Transcutaneous Electroacupuncture for Gastrointestinal Motility Disorders: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Transcutaneous Electroacupuncture for Gastrointestinal Motility Disorders (NCT04349891), a randomized na study. The primary outcome is Change in the Gastroparesis Cardinal Symptom Index (GCSI) Score.

2. Clinical Question

The registry’s background describes gastrointestinal dysmotility symptoms such as nausea, vomiting, fullness, early satiety, bloating, and abdominal discomfort. It also notes the investigators’ hypothesis that TEA might affect gastrointestinal symptoms, motility, and quality of life. That hypothesis is a rationale for the study, not a result. Although the record lists constipation-related and quality-of-life outcomes as secondary measures, their names alone do not show whether those outcomes changed. The available record therefore defines a clinical question and an intended comparison, but does not answer that question with outcome estimates.

3. Trial Design

This was a randomized, quadruple-masked, crossover study of transcutaneous electroacupuncture for gastrointestinal motility disorders. The listed condition is gastroparesis. The registry reports enrollment of 27 and a status of terminated. The study began on 2020-10-01, and the primary completion date is listed as 2022-07-29. The phase is recorded as NA. The sponsor was Johns Hopkins University.

In a crossover design, participants receive more than one intervention in sequence, allowing outcomes under different conditions to be compared within the same participant. The record describes two sequences. One begins with TEA at ST36 and PC6 for 4 weeks, followed by a 2-week washout, then 4 weeks of sham TEA. The other begins with sham TEA for 4 weeks, has the same 2-week washout, and then proceeds to 4 weeks of TEA at ST36 and PC6. Random assignment to sequence is reported; the method of sequence generation is not reported in the registry record.

Quadruple masking is recorded, but the registry excerpt does not identify which participant, investigator, assessor, or other roles were masked, or explain how masking was maintained. The record also does not state whether the washout period was selected to address carryover, or how any possible carryover or period effects were handled analytically. These details matter in crossover studies because outcomes in a later period can be influenced by the earlier intervention, by time, or by changes in the underlying condition.

The primary endpoint was a change in GCSI score over up to 10 weeks. The registry lists secondary outcomes for spontaneous complete bowel movements, constipation symptoms, upper gastrointestinal quality of life, and health dimensions measured by the SF-36v2 Health Survey. The record does not report results for these outcomes. Nor does it describe the reason for termination or whether all planned study procedures were completed.

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: Once the inclusion and exclusion criteria were satisfied, patients were assigned randomly to either the treatment group or the sham group. No subjects were excluded prior to the assignment of participants to their respective groups.

First Intervention - 4 Weeks

Reasons for not completing this period:

Washout - 2 Weeks

Reasons for not completing this period:

Second Intervention - 4 Weeks

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The number of participants analyzed are the ones who completed each study intervention.

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 Change in the Gastroparesis Cardinal Symptom Index (GCSI) Score, measured over Up to 10 weeks.

The primary endpoint was change in the Gastroparesis Cardinal Symptom Index (GCSI) score, reported as a mean with standard deviation, over a timeframe of up to 10 weeks. The index covers 9 symptoms: nausea, retching, vomiting, stomach fullness, inability to finish a normal-sized meal, excessive fullness after meals, loss of appetite, bloating, and a visibly larger stomach or belly. Each symptom is graded from 0 to 5, from none to very severe. The total score can range from 0 to 5, with higher scores indicating greater symptom severity.

A symptom index can provide a structured way to summarize multiple experiences relevant to the condition, rather than focusing on a single symptom. A change score describes how the measured score differs over the stated assessment period. The registry’s choice of GCSI makes symptom severity the primary focus; it does not directly measure gastric emptying or another physiological process. The record says that the analyzed participants are those who completed each intervention, but does not describe how individual symptom responses were combined beyond identifying the GCSI total score.

The registry record does not report a mean change, standard deviation, comparison between TEA and sham TEA, confidence interval, or test result for this endpoint. Consequently, the endpoint definition explains what the study intended to measure, but the posted information does not quantify the change or its precision.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a randomized crossover design, with participants assigned to an order of TEA and sham TEA. In this design, each participant can contribute observations under both conditions. The intended comparison is therefore not simply a comparison of two unrelated groups: the sequence and period in which each intervention is received can matter. The registry does not report the statistical model used to account for this structure, whether the analysis was paired, or how period and sequence effects were assessed.

What does randomization contribute?

In general, randomization helps balance measured and unmeasured characteristics across assigned groups or sequences, on average, and reduces the risk that assignment is determined by prognosis. In a crossover trial, randomization of treatment order can help distribute order effects across sequences. Randomization does not ensure that all participants complete all periods, and it does not remove potential carryover from an earlier intervention. The method used to generate the sequence and any allocation-concealment procedure are not reported in the registry record.

How should a crossover comparison be understood?

In general, a crossover comparison uses within-participant information, which can reduce the influence of stable differences between participants. This benefit depends on appropriate design and analysis. If the effect of the first period persists into the next period, if the outcome changes over time independently of treatment, or if completion differs across periods, a simple comparison may be misleading. The registry describes a 2-week washout between 4-week intervention periods, but does not report evidence that this washout was sufficient or a plan for testing or adjusting for carryover and period effects. These are unknowns, not evidence that such effects occurred.

What do the reported summary measures mean?

The primary endpoint is described as a mean change in a continuous score, with standard deviation. In general, the mean summarizes the average score change among the analyzed observations. The standard deviation describes how much individual observations vary around that mean; it is not the same as the uncertainty in the estimated mean. The registry record gives the measure and summary format but reports no numerical mean, standard deviation, or treatment contrast. The result therefore cannot be reconstructed or judged for variability from the posted information.

In general, a confidence interval communicates uncertainty around an estimated quantity, under the assumptions of the statistical method used. A narrower interval indicates greater precision for that estimate, while a wider interval indicates less precision. A confidence interval is not a guarantee that the true value lies within a particular calculated interval. No confidence interval is reported for the primary endpoint, so the precision of any treatment comparison is unknown.

Why can over-dispersion matter?

In general, over-dispersion means that the observed variability in a count outcome exceeds what a chosen statistical model expects. If it is ignored, standard errors can be too small and inference can appear more certain than warranted. This concept is especially relevant to some count outcomes, such as numbers of bowel movements, but the registry does not report an analysis model or evidence of over-dispersion for any outcome. It is therefore a general consideration, not a finding about this study.

The primary GCSI score is continuous as described in the registry, while one secondary outcome concerns the number of spontaneous complete bowel movements. Different outcome types may call for different statistical approaches. In general, count data may have skewed distributions or many repeated measurements, while continuous scores can also depart from model assumptions. The statistical plan, distributional checks, adjustment strategy, and handling of repeated observations are not reported in the registry record.

What can be learned from a p-value?

In general, a p-value measures how unusual data at least as incompatible with a specified null hypothesis would be, assuming that hypothesis and the statistical model. It is not the probability that the null hypothesis is true, nor a measure of the size or importance of an effect. A p-value also does not replace an effect estimate and an uncertainty interval. No primary outcome p-value is reported, so there is no such test result to interpret for TEA versus sham TEA.

The registry’s sample-size assumptions describe a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation; the effect to detect is framed as a stated fraction of the observed effect. Such an illustration is not the trial’s observed result and is not observed power. The actual numerical planning outputs and the trial’s own sample-size justification are not reported in the registry record. Without a posted outcome estimate, no numerical effect or precision can be inferred from those general assumptions.

10. Multiplicity, Missing Data and Analysis Populations

The record lists a primary outcome and several secondary outcomes, and notes that the primary outcome has several categories or time points rather than one reduced comparison. It does not report which specific primary time point or comparison was selected for inferential testing, whether outcomes were prioritized beyond the primary designation, or how multiple tests were handled. There is no reported multiplicity adjustment, hierarchy, or strategy for controlling the chance of false-positive findings across outcomes and time points. These details are not reported in the registry record.

Missing data are important in a crossover study because participants may complete one intervention period but not the other, or may have incomplete symptom assessments. The endpoint description says that participants analyzed are those who completed each study intervention. This identifies a completion-based analysis population but does not explain the number of participants in it or whether participants with incomplete observations were excluded. The record does not report reasons for missing data, how incomplete questionnaires were handled, whether any imputation was used, or whether sensitivity analyses were performed.

The record also does not describe an intention-to-treat analysis, a per-protocol analysis, or the statistical handling of participants who did not complete both periods. It is therefore unclear how the reported enrollment of 27 relates to the primary analysis population. In general, analyses restricted to completers can be affected if completion is related to symptoms, tolerability, or other factors associated with outcomes. This is a general concern, not a claim that such bias occurred in this trial.

Although the registry lists adverse-event counts for both intervention groups, it does not explain missing safety assessments or the time window used to attribute events. Together, the lack of outcome-level analysis details and participant accounting limits assessment of how complete and comparable the available data were.

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

The registry record establishes that a randomized, quadruple-masked crossover study was registered to evaluate TEA at ST36 and PC6 against sham TEA, with change in GCSI score as the primary endpoint. It also describes the treatment sequence, washout, symptom scale, and secondary outcome topics. These details explain the intended clinical question and how the interventions were organized.

The record does not establish whether GCSI scores improved, worsened, or differed between TEA and sham TEA. It includes no primary outcome effect estimate, uncertainty interval, or statistical test. It therefore cannot support a statement that either intervention produced a greater change, that the conditions were equivalent, or that a meaningful difference was ruled out. Lack of a reported analysis is not evidence of no effect.

The reported enrollment of 27 is not itself an efficacy result. The record does not state the number of participants included in the primary analysis or explain the trial’s termination. Similarly, adverse-event entries describe reported counts, but absent event details, denominators for serious events, and a clear account of exposure across crossover periods, they do not provide a complete comparison of harms.

In general, a clinical result is interpreted by considering the estimated effect, its precision, the outcome definition, and the design and analysis assumptions. A statistically detectable difference would not alone establish that the difference is important to patients; a non-significant result would not by itself establish equivalence or absence of an effect. Since no primary estimate is reported, those considerations cannot be applied to the study’s primary question. The appropriate interpretation is limited to the study’s registered design and the absence of a posted primary outcome analysis.

12. Why This Trial Matters Statistically

This study is statistically interesting because its crossover structure makes the comparison dependent on more than the intervention labels. Participants were scheduled to receive both TEA and sham TEA, with order randomized and a washout between periods. This design can use each participant as their own comparator, but interpretation depends on completion in both periods and on whether period, sequence, or carryover effects were addressed. The registry describes the treatment schedule without reporting how those features were incorporated into analysis.

The primary endpoint is a symptom score that combines several patient-reported experiences. This makes the definition of the total score and timing of measurement important to interpretation. The record describes the symptoms, grading range, and direction of severity, but gives no numerical changes or estimate of the between-condition contrast. A clear endpoint definition cannot substitute for a result or its uncertainty.

The record also illustrates why enrollment is not interchangeable with an analyzed sample. It reports enrollment of 27 while defining the primary analysis population by completion of each intervention, without reporting the number of completers. In a crossover study, incomplete participation can affect the available within-person comparisons. Without disposition and missing-data details, readers cannot assess how much information contributed to the intended comparison.

Finally, the record has a terminated status and no listed primary analysis. It documents a planned clinical question but does not give the statistical evidence needed to answer it. This distinction matters: design details indicate what investigators intended to evaluate, whereas estimates and their precision are needed to describe what the collected data show.

13. 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.

A central limitation of the available record is that it contains no primary outcome analysis. No GCSI change estimate, standard deviation, treatment contrast, confidence interval, or p-value is reported. The primary outcome is also flagged as involving several categories or time points rather than one comparison, so the specific comparison intended for interpretation is not clear from the posted information.

Participant accounting is incomplete. The record reports enrollment of 27, but the primary outcome description defines analyzed participants as those who completed each intervention. It does not report completion counts, period-specific observations, withdrawals, or reasons for non-completion. The reason for the terminated status is not reported in the registry record. These gaps prevent assessment of the analyzed population and the completeness of the crossover data.

Important analytic details are also absent. The record does not report how randomization was generated, which roles were masked, how the crossover structure was modeled, or how potential period and carryover effects were considered. It does not describe missing-data methods, the analysis population beyond completion, adjustment for multiple outcomes or time points, or a detailed statistical analysis plan. The trial’s own sample-size justification is not reported in the registry record.

Safety information is limited to counts. The entries list 22 at risk and 1 affected for other adverse events in each intervention group; serious adverse events have 0 at risk and 0 affected, and deaths are listed as 0. There are no event descriptions or explanations of the reported denominators. Because treatment is crossed over, the record also does not clarify whether the intervention-group counts represent distinct participants over the full study. These limitations concern what can be assessed from the registry record and do not establish that an unreported analysis or event did not occur.

14. Related Tutorials

15. Related Statistical Calculators

16. Sources

• ClinicalTrials.gov: Transcutaneous Electroacupuncture for Gastrointestinal Motility Disorders — NCT04349891.
• Registry record last updated 2024-09-19; status last verified 2024-09.
• Results first posted 2023-11-24.
• 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.

17. Record Summary

The registry record describes a randomized, quadruple-masked crossover study of transcutaneous electroacupuncture at ST36 and PC6 versus sham TEA for gastroparesis. It reports enrollment of 27, a terminated status, and a primary completion date of 2022-07-29. Participants were scheduled to receive two 4-week intervention periods separated by a 2-week washout, in randomized order.

The primary outcome was change in GCSI score over up to 10 weeks. The registry specifies a score range from 0 to 5, with higher scores reflecting greater symptom severity, and identifies completers of each intervention as the analyzed population. It lists secondary bowel, constipation-symptom, and quality-of-life outcomes. No primary outcome analysis is listed, and the reason for termination, completion counts, and detailed statistical methods are not reported in the registry record.