The Use of Dexmedetomidine for EEG Sedation in Children With Behavioural Disorders: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for The Use of Dexmedetomidine for EEG Sedation in Children With Behavioural Disorders (NCT03799783), a na phase 2 study. The primary outcome is Number of Patients That Reach a Score Equal or Lower Than 2 Ten Minutes After the Infusion of Dexmedetomidine (Assessed With the PSSS Pediatric Sedation State Scale).

2. Clinical Question

The clinical question concerns whether the planned level of procedural sedation was reached at the specified assessment time in children needing sedation for EEG. This endpoint is about sedation state, not by itself about the quality or interpretability of the EEG, the duration of the procedure, or whether the procedure was completed. Those outcomes are not reported in the registry record.

The study summary also describes recording vital signs and sedation level before, during, and after the procedure until the offset. The listed vital signs are oxygen saturation, respiratory rate, end-tidal carbon dioxide, heart rate, and blood pressure. These measurements describe the monitoring plan; they do not supply results for those measures. The registry record does not report how many children had successful EEG acquisition or how EEG wave patterns were evaluated.

3. Trial Design

This was a completed phase 2 interventional study with a single group and an enrollment of 19. The registry lists the study start as 2018-03-01 and primary completion as 2019-02-28. The sponsor is Azienda Ospedaliera di Padova. These details describe the registry record and do not establish when individual participants were recruited or assessed.

All participants were assigned to the dexmedetomidine group described in the record. Allocation is listed as NA, masking as none, and the study model as single group. No randomized comparison is described. As a result, the design can describe observations in the treated group, but it cannot directly estimate how those observations would differ under another treatment or under no sedation. There is no control group against which to distinguish an intervention-related change from other explanations.

The intervention description specifies intravenous dexmedetomidine, with an initial dose of 2 mcg/Kg that could be repeated up to 2 times, followed by continuous infusion at 1-2 mcg/Kg/hour. The study summary says the protocol aimed for a PSSS score of 2 and describes vital-sign and sedation monitoring before, during, and after the procedure until the offset. The registry record does not report further operational details such as how the infusion was adjusted, who rated sedation, or how departures from the planned dosing were handled.

The registry lists a primary outcome concerning the number of participants reaching a PSSS score equal to or lower than 2, assessed 10 minutes after infusion. It also lists the number of patients with adverse events as a secondary outcome. Although the study is marked completed, the primary endpoint result and an inferential analysis are not reported in the registry record. The registry does not report the protocol’s sample-size justification, an analysis plan, or the reasons for the single-group design.

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 Number of Patients That Reach a Score Equal or Lower Than 2 Ten Minutes After the Infusion of Dexmedetomidine (Assessed With the PSSS Pediatric Sedation State Scale), measured over 10 minutes.

The primary endpoint is the number of participants who reached a PSSS score equal to or lower than 2, assessed 10 minutes after the infusion of dexmedetomidine. The record identifies the PSSS as a validated scale for procedural sedation. It describes a six-item scale ranging from 0 to 5, with 5 representing an alert patient and 0 representing deep sedation with abnormal vital signs. The study summary says the intended target was a score of 2.

A threshold endpoint turns a scale assessment into a count: participants are classified according to whether their score meets the stated cutoff at the stated assessment time. Such a measure can make the study’s target explicit and provide a direct description of how often that target was reached in the group. It does not retain all the detail in the scale. In particular, a count at a cutoff does not show the distribution of scores, how close scores were to the cutoff, or how sedation changed over time.

The timing matters because this endpoint concerns assessment 10 minutes after infusion, not necessarily the whole EEG procedure or the full period of monitoring. The registry record does not report the number who met the endpoint, the total assessed for it, or how missing assessments were handled. It therefore describes what was intended to be measured but does not allow the endpoint result to be interpreted.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The main statistical issue is the distinction between a planned endpoint and a reported result. The registry identifies a primary endpoint as a participant count defined by a PSSS threshold and assessment time. It does not give the endpoint count or an analysis result. A clearly defined outcome can make a study question interpretable, but it cannot establish what was observed when the result itself is absent.

What does a count endpoint represent?

A binary endpoint places each participant into one of two categories for analysis: the stated criterion was met or it was not met. The resulting count is the number meeting the criterion. When a denominator is available, the count can also be described as a proportion. This study’s endpoint definition supplies the criterion and timing, but the registry record does not report the count or the number assessed. No proportion should therefore be inferred from the endpoint description.

Reducing a scale to a cutoff can make a target easier to communicate, but it discards information. Participants on either side of the threshold may have scores close together or far apart, and a threshold count cannot show the full spread of scores. It also does not describe the course of sedation over the procedure. The registry record does not report participant-level scores or a distribution of PSSS results.

Why does the study design matter?

A single-group study provides observations for the group receiving the intervention. Without a concurrent comparator, the data do not directly estimate a between-group treatment contrast. Changes or outcomes observed after treatment can have explanations other than the intervention, including participant characteristics, the procedure, or other aspects of care. This is a general limitation of uncontrolled designs, not a claim about what caused any particular outcome in this study.

Allocation is listed as NA, the model as single group, and masking as none. No randomized allocation or blinded outcome assessment is reported. The record does not explain the rationale for these design choices or provide details about who assessed the PSSS. Because the endpoint involves a scale assessment, information about assessor procedures could help readers evaluate how consistently it was measured; that information is not reported in the registry record.

What can inferential statistics add?

Inferential methods quantify uncertainty around estimates or assess a stated hypothesis. A confidence interval generally gives a range of values compatible with the data and method, while a p-value generally describes how surprising data would be under a specified null hypothesis and assumptions. Neither can be interpreted without a reported estimate, analysis, and relevant assumptions. The registry lists no analyses and reports no confidence interval or p-value for the primary endpoint.

The sample-size assumptions describe a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The assumed effect is described as a stated fraction of the observed effect. These are planning assumptions, not evidence that the trial itself had two arms. The actual trial is registered as single group. The registry record does not report the trial’s own sample-size justification, and a planning illustration must not be read as observed power or as evidence that the primary result was precise.

How should adverse-event counts be understood?

The safety information is descriptive: it reports how many participants were at risk and how many were affected in the listed categories. Counts can identify what was recorded, but without a comparator they cannot estimate a relative difference between treatments. General comparisons of event rates also require consistent definitions, observation periods, and ascertainment. The registry record does not give enough detail to assess those features for the non-serious events.

Over-dispersion is a general statistical concern for some count outcomes: it occurs when observed variability is greater than expected under a simple model. Methods that account for over-dispersion may be appropriate for event counts with repeated events or substantial between-person variation. The posted safety summary is expressed as participant counts, and no model or event-frequency analysis is reported. There is therefore no basis in the registry record for fitting or interpreting an over-dispersion model.

In short, the design and endpoint definitions clarify what the study intended to examine. The absence of a primary result and of inferential analyses limits conclusions about the observed sedation endpoint, while the adverse-event figures remain descriptive counts from one group.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Dexmedetomidine")
n      <- c(19)
events <- c(13)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Dexmedetomidine  19  13  68.4  43.4  87.4  46.0  84.6  45.7  84.6

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 2 outcome measures: a primary sedation endpoint and a secondary outcome titled as the number of patients with adverse events. It does not report a multiplicity strategy, such as a hierarchy of tests or an adjustment for examining more than one outcome. Because no analyses are listed, there are no reported hypothesis tests for which the effects of multiplicity can be evaluated. The record does not establish whether any additional outcomes were assessed outside the registry listing.

Missing-data handling is not reported in the registry record. In particular, it does not state how many participants had a PSSS assessment at the planned time, whether any assessments were missing, or how missing endpoint data would be treated. The enrollment count alone does not establish the number included in a primary analysis. The record also does not describe whether all participants contributed to the adverse-event summary for the same observation period.

Analysis populations are not reported. There is no description of an intention-to-treat population, a per-protocol population, or another defined group used for analysis. These labels have specific implications for which participants are included and how departures from the planned intervention are handled; none can be assigned from the information in the registry record.

These omissions matter because endpoint definitions, multiplicity, missingness, and analysis populations affect interpretation and reproducibility. The completed status and the recorded adverse-event counts do not reveal how the primary outcome was analyzed or whether participants with incomplete assessments were excluded. The registry record also does not report interim analyses or a statistical analysis plan.

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 non-serious adverse event terms

The registry safety summary lists 19 participants at risk for serious adverse events and 0 affected. It lists 19 at risk for other adverse events and 10 affected. The death count is 0. These figures describe counts in the dexmedetomidine group; the study does not include a comparison group.

The distinction between serious and other adverse events is important. A count of 0 serious events means none were recorded as affecting participants in the listed group. It does not establish that the risk is absent or that no event could occur in a larger group or under a different observation period. The record does not report a confidence interval for the serious-event count or describe completeness of follow-up.

The 10 participants recorded with other adverse events are not accompanied by specific event terms in the registry record. The record also does not report event severity within this category, onset, duration, relationship to dexmedetomidine, or whether participants could experience more than one event. The number of affected participants should therefore be read as a broad summary rather than a detailed account of event types or frequency.

These figures are descriptive and do not establish a comparative safety profile. Differences from another treatment cannot be assessed without a comparator and compatible event-collection methods. The record’s safety counts should be considered alongside its lack of detail on event definitions and follow-up.

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

The registry record establishes that a completed phase 2, single-group study enrolled 19 participants and examined dexmedetomidine for sedation during EEG in children with behavioural disorders. It identifies a primary sedation endpoint: the number reaching a PSSS score equal to or lower than 2, assessed 10 minutes after infusion. It also records adverse-event counts for the dexmedetomidine group.

The record does not report the primary endpoint count. It therefore does not show how many participants reached the stated sedation threshold, and it cannot support a conclusion about the frequency of reaching that target. No uncertainty interval or inferential result for the primary endpoint is reported. The endpoint definition alone is not a result.

The safety summary records 0 participants affected by serious adverse events among 19 at risk, 10 affected by other adverse events among 19 at risk, and 0 deaths. These observations describe the recorded group only. They do not show how the counts would compare with another sedative or with no intervention, and they do not establish that serious events are impossible. The specific other adverse events are not reported in the registry record.

The single-group design also limits causal interpretation. Without a comparator, the outcomes cannot separate the effect of dexmedetomidine from other influences on sedation or procedure experience. The record does not report EEG quality, whether the EEG was completed, or the results of vital-sign monitoring. It also does not provide analysis-population definitions or missing-data methods.

Accordingly, the record supports a description of the study question, intervention, design, and posted safety counts. It does not support a statistical estimate of the primary sedation outcome, a treatment comparison, or a complete characterization of safety.

14. Why This Trial Matters Statistically

This study illustrates why outcome definitions and outcome results must be kept distinct. The registry specifies a concrete sedation endpoint, including a PSSS cutoff and assessment time. That clarity helps define what the study intended to measure. But because the endpoint count is not reported, readers cannot assess how often the target was reached or how precise an estimate would be.

The single-group design is also statistically important. It can provide descriptive information about participants receiving dexmedetomidine, but it does not create a concurrent counterfactual for comparison. Even a fully reported endpoint count would not by itself show whether the observed outcomes were attributable to the intervention. A control group and an analysis suited to the design would be needed to estimate a comparative effect.

The safety summary shows a second distinction: a zero count is an observation, not proof of zero risk. Counts from a group of 19 offer limited information about uncommon events, and interpretation also depends on the event definitions and completeness of follow-up. The record gives no specific terms for the 10 participants with other adverse events.

Finally, statistical planning assumptions should not be confused with evidence from the trial. The described planning illustration assumes equal allocation between two arms, whereas the registered study model is single group. Planning calculations are hypothetical illustrations, not observed results and not a substitute for the study’s own sample-size justification. That justification is not reported in the registry record.

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 statistical interpretation is that the registry record does not report the primary endpoint result. The number of participants reaching the PSSS threshold at the specified assessment time is absent, as are the number assessed, any estimate of uncertainty, and an inferential analysis. The study’s completed status does not resolve this gap.

The single-group design has no comparator, so the record cannot support a direct treatment contrast. The lack of masking is recorded, but the registry does not say who assessed the sedation scale or whether any safeguards were used to promote consistent scoring. The intervention description gives the dosing schedule, but details of dose adjustment and adherence are not reported.

The participant description is limited. The registry identifies children with behavioural disorders who required sedation for EEG, but the age range and other participant characteristics are not reported. The record does not report how participants were selected, how many were screened, or whether any enrolled participants did not receive the intervention.

The safety summary is also limited in detail. It reports counts of affected participants but does not list the specific non-serious adverse events, their timing, duration, or relationship to the intervention. The period over which safety was assessed and the completeness of follow-up are not reported. The record does not report EEG quality, procedural completion, or detailed vital-sign results.

Missing-data procedures, analysis populations, multiplicity handling, interim analyses, and the statistical analysis plan are not reported in the registry record. The trial’s own sample-size justification is also not reported. These gaps limit reproducibility and prevent readers from evaluating how planned methods relate to the posted findings.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: The Use of Dexmedetomidine for EEG Sedation in Children With Behavioural Disorders — NCT03799783.
• Registry record last updated 2021-02-02; status last verified 2021-01.
• Results first posted 2021-01-15.
• 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

NCT03799783 is registered as a completed phase 2 interventional study sponsored by Azienda Ospedaliera di Padova. It enrolled 19 participants and is listed as single group, with allocation NA and no masking. The recorded start date is 2018-03-01, and primary completion is listed as 2019-02-28.

The study concerned intravenous dexmedetomidine for EEG sedation in children with behavioural disorders. Its primary endpoint was the number reaching a PSSS score equal to or lower than 2, assessed 10 minutes after infusion. The registry record does not report the primary endpoint result or an analysis.

The safety summary lists 0 serious adverse events among 19 at risk, 10 participants with other adverse events among 19 at risk, and 0 deaths. Specific terms for the other events are not reported. The record does not describe a comparator group, missing-data methods, or analysis populations.