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 Treatment of Severe Destructive Behavior: FCT Versus Wait-List Control (NCT02483572), a randomized na study. The primary outcome is Rate of Destructive Behavior After Treatment or Initial Wait Period.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02483572 |
| Phase | NA |
| Condition | Aggression, Self-Injurious Behavior |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 4 |
| Arms in the primary outcome | 2 |
| Lead sponsor | University of Nebraska |
| Results posted | Yes |
2. Clinical Question
Population
Children with intellectual disability and severe destructive behavior, including aggression or self-injurious behavior. Further eligibility details are not reported in the registry record.
Intervention
Functional communication training (FCT), a behavioral intervention intended to teach an appropriate communication response as an alternative to destructive behavior. The registry describes immediate treatment assignment for participants in this arm.
Comparator
A wait-list control condition. Participants assigned to it did not immediately receive services; the registry describes their wait as linked to the treatment timing of a paired FCT participant.
Primary question
How did the rate of destructive behavior after FCT compare with the rate after an initial wait period? The intended measure was responses per min, assessed after treatment or the initial wait period, approximately 16 weeks.
The clinical question concerns whether the measured rate differs between the assigned conditions at the specified assessment point. The registry describes FCT as teaching a functional communication response and describes destructive behavior as the outcome of interest. The wait-list condition was intended to provide a comparison before treatment was implemented for those participants. This setup makes the timing of measurement important: the intended contrast was between post-treatment behavior in the FCT condition and behavior measured at the end of the initial waiting period in the control condition.
The registry record does not establish a usable comparison of those outcomes. It says posttest data were not collected because subjects were withdrawn before the posttest period, with relocation given as an example. The posted primary outcome information nevertheless contains a value for the wait-list condition, while the FCT arm has no reported value. These entries do not provide a paired or randomized between-arm estimate of the treatment contrast. The registry does not report a treatment effect estimate or statistical test for the primary question.
3. Trial Design
The trial was registered as a randomized, parallel-group study with no masking. Its listed enrollment was 4, and its status is terminated. The sponsor was the University of Nebraska. The listed phase is NA. The registry gives a start date of 2016-09-01 and a primary completion date of 2019-01-25. The reason for termination is not reported in the registry record.
In a parallel design, participants are assigned to a condition and assessed according to that condition rather than crossing through both conditions as part of the same comparison. Random allocation is intended to reduce systematic differences between assigned groups, although it cannot guarantee balance, particularly when the amount of available data is limited. The registry does not report the allocation ratio or the method used to generate or conceal the random sequence. It also does not describe masking; the listed design indicates none.
The FCT arm was described as receiving treatment after assignment. The wait-list arm was described as not immediately receiving services, with its no-treatment duration linked to the treatment duration of a paired FCT participant. This design allows an initial comparison of behavior after treatment versus behavior after waiting, if the planned outcome assessments are collected. The registry’s primary outcome description says the relevant posttest data were not collected because subjects withdrew before that period. The reason for each withdrawal and the number of participants completing each assessment are not reported in the registry record.
The posted arm information contains no primary endpoint value for FCT and a value for the wait-list arm. Because this is not a complete outcome comparison, randomization alone does not make the available values a reliable estimate of the effect of assignment. The registry does not report protocol deviations, the allocation sequence, the analysis population, or a statistical analysis plan. The registration status and dates describe the record but do not explain why the study ended or whether any additional results were collected outside the posted results.
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
| Stage | Functional Communication Training | Waitlist-Control Condition |
|---|---|---|
| STARTED | 2 | 2 |
| COMPLETED | 0 | 1 |
| NOT COMPLETED | 2 | 1 |
Reasons for not completing this period:
| Reason | Functional Communication Training | Waitlist-Control Condition |
|---|---|---|
| Withdrawal by Subject | 1 | 0 |
| Lost to Follow-up | 1 | 0 |
| Physician Decision | 0 | 1 |
Analysis population for the primary outcome, as defined in the registry: We did not collect these posttest data because subjects were withdrawn prior to the posttest period (e.g., due to relocation).
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 | Functional Communication Training | Waitlist-Control Condition | Total |
|---|---|---|---|---|
| Participants analysed | 2 | 2 | 4 | |
| Age, Categorical: <=18 years | Participants | 2 | 2 | 4 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 | 0 | 0 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Age, Continuous | years | 6 (4 to 9) | 7 (6 to 8) | 7 (4 to 9) |
| Sex: Female, Male: Female | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Male | Participants | 2 | 2 | 4 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 1 | 1 |
| Race (NIH/OMB): White | Participants | 2 | 0 | 2 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 1 | 1 |
| Region of Enrollment: United States | participants | 2 | 2 | 4 |
| Destructive behavior per min | responses per min | 1 (.8 to 1.2) | .9 (.4 to 1.3) | .9 (.4 to 1.3) |
6. Primary Endpoint
The registry lists the primary outcome as Rate of Destructive Behavior After Treatment or Initial Wait Period, measured over After treatment or initial wait period (approximately 16 weeks).
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Full Range |
| Unit | responses per min |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the rate of destructive behavior, measured in responses per min. The planned assessment was after treatment in the FCT condition or after the initial wait period in the wait-list condition, approximately 16 weeks. The registry describes measurement after successful treatment when implemented by caregivers, while the wait-list assessment was intended to capture any change during the passage of time before treatment.
A rate expresses how frequently an event occurs relative to time. For behavior that can occur repeatedly, this can be more informative than simply recording whether it occurred at least once. It also makes the time basis of measurement essential: rates are comparable only when the observation procedures and time definitions are sufficiently consistent. The registry does not report the detailed observation protocol or the way the rate was calculated.
The endpoint targets behavior that the intervention is intended to address, and the wait-list assessment was intended to help distinguish change after treatment from change during waiting. However, the registry says the posttest data were not collected because subjects were withdrawn before the posttest period. The posted results list no FCT value and one wait-list value: a mean of 2.0 responses per min, with a full range from 0.0 to 4.6. Those entries do not establish a between-condition difference. The endpoint is therefore clinically relevant to the stated study question, but the posted information does not answer that question comparatively.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The primary endpoint is reported as a mean rate of destructive behavior. For the wait-list control condition, the registry lists a value of 2.0 responses per min, based on n=1.0, with a full range of 0.0 to 4.6. For the FCT condition, the registry lists n=0.0 and no value or range. The posted information therefore gives no corresponding FCT result and no randomized between-arm estimate.
The numerical result in the wait-list arm is descriptive. It summarizes the reported observation for that condition; it does not tell whether FCT changed the rate relative to waiting. The full range describes the recorded spread in that arm, but it is not a confidence interval and does not express uncertainty around a treatment contrast. The registry does not report an inferential test, a confidence interval, or an adjusted analysis for the primary outcome.
There is an important qualification in the record: the primary outcome description states that posttest data were not collected because subjects were withdrawn before the posttest period, for reasons such as relocation. That statement sits alongside the listed wait-list value. The record does not explain how that value relates to the stated lack of posttest collection, so the two pieces of information should be read together rather than treating the reported value as a complete outcome dataset.
Study status is listed as terminated. The reason is not reported in the registry record, and termination by itself does not show whether the study ended for administrative, recruitment, logistical, safety, or other reasons. No such explanation should be inferred. Similarly, the absence of a reported FCT endpoint value is not evidence that the outcome was unchanged, nor does it show that treatment was ineffective or effective.
The registry lists 4 as enrollment, but the posted primary endpoint information is much more limited than that enrollment figure might suggest. Enrollment is not the same as the number contributing endpoint data. The record does not give a full participant flow, assessment completion counts by time point, or reasons for withdrawal by assigned group. Those omissions prevent a clear assessment of how representative the reported wait-list value is of the randomized group.
Overall, the posted primary outcome cannot support a claim about the magnitude, direction, or precision of the FCT-versus-wait-list effect. The available information documents a limited descriptive result and important missingness, not a conclusive comparative result. A lack of an estimable comparison should not be interpreted as evidence of no difference.
9. Statistical Methods Explained
Statistical interpretation begins by distinguishing the question a trial was designed to answer from the data that are available to answer it. This trial’s intended primary comparison was a rate of destructive behavior after FCT versus a rate after an initial wait period. A valid comparison requires outcome information for both assigned conditions, measured and analyzed in a way that corresponds to that question. The registry does not provide a primary endpoint value for the FCT arm, so the intended contrast is not estimable from the posted primary results.
What a mean and range describe
A mean is a measure of the average observed outcome. It can be a compact summary, but it does not show how individual observations are distributed. A range reports the lowest and highest observed values, giving a sense of the span of observations. It does not indicate how frequently values occurred within that span, nor does it quantify the precision of the mean or of a comparison between groups. In this record, the wait-list mean and full range are descriptive information; they are not a treatment effect.
The registry reports responses per min, so the endpoint is a rate rather than an unscaled event count. In general, rates depend on both the event count and the time over which events are observed. Meaningful comparisons therefore rely on consistent observation periods and operational definitions. Those procedural details are not reported in the registry record. The reported unit identifies the intended scale but does not, by itself, establish that observation or measurement was identical across participants.
Why a confidence interval matters
In general, a confidence interval describes uncertainty around an estimated quantity under the assumptions of the statistical method used. For a randomized comparison, an interval around the between-condition effect would help readers assess both the range of effect sizes compatible with the data and the precision of the estimate. It is not a range of individual participant outcomes. No confidence interval for the primary between-arm effect is reported in the registry record, and the missing FCT value means a comparative interval cannot be interpreted from the posted results.
A significance test, in general, evaluates how compatible the observed data are with a specified null hypothesis under a model. A p-value is not the probability that the null hypothesis is true and does not measure the size or practical importance of an effect. The registry lists no analyses for the posted results, and no primary-outcome p-value is reported. It would therefore be inappropriate to infer statistical significance or non-significance from the descriptive wait-list value alone.
Randomization and analysis
Randomization assigns participants by chance to the study conditions. In general, this supports a comparison based on assignment because it can reduce systematic selection differences between groups. It does not remove uncertainty, correct missing outcomes automatically, or guarantee that a comparison is unbiased if outcome availability differs after assignment. The registry identifies the allocation as randomized but does not report the sequence-generation method, allocation concealment, or a defined analysis population.
An intention-to-treat analysis, in general, compares participants according to their randomized assignments, regardless of treatment received. Such an analysis still needs a principled way to handle missing outcomes; the label does not mean that unavailable outcomes are observed or that their values can be assumed. A per-protocol analysis, in general, focuses on participants who followed specified treatment procedures, but can lose some benefits of randomization if adherence is related to prognosis. The registry does not say which approach was planned or used. It also does not provide enough participant-flow information to reconstruct either population.
Rates, variability, and model choice
For count and rate outcomes, statistical methods may need to account for features such as unequal observation time, skewed values, or over-dispersion. In general, over-dispersion occurs when observed variability is greater than a selected model expects. Ignoring it can make uncertainty estimates too small and conclusions too confident. Other methods may be appropriate when observations are clustered or repeated, depending on the design and data structure. These are general considerations, not descriptions of an analysis performed in this trial. The registry does not report the model, distributional assumptions, or diagnostics used for the primary endpoint.
Because the posted primary data do not provide a two-arm result, recalculating an unadjusted comparison from summary statistics is not possible from the stated endpoint entries. No recalculated treatment effect should be inferred from the wait-list mean and range. The registry does not report a sponsor analysis for this comparison, and no discrepancy between such an analysis and a recalculation is described.
Planning illustrations and observed power
In general, sample-size planning asks how much information a future study would need to detect a prespecified effect under selected assumptions. The registry’s planning illustration is described as using the observed effect, a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the target effect expressed as a fraction of the observed effect. Such calculations are planning illustrations, not evidence about what the trial observed, and they are not observed power.
Power is a design property calculated for a specified effect, sample size, variability assumption, and analysis procedure. Calculating power after the results are known from the observed effect does not resolve uncertainty in the estimate or establish whether a treatment effect exists. In this record, the primary comparison lacks a reported FCT result, so the planned-effect basis for interpreting any effect-dependent illustration is especially important. The planning assumptions do not substitute for the absent comparative outcome or establish the adequacy of the trial design.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 4 outcome measures, including the primary outcome and three secondary outcomes. The secondary outcomes concern functional communication response rates after treatment or waiting, including measures after a longer wait period in the wait-list group. The registry reports no analyses for these outcomes, and no secondary results are included in the posted information. A detailed analysis plan is not reported in the registry record.
When a study examines multiple outcomes, time points, or statistical comparisons, the chance of finding an apparently notable result by chance can increase. In general, multiplicity procedures can address this by adjusting how results are evaluated or by identifying a primary comparison in advance. The registry does not report whether any multiplicity adjustment was planned or used. Since no analysis results are listed, there is no reported set of tests from which to assess how multiplicity was handled.
Missing data are central to interpreting the primary endpoint. The registry says the posttest data were not collected because subjects were withdrawn before the posttest period, with relocation given as an example. It does not state the number withdrawn from each assigned condition, whether withdrawal occurred before or after treatment began, or whether any other reasons applied. The posted arm information includes a wait-list result but no FCT result; the relationship between that result and the statement about missing posttest data is not explained.
Missingness can affect the interpretation of a randomized comparison if the likelihood of having an outcome is related to assignment or to the outcome itself. In general, analyses that use only observed outcomes may not represent all randomized participants. Methods for missing data require assumptions, and those assumptions should be made explicit. No imputation method, sensitivity analysis, or missing-data assumption is reported in the registry record. The analysis population and participant flow are also not reported, so the extent and consequences of missing outcome data cannot be determined.
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 |
|---|---|---|---|
| Functional Communication Training | 0 | 2 | 0.0% |
| Waitlist-Control Condition | 0 | 2 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Functional Communication Training | 0 of 2 |
| Waitlist-Control Condition | 0 of 2 |
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 |
|---|---|
| Functional Communication Training | 0 of 2 |
| Waitlist-Control Condition | 0 of 2 |
The adverse-event information lists serious adverse events for the FCT and wait-list conditions. Each arm lists 2 participants at risk, 0 with a serious adverse event, and 0 deaths. For other adverse events, each arm also lists 2 participants at risk and 0 affected. No serious adverse-event terms are listed.
These figures describe what the registry reports for the listed at-risk groups. They do not establish that no adverse events occurred outside the recorded categories or reporting period, and they do not show that the conditions have equivalent safety profiles. The record does not describe the event-collection procedures, the duration of safety follow-up, or whether all randomized participants contributed to the at-risk figures. The listed enrollment is 4, but the safety denominators should be read as reported rather than replaced with enrollment.
With no serious events listed in either arm, a comparative safety estimate cannot be inferred from these counts. In general, zero recorded events in a limited dataset do not rule out events that were not observed, and sparse event data provide little precision for comparing risks. The registry does not report a formal safety analysis or an analysis of differences between arms. These entries are descriptive safety reporting, not proof of absence of risk.
12. What the Result Does, and Does Not, Mean
The registry record documents a randomized comparison of FCT with a wait-list control, but the posted primary outcome information does not yield a comparative result. The FCT arm has no reported primary endpoint value. The wait-list arm has a reported mean of 2.0 responses per min, based on n=1.0, with a full range of 0.0 to 4.6. These descriptive entries cannot establish how the conditions differed.
The result does not show that FCT reduced destructive behavior, and it also does not show that FCT failed to reduce it. Without a reported FCT endpoint value and a corresponding estimate of the contrast, neither the direction nor the magnitude of a treatment effect can be determined. A missing or unestimable comparison is not evidence that the conditions are the same.
The record’s statement that posttest data were not collected because subjects were withdrawn before the posttest period is an important limit on interpretation. The registry does not explain how that statement relates to the wait-list value that is posted. It also does not report a complete participant flow, the reasons for withdrawal by arm, or methods for addressing missing outcomes. Those gaps make it difficult to assess the completeness and representativeness of the recorded endpoint information.
The listed enrollment, randomization, and study status provide context, but enrollment does not indicate how many participants had an outcome measured. Random allocation is a design feature, not a substitute for outcome data. Likewise, the terminated status does not explain why the study ended; the reason is not reported in the registry record.
The safety entries list no serious or other adverse events in the reported at-risk groups, but they do not establish absence of risk or support a precise comparison. The registry also gives no analysis results for the listed secondary outcomes. Taken together, the posted information describes the trial’s intended question and some limited outcome and safety entries, while leaving the primary comparative question unanswered.
13. Why This Trial Matters Statistically
This trial matters statistically because it illustrates the difference between a randomized design and an interpretable randomized comparison. Random allocation can support a fair comparison when outcomes are measured and analyzed for the assigned groups. It cannot produce a treatment-effect estimate when one arm has no reported primary endpoint value. The presence of a randomized design should therefore not be mistaken for evidence that the intended comparison was completed successfully.
The record also illustrates why outcome availability and participant flow are essential parts of trial reporting. A listed enrollment does not tell readers how many participants reached the assessment, and a result in one arm does not answer a two-arm question. When withdrawal occurs before the planned endpoint, readers need to know how many participants were affected, the timing and reasons, and how missing data were handled. Those details are not reported in the registry record.
Another statistical lesson concerns the difference between descriptive values and inferential results. A mean and range can describe observed data, but without an estimate comparing conditions they do not quantify an intervention effect. A range is not a confidence interval, and a planning illustration is not observed evidence about treatment performance. Keeping these quantities distinct prevents descriptive information from being overstated.
Finally, the registry’s listed secondary outcomes and safety counts show why completeness matters across all outcome domains. Without posted analyses or sufficient explanation of missing information, readers cannot assess the planned multiplicity approach, the results for secondary questions, or the precision of comparative safety estimates. This record is therefore informative about the intended design and the limits of the available results, but not about the magnitude or certainty of an FCT effect.
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 primary limitation is that the registry reports no primary endpoint value for the FCT arm. The wait-list entry is not enough to estimate a between-arm effect. The registry’s statement that posttest data were not collected because subjects were withdrawn before the posttest period further limits interpretation, while the relationship between that statement and the posted wait-list result is not explained.
The participant flow is incomplete. Although enrollment is listed as 4, the record does not report the number assessed at each time point, the number withdrawn in each condition, or whether participants began their assigned treatment. Relocation is mentioned as an example reason for withdrawal, but the reasons and timing for each withdrawal are not reported. The analysis population is not identified.
Important design and analysis details are also absent. The randomization method, allocation concealment, analysis plan, statistical model, missing-data procedures, and multiplicity approach are not reported in the registry record. The outcome description does not give the detailed behavior-observation procedure, and the record does not provide a comparative estimate, confidence interval, or test for the primary outcome.
The study is listed as terminated, but the reason for termination is not reported. The registry does not explain whether termination was related to recruitment, logistics, safety, or another consideration, so no cause can be inferred. The listed safety counts are descriptive, and the record does not describe the safety-monitoring or follow-up procedures. These limitations prevent strong conclusions about either comparative effectiveness or comparative safety from the posted results.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Treatment of Severe Destructive Behavior: FCT Versus Wait-List Control — NCT02483572.
- Registry record last updated 2023-09-18; status last verified 2023-08.
- Results first posted 2019-08-29.
- 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
The registry record describes a randomized, parallel-group, unmasked trial of functional communication training versus a wait-list control for severe destructive behavior. Enrollment is listed as 4, and the study status is terminated. The primary endpoint was the rate of destructive behavior in responses per min after treatment or an initial wait period, approximately 16 weeks.
The posted primary endpoint information lists no value for FCT and a wait-list mean of 2.0 responses per min, with a full range of 0.0 to 4.6 and n=1.0. The record says posttest data were not collected because subjects were withdrawn before the posttest period. No primary between-arm analysis is reported. Three secondary outcomes are listed, but their results and analyses are not reported. Safety entries list 0 serious adverse events, 0 other adverse events, and 0 deaths in each arm among the reported at-risk participants.
The available information does not establish the direction, size, or precision of an FCT-versus-wait-list effect. The termination reason, participant flow, missing-data methods, and statistical analysis plan are not reported in the registry record.