Extended-release Epidural Morphine for Acute Post-operative Analgesia Following Selective Dorsal Rhizotomy in Children: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Extended-release Epidural Morphine for Acute Post-operative Analgesia Following Selective Dorsal Rhizotomy in Children (NCT00955877), a randomized na study. The primary outcome is Adequacy of Analgesia as Judged by Age-adjusted Pain Scales.

2. Clinical Question

3. Trial Design

The registry describes a randomized, quadruple-masked, parallel-group trial comparing extended-release epidural morphine with saline after selective dorsal rhizotomy in children with spastic cerebral palsy. The listed intervention groups were DepoDur80, DepoDur120, and Control. The drug was to be placed in the surgical defect before wound closure; the control group received preservative-free saline. The registry does not report the method used to generate the random allocation sequence, how allocation was concealed, or who was included in the quadruple-masking description.

The enrollment figure is 13. For the posted primary outcome, the DepoDur80 group has 6 participants and the control group has 7. The DepoDur120 group has 0 participants and no reported outcome value. The record does not explain why there were no participants in that group, whether the arm was discontinued, or how the enrolled participants were assigned among the intended groups. The total enrollment should therefore not be read as evidence that all three groups contributed primary outcome data.

The trial status is terminated. The registry record lists a start date of 2010-03 and a primary completion date of 2015-01. The reason for termination, timing of termination, and whether the study stopped before its planned enrollment or follow-up are not reported in the registry record. The phase is listed as NA. The sponsor is Washington University School of Medicine.

The record describes scheduled postoperative pain assessment at 24hrs and 48hrs after surgery, with the primary outcome summarized over the 48 hour post-operative period. The registry does not report a statistical analysis plan, target enrollment rationale, or planned allocation ratio. This account describes the posted design and results, rather than filling in design details that are absent from the record.

4. Participant Flow and Accounting

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

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 Adequacy of Analgesia as Judged by Age-adjusted Pain Scales, measured over 48 hour post-operative period.

The primary endpoint is titled “Adequacy of Analgesia as Judged by Age-adjusted Pain Scales.” It summarizes pain scores during the 48 hour post-operative period. The registry describes four age-appropriate scales: FLACC for participants aged 0-3, FACES for participants between the age of 3 and 5, NRS for participants between the age of 5 and 8 years, and INRS for participants greater than or equal to 8 years of age. Each scale ranges from 0-10, with 0 indicating no pain and 10 indicating extreme pain.

Each patient had a score at 24hrs and a score at 48hrs post surgery. The reported endpoint is the average of all scores for all patients within each group, expressed as a mean and standard deviation. The registry does not explain whether scores from the different instruments were transformed or otherwise combined beyond describing the group average.

Using age-appropriate measures allows pain to be assessed in children who may differ in their ability to describe or rate pain. Combining the scores into a group summary offers a concise description of the observed pain measurements, but it does not show the range of individual experiences or the pattern of scores at each assessment time. The outcome is a pain-score summary, not a direct measure of medication use, recovery, or a clinical event.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous: it is a mean pain-score summary, with a standard deviation describing variation among observations. A mean gives a compact summary of the recorded scores, while the standard deviation indicates how spread out those scores were within a group. Neither quantity, considered alone, describes every participant's experience. The values posted are group-level summaries, not individual-level data.

What do the group summaries show?

The registry reports a mean of 0.545 and standard deviation of 1.214 for DepoDur80, with 6 participants. For control, it reports a mean of 1.857 and standard deviation of 1.834, with 7 participants. The scale runs from 0-10, where 0 is no pain and 10 is extreme pain. As a descriptive reading, the DepoDur80 group had the lower posted average score. This statement describes the observed summaries; it is not a claim about the size or certainty of a causal effect.

The registry does not post an estimated contrast between the groups, a standard error for that contrast, a confidence interval, or a p-value. A confidence interval is a statistical range intended to express uncertainty around an estimate under a specified method and its assumptions. Without a posted interval or analysis, readers cannot use the registry results to judge the precision of a between-group estimate. The group standard deviations are not substitutes for an interval around a group difference.

Why does the absent dose group matter?

The intended design names DepoDur80, DepoDur120, and Control, but the primary outcome has no participants or values for DepoDur120. The available summaries therefore cover only DepoDur80 and control. No comparison with the 120 μg/kg dose can be made from these results. The registry record does not report whether the planned analysis changed, why no participants appear in that group, or how the absence of this arm affected the study's analysis.

How should the pain-scale summary be understood?

The registry describes age-adjusted instruments and states that scores from 24hrs and 48hrs were averaged across patients within each group. A group average is useful for a concise summary, but it can conceal variation across people, differences between assessment times, and differences among instruments. The record does not report separate means by assessment time, by age group, or by pain scale. It also does not detail how scores from the instruments were combined beyond the statement that all scores were averaged within each group.

The recorded standard deviations show dispersion in the observed scores. In general, greater dispersion can make a group mean less representative of any one participant and can affect the precision of an estimated comparison. This is a general statistical point; the registry does not report a model that accounts for the score distribution or any adjustment for the repeated measurements within a participant. The posted summary also does not describe whether assumptions for a particular inferential model were evaluated.

What can be learned from the analysis record?

The registry reports no analyses. It does not describe an analysis population, a model, covariate adjustment, a prespecified contrast, or a method for handling repeated pain measurements. It also does not report a statistical analysis plan or sample-size justification. These omissions mean that readers cannot check whether the descriptive endpoint summaries match a planned analysis or determine what inferential procedures were intended.

The sample-size section uses planning illustrations based on an observed effect and stated assumptions. Such illustrations describe hypothetical participant requirements under those assumptions; they are not observed power, proof that the trial was adequately or inadequately powered, or evidence of a result. They should not be confused with an enrollment target or with a sample-size rationale documented by the investigators. The registry record does not report the trial's own design calculation.

Finally, randomization and masking are features of the registered design, not guarantees that every source of bias or uncertainty is removed. The registry identifies the study as randomized and quadruple-masked, but does not describe the implementation details needed to assess sequence generation, allocation concealment, masking success, or departures from the assigned interventions. The small number of participants with posted primary outcome data and the absent DepoDur120 results further constrain interpretation. These are limits on what can be inferred from the record, not evidence about unreported procedures.

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("DepoDur80", "Control")
n   <- c(6, 7)
m   <- c(0.5454, 1.8571)
sp  <- c(1.2136, 1.8337)
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  DepoDur80  6  0.545  1.214  -0.728  1.819
CARM  Control  7  1.857  1.834  0.161  3.553

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome and multiple secondary outcomes, including respiratory depression, hemodynamic instability, CSF leaks, urine retention, nausea and/or vomiting, pruritis, codeine use, and Zofran use. The registry does not report a multiplicity strategy, such as how the interpretation of several outcomes was to be managed or whether any adjustment was planned. The analysis record lists no analyses. It is therefore unclear which outcome comparisons, if any, were prespecified for formal testing.

For the primary outcome, the record posts group summaries for DepoDur80 and control, but no inferential comparison. The DepoDur120 group has no participants or primary outcome value. The registry does not report whether the primary analysis was intended to include all randomized participants, only participants with observed outcomes, or another analysis population. It also does not describe exclusions, protocol deviations, or how participants were handled after randomization.

Missing-data methods are not reported in the registry record. The available information does not explain whether missing pain measurements occurred, how many measurements were available at each time, or whether the group averages include both scheduled assessments for every participant. It also does not report imputation, sensitivity analyses, or a rule for incomplete observations. The absence of a DepoDur120 result is distinct from a stated method for handling missing data; the reason for that absence is not reported.

These gaps matter because multiplicity and missingness can affect how much confidence readers place in observed patterns. Without a documented analysis plan, readers cannot establish how the listed outcomes were prioritized, how incomplete observations were treated, or whether the displayed summaries were selected from a broader set of analyses. No such procedures should be inferred from the registry record.

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.

The posted adverse-event summary reports 0 serious adverse events and 0 other adverse events among 6 participants at risk in DepoDur80. For control, it reports 0 serious adverse events and 0 other adverse events among 7 participants at risk. Deaths are reported as 0 in both groups. The DepoDur120 group has 0 participants at risk and no reported events.

These counts describe what is recorded in the adverse-event summary; they do not establish that no adverse events could occur or that the groups have equivalent safety. In general, an observed count of zero in a small group leaves uncertainty about events that might occur in a larger group or under different follow-up. The registry does not report confidence intervals for these event counts or additional details about ascertainment and reporting.

The listed secondary outcomes include several specific postoperative events, but the adverse-event summary should not be treated as a substitute for detailed results for every secondary endpoint. The record does not provide a full account of event definitions or participant-level event timing. The DepoDur120 group contributes no safety observations in the posted table. Interpret the safety figures as limited recorded counts, not as a comparative estimate of risk.

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

The posted primary outcome is a descriptive comparison of average pain scores for DepoDur80 and saline control during the 48 hour post-operative period. The mean is 0.545 for DepoDur80 and 1.857 for control; the corresponding standard deviations are 1.214 and 1.834. The registry's pain scales range from 0-10, with lower values indicating less pain. The summaries therefore show a lower observed average in DepoDur80 than in control in the posted data.

That observation does not establish the magnitude or precision of a treatment effect. The record does not provide a formal between-group estimate, confidence interval, p-value, or analysis. It does not state a prespecified statistical criterion for judging the primary outcome. The numbers also do not demonstrate that the result would be similar in other participants or settings.

The record gives no primary outcome data for DepoDur120 because that arm has 0 participants in the posted results. This page cannot compare the two intended morphine dose groups or draw conclusions about the unrepresented dose. Nor does the absence of those results explain why the trial was terminated; the reason for termination is not reported in the registry record.

The endpoint itself is an average of age-appropriate pain-scale scores collected at 24hrs and 48hrs. It is not a complete description of each child's pain, and the posted summary does not separate results by assessment time or scale. The data do not directly establish an effect on pain medication use, complications, recovery, or later outcomes.

The adverse-event table reports no events in the groups with participants at risk, but these counts are limited observations from small groups, and the DepoDur120 arm has no safety observations. They do not prove absence of risk. Overall, the record supports a careful description of the posted group summaries and their limitations, not a definitive conclusion about efficacy or safety.

14. Why This Trial Matters Statistically

This trial raises several important statistical issues that are easy to miss when reading only the group averages. First, the registered design names three groups, while the posted primary outcome contains data for only DepoDur80 and control. A missing arm affects the scope of any comparison: the available results cannot address the 120 μg/kg group or compare the two intended doses.

Second, the outcome combines repeated measurements and age-adjusted instruments. The record describes scores at 24hrs and 48hrs and averages them across patients within each group. Such a summary is compact, but it can obscure changes over time, differences among measurement tools, and variation between children. A statistical analysis would need to make clear how the repeated observations and instrument differences were handled; those details are not reported in the registry record.

Third, small groups and absent inferential results make uncertainty central. Means and standard deviations alone do not provide a confidence interval for a between-group contrast. The record lists no analyses, so readers cannot assess a reported estimate's precision or a prespecified test. This is a useful reminder that a visible difference between group averages is not, by itself, a complete statistical result.

Finally, the study is marked terminated, with no reason reported. That context, alongside the incomplete arm-level outcome record, makes transparency about planned analyses, missing data, and study conduct especially relevant. The record does not answer those questions. The case illustrates why statistical interpretation depends not only on numerical summaries, but also on knowing what was planned, what data were observed, and how uncertainty was evaluated.

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 primary outcome is reported only as group means and standard deviations. The registry does not provide a confidence interval, p-value, between-group estimate, or analysis method. Readers therefore cannot assess the precision of a formal comparison or verify how the investigators intended to analyze the endpoint.

The results cover 6 participants in DepoDur80 and 7 in control, while DepoDur120 has 0 participants and no outcome value. The registry does not explain the empty arm, the reason for termination, or whether the intended design changed. The recorded enrollment is 13, but the registry does not provide a participant flow account that would clarify enrollment, allocation, follow-up, and analysis by arm.

The endpoint combines pain scores at 24hrs and 48hrs from four age-appropriate scales. The record does not give separate results by time, age, or instrument, nor detail how the scores from different instruments were combined beyond describing an average of all scores within each group. This limits assessment of whether the group summary represents a consistent pattern across times and measures.

The registry does not report missing-data procedures, an analysis population, a sample-size justification, or a statistical analysis plan. It also does not describe the randomization procedure, allocation concealment, or masking implementation. These details are needed to assess how the registered design was carried out and how robust the results may be to analytic choices.

Safety counts are also limited: no events are reported in the groups with participants at risk, while DepoDur120 has no participants at risk. The registry does not provide event-level detail or precision estimates. These limitations restrict interpretation of both the pain summaries and the safety record; they do not, on their own, establish why the study ended or what results might have been observed with complete data.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Extended-release Epidural Morphine for Acute Post-operative Analgesia Following Selective Dorsal Rhizotomy in Children — NCT00955877.
• Registry record last updated 2018-07-11; status last verified 2018-06.
• Results first posted 2018-06-13.
• 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

This registry record describes a randomized, quadruple-masked, parallel-group trial of extended-release epidural morphine after selective dorsal rhizotomy in children with spastic cerebral palsy. The intended groups were DepoDur80, DepoDur120, and saline control. Enrollment was 13; the trial is listed as terminated. The record lists a start date of 2010-03 and a primary completion date of 2015-01.

The primary outcome was an age-adjusted pain-scale summary over the 48 hour post-operative period. Results are posted for 6 participants in DepoDur80 and 7 in control. The respective means are 0.545 and 1.857, with standard deviations of 1.214 and 1.834. DepoDur120 has 0 participants and no outcome value. The registry lists no analyses and does not report a formal between-group estimate or its uncertainty.

The adverse-event summary reports no serious or other adverse events and no deaths in the groups with participants at risk. The reason for termination, analysis plan, missing-data methods, and sample-size justification are not reported in the registry record.