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 Pilot Study of Vyvanse™ In ADHD Adolescents at Risk for Substance Abuse (NCT00573534), a na phase 4 study. The primary outcome is Number of Participants With at Least 70% Reduction in ADHD Symptoms as Measured by Change in ADHD Rating Scale From First to Last Visit.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00573534 |
| Phase | Phase 4 |
| Condition | Attention Deficit Hyperactivity Disorder |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 8 |
| Arms in the primary outcome | n/a |
| Lead sponsor | New York State Psychiatric Institute |
| Results posted | Yes |
2. Clinical Question
Population
Adolescents ages 11-15 with attention deficit hyperactivity disorder (ADHD) and an older sibling with substance dependence. The official title describes this family history; the brief summary refers to young people with an older sibling with substance abuse. The study enrolled 8 participants.
Intervention
Open-label Vyvanse, also identified as lisdexamfetamine dimesylate. The arm description states doses of 30-70 mgs over 8 weeks.
Comparator
There was no separate comparison group. The registry describes a single-group study with allocation listed as NA, so participants were not assigned between treatment arms for a like-for-like comparison.
Primary question
How many participants had at least 70% reduction in ADHD symptoms, measured by change in ADHD Rating Scale from the first to the last visit? The registry gives the primary outcome timeframe as up to 24 weeks but does not report the result.
The study was framed as an open-label pilot and feasibility study. Its stated aim was to learn about studying young adolescents with ADHD who may be at risk of substance abuse, in part because of ADHD and a family history of substance abuse. It also aimed to study treatment in this group before participants developed substance abuse. These aims are distinct from establishing a comparative treatment effect: without a separate control group, the record cannot show how the observed course would compare with an untreated group or another treatment.
The primary outcome focuses on a threshold reduction in symptoms rather than a reported average change for the group. The record defines the threshold as a 70% reduction from baseline on the ADHD Rating Scale. It also lists substance-use outcomes based on a confidential clinician-administered Timeline Follow Back and urine toxicology. Results for those secondary outcomes are not reported in the registry record. Thus, the record sets out the questions the pilot intended to explore, but does not give the outcome findings needed to answer them.
3. Trial Design
This was a Phase 4, completed, open-label pilot study sponsored by New York State Psychiatric Institute. The registry lists a single-group model, no masking, and allocation as NA. Enrollment was 8. The study began in 2008-03 and its primary completion was 2010-01. The stated status is completed.
All participants were in the open-label Vyvanse arm. Its description specifies lisdexamphetamine at doses of 30-70 mgs over 8 weeks, in younger siblings of older siblings with substance abuse and a history of treatment for ADHD. Because there was no separate control arm, the design does not provide a randomized comparison. Any change from baseline during follow-up could reflect the intervention, the course of symptoms over time, measurement variability, or other influences; a one-group record cannot separate those explanations.
The primary outcome is a participant count for a clinically meaningful reduction in ADHD symptoms. The registry states that this is a 70% reduction from baseline on the ADHD Rating Scale, assessed from the first to the last visit, with a timeframe of up to 24 weeks. It says the final outcome used Last Observation Carried Forward. The record does not explain the relationship between the 8-week treatment duration and the primary outcome timeframe of up to 24 weeks.
The listed secondary outcome concerns the number of participants with low or no substance use during the study versus intermittent use, judged by Timeline Follow Back and urine toxicology. The record lists 2 outcome measures, but reports no analyses. Detailed eligibility criteria, a statistical analysis plan, sample-size justification, and interim-analysis procedures are not reported in the registry record. The stated feasibility purpose is relevant to interpretation: this was a small pilot, not a randomized trial designed to provide a controlled estimate of treatment effect.
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: This was an open-label study, hence no group assignment. Thirteen families were offered study participation, 8 accepted. The five families that declined participation cited the impracticality of weekly visits and/or the adolescent's oppositional behavior as primary reasons for nonparticipation.
Overall Study
| Stage | Group 1 |
|---|---|
| STARTED | 8 |
| COMPLETED | 5 |
| NOT COMPLETED | 3 |
Reasons for not completing this period:
| Reason | Group 1 |
|---|---|
| oppositional behavior | 3 |
Analysis population for the primary outcome, as defined in the registry: All patients who agreed to participate. Last Observation Carried Forward was used final outcome.
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 | Group 1 |
|---|---|---|
| Participants analysed | 8 | |
| Age, Categorical: <=18 years | Participants | 8 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 |
| Age, Categorical: >=65 years | Participants | 0 |
| Age, Continuous | years | 14.2 (SD 2) |
| Gender: Female | Participants | 1 |
| Gender: Male | Participants | 7 |
| Region of Enrollment: United States | participants | 8 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With at Least 70% Reduction in ADHD Symptoms as Measured by Change in ADHD Rating Scale From First to Last Visit, measured over up to 24 weeks.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint counts participants who achieved at least 70% reduction in ADHD symptoms, using change in the ADHD Rating Scale from the first to the last visit. The registry defines the reduction relative to baseline and describes the outcome as a clinically meaningful reduction. The scale rates symptoms from 0-3, where 0 means never present, 1 sometimes, 2 often present, and 3 very often present. For this study, clinicians administered the scale using both parent and adolescent input to reach a consensus score, or a clinician's best estimate if consensus could not be achieved.
A threshold-based count can make an outcome easier to interpret in terms of how many participants crossed a prespecified symptom-reduction benchmark. It does not, by itself, show the distribution of individual changes or the average change in the group. Participants just above and just below the threshold are counted differently even if their measured changes are close. General statistical context: a threshold outcome can therefore discard information contained in the underlying scale values.
The registry identifies the primary outcome timeframe as up to 24 weeks and says Last Observation Carried Forward was used for the final outcome. However, it does not report how many participants met the threshold. The endpoint definition is available, but its observed result is not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record gives the design, the primary endpoint definition, and enrollment, but it does not report the primary endpoint count. It therefore does not establish how many participants achieved at least 70% reduction in ADHD symptoms. The record also does not provide a reported estimate of change in ADHD Rating Scale, an uncertainty interval, or a statistical test for this endpoint. No effect estimate or precision assessment can be described from the registry results available in the record.
The study's single-group, open-label design is central to interpretation. It can describe outcomes among participants who received the study intervention, if those outcomes are reported, but it cannot create a controlled comparison with usual care, another treatment, or no treatment. A before-and-after change would not by itself establish that the intervention caused the change. General statistical context: a concurrent control group helps distinguish an intervention-related difference from changes that could occur over time or from influences shared by participants and their setting.
The enrollment of 8 indicates that the pilot was small. Small studies generally yield imprecise estimates, and estimates can be sensitive to the outcomes of individual participants. That general consideration is especially important for a binary endpoint, which classifies each participant as either meeting or not meeting a threshold. Here, the record does not report the number meeting the threshold, so neither the observed count nor its uncertainty can be characterized.
The primary endpoint uses a 70% reduction threshold, while the scale itself is described as a clinician-administered measure drawing on parent and adolescent input. The record notes consensus scoring or a clinician's best estimate when consensus could not be achieved. It does not report how often consensus was reached, how scoring consistency was assessed, or whether assessors were masked. Masking is listed as none, so expectations may have influenced reporting or assessment; this is a design consideration, not evidence that bias occurred.
Substance use was a stated area of interest, with the secondary outcome assessed through Timeline Follow Back and urine toxicology. The corresponding results are not reported in the registry record. The listed safety figures show 0 serious adverse events among 8 at risk and 0 other adverse events among 8 at risk in Group 1. These are descriptive registry entries, not evidence that risk is absent. Deaths are not reported in the registry record.
Overall, the record documents a feasibility-oriented pilot question and its measurement approach, but it does not report efficacy or substance-use outcome findings. The posted information cannot support a conclusion about symptom changes, substance-use patterns, or comparative effects.
9. Statistical Methods Explained
What does a single-group design establish?
The registry identifies this as a single-group study with no masking and no allocation between arms. Participants received open-label Vyvanse; there was no separate control group. General statistical context: a one-group study can describe the participants' outcomes over time, but any observed change combines possible treatment effects with other influences, including natural fluctuation, changes in circumstances, measurement variation, and expectations. A control group offers a contemporaneous comparison that can help distinguish these influences. This record does not provide such a comparison, so a causal treatment contrast is not available.
Open-label means the study was not masked. The record lists masking as none. General context: when participants and assessors know the treatment being given, expectations may affect symptom reports, clinical ratings, or other observations. This possibility matters for a clinician-administered symptom scale that incorporates parent and adolescent input. It does not demonstrate that ratings were biased, and the registry does not report procedures to assess or reduce that possibility.
How should the threshold endpoint be read?
The primary outcome is a count of participants with at least 70% reduction in ADHD symptoms from baseline, measured using change in ADHD Rating Scale from the first to the last visit. A count endpoint asks how many participants crossed a defined threshold, rather than reporting each participant's exact scale change. General statistical context: binary outcomes are straightforward to describe as event counts, but they preserve less detail than the underlying continuous measurements. The registry does not report the count, so no outcome proportion or uncertainty interval can be interpreted.
The scale is described as ranging from 0-3, with categories from never present to very often present. Ratings were clinician administered and used parent and adolescent input to reach consensus, or a clinician's best estimate when consensus could not be achieved. The record does not report an average scale change, variability, or measurement reliability. Those details would help readers understand the distribution and consistency of symptom ratings, but they are not reported in the registry record.
What does uncertainty mean?
General statistical context: an estimate summarizes what was observed in a study, while a confidence interval expresses the range of values reasonably compatible with the data under the method's assumptions. A narrow interval indicates greater precision than a wide interval. A small study can have substantial uncertainty because relatively few participant outcomes contribute to the estimate. Here, the registry does not report the primary count or an interval, so precision cannot be evaluated. No hypothesis test or p-value for the primary outcome is reported in the registry record.
When a study has no comparator, an interval around a one-group outcome would describe uncertainty about that group's outcome, not uncertainty about a treatment-versus-control difference. General statistical context: precision and causal interpretation are separate issues. Even a precisely estimated single-group outcome does not remove confounding by time or other influences, and a comparative effect cannot be estimated without a relevant comparison.
How should the planning illustration be interpreted?
The registry record includes assumptions for a planning illustration based on the observed effect: a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It states that the effect to detect is a stated fraction of the observed effect. It also distinguishes total events for time-to-event illustrations from participants per arm for other outcomes. These are planning assumptions, not a description of this pilot's single-group design. General statistical context: sample-size planning asks how many participants a future study might need under specified assumptions. It does not indicate the chance that this completed study found a true effect, and it is not observed power. The record does not report a trial-specific design justification, and the assumptions do not turn this study into a randomized comparison.
Over-dispersion is a general concern when count data vary more than a chosen statistical model expects. In that circumstance, standard errors based on the simpler model may understate uncertainty. It is not possible to assess over-dispersion for this trial from the registry record: the primary endpoint is a participant count, its observed value is not reported, and no count-model analysis is listed. This is a general methodological point, not a claim that over-dispersion occurred in this study.
What can be inferred from the listed analyses?
The registry lists 0 analyses. This means no analyses are listed in the record; it does not establish what analyses may have been conducted outside the registry. The primary endpoint definition is present, but no result, model, test, or estimate is reported. The secondary substance-use outcome is also described without results. Consequently, statistical interpretation must stay at the level of design and measurement rather than infer findings that are not posted.
10. Multiplicity, Missing Data and Analysis Populations
The record lists 2 outcome measures: the primary symptom-reduction count and a secondary substance-use outcome. It lists 0 analyses. The registry does not provide an analysis plan describing how outcomes were prioritized analytically, whether multiple comparisons were planned, or whether any adjustment for multiplicity was intended. Such procedures are not reported in the registry record. Without reported estimates or tests, it is not possible to assess the effect of multiple testing on statistical conclusions.
The primary outcome population is described as all patients who agreed to participate, with Last Observation Carried Forward used for the final outcome. The record does not report how many participants had missing endpoint assessments, the reasons for missingness, or the timing and amount of missing data. It also does not report sensitivity analyses evaluating the effect of the imputation approach. Therefore, the impact of missing observations on the primary result cannot be assessed.
General statistical context: Last Observation Carried Forward uses a participant's last recorded value as the final value when a later observation is missing. This approach can make an assumption that the last observation remains a reasonable representation of the later outcome. Whether that assumption is appropriate depends on why data are missing and how outcomes change over time. The registry does not report information that would permit evaluation of that assumption in this study.
The registry does not describe other analysis populations, such as a population defined by treatment received or by protocol adherence. The stated primary population is all patients who agreed to participate. No additional population definitions or analysis details are reported in the registry record.
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 |
|---|---|---|---|
| Group 1 | 0 | 8 | 0.0% |
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 |
|---|---|
| Group 1 | 0 of 8 |
The registry lists Group 1 with 8 participants at risk for serious adverse events and 0 participants affected. It also lists 8 at risk for other adverse events and 0 affected. These are the posted counts for the group. The deaths field is not reported in the registry record. No serious adverse-event terms are listed.
These figures should be read as descriptive safety entries, not as proof that serious or other adverse events could not occur. General statistical context: when a study includes few participants, an absence of reported events does not rule out events that are uncommon or that might appear in a larger group or with longer observation. A registry count also does not, on its own, describe event severity, timing, duration, or how events were assessed.
The registry does not provide additional safety details such as event-specific narratives or a comparison group. Because this was a single-group study, the listed counts cannot be compared with safety counts under another treatment or under no study intervention. The figures therefore describe what the record reports for this group and do not establish comparative safety.
12. What the Result Does, and Does Not, Mean
The record describes a completed, open-label pilot of Vyvanse in 8 adolescents with ADHD and an older sibling with substance dependence. It defines a primary symptom endpoint based on a 70% reduction from baseline and describes a secondary outcome for substance use. It also provides limited safety counts. Those details show what the study set out to measure and how the primary outcome was defined.
The record does not report the primary endpoint count, symptom-scale results, or secondary substance-use results. It therefore does not establish whether participants met the symptom-reduction threshold or what substance-use patterns were observed. No comparative effect estimate, confidence interval, or statistical test is reported. The absence of posted results should not be interpreted as evidence of either benefit or lack of benefit.
The design also limits what any reported before-and-after change could mean. With one open-label group and no control arm, changes during follow-up could not be separated from changes that might have occurred for other reasons. General statistical context: a result can be informative about feasibility and about outcomes in the enrolled group while remaining insufficient to establish a causal treatment effect.
The safety listing records 0 serious adverse events and 0 other adverse events among 8 at risk. These counts do not establish that no risk exists, especially in a small pilot, and the record does not provide event details or a comparator. The death count is not reported in the registry record.
The appropriate reading is therefore narrow: this registry entry documents a feasibility-oriented study and its planned outcome definitions, but the posted results do not provide the outcome findings required to judge symptom change, substance use, or comparative safety.
13. Why This Trial Matters Statistically
This trial is statistically notable for the gap between a clearly defined clinical question and the limited results reported in the registry. The primary endpoint specifies a threshold for symptom reduction and identifies the measurement instrument, timeframe, and analysis population. Those elements help readers understand what the study intended to count. Yet the actual number of participants meeting the threshold is not reported in the registry record, so the main outcome cannot be interpreted from the posted results.
The pilot's feasibility purpose also matters. A study in 8 adolescents can help describe the study approach and its measurement plan, but a small single-group study is not a substitute for a controlled comparison. General statistical context: pilot studies often address whether a larger investigation can be carried out, while estimates from small samples can be imprecise and sensitive to individual observations. The registry does not report a specific feasibility result or a trial-specific sample-size justification.
The population is defined by both ADHD and an older sibling with substance dependence, and the listed secondary outcome concerns substance use. That focus makes clear why the study measured both symptoms and substance use. However, the registry does not report the secondary outcome findings, so it is not possible to assess whether the planned measurement approach generated interpretable results.
Finally, the record illustrates why outcome definitions, results, and design must be read together. A threshold endpoint can be clearly specified without an available result; a count of events can be reported without supporting a broad safety conclusion; and a planning illustration does not provide evidence of observed treatment effect. Here, the registry supports careful description of the study's methods and limits, but not conclusions about the intervention's effects.
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 most direct limitation for interpretation is that the registry record does not report the primary endpoint result. It also does not report the results for the secondary substance-use outcome. This prevents assessment of the study's observed symptom or substance-use findings, regardless of the endpoint definitions.
The study enrolled 8 participants and used a single-group, open-label design. It had no like-for-like control comparison, so the design cannot isolate an intervention effect from other influences over time. The absence of masking may also matter for clinician-administered ratings that incorporate parent and adolescent input, although the record does not establish that any ratings were biased.
The endpoint is a threshold count based on a 70% reduction. The registry does not report the underlying ADHD Rating Scale changes, their distribution, or how many participants were near the threshold. It also does not report information about agreement between parent and adolescent ratings, frequency of consensus, or consistency of clinician scoring.
Last Observation Carried Forward is stated for the primary outcome, but the record does not report missing-data amounts, reasons, or sensitivity analyses. The primary outcome timeframe is listed as up to 24 weeks, whereas the intervention description specifies 8 weeks; the record does not explain how these periods relate. The registry also does not report a statistical analysis plan, sample-size justification, interim analyses, or analyses of the listed outcomes. These limitations leave the result, its uncertainty, and the handling of incomplete data unclear.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Pilot Study of Vyvanse™ In ADHD Adolescents at Risk for Substance Abuse — NCT00573534.
- Registry record last updated 2017-02-20; status last verified 2016-12.
- Results first posted 2011-11-29.
- 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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18. Record Summary
NCT00573534 is a completed Phase 4, open-label, single-group pilot sponsored by New York State Psychiatric Institute. Enrollment was 8, with a study start of 2008-03 and primary completion in 2010-01. The population was adolescents ages 11-15 with ADHD and an older sibling with substance dependence. The intervention was Vyvanse (lisdexamfetamine), with the arm description stating doses of 30-70 mgs over 8 weeks.
The primary outcome counted participants with at least 70% reduction in ADHD symptoms on the ADHD Rating Scale, with a timeframe of up to 24 weeks. The record states that Last Observation Carried Forward was used for the final outcome. A secondary outcome concerned substance-use status assessed with Timeline Follow Back and urine toxicology. The primary and secondary results are not reported in the registry record, and no analyses are listed.
The safety listing reports 0 serious adverse events and 0 other adverse events among 8 at risk in Group 1. Deaths are not reported in the registry record. The single-group design provides no randomized control comparison, and the posted information does not establish a comparative treatment effect.