Reward Re-Training: A New Treatment to Address Reward Imbalance During the COVID-19 Pandemic: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Reward Re-Training: A New Treatment to Address Reward Imbalance During the COVID-19 Pandemic (NCT04661410), a randomized na study. The primary outcome is Binge Eating Frequency Assessed by the Eating Disorder Examination.

2. Clinical Question

3. Trial Design

This is a randomized, single-masked, parallel-group pilot trial sponsored by Drexel University. The registry record lists an enrollment of 59. Its brief summary describes random assignment to 10 sessions of RRT or supportive therapy, with both treatments delivered in groups through videoconferencing software. The record does not explain who was masked or how randomization and allocation were implemented.

The study dates are listed as 2020-12-01 for start and 2021-09-15 for primary completion, and the status is completed. The trial is listed with phase NA. The brief summary describes aims concerning feasibility and acceptability, engagement of proposed treatment targets, preliminary estimates of eating-disorder symptom outcomes, and secondary outcomes. Those aims describe the intended scope; they are not evidence that the corresponding analyses or results were reported.

The brief summary describes planned groups of 30 participants each, while the registry enrollment is 59. The registry record does not explain the relationship between the planned group sizes and the recorded enrollment. It also does not report recruitment flow, the number assigned to each arm, treatment attendance, follow-up completion, or protocol deviations. These details would be useful for understanding how many participants contributed data at each assessment and whether the planned treatment exposure was achieved.

The intervention descriptions identify the treatment format and session schedule, but not session content beyond the broad treatment labels. Details about therapist training, treatment fidelity, participant eligibility, and any changes to the planned procedures are not reported in the registry record. The design therefore establishes the intended comparison, but the posted information does not provide enough operational detail to reconstruct how the trial was conducted.

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

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 Binge Eating Frequency Assessed by the Eating Disorder Examination, measured over Each assessment time point throughout treatment (Pretreatment (Baseline), Mid-treatment (Week 5), Posttreatment (Week 10)) and a 3-month post-treatment follow-up assessment..

The primary outcome is binge eating frequency assessed by the Eating Disorder Examination. It is defined as the number of binge eating episodes over the past 28 days. The registry lists the outcome as a mean with standard deviation, indicating a continuous measure summarized by its average and spread rather than only as a category such as whether any episode occurred.

Assessments were planned at pretreatment (baseline), mid-treatment (Week 5), posttreatment (Week 10), and a 3-month post-treatment follow-up. Repeated assessments can describe the outcome across treatment and follow-up, rather than relying only on a single measurement. The endpoint is relevant to the stated study aims because the brief summary identifies preliminary estimates of eating-disorder symptom outcomes as an aim.

In general, a mean conveys the average observed frequency, while a standard deviation describes how dispersed participants' measurements are around that average. These summaries do not by themselves show whether changes differ between randomized groups or how uncertain an estimated group contrast is. The registry record does not report group means, standard deviations, changes from baseline, or inferential results for the endpoint. The outcome definition and assessment schedule are reported, but the result needed to evaluate the treatment comparison is not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The record identifies a randomized, single-masked, parallel-group design. Randomization is intended, in general, to make treatment assignment independent of participant characteristics, helping support a fair comparison between groups. It does not guarantee that groups will be identical, especially in a pilot with a limited enrollment. Details of the random sequence, allocation concealment, and the person or people masked are not reported in the registry record. The parallel-group label indicates that the two treatment groups are compared as separate arms rather than participants crossing from one treatment to another.

What does the outcome summary mean?

The primary outcome is a continuous measure summarized as a mean and standard deviation. The mean is the arithmetic average of participants' recorded binge eating frequency. The standard deviation describes the spread of individual values around that average. In general, the mean and standard deviation help characterize the data, but they do not alone quantify the difference between randomized arms or the uncertainty of that difference. The registry record does not report the arm-specific summaries or a comparative estimate.

The primary outcome is assessed repeatedly, from pretreatment through a 3-month post-treatment follow-up. Repeated observations can be analyzed in ways that account for measurements from the same participant being related to each other. Such analyses can estimate group patterns over time, but they require decisions about the time points, the treatment contrast of interest, and how incomplete observations are handled. The statistical model and those decisions are not reported in the registry record. The record also does not report an analysis for any particular time point.

Why does over-dispersion matter?

In general, over-dispersion describes count data that vary more than a statistical model assumes. A model that understates variability can produce uncertainty estimates that are too narrow. For count outcomes, an analyst may consider whether the data have more spread than a basic count model allows. The endpoint is expressed as a frequency of episodes, but the registry record does not describe a count model, an assessment of over-dispersion, or any fitted statistical model. This is a general consideration, not a claim about the analysis performed in this trial.

What can a significance test or confidence interval tell readers?

In general, a significance test evaluates how compatible the observed data are with a specified null hypothesis under a statistical model. A p-value is not the probability that a treatment works, nor does it measure the size or practical importance of an effect. A confidence interval conveys uncertainty around an estimated effect and can show which magnitudes are compatible with the data and model. Neither an inferential test nor an interval is reported for the primary outcome in the registry record. The record therefore supplies no basis for interpreting statistical significance or precision.

The sample-size planning assumptions described in the record use a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. The planning illustration is described as based on a fraction of an observed effect. Such calculations are planning illustrations, not observed power and not evidence that the planned study could detect a particular effect in practice. The record does not report the actual illustration values in the registry record for this account, nor does it report a sample-size justification from the trial's own design. The effect size used in the trial's planning and its justification are not reported in the registry record.

Sample-size calculations depend on assumptions about the outcome, variability, target effect, allocation, and analysis. If those assumptions differ from the data or the chosen model, the actual precision may differ from the planning expectation. For a pilot study, estimates may be especially uncertain; the purpose of a pilot can include assessing procedures and obtaining preliminary information, rather than providing a definitive estimate. The study's brief summary does describe pilot aims, but the registry record does not report estimates or uncertainty for those aims.

Most importantly, no analysis results are listed in the registry record. The design and outcome description allow readers to understand what was intended to be compared, but they do not substitute for an analysis. Methods such as covariate adjustment, repeated-measures modeling, handling of outliers, or transformation of the outcome cannot be attributed to the investigators because they are not reported in the registry record. Any interpretation of statistical effects must therefore remain limited to the outcome definition, assessment schedule, and the absence of posted analysis results.

10. Multiplicity, Missing Data and Analysis Populations

The primary outcome is planned for several assessment time points: pretreatment, mid-treatment, posttreatment, and a 3-month post-treatment follow-up. Testing or estimating effects at multiple time points can raise multiplicity concerns. In general, when many comparisons are considered, the chance of at least one apparently unusual result can increase if the analyses are treated as independent opportunities for discovery. Approaches to this issue can include defining a primary time point in advance, using a model that estimates a trajectory, or adjusting inference across selected comparisons. The registry record does not report a multiplicity strategy or identify a single time-point comparison as the primary analysis.

The record lists no analysis entries for the primary outcome. It also does not describe the planned analysis population, whether participants would be analyzed according to randomized assignment, or whether the analysis would include only participants with observed measurements. Such choices matter because they determine which observations contribute to an estimate and how the estimate relates to the randomized comparison.

Missing outcome data are a particular concern in repeated assessments. In general, complete-case analysis can be biased if participants with missing measurements differ systematically from those with observed measurements. Statistical models can use incomplete repeated measurements under assumptions, but those assumptions must be considered and described. The registry record does not report the number of missing measurements, reasons for missingness, an imputation method, or sensitivity analyses.

The brief summary names secondary outcomes involving depressive symptoms, substance use, and quality of life. It does not provide results or a plan for controlling multiplicity across these outcomes. The registry record also does not report a prespecified statistical analysis plan, so the handling of multiple outcomes and time points cannot be evaluated from the posted information.

11. 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.

The registry lists no serious adverse events, no other adverse events, and no deaths in either treatment arm. For Reward Re-Training, 29 participants are listed as at risk for serious events and 29 for other events; the corresponding event counts are 0 and 0, with deaths listed as 0. For Supportive Therapy, 30 participants are listed as at risk for serious events and 30 for other events; the corresponding event counts are 0 and 0, with deaths listed as 0.

These figures describe the registry's event counts and at-risk denominators. A zero count means no events of that category are recorded in the posted results for the listed group; it does not demonstrate that an event is impossible or that risk is absent. Rare events can be difficult to characterize in a pilot, and the registry record does not provide enough detail to assess the completeness of event ascertainment.

Definitions of serious and other adverse events, the period of surveillance, the method of collection, and judgments about relatedness to treatment are not reported in the registry record. The counts should therefore be read as a brief safety record, not as a comprehensive comparison of harms.

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

The registry record documents a randomized pilot comparing RRT with supportive group therapy and identifies binge eating frequency as the primary outcome. It gives a clear outcome definition and a schedule that extends from pretreatment through follow-up. It also records adverse-event counts for both arms. These features describe the question the trial set out to address and some of the information relevant to interpreting its conduct.

The posted information does not report outcome values or a statistical comparison for binge eating frequency. It therefore cannot establish whether the arms differed, how large any difference might have been, or how precisely an effect was estimated. Neither a positive effect nor a null effect can be inferred from the absence of analysis results. Likewise, the listed study aims concerning feasibility, acceptability, treatment targets, and secondary outcomes should not be read as results.

General statistical interpretation depends on the estimate, its uncertainty, the analysis population, and the assumptions used by the model. None of those primary-outcome results are reported in the registry record. A study's randomized design can support a comparative interpretation when results and methods are available, but randomization alone does not establish the direction or size of an effect.

The safety record lists zero events in the reported categories, but the limited counts and missing ascertainment details constrain what can be concluded about harms. The registry record also does not explain the relationship between planned group sizes in the brief summary and the recorded enrollment. These gaps make it important to distinguish the planned aims and procedures from findings that are actually posted.

In short, the record describes a treatment comparison and a clinically relevant symptom measure, but does not report the statistical results needed to judge comparative outcomes. The appropriate conclusion is about the information available: the registry describes the trial, while its primary efficacy findings are not reported in the registry record.

13. Why This Trial Matters Statistically

This trial is statistically notable as a randomized pilot with repeated measurement of a continuous symptom-frequency outcome. A pilot can help establish whether procedures are workable and can generate preliminary information for later research. The brief summary explicitly identifies feasibility and acceptability, engagement of treatment targets, and preliminary symptom estimates as aims. These aims differ from a definitive efficacy claim, and their value depends on the results and methods being reported transparently.

The primary outcome is assessed at multiple stages, including a post-treatment follow-up. This makes the choice of estimand and analysis important: readers need to know whether the main interest is a between-arm contrast at a particular assessment, a difference in change over time, or another summary of the repeated measurements. The registry record does not specify such an analysis. Without that information and without outcome estimates, statistical precision and the interpretability of the planned comparisons cannot be assessed.

The record also illustrates why a registered study description and a posted analysis answer different questions. The design indicates how investigators intended to compare treatments; the results are needed to estimate what was observed. In this case, the registry records no analysis entries, so the treatment comparison cannot be evaluated statistically from the reported results.

Finally, the enrollment record and the brief summary's planned group sizes are not identical descriptions, and the registry does not explain their relationship. That distinction matters for understanding the achieved sample and the precision one might expect. The posted safety counts add some descriptive information, but they do not replace a full account of outcome results, participant flow, or analysis methods.

14. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The central limitation is that the registry record does not report the primary outcome results or any analysis entries. Without arm-level outcome summaries, effect estimates, or measures of uncertainty, the comparative effect cannot be quantified or assessed for precision. The record's stated assessment schedule does not resolve this limitation because no values are reported for the assessments.

Some trial details that would clarify interpretation are also absent. The registry does not report detailed eligibility criteria, baseline characteristics, the randomization procedure, allocation concealment, or who was masked. It does not provide participant flow, assignment counts by arm, attendance, follow-up completion, or reasons for missing measurements. The absence of these details limits assessment of the trial's implementation and of potential bias from missing data or departures from assigned treatment.

The brief summary describes planned groups of 30 participants, while enrollment is listed as 59; the registry record does not explain this relationship. The record also does not report the trial's own sample-size justification or a prespecified analysis plan. In particular, the approach to repeated assessments, multiplicity, analysis populations, and missing observations is not reported in the registry record.

The study is described as a pilot, and conclusions about feasibility, acceptability, treatment-target engagement, and secondary outcomes would require their corresponding reported results. Those results are not reported in the registry record. Safety counts are available, but definitions, collection procedures, surveillance period, and relatedness assessments are not described. These limitations restrict interpretation to what the registry documents, rather than allowing evaluation of the trial's treatment effects or the full conduct of the study.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Reward Re-Training: A New Treatment to Address Reward Imbalance During the COVID-19 Pandemic — NCT04661410.
• Registry record last updated 2024-03-21; status last verified 2024-03.
• Results first posted 2024-03-21.
• 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.

18. Record Summary

NCT04661410 is a completed randomized, single-masked, parallel-group pilot sponsored by Drexel University. The registry lists enrollment of 59 and dates of 2020-12-01 for start and 2021-09-15 for primary completion. The comparison is 10 weekly sessions of Reward Re-Training group therapy versus 10 weekly sessions of supportive group therapy, both described as delivered by videoconferencing.

The primary outcome is binge eating frequency over the past 28 days, assessed by the Eating Disorder Examination at pretreatment, mid-treatment, posttreatment, and a 3-month post-treatment follow-up. The record lists secondary outcomes for depressive symptoms, substance use, and quality of life. No analysis entries or primary outcome results are reported in the registry record. The posted adverse-event counts are zero for serious events, other events, and deaths in both arms.