Post-operative Pain Control After Pediatric Adenotonsillectomy: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Post-operative Pain Control After Pediatric Adenotonsillectomy (NCT02296840), a randomized phase 4 study. The primary outcome is Faces Pain Score.

2. Clinical Question

The clinical question brings together two concerns described in the registry record: managing pain after adenotonsillectomy and monitoring post-operative bleeding. The primary endpoint is a group mean of summed self-reported pain scores, rather than a direct measure of bleeding or respiratory effects. The secondary endpoint records the number of participants with post-operative bleeding during the stated timeframe.

The posted primary results are based only on children who returned the completed two-week survey. The registry record gives a mean and standard deviation for each group, but does not provide a comparative analysis for this continuous outcome. The results therefore describe the observed scores among survey respondents; they do not establish a quantified between-group effect with a confidence interval or inferential test.

The study status is terminated. The reason for termination is not reported in the registry record. The record also does not report a basis for interpreting the posted findings as a definitive answer to the clinical question. The appropriate reading is descriptive: the posted values show the pain scores recorded for the two groups, while the extent and precision of any group difference remain uncertain.

3. Trial Design

The registry record describes NCT02296840, titled Post-operative Pain Control After Pediatric Adenotonsillectomy, as a Phase 4, randomized, single-blind, parallel-group study sponsored by Emory University. The recorded enrollment is 45. The study start is listed as 2014-11, and primary completion is listed as 2016-11-30. Its status is terminated; the reason is not reported in the registry record.

The interventions were ibuprofen and hydrocodone-acetaminophen, administered after adenotonsillectomy according to the arm descriptions. The registry record states that participants were randomized to the test or control intervention and identifies the study as single-blind. It does not report who was blinded or how blinding was maintained. Further details of allocation procedures are not reported in the registry record.

The brief study description outlines an initial retrospective study intended to collect pilot information on post-operative hemorrhage and indicators of adequate or inadequate pain control, followed by a prospective, randomized, single-blind controlled study. It does not establish which parts of that planned sequence were completed. The registry record does not report a detailed protocol, the criteria for terminating the study, or whether the recorded enrollment reflects all participants who entered the randomized comparison.

The primary endpoint is the Faces Pain Score at two weeks after surgery, reported as a group mean and standard deviation. Its stated analysis population is children who returned the completed survey at two weeks. The secondary endpoint is the number of participants with post-operative bleeding at two weeks. The recorded group sizes differ between the posted primary pain results and the bleeding results, and the registry record does not explain the difference. No detailed analysis population definition beyond the primary survey-return description is reported.

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.

Before assignment: Eight of the 53 individuals who consented to taking part in the study did not meet eligibility criteria, resulting in 45 participants who began the intervention.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Children who returned the completed the survey at two weeks post-surgery.

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.

Population: Children undergoing tonsillectomy who met all eligibility criteria and enrolled in the study.

6. Primary Endpoint

The registry lists the primary outcome as Faces Pain Score, measured over 2 weeks after surgery.

The primary endpoint is the Faces Pain Score at two weeks after surgery. The registry describes the Faces Pain Scale Revised as a dimensionless 10 point Likert scale for self-reported pain intensity, with values from 0 for no pain to 10 for the most pain a child can imagine. Higher scores indicate more severe pain. The children indicated pain at scheduled intervals, described as 7 times per day for 14 days after surgery.

For the posted analysis, participant pain scores were summed and a mean was calculated for each group. The registry description says the total summed scores could range from 0 to 980. The outcome is therefore a summary across repeated pain reports over the stated period, not a single rating at the two-week visit. The endpoint is used to describe reported pain in the post-operative period and compare the group summaries.

A mean gives a measure of the group’s average recorded score, while the standard deviation describes variation in the observed scores around that mean. Neither statistic alone gives the uncertainty in the difference between group means. The registry record does not report a comparative estimate or confidence interval for this continuous endpoint. The posted summaries also apply to children who returned the completed survey, so they do not describe the pain scores of children without a completed survey.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous: each participant contributes a summed pain score, and the posted group summaries are means with standard deviations. General: a mean describes the center of observed measurements, while a standard deviation describes their spread. These summaries are useful for describing a distribution, but they do not by themselves answer how precisely the difference between randomized groups has been estimated. An estimate of that difference and its uncertainty would be needed for a direct inferential comparison.

What does the primary endpoint summarize?

The registry describes repeated child-reported pain ratings using the Faces Pain Scale Revised. Ratings were scheduled 7 times per day for 14 days, and participant scores were summed before the group mean was calculated. The scale runs from 0 to 10, and the registry says summed scores could range from 0 to 980. Because this is a sum across repeated reports, its interpretation differs from the interpretation of one rating at a single time. A lower summed score represents lower reported pain across the recorded assessments, according to the scale description.

The primary result is restricted to children who returned the completed survey at two weeks after surgery. The posted means are 158.9 for ibuprofen and 219.9 for hydrocodone-acetaminophen; the corresponding standard deviations are 9.33 and 21.43. The registry record does not explain why the completed-survey group sizes are n=10 and n=8, or how missing survey responses were handled. No comparative confidence interval or p-value for the primary outcome is reported in the registry record.

How should the secondary risk difference be read?

The secondary outcome is a binary participant-level measure: whether post-operative bleeding was recorded during the two-week timeframe. The posted counts are 2 of 18 for ibuprofen and 0 of 27 for hydrocodone-acetaminophen. The recalculated risk difference is expressed as the hydrocodone-acetaminophen risk minus the ibuprofen risk. Its estimate is -0.111, with a confidence interval from -0.256 to 0.034. The interval includes 0, which represents no risk difference on this scale.

General: a confidence interval conveys uncertainty around an estimated effect under the method used to construct it. An interval that includes 0 for a risk difference does not rule out no difference, and it also does not establish that the groups have identical risks. Here the interval extends on both sides of 0, so the recalculated estimate is not precise enough to isolate a single direction of effect. The unadjusted p-value is 0.076. It is a secondary, unadjusted result, not a substitute for an analysis plan or a complete account of uncertainty.

The comparison is labelled recalculated because it is an unadjusted re-calculation from posted summary counts. The registry record lists no reported analyses for the secondary endpoint. There is no discrepancy flag, so no conflict between a sponsor-reported analysis and this recalculation is identified in the record. This does not make the recalculation a prespecified sponsor analysis; it remains a summary-based calculation.

Why does the analysis population matter?

Randomization is intended to make treatment groups comparable at the time of allocation, but an outcome analysis restricted to survey respondents may not preserve that comparability if response is related to group assignment or pain. The record says the primary analysis population is children who returned the completed survey, but it does not report the number or characteristics of nonrespondents, reasons for missing responses, or any method for handling missing data. It is therefore not possible to assess from the registry record whether the posted primary summaries represent all randomized participants.

The bleeding endpoint has different posted denominators from the primary pain endpoint. The registry record does not explain the difference or report a detailed analysis population definition for this secondary result. These outcomes should be read according to their own stated groups and denominators rather than treated as if they came from an identical analysis population.

What do the planning assumptions mean?

The registry record describes sample-size calculations as planning illustrations based on the observed effect, not the trial’s own design. The stated assumptions are a two-sided significance level of 0.05, equal allocation between the arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. The sample-size section uses participants per arm for non-time-to-event outcomes. These are planning assumptions, not evidence that the study was designed around those assumptions, and they do not represent observed power. The registry record does not report the trial’s original sample-size justification.

General: a planning calculation estimates how much information a future study might need under specified assumptions. It does not show that a completed study had adequate precision, and it cannot repair uncertainty in a small or incomplete observed dataset. Any planning illustration based on an observed effect also depends on that effect being a useful planning value. No sample-size output values are stated in the registry record used for this interpretation.

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("Ibuprofen", "Hydrocodone-acetaminophen")
n   <- c(10, 8)
m   <- c(158.95, 219.94)
sp  <- c(9.33, 21.43)
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  Ibuprofen  10  158.950  9.330  152.276  165.624
CARM  Hydrocodone-acetaminophen  8  219.940  21.430  202.024  237.856

11. Multiplicity, Missing Data and Analysis Populations

The registry record identifies a primary Faces Pain Score endpoint and a secondary post-operative bleeding endpoint. It does not report a statistical analysis plan describing which comparisons were prespecified, how outcomes were prioritized beyond those labels, or whether any adjustment for multiple testing was planned. It also does not report interim analyses. Their presence or absence cannot be inferred from the terminated status alone.

The secondary comparison has an unadjusted p-value of 0.076 and is a recalculation from posted summary counts. No multiplicity adjustment is reported. General: when multiple hypotheses are tested, an unadjusted p-value addresses a single comparison without accounting for the wider set of tests; it should not be treated as confirmatory evidence when the testing context is unknown. The registry record does not describe a broader set of analyses, so the scope of any multiplicity issue cannot be determined.

Missing data are especially relevant to the primary endpoint because its stated population consists of children who returned the completed survey at two weeks after surgery. The posted pain summaries include n=10 in the ibuprofen group and n=8 in the hydrocodone-acetaminophen group. The record does not report how many randomized participants did not return a survey, why responses were missing, whether participants with partial surveys were included, or whether any imputation or sensitivity analysis was used. It is not reported in the registry record whether the analysis followed an intention-to-treat approach.

The bleeding result uses group sizes of 18 and 27, rather than the primary endpoint’s survey-return group sizes. The registry record does not explain the difference or describe missing-outcome handling for the secondary endpoint. The analysis populations therefore should not be assumed to match across outcomes.

The record reports enrollment of 45 and status as terminated, but the reason for termination and any consequences for outcome collection are not reported in the registry record. A detailed statistical analysis plan, sample-size justification, and account of planned versus completed analyses are also not reported. These omissions limit assessment of selective outcome reporting, missing-data bias, and whether the available results represent the intended analyses.

12. Safety Results

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

Deaths

Other (non-serious) adverse events

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

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: hospitalization due to low oral intake and dehydration (5.6%).

The registry record posts serious adverse event figures for both intervention groups. In the ibuprofen group, 1 participant among 18 at risk was recorded with a serious adverse event; in the hydrocodone-acetaminophen group, 0 among 27 at risk were recorded with a serious adverse event. The listed top serious term is hospitalization due to low oral intake and dehydration, with 5.6%. The record does not identify the group for that listed term, so it should not be attributed to either group from these figures alone.

For other adverse events, the posted figures are 1 participant among 18 at risk in the ibuprofen group and 1 among 27 at risk in the hydrocodone-acetaminophen group. Deaths are recorded as 0 in both groups. These are the adverse event figures in the registry record; the record does not provide a detailed narrative, timing, severity breakdown beyond the serious classification, or an analysis comparing groups.

These counts are descriptive and should be read in light of the recorded at-risk groups and the terminated study. They do not establish that an event was caused by an intervention, and the absence of a recorded event in a group does not establish that such an event cannot occur. The registry record does not report additional safety-analysis methods or adjudication details.

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

The posted primary data describe average summed pain scores among survey respondents in the two randomized groups. The ibuprofen group has a mean of 158.9 and standard deviation of 9.33, while the hydrocodone-acetaminophen group has a mean of 219.9 and standard deviation of 21.43. The lower observed mean is in the ibuprofen group. Because the record does not report a comparative analysis for this continuous endpoint, these summaries do not quantify the precision of the between-group difference or support a definitive inference about comparative pain outcomes.

The secondary bleeding data show 2 participants with recorded bleeding among 18 in the ibuprofen group and 0 among 27 in the hydrocodone-acetaminophen group. The unadjusted recalculated risk-difference confidence interval includes 0 and extends in both directions. It is therefore an uncertain estimate, not a definitive finding that there is or is not a difference between groups.

The record does not establish why the study was terminated, whether the planned study sequence was completed, or how missing survey responses were handled. The primary and secondary outcomes also have different posted group sizes. These limitations restrict how far the results can be generalized beyond the participants and outcomes recorded.

General: a randomized design can support causal comparisons when allocation, follow-up, and analysis preserve the randomized groups and the analysis is appropriate to the question. The registry information does not provide enough detail to assess all of those conditions. A difference in descriptive group means is not, by itself, evidence of a treatment effect, and an imprecise secondary comparison is not proof of equivalence. These results are best understood as limited descriptive evidence from a terminated study, not as a complete resolution of the clinical question.

The findings do not establish that either medication is preferable, and they do not provide medical advice. They describe the posted pain summaries, bleeding counts, and adverse event figures, alongside substantial uncertainty about comparative effects and the handling of incomplete data.

14. Why This Trial Matters Statistically

This study illustrates why a reported endpoint and an inferential comparison are not the same thing. The primary outcome is clinically interpretable as a summary of repeated child-reported pain ratings, and the record provides group means and standard deviations. Without an estimated between-group contrast and its uncertainty, however, the reader cannot judge how precisely the observed difference is estimated. Descriptive values answer what was observed in the analyzed respondents; they do not alone answer how compatible the observations are with a range of underlying effects.

It also illustrates the importance of denominators and analysis populations. The primary pain summaries are based on children who returned completed surveys, while the bleeding endpoint has different posted group sizes. Without an account of nonresponse and endpoint-specific analysis populations, it is difficult to assess whether all randomized participants are represented or whether missing information could affect interpretation.

The bleeding endpoint shows another central statistical issue: sparse event counts can yield imprecise estimates. The recalculated confidence interval extends across 0, while the point estimate alone might invite an overly definite reading. A confidence interval communicates that uncertainty and is more informative than treating the point estimate or unadjusted p-value as a standalone conclusion.

Finally, a terminated study with no reported reason, no detailed analysis plan, and no reported primary comparison places limits on what can be concluded. The record includes useful descriptive outcomes, but the missing analysis details matter for interpretation, reproducibility, and planning future work. The planning assumptions described in the registry record should not be confused with the study’s original design justification or with evidence of observed power.

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 for children who returned the completed survey at two weeks after surgery. The registry record does not report the number of missing surveys, the reasons for missingness, or methods used to handle missing data. This restricts interpretation of whether the pain summaries represent the randomized groups beyond survey respondents. The record also does not report a comparative estimate, confidence interval, or p-value for the primary continuous outcome.

The group sizes differ across the posted primary and secondary outcomes. The registry record does not explain this difference or provide enough detail to establish the complete analysis population for each endpoint. The posted bleeding comparison is based on sparse event counts and is an unadjusted recalculation rather than a reported registry analysis.

The study is listed as terminated, but the reason and its effect on planned enrollment, follow-up, or outcome collection are not reported in the registry record. The brief description outlines a retrospective pilot phase followed by a prospective randomized phase, but the record does not establish which components were completed. It also does not report who was blinded, the allocation procedure, detailed eligibility criteria, or the original sample-size justification.

The registry record does not report a detailed statistical analysis plan, interim analyses, or multiplicity procedures. These omissions make it difficult to assess whether the posted results reflect all planned outcomes and analyses. The available information supports description of the recorded results, but not a complete assessment of bias, precision, or generalizability.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Post-operative Pain Control After Pediatric Adenotonsillectomy — NCT02296840.
• Registry record last updated 2018-04-25; status last verified 2018-03.
• Results first posted 2018-03-27.
• 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

NCT02296840 is a Phase 4, randomized, single-blind, parallel-group study sponsored by Emory University. It compares post-operative ibuprofen with hydrocodone-acetaminophen after pediatric adenotonsillectomy and is listed as terminated. Enrollment is recorded as 45.

The primary endpoint is the Faces Pain Score at two weeks after surgery, summarized as a mean and standard deviation among children who returned the completed survey. The record also posts a secondary endpoint for participants with post-operative bleeding. The primary results are descriptive, with no reported comparative analysis; the secondary comparison is an unadjusted recalculation with a confidence interval that includes 0.

The termination reason, detailed analysis plan, missing-data handling, and sample-size justification are not reported in the registry record. The posted results provide limited descriptive evidence, with uncertainty about comparative effects and analysis populations.