Acupuncture for Post-Operative Pain Control for Patients Undergoing Gynecological Surgery: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Acupuncture for Post-Operative Pain Control for Patients Undergoing Gynecological Surgery (NCT02855567), a randomized na study. The primary outcome is Morphine Equivalent Usage While in the Hospital.

2. Clinical Question

This is the clinical question implied by the trial's registered intervention and primary outcome. The endpoint is described as mean morphine-equivalent usage in milligrams, with a standard deviation as its measure of dispersion. The registry frames the measurement as a way to assess post-operative pain control through narcotic use. It says medication use was monitored using hospital records when a patient remained admitted, or by telephone when the patient went home before 24 hours after surgery.

The registry record does not report a numerical outcome for either arm, an estimated difference between arms, or an uncertainty interval. It also says the primary outcome has several categories or time points and was not reduced to one comparison. Therefore, the question can be stated from the registered design, but the posted record does not give a numerical answer to it.

3. Trial Design

The registry record describes a randomized, single-masked, parallel trial with enrollment of 110. Its status is completed. The recorded start date is 2016-08-06 and the primary completion date is 2017-12-05. The phase is listed as NA. The sponsor is Icahn School of Medicine at Mount Sinai.

Participants were assigned to acupuncture or sham acupuncture during gynecological surgery. For the acupuncture group, the registry describes needle placement at 5 known points for pain control. An anesthesiologist trained in acupuncture placed the needles after induction of anesthesia while the patient was prepared for surgery; they were to remain in place for 15 minutes. For sham acupuncture, needles were placed at sham points not associated with pain control. The registry says a gynecologic surgeon who was not trained in acupuncture placed them after induction of anesthesia and before the start of surgery. The sham-arm description ends before the full procedure is given, so its remaining details are not reported in the registry record.

Random allocation is intended, in general, to reduce systematic differences between groups at assignment. A parallel design means the groups receive their respective assigned approaches rather than crossing over between them. The registry identifies the masking as single but does not state who was masked in the registry record. It does not report the allocation method, how concealment was implemented, or further operational details of masking.

The primary outcome is morphine-equivalent usage while in the hospital, described as covering the intra-operative period and 24 hours post-operatively. The registry lists four secondary outcomes: pain medication tablets used at home after surgery, hospital readmission, pain score, and pain score at home after surgery. It lists five outcome measures in total. The record does not report a numerical primary outcome comparison or analysis results for these outcomes.

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 Morphine Equivalent Usage While in the Hospital, measured over Intra-operative and 24 hours post-operatively.

The registered primary endpoint is mean morphine-equivalent usage, measured in milligrams. It is intended to summarize narcotic medication use during the intra-operative period and the first 24 hours after surgery. The registry describes this as a measure of pain control, with medication use monitored from hospital records for patients who remained admitted, or by telephone for patients discharged home before the 24-hour point.

Using a common morphine-equivalent scale can, in general, provide a summary when medication use involves narcotics that may differ in type or dose. It expresses use on a shared scale, rather than treating each medication as a separate endpoint. The registry specifies a mean and standard deviation, which indicates that the endpoint was planned as a continuous measurement summarized by its average and spread.

This endpoint captures medication use, not pain experience directly. The registry separately lists pain score and home pain score among the secondary outcomes. Medication use can be influenced by more than pain intensity, including clinical practice and whether measurement came from hospital records or a telephone report. These are general considerations when interpreting a medication-use endpoint; the registry record does not provide information about how such factors were handled.

The record says the primary outcome has several categories or time points and was not reduced to one comparison. It does not report group means, standard deviations, a between-group estimate, or an uncertainty interval. Thus, the endpoint's intended role is clear, but the posted record does not show a numerical result for it.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The record gives some design information, but it does not describe the statistical methods used to analyze the trial outcomes. In particular, it does not report a model, a test, a confidence-interval method, an adjustment strategy, or an analysis population. The concepts below explain how such methods are generally interpreted; they are not claims about methods used in this trial.

What does a mean and standard deviation describe?

For a continuous outcome such as morphine-equivalent usage in milligrams, the mean is the arithmetic average across the measurements included in a group summary. It gives a central description of medication use but can be affected by unusually large or small observations. The standard deviation describes the spread of individual measurements around the mean. A larger spread indicates more variability among the observations, but does not itself indicate whether the group average differs from another group's average.

To compare randomized groups, an analysis might estimate a difference between their means. The difference would describe the contrast in the measurement's original units, here milligrams. An uncertainty interval around that estimate would show a range of values compatible with the data and the assumptions of the analysis. A narrow interval indicates greater precision than a wide one. A p-value, when reported, addresses how compatible the data are with a specified null model; it does not measure the size or clinical importance of an effect. None of these numerical comparison results is reported in this registry record.

Why might the measurement distribution matter?

General statistical considerations apply to medication-use data. Continuous measurements can be skewed, contain many low values, or include a small number of high values. If the distribution is far from the assumptions of a chosen method, a simple comparison of means may require careful interpretation or a different analysis approach. The record does not report the observed distribution, diagnostic checks, transformations, or any alternative methods, so no conclusion can be made about which approach would be suitable for these data.

Over-dispersion is a general issue for count outcomes when the variability is greater than a model expects. It can make standard errors too small if ignored. This may be relevant to some outcomes listed in the registry, such as numbers of tablets used, but the record does not describe the distributions or models for those outcomes. It is not possible to say that over-dispersion occurred in this trial.

What does the time window imply?

The primary endpoint description refers to intra-operative use and use during 24 hours after surgery. It also describes different collection routes: hospital records for participants still admitted, and telephone monitoring for those discharged before the 24-hour point. In general, outcome timing and collection methods matter because all participants need a clearly defined measurement window for a fair comparison. The record does not explain how measurements from the different sources were combined, how incomplete collection was handled, or whether all observations covered the same period.

The record also indicates that the primary outcome has several categories or time points and was not reduced to one comparison. Multiple time points can create several possible contrasts. An analysis plan ordinarily clarifies which contrast is primary and how other comparisons will be interpreted. Without that information, readers cannot identify a single numerical primary comparison from the posted record.

How should planning illustrations be read?

Sample-size calculations are planning tools. In general, they estimate how many participants or events would be needed to detect an effect of a chosen size under specified assumptions. The registry describes its illustrations as based on the observed effect, a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. It also states that the effect to detect is a stated fraction of the observed effect. These assumptions describe illustrations on the page, not necessarily the original design decisions for the trial.

A planning calculation is not observed power. Observed power uses the effect estimate from the completed study and can be misleading as a retrospective summary of evidence. Planning illustrations instead show how a hypothetical design would perform under assumptions. They do not add information about the trial's actual result, and they cannot fill in an unreported effect estimate. The registry record does not report a sample-size justification for the original trial.

The distinction between participants per arm and total events also matters in general. For ordinary outcome settings, a planning table may express a target as participants per arm. Time-to-event settings often express the target as a total number of events. The registry's note distinguishes these conventions. The primary endpoint is described as a continuous measure, not as a time-to-event outcome, and the record does not report an applicable primary-outcome planning value.

Overall, statistical interpretation requires both an estimate and its uncertainty, together with a clear account of what was measured and analyzed. The registry supplies the endpoint definition and some design details, but the result and analysis methods are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists five outcome measures in total: the primary measure of morphine-equivalent usage and secondary measures covering tablets used at home, hospital readmission, pain score, and pain score at home. It does not report a multiplicity strategy, such as prioritizing a family of comparisons, adjusting significance thresholds, or defining a hierarchy of outcomes. The number of analyses is listed as 0. No outcome analysis results are reported in the registry record.

Multiplicity is a general concern when several outcomes, time points, or group contrasts are assessed. Testing many comparisons can increase the chance of seeing an apparently unusual result even if there is no underlying difference. Statistical plans may address this by identifying one primary comparison or by adjusting how evidence is assessed. The registry notes that the primary outcome has several categories or time points and was not reduced to one comparison. It does not explain how those categories or time points were handled in an analysis.

Missing-data handling is also not reported in the registry record. The endpoint description says medication use could be recorded from hospital records or monitored over the phone, depending on whether a patient remained admitted or went home before 24 hours. The record does not state whether any measurements were missing, how missing observations were treated, or whether sensitivity analyses were performed. It also does not specify an analysis population, such as whether the primary comparison was based on all randomized participants or a subset.

These are absences in the registry record, not evidence that missing data or multiplicity problems occurred. Without the analysis plan and results, readers cannot determine how those issues affected the reported findings.

11. Safety Results

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

Deaths

Other (non-serious) adverse events

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

The registry's adverse-event figures list 54 participants at risk in the acupuncture group and 56 in the sham acupuncture group. In the listed figures, serious adverse events affected 0 participants in each group, other adverse events affected 0 participants in each group, and deaths were 0 in each group. The record lists no top serious-event terms.

These figures describe what is recorded in the registry's adverse-event section. A zero count means that no events were recorded in that category for the listed group; it should not be read as proof that no event of any kind occurred or that an intervention is risk-free. The registry record does not explain the event-collection procedures, the period covered, or whether events were assessed using a prespecified definition. It also does not provide further safety details or event narratives.

The listed participants at risk are the denominators for the displayed adverse-event information. They should not automatically be treated as denominators for the primary outcome or as a complete description of outcome follow-up. Safety counts answer a different question from the comparison of medication use, and they do not establish the primary endpoint result.

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

This record can establish the broad structure of the trial: it was randomized, single-masked, and parallel, and compared acupuncture with sham acupuncture during gynecological surgery. It identifies morphine-equivalent usage across the intra-operative period and 24 hours after surgery as the primary outcome. It also describes how medication use was to be monitored and lists several secondary outcomes.

It cannot establish the size or direction of a difference in morphine-equivalent usage. No group means, standard deviations, estimated contrast, confidence interval, or p-value are reported. The record's note that the primary outcome has several categories or time points and was not reduced to one comparison further limits interpretation: the posted information does not identify a single numerical contrast to evaluate. The same lack of results applies to the listed secondary outcomes.

In general, a randomized design can support a comparison between groups when the allocation, follow-up, outcome measurement, and analysis are adequately documented. But design labels alone do not show that groups were comparable in all relevant respects after assignment, nor do they reveal how much uncertainty surrounds an estimated effect. A result needs to be reported and interpreted alongside its precision and the methods used to obtain it. Those details are not available in this registry record.

The adverse-event section lists zero serious events, zero other events, and zero deaths in each group, with 54 and 56 participants at risk respectively. These are registry counts, not a complete characterization of all possible safety outcomes. The record does not describe the scope or completeness of safety monitoring.

Thus, the page supports a description of the registered trial question and its recorded design, but not a conclusion about whether acupuncture changed medication use or pain outcomes. Any planning illustrations are hypothetical calculations under stated assumptions; they are not trial results and should not be interpreted as observed power.

13. Why This Trial Matters Statistically

This trial is statistically interesting because its primary endpoint links a clinical question to a continuous medication-use measure. Reporting a mean and standard deviation can help characterize medication use, but a meaningful comparison also requires the group estimates, a between-group contrast, and a measure of precision. The registry record does not report those results, so the statistical story remains incomplete despite the clear endpoint description.

The collection window also makes the measurement process important. The record describes intra-operative use and medication use during the first 24 hours after surgery, with information gathered from hospital records or by telephone depending on whether a patient remained admitted. In general, changes in source or timing can affect the comparability and completeness of outcome measurements. Transparent reporting of the collection process and how different sources were combined would help readers assess that issue. Those details are not reported.

The record's note that the primary outcome contains several categories or time points is another important statistical point. A clearly specified primary contrast helps readers distinguish the central question from additional analyses and understand how multiple comparisons were treated. Here, the record says the outcome was not reduced to one comparison and does not report a multiplicity strategy or analysis results.

Finally, planning illustrations and observed results answer different questions. A planning section can show how sample-size requirements vary under assumptions, while completed-trial results describe what the data estimate and how uncertain that estimate is. Keeping those purposes separate is essential when interpreting a registry page that documents a completed randomized trial but does not post its outcome analysis.

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 most important limitation for interpretation is that the registry record does not report numerical results for the primary endpoint. It provides no group means or standard deviations, no between-group estimate, and no confidence interval or p-value. The registry also states that the primary outcome has several categories or time points and was not reduced to one comparison, leaving the intended primary contrast unresolved in the posted results.

The statistical analysis is not described. The record does not report a model or test, a method for calculating uncertainty, an analysis population, or an approach to missing observations. It lists five outcome measures and no analyses. It also does not report how multiple outcomes or time points were handled. These omissions prevent readers from assessing the reported analysis because no analysis is posted.

Details of the trial procedures are incomplete in the record. The sham-arm description ends before the full needle-removal procedure is given. The record identifies single masking but does not name the masked party. It does not report the allocation method or concealment procedures. These omissions limit the available description of how the comparison was implemented; they do not establish that the procedures were inadequate.

The endpoint uses different sources for medication-use monitoring, depending on whether a patient remained in hospital or went home before 24 hours. The record does not explain how those sources were reconciled, whether observations were incomplete, or how the measurement period was handled for each participant. Participant characteristics and fuller eligibility criteria are not reported in the registry record.

These are limitations of the registry information available for interpretation. They should not be taken as proof that the full study report or other documentation lacks these details.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Acupuncture for Post-Operative Pain Control for Patients Undergoing Gynecological Surgery — NCT02855567.
• Registry record last updated 2019-06-25; status last verified 2019-06.
• Results first posted 2019-06-19.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

The registry record describes a completed, randomized, single-masked, parallel trial sponsored by Icahn School of Medicine at Mount Sinai. Enrollment was 110. The recorded start date is 2016-08-06, and the primary completion date is 2017-12-05. The phase is listed as NA.

The comparison was acupuncture at known points versus sham acupuncture at points not associated with pain control during gynecological surgery. The primary outcome was mean morphine-equivalent usage in milligrams, described for the intra-operative period and 24 hours after surgery. Four secondary outcomes are listed: home pain-medication tablets, hospital readmission, pain score, and pain score at home.

The registry does not report a primary outcome comparison or statistical analysis results. It says the primary outcome has several categories or time points and was not reduced to one comparison. Its adverse-event figures list zero serious events, zero other events, and zero deaths in each group, with 54 participants at risk in the acupuncture group and 56 in the sham acupuncture group.