.
The entry also illustrates the importance of distinguishing enrollment, analysis populations, and outcome denominators. Enrollment is recorded as 134, while the intent-to-treat definition has an additional treatment-receipt condition. The registry does not report the number in that population or the number with endpoint data. Those quantities cannot be assumed to be identical.
Finally, nine outcome measures and nine analyses are listed, but no multiplicity approach is reported. In general, a prespecified outcome hierarchy and analysis plan help readers understand which results are primary and how multiple tests are interpreted. Their absence from the record makes it harder to assess how secondary findings, if reported elsewhere, would relate to the principal question. The trial therefore offers a useful example of the gap between a registered research question and the information needed to judge a comparative result.
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 central limitation for interpreting efficacy is that the registry record does not report the primary endpoint counts or a comparison between treatment groups. No effect estimate, confidence interval, or p-value for adjudicated secondary stroke is reported. The endpoint description also identifies this outcome as one component of a composite primary endpoint, while the other components and the composite analysis are not described in the record.
The study was terminated early, and the endpoint timeframe is defined as treatment start to treatment end, up to 30 Months. The reason for termination, participant-level follow-up, and the effect of early termination on the planned analysis are not reported. This leaves uncertainty about the amount of outcome information available and how differing observation periods were addressed.
The record reports enrollment but not the number randomized, treated, included in the defined intent-to-treat population, or analyzed for each outcome. It does not report losses to follow-up, missing outcome data, exclusions, protocol deviations, adherence, or crossover. No primary statistical method, missing-data method, multiplicity procedure, or interim-analysis plan is reported. The registry’s sample-size description concerns planning illustrations based on an observed effect and does not supply the trial’s own sample-size rationale.
The safety figures lack reported denominators for the listed serious-event percentages, and the registry entries do not establish event attribution or a comparative safety analysis. The status and design fields help describe the study, but cannot resolve these missing details. These limitations arise from what is not reported in the registry record; they should not be replaced with assumptions about the conduct or analysis of the trial.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Stroke With Transfusions Changing to Hydroxyurea — NCT00122980.
- Registry record last updated 2013-01-18; status last verified 2012-08.
- Results first posted 2012-08-17.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT00122980 is a Phase 3, randomized, parallel-group study with no masking, sponsored by St. Jude Children's Research Hospital. The registry lists enrollment of 134, a start date of 2006-10, primary completion in 2010-06, and status as terminated. The comparison was hydroxyurea and phlebotomy versus transfusion and chelation for children with sickle cell anemia.
The primary endpoint concerns participants with an adjudicated secondary stroke during treatment, up to 30 Months because the study ended early. The registry identifies this as the first component of a composite primary endpoint. It defines the intent-to-treat population as randomized subjects who received any on-study treatment. Nine outcome measures and nine analyses are listed. Group-specific primary endpoint results, a comparative estimate, and details of the statistical analysis are not reported in the registry record.