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 Effects of Methylphenidate on Attention Deficits in Childhood Cancer Survivors (NCT01100658), a randomized na study. The primary outcome is Effectiveness of Methylphenidate on Neurocognitive Components.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01100658 |
| Phase | NA |
| Condition | ALL, Childhood, Leukemia, Lymphoblastic, Leukemia, Lymphoblastic, Acute |
| Allocation | Randomized |
| Design model | Crossover |
| Masking | Double |
| Enrollment | 1 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Minnesota |
| Results posted | Yes |
2. Clinical Question
Population
Children with attention deficits associated with childhood cancer were the intended population. The listed conditions include childhood acute lymphoblastic leukemia and malignant brain tumors. The registry record lists enrollment of 1, while its primary-outcome description states that no patients received treatment.
Intervention
Methylphenidate, described as Metadate CD, was to be given as one capsule each day for one week at a .3 mg/kg dose.
Comparator
Participants were to receive placebo as one capsule each day for one week. The treatment description states that participants would receive one week of methylphenidate and one week of placebo in a double-blind fashion.
Primary question
The primary question was whether neuropsychological test performance differed across the two treatment weeks, including performance on the Test of Variables of Attention and the working memory index of the WisSC IV.
The study addressed a clinical research question about attention and related neurocognitive functioning after childhood cancer. The registry background notes that attention, memory, and executive-function impairments are commonly reported in childhood leukemia and brain tumors, and that treatment of attention deficits in this population had received less study than methylphenidate treatment for children with ADHD. That background establishes the research motivation; it does not establish a benefit or harm from the study medication.
The planned comparison was within a crossover design: each participant was described as receiving both methylphenidate and placebo, in separate one-week periods. Such a design can compare each participant’s measurements across treatments, but interpretation depends on the conduct and analysis of both periods. The registry record does not report the treatment sequence, whether a washout period was used, or how period and carryover effects were to be handled.
The record does not contain a treatment-effect estimate for the primary question. It states that no patients received treatment and that analysis was not done. Consequently, the clinical question is identifiable from the intended design and outcome description, but the registry record cannot answer it with comparative results.
3. Trial Design
The study is listed as randomized, double-blind, and crossover. Its stated plan was for patients to receive one week of Metadate CD, a controlled-release form of methylphenidate, and one week of placebo. The medication description specifies one capsule each day for one week at a .3 mg/kg dose; the placebo description specifies one capsule each day for one week. The registry does not describe the sequence used to assign the two treatment periods.
The trial’s phase is listed as NA. The sponsor is the University of Minnesota. The record lists a start in 2010-05 and primary completion in 2010-11, and the status is TERMINATED. It does not report the reason for termination. Enrollment is listed as 1. That figure describes the registry’s enrollment entry and should not be read as evidence that a participant completed either treatment period: the primary-outcome description explicitly states that no patients received treatment.
The planned primary assessment covered Week 1 and Week 2. It was based on neuropsychological testing, including the Test of Variables of Attention (TOVA) and the working memory index of the WisSC IV. A secondary outcome is described as changes in parent and teacher ratings of attention, executive functioning, and behavior. The registry record does not give further details about the timing of those ratings or the instruments used to collect them.
The record identifies two outcome measures and reports no analyses. The primary-outcome entry says analysis was not done because no patients received treatment. The listed adverse-event group has zero participants at risk for serious and other adverse events, and zero affected; this does not provide a treated population for evaluating safety. Sequence generation, concealment procedures, the masking assessment, treatment adherence, and any washout arrangements 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: Only 1 patient was enrolled in this study. This patient completed baseline assessment, but withdrew from the study before beginning the medication trial. No medications/placebo were administered.
Overall Study
| Stage | Participant With Attention Deficit |
|---|---|
| STARTED | 1 |
| COMPLETED | 0 |
| NOT COMPLETED | 1 |
Reasons for not completing this period:
| Reason | Participant With Attention Deficit |
|---|---|
| Withdrawal by Subject | 1 |
Analysis population for the primary outcome, as defined in the registry: No patients received treatment, therefore analysis was not done.
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 | Participant With Attention Deficit |
|---|---|---|
| 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 | 0 |
| Sex: Female, Male: Male | Participants | 1 |
6. Primary Endpoint
The registry lists the primary outcome as Effectiveness of Methylphenidate on Neurocognitive Components, measured over Week 1 and Week 2.
| 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 concerns child performance on neuropsychological testing during Week 1 and Week 2. The registry description names the Test of Variables of Attention (TOVA), a computerized attention test described as assisting in the screening, diagnosis, and treatment monitoring of attention disorders such as ADHD. It also names the working memory index of the WisSC IV. The record describes standard scores as averaging 100 +/- 15, with higher scores indicating better performance, and says scores at or below 1 SD lower than the mean represent an area of deficit.
These measures were selected to assess attention and working memory, domains relevant to the study’s stated concern about attention deficits after childhood cancer. In general, standardized neuropsychological measures can express performance relative to a reference scale, while a repeated assessment across treatment periods can support a within-participant comparison when the trial is completed and analyzed appropriately. The registry record does not provide observed scores, a treatment contrast, or details about how results from the named measures were combined or interpreted as a single endpoint.
The primary-outcome entry states that no patients received treatment, so analysis was not done. Thus the endpoint is described, but no result indicates how participants performed during either treatment period or whether performance differed between them. The registry record does not report further scoring rules, a prespecified primary time point beyond Week 1 and Week 2, or an analysis method for the test scores.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes the intended design and outcome question, but it does not provide an estimate of the effect of methylphenidate on neuropsychological performance. The primary-outcome entry says that no patients received treatment and analysis was not done. The record also lists zero analyses. There are therefore no posted comparative scores, treatment-effect estimates, confidence intervals, or hypothesis-test results to interpret for the primary question.
Enrollment is listed as 1, but enrollment and treatment exposure are distinct. In this record, the primary-outcome text explicitly says no patients received treatment. The enrollment entry alone cannot establish that anyone completed the planned methylphenidate or placebo period, nor can it establish that outcome measurements were collected. The registry record does not explain the relationship between the enrollment entry and the absence of treated patients.
The design was intended to compare methylphenidate and placebo within a double-blind crossover. In general, this design can account for stable differences between participants because treatment periods are compared within the same participant. But the validity and precision of such a comparison depend on obtaining usable measurements in both periods and on addressing the order of treatment, period effects, and possible carryover. No treatment sequence, washout information, or analysis of these issues is reported in the registry record. With no treatment and no analysis reported, those design features cannot be evaluated from results.
The registry describes the primary testing measures and a secondary outcome involving parent and teacher ratings, but it does not post results for either. The primary outcome includes attention and working-memory measures; no individual score or summary is available for interpreting the direction or size of any change. The secondary outcome description likewise does not establish that ratings were collected or analyzed.
The adverse-event entry reports zero participants at risk and zero affected for the listed group. In the context of the statement that no patients received treatment, these entries do not support an inference about the frequency of adverse events during methylphenidate exposure. They also do not establish that the treatment is free of adverse events. No comparative safety analysis is reported.
The status is TERMINATED, but the reason for termination is not reported in the registry record. It would be speculative to attribute termination to recruitment, safety, feasibility, or an interim finding. Overall, the posted record documents a planned randomized, double-blind crossover study and an endpoint, but supplies no analyzable treatment comparison. No conclusion about the magnitude, direction, or precision of a treatment effect can be drawn from the registry results.
9. Statistical Methods Explained
The methods described in the registry record are limited. It identifies randomization, double masking, and a crossover model, and it describes planned outcomes. It does not report the statistical analysis plan or any completed analysis. General explanations below clarify what these design and analysis concepts mean; they are not claims about procedures used in this trial beyond what the registry states.
What does a randomized crossover design aim to do?
In a randomized study, allocation to treatment order is intended to reduce systematic differences in how treatment conditions are assigned. In a crossover study, participants receive more than one treatment condition during separate periods, so outcomes can be compared within the same participant. This can be useful when the outcome is measured repeatedly and the condition being studied can be assessed across periods. The registry says participants were to receive one week of methylphenidate and one week of placebo, but does not report how the order was randomized or how allocation was generated or concealed.
A crossover comparison requires attention to time and sequence. A participant’s measurement in the second period may be affected by the first period, the passage of time, or both. A washout interval can sometimes be used to reduce lingering treatment effects, but whether one was planned or implemented is not reported in the registry record. The statistical plan for period effects, sequence effects, and carryover is also not reported. These are general considerations for interpreting crossover trials, not evidence that a particular problem occurred in this study.
What does double masking mean?
Double masking generally means that participants and relevant study personnel do not know which treatment is being administered during a period. Masking can reduce the influence of treatment expectations on behavior, reporting, and assessment. The registry labels the study double-blind and states that the treatment periods were to be conducted in a double-blind fashion. It does not identify which roles were masked, explain how the placebo was matched to the active medication, or report whether masking was assessed. No claim about the success of masking can be made from the record.
How should the endpoint be understood?
The primary outcome concerns neuropsychological test performance during Week 1 and Week 2. It names TOVA, a computerized attention test, and the working memory index of the WisSC IV. The registry states that higher standard scores indicate better performance and defines scores at or below 1 SD lower than the mean as an area of deficit. General interpretation of a standardized score depends on the measure’s scoring and reference framework. The registry record does not describe a combined score, a hierarchy among the named measures, or the statistical model for comparing scores across periods.
What can a confidence interval or p-value tell a reader?
In general, a confidence interval expresses the uncertainty around an estimated effect under the assumptions of the analysis. A narrower interval indicates greater precision than a wider interval, while the interval’s location helps show which effect sizes are compatible with the data and method. A p-value, in general, measures how unusual the observed data would be under a specified null hypothesis and statistical model; it is not the probability that the null hypothesis is true. Neither measure substitutes for the estimated effect or its clinical interpretation. The registry record reports no analysis, so it gives no effect estimate, confidence interval, or p-value for the primary outcome.
Why does over-dispersion matter in general?
Over-dispersion occurs when variability in the data is greater than a statistical model assumes. If it is ignored, standard errors and inferential conclusions can be unreliable. The appropriate model depends on the outcome type and the distribution of observed data. The primary outcome is described as test performance, but no outcome values or analysis model are reported; there is no basis for asserting that over-dispersion occurred or that a particular method was needed.
What do the planning assumptions mean?
The registry describes a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says that the effect to detect is expressed as a stated fraction of the observed effect, and distinguishes participant-per-arm planning for non-time-to-event outcomes from total-event planning for time-to-event outcomes. These are assumptions for planning illustrations, not descriptions of observed trial results. The registry record does not report a completed treatment comparison from which an observed effect can be interpreted. Any sample-size illustration should therefore be read as a planning exercise, not as evidence about efficacy, actual precision, or observed power.
Because no patients received treatment and no analysis was done, none of the usual statistical outputs can resolve the treatment question in this record. The trial’s randomized and masked design labels describe the intended study structure; they do not, by themselves, produce an estimate or guarantee that the planned comparison was completed.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary outcome based on neuropsychological testing, naming both TOVA and the working memory index of the WisSC IV. It also lists a secondary outcome concerning changes in parent and teacher ratings of attention, executive functioning, and behavior. Considering multiple outcomes or multiple measures can create multiplicity: when many statistical comparisons are made, the chance of at least one apparently notable finding can increase. General approaches include prespecifying a primary comparison, adjusting the interpretation or testing procedure, or treating additional analyses as exploratory. The registry record does not report a multiplicity strategy or a hierarchy for the named measures and ratings.
The analysis plan, including the statistical model, covariates, handling of the crossover periods, and rules for interpreting test scores, is not reported in the registry record. The record lists no analyses and says that analysis of the primary outcome was not done because no patients received treatment. Accordingly, there are no reported inferential results to assess for multiplicity or to distinguish as prespecified versus exploratory.
Missing-data methods are not reported in the registry record. The record does not explain whether any outcome measurements were collected, whether any were incomplete, or how incomplete measurements would have been handled. The statement that no patients received treatment does not, on its own, describe the status of every planned measurement or establish a missing-data mechanism.
The analysis populations are also not defined in the registry record. It does not say whether the intended analysis was based on randomized participants, participants who received both treatments, or another population. In crossover studies, conclusions may depend on whether participants contribute data from both periods and how incomplete period pairs are treated. No such analysis is reported. These absences limit assessment of the planned statistical approach; they are not evidence that a particular method was or was not used outside the registry record.
11. What the Result Does, and Does Not, Mean
The registry record documents a research question about methylphenidate and neuropsychological functioning in children with attention deficits associated with childhood cancer. It describes a randomized, double-blind crossover plan involving one week of methylphenidate and one week of placebo, and identifies attention and working-memory testing as the primary outcome. Those details explain what the study was intended to investigate.
The record does not document a treatment effect. It states that no patients received treatment and that the primary analysis was not done. It lists no analyses, and it contains no outcome scores or comparison between treatment periods. Therefore, the posted results do not show whether performance was better, worse, or unchanged during either period, and they do not quantify the precision of a treatment comparison.
The enrollment entry of 1 should not be interpreted as one completed participant with outcome data. Enrollment is listed, but the primary-outcome entry says no patients received treatment. The record does not explain this distinction further. It also does not report why the study was terminated, so the termination cannot be attributed to any particular scientific or operational reason.
The adverse-event listing shows zero participants at risk and zero affected, alongside the statement that no patients received treatment. Those entries do not provide an informative assessment of adverse events during study-drug exposure. They cannot establish either the presence or absence of risk.
In general, a planned randomized comparison and a completed, analyzed comparison are different kinds of evidence. Design labels describe how a study was intended to limit bias; they do not replace observed data. Here, the registry supports a description of the intended design and endpoint, but not a conclusion about treatment benefit, lack of benefit, safety, or the size of any effect. Such conclusions are not reported in the registry record.
12. Why This Trial Matters Statistically
This record illustrates why trial design and trial results need to be read separately. Randomization, double masking, and a crossover structure describe a plan for comparing treatments. They do not establish that participants received the assigned treatments or that usable outcome data were collected. The registry lists enrollment of 1, while also stating that no patients received treatment and that the primary analysis was not done. That distinction matters when interpreting any planned comparison.
The crossover model is statistically relevant because it is intended to compare treatment periods within participants. In general, that can help account for stable differences between participants, but it also makes the treatment sequence, period effects, and possible carryover important to the analysis. Those details are not reported in the registry record. Without treatment exposure and an analysis, the conceptual advantages and assumptions of the design cannot be evaluated using results.
The endpoint also makes the record useful for understanding the intended measurement strategy. It names a computerized attention test and a working-memory index, with parent and teacher ratings as a secondary outcome. This distinguishes neuropsychological test performance from reported attention, behavior, and executive functioning. The registry does not provide results for either kind of assessment, so their relationship cannot be examined.
Finally, the record shows why non-results should not be converted into evidence of no effect. No completed comparison means the direction, magnitude, and precision of an effect are unknown from the registry. The listed status is TERMINATED, but the reason is not reported. Statistically, the most defensible reading is that the intended question is identifiable while its treatment effect remains unanswered by the posted results.
13. 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 most consequential limitation is that the registry record says no patients received treatment and that the primary analysis was not done. Although enrollment is listed as 1, the record does not report treated participants, completed treatment periods, or primary outcome measurements. No treatment-effect estimate or uncertainty measure is available.
The record’s termination status is not accompanied by a reason. It is therefore not possible to determine from the registry whether termination related to recruitment, feasibility, funding, safety, or another factor. Such explanations should not be inferred. The relationship between listed enrollment and the absence of treatment is also not explained.
Several design details that would matter for evaluating a completed crossover comparison are not reported in the registry record. These include treatment sequence, washout arrangements, period and carryover handling, adherence, and how missing period data would be handled. The record does not provide the statistical analysis plan, the analysis population, or a method for addressing multiple named measures and outcomes.
Outcome descriptions identify TOVA, the working memory index of the WisSC IV, and parent and teacher ratings, but do not provide observed scores, scoring procedures beyond the stated standard-score interpretation, or results for the secondary outcome. The adverse-event listing has zero participants at risk and does not support a safety assessment in the absence of treatment exposure. Together, these gaps mean the registry record can describe the intended research but cannot establish a comparative effectiveness or safety result.
14. Related Tutorials
15. Related Statistical Calculators
16. Sources
- ClinicalTrials.gov: Effects of Methylphenidate on Attention Deficits in Childhood Cancer Survivors — NCT01100658.
- Registry record last updated 2015-03-27; status last verified 2015-03.
- Results first posted 2011-11-22.
- 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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17. Record Summary
The registry record describes a randomized, double-blind crossover study of methylphenidate and placebo for attention-related neuropsychological functioning in children with attention deficits associated with childhood cancer. The plan called for one week of each treatment. Primary assessments were described as TOVA and the working memory index of the WisSC IV during Week 1 and Week 2; a secondary outcome concerned parent and teacher ratings.
The record lists enrollment of 1, a start in 2010-05, primary completion in 2010-11, and status TERMINATED. It states that no patients received treatment and that primary analysis was not done. No analyses or comparative outcome results are reported, and the reason for termination is not reported in the registry record.