Oral Naltrexone In Pediatric Eating Disorders: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Oral Naltrexone In Pediatric Eating Disorders (NCT05073679), a randomized phase 2, phase 3 study. The primary outcome is ED-15 Score.

2. Clinical Question

The study asks whether oral naltrexone differs from placebo in the management of pediatric and adolescent eating disorders, particularly anorexia nervosa and bulimia nervosa. The registry describes participants as patients in a partial hospitalization program or intensive outpatient program for an eating disorder. It does not report age limits or further eligibility details.

The broad study objective concerns effectiveness, but the primary outcome timing in the registry is specifically enrollment. The registry record does not report a later primary endpoint measurement or an analysis comparing change between groups. Thus, the clinical question stated in the objective and the available primary outcome information do not amount to a posted estimate of treatment effect.

3. Trial Design

The study is registered as a randomized, parallel-group trial with triple masking and is listed as Phase 2 and Phase 3. Its official title describes a double-blind, placebo-controlled evaluation. The registry does not identify which specific people or roles were masked, nor does it describe the randomization sequence, allocation concealment, or the procedures used to maintain masking.

The intervention arm received oral naltrexone, described as 25mg for three days followed by 50mg a day for 6 weeks. The control arm received placebo capsules by mouth once a day for six weeks. Both were described as opaque gelatin capsules containing methylcellulose filler. The registry does not provide further information about adherence, treatment interruptions, or whether participants could switch or stop treatment.

The study began on 2022-04-22, and the primary completion date is listed as 2024-05-21. Its status is TERMINATED. Enrollment was 9 participants; the arm-level enrollment outcome entries list 5 in the intervention group and 4 in the control group. The reason for termination is not reported in the registry record.

Phase 2 and Phase 3 are both listed, but the registry record does not explain whether these designations correspond to separate stages, a combined protocol, or another arrangement. It also does not report the planned enrollment, recruitment targets, or the intended duration of follow-up beyond the listed treatment schedules and the primary endpoint timepoint.

The registry lists secondary outcomes including the Eating Disorder Examination Questionnaire Score (EDE-Q) and Patient Health Questionnaire Score (PHQ-9). It records 62 outcome measures and 34 posted secondary outcomes. These entries do not, on their own, show which measures were collected for each participant or what results were observed for those outcomes.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Analysis population for the primary outcome, as defined in the registry: Numbers represent participants enrolled at this time point.

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.

6. Primary Endpoint

The registry lists the primary outcome as ED-15 Score, measured over Time Frame: Measured at the following timepoints: enrollment.

The primary endpoint is the ED-15 score, recorded in score units. The registry describes ED-15 as an evidence-based measure of eating-disorder symptom severity and frequency. Its global score ranges from 0 to 6, with higher scores indicating more eating-disordered psychopathology. A continuous score can represent variation in symptom burden rather than reducing participants to a binary category.

The listed timepoint is enrollment. The registry says the numbers represent participants enrolled at that timepoint. This makes the posted arm values a description of scores at enrollment, not a reported measure of improvement, worsening, or change after treatment. The registry record does not list later primary endpoint values, a change-from-enrollment outcome, or an adjusted treatment comparison.

For a randomized trial, a primary endpoint is generally intended to focus the main comparison between assigned groups. In general, a clearly specified primary measure and timepoint can help readers distinguish the central question from the many other outcomes that may be assessed. Here, however, the timing available for the primary measure is enrollment, and the registry contains no posted statistical analysis of the two groups on this endpoint.

The reported ED-15 means are 3.5 for the intervention arm and 4.7 for the control arm. Those values describe the enrolled participants at the listed timepoint. They do not establish whether scores later differed, whether either group changed, or whether any difference was attributable to treatment.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous: it is a score on a scale, summarized by a mean and standard deviation. In general, a mean describes the central level of the observed scores, while a standard deviation describes how dispersed individual scores are around that mean. These quantities answer different questions. A mean does not show the range of individual scores, and a standard deviation is not the uncertainty around the mean or a confidence interval.

The registry gives the intervention arm a mean ED-15 score of 3.5 and standard deviation of 2.016, based on 5 participants. The control arm has a mean of 4.7 and standard deviation of 0.872, based on 4 participants. The score's stated range is 0 to 6, and higher scores indicate more eating-disordered psychopathology. These are summary statistics at enrollment. They do not describe within-person change or a treatment contrast after the assigned regimen.

What does a confidence interval add?

In general, a confidence interval expresses the uncertainty around an estimated quantity, such as a group mean or the difference between groups. It gives a range of values compatible with the data under the method's assumptions. A narrow interval indicates greater precision than a wide interval, although interpretation also depends on the endpoint and analysis. No confidence interval for the primary endpoint comparison is reported in the registry record.

A standard deviation should not be mistaken for a confidence interval. The standard deviations posted for ED-15 describe observed score variation within each arm. They do not directly state how uncertain the difference between the arm means would be. With only 5 and 4 participants, estimates of both the mean and the variability can be sensitive to individual observations.

Why is there no inferential comparison?

The registry record lists zero analyses and states that values are missing or not estimable for a two-arm comparison of the continuous endpoint. As a result, no inferential result is available to interpret. In general, a two-arm analysis could estimate a difference in means and its uncertainty, but the particular model, any covariate adjustment, and any test used for this trial are not reported in the registry record. No method should be attributed to the investigators without that information.

For a randomized trial, an analysis comparing groups according to assigned treatment can preserve the original randomization, but the registry does not report the analysis population or whether an intention-to-treat approach was used. It does not say how participants who discontinued, missed an assessment, or had incomplete scores were handled. General statistical principles cannot fill in those trial-specific details.

What do the planning illustrations mean?

The registry's sample-size assumptions describe a planning illustration based on the observed effect, rather than the trial's own design. The stated assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The illustrations are framed in terms of an effect to detect expressed as a fraction of the observed effect. In general, sample-size planning asks how many participants would be needed under specified assumptions to detect a chosen effect at a specified significance level.

Those planning illustrations are not observed power. Observed power is not a substitute for an estimate and confidence interval, and a planning scenario cannot show that a small study did or did not detect a treatment effect. The registry does not report the original sample-size calculation or the assumptions used to set a recruitment target. No numerical planning result or target enrollment is available in the registry record.

The stated normal approximation is a general modeling assumption for the planning exercise. Whether a particular analysis is appropriate depends on the outcome distribution, study design, and analysis plan. The registry does not report diagnostic checks, transformations, robust methods, or other model details for the primary endpoint. Because no endpoint analysis is posted, there is no fitted model to evaluate.

How should the endpoint scale be understood?

In general, a continuous scale retains more gradation than a simple yes-or-no outcome. It can reveal differences in average score while also allowing individual observations to vary. Such a summary can nevertheless hide the shape of the score distribution: the same mean and standard deviation can arise from different patterns of individual values. The registry does not post individual ED-15 scores or distribution plots in the registry record for this explanation.

The ED-15 score's stated range and direction help interpret the meaning of higher or lower values, but they do not supply a threshold for a meaningful difference. A clinically important difference, minimal important change, or responder definition is not reported in the registry record. Therefore, the descriptive difference between the posted enrollment means should not be assigned a clinical interpretation based on an unstated threshold.

Finally, statistical precision and clinical importance are distinct ideas. In general, an estimate can be precise yet small, or imprecise while still compatible with a range of effects. Here, the registry does not post a treatment-effect estimate or its uncertainty, so neither precision nor the size of a treatment-period effect can be judged from the primary outcome information.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Intervention", "Control")
n   <- c(5, 4)
m   <- c(3.5, 4.7)
sp  <- c(2.016184515, 0.871779789)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Intervention  5  3.500  2.016  0.997  6.003
CARM  Control  4  4.700  0.872  3.313  6.087

11. Multiplicity, Missing Data and Analysis Populations

The registry lists several secondary outcome measures, including EDE-Q scores and PHQ-9 scores, and records 34 posted secondary outcomes among 62 outcome measures. When a study examines multiple outcomes or timepoints, the chance of obtaining apparently notable findings by chance can increase. In general, multiplicity methods or a prespecified hierarchy can help control how multiple comparisons are interpreted.

The registry record does not report a multiplicity adjustment, a primary-versus-secondary testing hierarchy, or which secondary outcomes were included in a planned confirmatory analysis. It also does not report a statistical analysis plan specifying how repeated measurements or multiple comparisons were to be handled. The list of outcome measures alone does not establish that every listed measure was analyzed or that results were selectively reported.

Missing-data procedures are not reported in the registry record. The record does not describe how incomplete questionnaires, missed visits, withdrawals, or unavailable endpoint scores were handled, nor does it report imputation or sensitivity analyses. The ED-15 population description says that the numbers represent participants enrolled at the timepoint. It does not clarify whether the displayed statistics include every enrolled participant with an available score or how any unavailable score was treated.

The analysis population is also not reported in the registry record. It is not stated whether analyses were intended to include all randomized participants, only participants who received treatment, or a different group. No interim analyses or stopping boundaries are reported. The termination status does not identify the reason for stopping or establish whether interim findings played a role.

Without these details, readers cannot assess the planned control of false-positive findings, the robustness of results to missingness, or the extent to which the analyzed population followed the original randomized assignment. In this record, the primary endpoint has no posted inferential analysis, so these issues cannot be resolved by examining a reported model or sensitivity analysis.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: motor vehicle accident (25.0%).

The registry reports serious adverse events for 0 of 5 participants at risk in the intervention group and 1 of 4 at risk in the control group. It reports no deaths in either group. These counts describe what is posted for the small groups and should not be read as precise estimates of comparative risk.

The registry also lists other adverse events for 3 of 5 participants at risk in the intervention group and 4 of 4 in the control group. These are distinct from the serious adverse event counts. The available information does not establish the severity, duration, timing, or relationship to study treatment for each other adverse event.

Motor Vehicle Accident is listed among the top serious adverse event terms with 25.0%. The registry information available for this summary does not identify the group associated with that term or provide enough context to interpret the percentage as a group-specific or overall event rate. It should therefore be read as a listed term and percentage, not assigned to an arm.

In general, adverse-event counts describe events recorded during a study and do not, by themselves, establish causation. The registry record does not state whether the serious event or other events were judged related to the intervention, nor does it provide event narratives. With the reported numbers of participants at risk, one participant's event changes the count noticeably. These safety data are descriptive and do not support a stable comparison between arms.

13. What the Result Does, and Does Not, Mean

The posted results show that the ED-15 enrollment mean was 3.5 in the intervention arm and 4.7 in the control arm. They also show the standard deviations and group sizes: 2.016 and 5 participants for intervention, and 0.872 and 4 participants for control. These are descriptions of scores at enrollment, when the registry says the primary measure was assessed.

They do not show how ED-15 scores changed over the 6-week intervention schedule. The registry does not post a later primary endpoint score, a change from enrollment, or a statistical comparison of treatment outcomes. No confidence interval or p-value for a treatment effect is reported. The available results therefore cannot establish the magnitude or precision of an effect of oral naltrexone relative to placebo.

The lower enrollment mean in the intervention arm is not evidence that treatment caused a lower score. The measure is listed at enrollment, and the record does not establish that the figures are post-treatment outcomes. Nor does the absence of a reported analysis show that there was no effect. It means the registry does not provide an inferential result to distinguish a treatment effect from sampling variation.

The status TERMINATED and the enrollment of 9 are important context, but they do not explain why the study stopped or whether the enrolled number matched the original target. That reason and the trial's sample-size justification are not reported in the registry record. The status should not be used to infer a favorable or unfavorable result.

The posted safety counts likewise describe few participants and cannot determine whether events were caused by treatment or whether the groups differ reliably in safety. Taken together, the record documents a small randomized study and enrollment measurements, but it does not provide the analyzed follow-up evidence needed to answer the stated effectiveness question.

14. Why This Trial Matters Statistically

This trial is statistically informative as an example of the difference between a registered study objective and the results available for evaluating that objective. The stated objective concerns effectiveness, yet the posted primary endpoint is an ED-15 score at enrollment. A baseline description is not the same as a comparison of outcomes after treatment, and it cannot show change over time.

The small enrollment also makes precision especially important. The primary outcome entries include 5 participants in one arm and 4 in the other. With such limited numbers, a few observations can meaningfully affect summaries, and any estimate would require careful attention to its uncertainty. Here, no primary inferential analysis or confidence interval is posted, so readers cannot evaluate precision directly.

The record also illustrates why trial status and sample-size planning should not be confused with evidence of effect. The study is marked TERMINATED, and planning illustrations are described, but the reason for termination and the original sample-size justification are not reported. A planning illustration is conditional on assumptions; it does not show what the trial actually observed or establish the chance that the trial detected an effect.

Multiple listed outcomes further highlight the importance of prespecified analysis plans. The registry names EDE-Q and PHQ-9 among secondary outcomes, but does not report how multiplicity, missing data, or analysis populations were handled. These details matter for evaluating the credibility and scope of conclusions when several measurements may be considered.

The central statistical lesson is not a conclusion about the intervention. It is that the posted enrollment summaries, without a treatment-period endpoint analysis and uncertainty estimate, do not answer the comparative question. Clear outcome timing, complete analysis reporting, and transparent handling of missing data are essential for turning trial observations into interpretable evidence.

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 main limitation for interpretation is that the primary outcome is listed at enrollment, with no later primary result or change analysis reported. Although the study objective concerns treatment effectiveness and the arms have distinct assigned regimens, the available ED-15 values do not document an outcome after those regimens.

Enrollment was 9, with 5 participants in the intervention group and 4 in control. The registry record does not report a planned enrollment target or explain whether this enrollment was expected. It does not state why the trial was terminated. These omissions limit assessment of the study's intended scope and the context for its small number of observations.

The record does not report the randomization method, concealment procedures, masked roles, treatment adherence, or participant flow. It does not specify the analysis population or missing-data methods. It also does not report a statistical analysis plan, endpoint hierarchy, multiplicity approach, or interim analyses. Consequently, the available registry information does not permit evaluation of these design and analysis details.

The endpoint information consists of arm-level means, standard deviations, and participant counts, without individual observations, confidence intervals, or an inferential comparison. The ED-15 scale's range and direction are stated, but a threshold for a meaningful difference is not. The record's list of secondary measures does not include inferential details sufficient to assess those outcomes.

Safety interpretation is also limited by the small at-risk groups and the absence of event-level details, timing, or stated attribution. The listed serious adverse event term and percentage lack sufficient group context in the record. These limitations mean the posted information is chiefly descriptive and cannot support a complete assessment of efficacy or comparative safety.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Oral Naltrexone In Pediatric Eating Disorders — NCT05073679.
• Registry record last updated 2025-08-19; status last verified 2025-07.
• Results first posted 2025-08-19.
• 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.

19. Record Summary

The registry describes a randomized, parallel, triple-masked study listed as Phase 2 and Phase 3, comparing oral naltrexone with placebo in pediatric and adolescent eating disorders. The study began on 2022-04-22, has a primary completion date of 2024-05-21, and is marked TERMINATED. Enrollment is 9.

The primary outcome is ED-15 score at enrollment, with higher scores on its 0 to 6 range indicating more eating-disordered psychopathology. The intervention arm has a mean of 3.5 and standard deviation of 2.016 among 5 participants; control has a mean of 4.7 and standard deviation of 0.872 among 4 participants. No primary inferential analysis is posted.

The record lists EDE-Q and PHQ-9 among secondary measures. It reports serious adverse events for 0 of 5 intervention participants and 1 of 4 control participants, and no deaths in either group. The reason for termination, sample-size justification, analysis populations, missing-data methods, and multiplicity strategy are not reported in the registry record.