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 A Study to Test the Safety and Efficacy of MK0249 in Patients With ADHD (0249-018)(COMPLETED) (NCT00475735), a randomized phase 2 study. The primary outcome is Mean Change From Baseline in the Adult Attention Deficit Hyperactivity Disorder Investigator Symptom Rating Scale (AISRS) Total Score After 4 Weeks of Treatment.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00475735 |
| Phase | Phase 2 |
| Condition | Attention-Deficit/Hyperactivity Disorder (ADHD) |
| Allocation | Randomized |
| Design model | Crossover |
| Masking | Double |
| Enrollment | 72 |
| Arms in the primary outcome | 3 |
| Lead sponsor | Merck Sharp & Dohme LLC |
| Results posted | Yes |
2. Clinical Question
Population
Adults ages 18 to 55 with attention deficit hyperactivity disorder (ADHD) were eligible for the trial. The registry reports enrollment of 72 participants. The primary analysis population was the Full Analysis Set, which included randomized patients who received at least one dose of study medication and had at least one assessment at baseline or after randomization.
Intervention
The study evaluated MK-0249, 10 mg, as an investigational treatment. The registry also lists Concerta (methylphenidate) and placebo among the interventions. The comparison of interest for MK-0249 was against placebo, with Concerta providing another active-treatment comparison against placebo.
Comparator
Placebo was the control. The trial was randomized, double-blind, and described as an incomplete-block, two-period crossover study. The registry lists distinct treatment arms and reports participant counts for each primary-outcome group, but does not report the treatment sequences or the detailed allocation of participants across crossover periods.
Primary question
The primary question concerned mean change from baseline in AISRS total score after 4 weeks of treatment. The scale measures ADHD symptoms, with higher scores corresponding to worse severity. The registry reports least-squares mean changes and 95% confidence intervals for MK-0249, Concerta, and placebo, along with mixed-model p-values for the two comparisons against placebo.
The key interpretive distinction is between the change estimated within each treatment group and the model-based comparison between groups. The posted group estimates describe score changes from baseline; by themselves, they do not establish how much change is attributable to a treatment relative to placebo. The reported mixed-model analyses address the between-group questions, but the registry does not provide their estimated contrasts or confidence intervals.
3. Trial Design
This was a Phase IIa, randomized, double-blind, placebo-controlled, incomplete-block, two-period crossover clinical trial of MK-0249, 10 mg, in adult patients ages 18 to 55 with ADHD. The registry identifies Merck Sharp & Dohme LLC as the sponsor and reports the study as completed. Enrollment was 72.
A crossover design assigns treatment across periods so that participants can contribute observations under more than one treatment condition, subject to the study’s allocation scheme. The incomplete-block description indicates that the design did not give every participant the full set of treatments. The registry record does not report the treatment sequences, the period-specific participant counts, or details about how carryover or period effects were handled. Those details matter when interpreting a crossover analysis because observed scores can reflect both treatment and features of the period or sequence.
The registry lists MK-0249, Concerta, and placebo. It reports primary-outcome analysis counts of 29 for MK-0249, 39 for Concerta, and 48 for placebo. These counts are not the same as the total enrollment and should be understood as the counts attached to the posted outcome results, rather than as a complete account of randomization or crossover exposure.
The primary outcome was change in AISRS total score after 4 weeks of treatment. Other posted outcomes include inattentive and hyperactive/impulsive symptom scores, responder and clinical-impression measures, and an observer rating scale. The registry record does not report a sample-size justification, detailed randomization procedures, masking procedures beyond double masking, or the planned statistical analysis document. Each of these points limits how completely the design can be reconstructed from the 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: Pre-Treatment consisted of 2 visits: Screening Visit1 \& Baseline Randomization Visit2. Patients continuing after Visit1 entered a 1-wk placebo Run-in period. At Visit2, patients were assessed using the protocol eligibility criteria. Then, if deemed eligible, patients were randomized at Visit2 to one of six 2-period cross-over treatment sequences.
Treatment Period 1
| Stage | MK-0249 Then Placebo | Placebo Then MK-0249 | MK-0249 Then Concerta | Concerta Then MK-0249 | Concerta Then Placebo | Placebo Then Concerta |
|---|---|---|---|---|---|---|
| STARTED | 14 | 13 | 7 | 7 | 16 | 15 |
| COMPLETED | 10 | 11 | 7 | 5 | 14 | 12 |
| NOT COMPLETED | 4 | 2 | 0 | 2 | 2 | 3 |
Reasons for not completing this period:
| Reason | MK-0249 Then Placebo | Placebo Then MK-0249 | MK-0249 Then Concerta | Concerta Then MK-0249 | Concerta Then Placebo | Placebo Then Concerta |
|---|---|---|---|---|---|---|
| Adverse Event | 2 | 0 | 0 | 0 | 0 | 0 |
| Lack of Efficacy | 1 | 0 | 0 | 0 | 0 | 0 |
| Lost to Follow-up | 0 | 0 | 0 | 0 | 0 | 1 |
| Protocol Violation | 0 | 0 | 0 | 1 | 0 | 0 |
| Withdrawal by Subject | 1 | 1 | 0 | 0 | 0 | 0 |
| DC due to AE but continuing | 0 | 0 | 0 | 1 | 2 | 2 |
| DC due to no efficacy but Continuing | 0 | 1 | 0 | 0 | 0 | 0 |
Treatment Washout
| Stage | MK-0249 Then Placebo | Placebo Then MK-0249 | MK-0249 Then Concerta | Concerta Then MK-0249 | Concerta Then Placebo | Placebo Then Concerta |
|---|---|---|---|---|---|---|
| STARTED | 10 | 12 | 7 | 6 | 16 | 14 |
| COMPLETED | 10 | 10 | 7 | 6 | 16 | 14 |
| NOT COMPLETED | 0 | 2 | 0 | 0 | 0 | 0 |
Reasons for not completing this period:
| Reason | MK-0249 Then Placebo | Placebo Then MK-0249 | MK-0249 Then Concerta | Concerta Then MK-0249 | Concerta Then Placebo | Placebo Then Concerta |
|---|---|---|---|---|---|---|
| Lost to Follow-up | 0 | 1 | 0 | 0 | 0 | 0 |
| Protocol Violation | 0 | 1 | 0 | 0 | 0 | 0 |
Treatment Period 2
| Stage | MK-0249 Then Placebo | Placebo Then MK-0249 | MK-0249 Then Concerta | Concerta Then MK-0249 | Concerta Then Placebo | Placebo Then Concerta |
|---|---|---|---|---|---|---|
| STARTED | 10 | 10 | 7 | 6 | 16 | 14 |
| COMPLETED | 10 | 9 | 7 | 4 | 15 | 13 |
| NOT COMPLETED | 0 | 1 | 0 | 2 | 1 | 1 |
Reasons for not completing this period:
| Reason | MK-0249 Then Placebo | Placebo Then MK-0249 | MK-0249 Then Concerta | Concerta Then MK-0249 | Concerta Then Placebo | Placebo Then Concerta |
|---|---|---|---|---|---|---|
| Adverse Event | 0 | 1 | 0 | 2 | 0 | 0 |
| Lack of Efficacy | 0 | 0 | 0 | 0 | 0 | 1 |
| Withdrawal by Subject | 0 | 0 | 0 | 0 | 1 | 0 |
Analysis population for the primary outcome, as defined in the registry: Full Analysis Set (FAS): The FAS included all randomized patients who received at least one dose of study medication. Patients with at least one assessment (baseline or post-randomization) were included in the FAS. Missing data were handled using the data as observed (DAO) approach.
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.
Only the first 6 of 7 groups are shown.
| Characteristic | Unit | MK-0249 Then Placebo | Placebo Then MK-0249 | MK-0249 Then Concerta | Concerta Then MK-0249 | Concerta Then Placebo | Placebo Then Concerta |
|---|---|---|---|---|---|---|---|
| Participants analysed | 14 | 13 | 7 | 7 | 16 | 15 | |
| Age, Continuous | years | 39.6 (SD 9.2) | 36.9 (SD 11.0) | 39.3 (SD 7.5) | 39.0 (SD 12.3) | 39.8 (SD 11.1) | 36.5 (SD 13.3) |
| Sex: Female, Male: Female | Participants | 6 | 4 | 2 | 5 | 3 | 7 |
| Sex: Female, Male: Male | Participants | 8 | 9 | 5 | 2 | 13 | 8 |
6. Primary Endpoint
The registry lists the primary outcome as Mean Change From Baseline in the Adult Attention Deficit Hyperactivity Disorder Investigator Symptom Rating Scale (AISRS) Total Score After 4 Weeks of Treatment, measured over after 4 weeks of treatment.
| Element | Registry entry |
|---|---|
| Result type | Least Squares Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | score on scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint was mean change from baseline in the Adult Attention Deficit Hyperactivity Disorder Investigator Symptom Rating Scale (AISRS) total score after 4 weeks of treatment. The AISRS total includes 18 items derived from the original ADHD Rating Scale and based on DSM-IV criteria for ADHD. Nine items address inattention, and nine address impulsivity and hyperactivity. Each item is rated from 0 to 3; the total score ranges from 0 to 54. A higher score corresponds to worse ADHD severity.
Change from baseline expresses how a participant’s score differs from the starting assessment. A negative change therefore represents a reduction in the score, while the clinical meaning of that change still depends on the comparison between treatment groups and the uncertainty around it. The registry reports least-squares mean changes rather than raw group means. Least-squares means are model-based estimates, so they can account for features of the analysis model; the registry does not provide enough model detail to identify all adjustments used.
The endpoint is used to quantify symptom severity in a structured way. It gives a continuous measure, retaining information across the scale rather than reducing the outcome to a responder/non-responder classification. A mean change is useful for summarizing average change, but it does not describe the range of individual responses, and it cannot by itself establish a clinically important difference. The registry record does not report a threshold for clinically meaningful change in AISRS total score.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The reported least-squares mean change was -9.8 for MK-0249, with a 95% confidence interval from -13.5 to -6.0, based on 29 participants. For Concerta, the reported change was -15.3, with a 95% confidence interval from -18.7 to -11.8, based on 39 participants. For placebo, the change was -7.6, with a 95% confidence interval from -10.5 to -4.7, based on 48 participants. Since higher AISRS scores indicate worse severity, the negative values describe decreases from baseline in each reported group.
The group estimates do not substitute for the direct treatment comparisons. The registry reports a mixed-model analysis comparing MK-0249 with placebo, with p = 0.341, and a mixed-model analysis comparing Concerta with placebo, with p = 0.001. These p-values concern the respective model-based comparisons, not whether each group’s change from baseline differs from zero. The registry does not report the estimated between-group differences or their confidence intervals, so the magnitude and precision of those contrasts cannot be read directly from the record.
The MK-0249 and placebo group confidence intervals overlap, while the reported comparison p-value is 0.341. That p-value does not provide evidence against the model’s null comparison at commonly used thresholds, but it does not prove that the treatments are equivalent or that any difference is exactly zero. The estimate and confidence interval for the contrast would be needed to describe the range of effects compatible with the data. Those contrast results are not reported in the registry record.
For Concerta versus placebo, the registry reports p = 0.001. This is evidence against the null comparison under the stated mixed-model analysis, but the record does not give the model-based contrast estimate or its confidence interval. The group changes alone should not be subtracted to create a treatment contrast: the trial used a crossover design, and the model may incorporate features not captured by a simple comparison of the posted group summaries.
These findings describe the registry’s posted primary outcome and analyses. They do not establish a broader conclusion about safety, efficacy, or patient benefit. Interpretation is limited by missing details about the crossover sequences, analysis model, multiplicity handling, and contrast estimates. Also, the number analyzed differs by treatment group, and the record does not explain the reasons for those differing counts. The results therefore warrant reading as model-based evidence for the specific registered comparisons, with important limitations in the detail available.
9. Statistical Methods Explained
The primary outcome is continuous: AISRS total score can take values across a score range, and the reported statistic is mean change from baseline. For a continuous outcome, a mean summarizes the center of the observed or estimated values, while a confidence interval describes uncertainty around an estimate. General explanation: a 95% confidence interval is a method for expressing the precision of an estimate under its statistical assumptions. It is not a range containing 95% of individual participants’ scores, nor does it by itself state the probability that a particular treatment effect is true.
The posted arm results are least-squares mean changes, with 95% confidence intervals. These are model-based summaries. General explanation: least-squares means are estimates obtained from a statistical model and may differ from unadjusted averages, depending on the model and the data structure. The registry record does not report the model’s complete specification, covariates, covariance structure, or assumptions. Consequently, the posted least-squares means should be read as the sponsor’s reported estimates, not as raw averages that can be fully reconstructed from the record.
The comparisons are identified as mixed-model analyses. General explanation: mixed models can account for correlated observations, such as repeated measurements from the same participant, and can represent sources of variation associated with study design. In a crossover trial, repeated observations and treatment periods can be related within a participant, making a model that reflects those dependencies important. The registry record does not describe which correlation structure or period terms were used, or whether sequence, carryover, or other design features were included. It is therefore not possible to assess those modeling choices from the posted description alone.
The p-values of 0.341 for MK-0249 versus placebo and 0.001 for Concerta versus placebo are attached to those mixed-model comparisons. General explanation: a p-value measures how incompatible the observed data are with a specified null hypothesis under the analysis assumptions. It is not the probability that the null hypothesis is true, and it does not measure the size or clinical importance of an effect. The absence of a reported contrast estimate and confidence interval means that the size and precision of each model-based comparison cannot be fully assessed using the registry record.
Confidence intervals for the individual treatment-group changes do not serve as confidence intervals for treatment contrasts. The contrast compares two treatment conditions and has its own estimate and uncertainty. Comparing whether separate group intervals overlap is not a substitute for analyzing the direct contrast, especially in a crossover study where observations may be paired or otherwise correlated. General explanation: the covariance between two estimates affects the uncertainty of their difference. The registry’s mixed-model p-values are direct comparison results, but the corresponding estimates and intervals are not reported in the registry record.
General explanation: over-dispersion occurs when the variability in the data is greater than a model assumes. It can make standard errors and resulting confidence intervals or tests unreliable if the model does not account for it. This is not a claim that over-dispersion occurred in this trial; the registry record does not report a diagnostic assessment of dispersion. Because the primary endpoint is continuous and model-based, relevant checks would include whether the model’s assumptions reasonably fit the score changes and repeated observations. Such checks are not reported.
The record says that missing data were handled using a data-as-observed approach. General explanation: this approach uses measurements that were observed rather than replacing missing values with modeled or imputed values. The record does not specify how many measurements were missing, why they were missing, or whether the likelihood of missingness differed across treatment or period. The implications depend on those circumstances, so the data-as-observed description alone is not enough to establish that missingness had no effect on the results.
The record also includes a planning illustration based on the observed effect, using a two-sided significance level of 0.05, equal allocation, and a normal approximation. Such calculations are planning illustrations rather than observed power, and they do not establish that the trial was designed with those assumptions. General explanation: sample-size calculations depend on assumptions about the effect to detect, variability, allocation, and statistical error rates. The trial’s own sample-size justification is not reported in the registry record. No conclusion about the trial’s design adequacy should be drawn from a planning illustration alone.
10. Analyses Reported by the Sponsor
| Method | Estimate | 95% CI | P-value |
|---|---|---|---|
| Mixed Models Analysis | not reported | 0.341 | |
| Mixed Models Analysis | not reported | 0.001 |
The registry reports the sponsor’s primary comparisons as mixed-model analyses: MK-0249 versus placebo has p = 0.341, and Concerta versus placebo has p = 0.001. It also reports the treatment-group least-squares mean changes and their 95% confidence intervals. These are distinct forms of information: the group estimates describe change from baseline, while the p-values relate to model-based comparisons between treatments.
A separate unadjusted recalculated contrast estimate is not reported in the registry record. The record also does not report contrast confidence intervals or enough model detail to reconstruct the sponsor’s mixed-model comparisons from the group summaries. The arm-level estimates should not be differenced to create a new comparison, particularly because the design was a crossover and observations may be related within participants and periods.
No discrepancy between a sponsor comparison and a recalculated comparison is indicated in the registry record. The sponsor’s mixed-model analyses are therefore the available direct comparison results. Their interpretation remains limited by the absence of reported contrast magnitudes, contrast intervals, and full model specifications. The p-values should be read as evidence about the stated model comparisons, not as estimates of the size of the treatment difference.
11. Multiplicity, Missing Data and Analysis Populations
The registry lists eight outcome measures overall and six posted secondary outcomes. The secondary measures include change in the inattentive and hyperactive/impulsive AISRS subscales, AISRS responder status, a clinical global impression improvement measure, observer-rated ADHD symptoms, and change in the clinical global severity measure. The primary endpoint is the AISRS total score after 4 weeks of treatment.
Testing multiple outcomes or comparisons can increase the chance of at least one result appearing noteworthy by chance. General explanation: multiplicity procedures can control that risk, but the choice depends on which outcomes and comparisons were planned and how they were prioritized. The registry record does not report a multiplicity adjustment or a hierarchy of hypotheses. The p-values should therefore be interpreted as the reported results for their individual comparisons, without assuming that family-wise error or another multiplicity criterion was controlled.
The record identifies a Full Analysis Set consisting of randomized patients who received at least one dose and had at least one assessment at baseline or after randomization. It states that missing data were handled using data as observed. This gives a broad description of the analysis population and missing-data approach, but does not identify the number with missing primary outcome measurements or explain the reasons for missingness.
The registry does not report a per-protocol analysis, a detailed intention-to-treat definition beyond the Full Analysis Set description, sensitivity analyses for missing data, or a detailed account of exclusions from each treatment comparison. The reported primary outcome counts are 29 for MK-0249, 39 for Concerta, and 48 for placebo. The differing counts call for caution when interpreting the available estimates; the registry record does not explain the differences. It also does not report whether interim analyses were conducted.
12. 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 |
|---|---|---|---|
| MK-0249 | 0 | 37 | 0.0% |
| Concerta | 0 | 44 | 0.0% |
| Placebo | 0 | 54 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 2% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| MK-0249 | 27 of 37 |
| Concerta | 33 of 44 |
| Placebo | 33 of 54 |
Most frequent non-serious adverse event terms
| Event term | Organ system | MK-0249 | Concerta | Placebo |
|---|---|---|---|---|
| Insomnia | Psychiatric disorders | 12 of 37 | 6 of 44 | 7 of 54 |
| Headache | Nervous system disorders | 3 of 37 | 4 of 44 | 8 of 54 |
| dry mouth | Gastrointestinal disorders | 1 of 37 | 10 of 44 | 1 of 54 |
| Blood pressure increased | Investigations | 3 of 37 | 3 of 44 | 3 of 54 |
| Decreased appetite | Metabolism and nutrition disorders | 3 of 37 | 4 of 44 | 2 of 54 |
| Anxiety | Psychiatric disorders | 0 of 37 | 7 of 44 | 1 of 54 |
| Pharyngolaryngeal pain | Respiratory, thoracic and mediastinal disorders | 3 of 37 | 3 of 44 | 2 of 54 |
| nausea | Gastrointestinal disorders | 3 of 37 | 2 of 44 | 2 of 54 |
| fatigue | General disorders | 0 of 37 | 4 of 44 | 3 of 54 |
| Increased appetite | Metabolism and nutrition disorders | 3 of 37 | 3 of 44 | 1 of 54 |
For serious adverse events, the registry reports zero affected participants among 37 at risk in the MK-0249 group, zero among 44 at risk in the Concerta group, and zero among 54 at risk in the placebo group. These are participant counts in the safety results. They do not mean that no adverse events of any kind occurred.
The registry separately reports other adverse events affecting 27 of 37 participants in the MK-0249 group, 33 of 44 in the Concerta group, and 33 of 54 in the placebo group. These counts concern a different category from serious adverse events. The record does not provide event-level descriptions or severity details for these other events in the listed results. The top serious-event terms list is empty, so no specific serious-event terms are posted there.
Deaths are not reported in the registry record. A blank death count should not be interpreted as a reported zero. The safety counts are descriptive and do not by themselves establish comparative risk; interpretation would require details about event definitions, timing, exposure, and statistical comparisons. The registry record does not report a comparative safety analysis or enough information to assess rare events. These data should be read as the posted counts, not as a complete characterization of safety.
13. What the Result Does, and Does Not, Mean
The primary outcome records change in ADHD symptom severity on the AISRS total score after 4 weeks of treatment. All three reported group estimates are negative, indicating lower scores relative to baseline. The reported least-squares mean changes are -9.8 for MK-0249, -15.3 for Concerta, and -7.6 for placebo. The confidence intervals describe uncertainty around each group’s estimated change, but they are not intervals for the treatment contrasts.
The direct comparisons reported by the registry are mixed-model tests against placebo. The p-value for MK-0249 versus placebo is 0.341, while the p-value for Concerta versus placebo is 0.001. These results speak to the respective model-based comparisons under the analysis assumptions. Since the registry does not report contrast estimates or their confidence intervals, the magnitude and precision of the differences between treatments cannot be established from the posted comparison results.
A result that does not provide evidence against a null comparison is not proof of equivalence, and a small p-value does not establish the clinical importance of a difference. The registry record does not give a clinically meaningful threshold for change on the AISRS total score. It also does not report enough detail about the mixed model, the crossover sequences, or multiplicity handling to support broader claims beyond these specified comparisons.
The findings do not establish that a treatment works or does not work in general, and they are not medical advice. They describe the outcomes posted for this particular trial, population, treatment duration, and analysis. They do not resolve how results might vary across patients, longer treatment periods, or other settings. Safety interpretation is also limited: the record reports serious-event and other-event counts, but not a complete comparative safety analysis or death counts.
14. Why This Trial Matters Statistically
This trial raises several statistical issues that are common in clinical research. The crossover design can make efficient use of within-participant comparisons, but interpretation depends on treatment sequence, period effects, possible carryover, and the handling of correlated observations. The registry identifies an incomplete-block, two-period design but does not report the details needed to evaluate those features. That makes the mixed-model description important, while also making its missing specifications consequential.
The outcome reporting illustrates the difference between within-group change and a treatment contrast. Each group’s mean change can be described, but it does not alone answer whether the change differs from placebo. The record reports mixed-model p-values for the direct comparisons, yet omits the contrast estimates and confidence intervals. This leaves readers with evidence about the tests but limited information about the size and precision of the treatment differences.
Missing-data methods also matter. The Full Analysis Set and data-as-observed approach are named, but the record does not explain the extent or pattern of missing outcomes. Without those details, it is difficult to assess how robust the results are to assumptions about unavailable measurements. In addition, multiple outcomes are listed, while no multiplicity strategy is reported. These are not minor technical details: they shape the interpretation of uncertainty and the strength of conclusions that can be drawn from posted results.
The statistical value of the record lies in showing both what is reported and what remains unavailable. Clear arm estimates and sponsor comparison p-values allow a focused reading of the primary endpoint. The absent model details and contrast intervals limit reconstruction and independent evaluation. That distinction is useful when interpreting registry results without extending them beyond the analyses and information actually reported.
15. 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 gives only a partial account of the crossover design. It does not report treatment sequences, period-specific counts, washout information, or the handling of period and carryover effects. Those details are pertinent because crossover outcomes can reflect more than the treatment assigned in a given period. The mixed-model analysis is named, but its full specification is not reported.
The primary results include group-level least-squares mean changes and 95% confidence intervals, but the registry does not give the model-based contrast estimates or their confidence intervals. This limits assessment of effect magnitude and precision for the primary comparisons. The participant counts attached to the primary outcome differ across treatment groups, and the registry does not explain why. The record also does not report the reasons for missing observations or sensitivity analyses addressing missing data.
The registry lists secondary outcomes but does not report a multiplicity plan. It does not report a sample-size justification, interim-analysis information, or a clinically meaningful threshold for AISRS total score change. The planning assumptions described in the record are not the trial’s own design justification, and planning calculations should not be treated as observed power.
Safety reporting is also limited. Serious-event affected counts are posted, but deaths are not reported in the registry record, and the record does not provide a comparative safety analysis or detailed event descriptions for the other adverse events. The posted outcome data should therefore be interpreted as a limited account of this completed study, not as a complete description of the trial methods or all clinically relevant outcomes.
16. Related Tutorials
17. Related Statistical Calculators
18. Sources
- ClinicalTrials.gov: A Study to Test the Safety and Efficacy of MK0249 in Patients With ADHD (0249-018)(COMPLETED) — NCT00475735.
- Registry record last updated 2015-07-28; status last verified 2015-07.
- Results first posted 2010-12-10.
- 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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19. Record Summary
The registry describes a completed Phase IIa randomized, double-blind, placebo-controlled, incomplete-block, two-period crossover trial of MK-0249, 10 mg, in adults ages 18 to 55 with ADHD. Enrollment was 72. The primary endpoint was mean change from baseline in AISRS total score after 4 weeks of treatment.
Reported least-squares mean changes were -9.8 for MK-0249, -15.3 for Concerta, and -7.6 for placebo, with 95% confidence intervals for each group. Mixed-model comparisons against placebo had p = 0.341 for MK-0249 and p = 0.001 for Concerta. Contrast estimates and confidence intervals are not reported in the registry record.
The record describes a Full Analysis Set and data-as-observed handling of missing data, but does not report full model details, the crossover sequences, a multiplicity plan, or the trial’s sample-size justification. Safety results report serious adverse event counts and other adverse event counts; deaths are not reported in the registry record.