Acupuncture in the Emergency Department for Pain Management: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Acupuncture in the Emergency Department for Pain Management (NCT04880733), a randomized na study. The primary outcome is Successful Recruitment of Participants Into the Study..

2. Clinical Question

The trial also collected treatment outcomes including pain intensity, state anxiety, and pain medication utilization, according to the study description. However, the posted primary result is recruitment, and the available secondary results in this record concern patient satisfaction. The record does not provide posted comparative results for pain intensity, anxiety, or medication utilization.

The randomized design was intended to inform procedures for a future fully powered multisite trial. Accordingly, the central question answered by the primary endpoint is whether recruitment could be achieved across the participating emergency-department sites, rather than whether the intervention produces a definitive clinical effect. Site-specific recruitment is relevant because a multisite study must be workable across different settings, not only in aggregate.

3. Trial Design

This was a completed, randomized, double-masked, parallel-group feasibility study. The registry names acupuncture and usual care as the two intervention arms. The brief study description characterizes the planned assignment as 1:1 and describes the study as a multisite trial intended to refine procedures for a future fully powered trial. The record does not explain who was masked or how masking was implemented.

The participating sites named in the study description were University Hospitals/Case Western Reserve University, Vanderbilt University Medical Center, and the University of California-San Diego. The description says sites would participate sequentially, allowing implementation evaluation findings to inform later sites. The planned study description says 165 participants would be enrolled, while the registry enrollment field reports 290. The record does not explain this difference. The posted safety risk sets are reported separately for the acupuncture, usual-care, and ED staff/provider groups.

The study began on 2021-05-03, reached primary completion on 2022-09-24, and has completed status. Its phase is listed as NA. The brief description includes development of a manualized acupuncture intervention and training of study coordinators and acupuncturists. It also describes qualitative interviews as part of the broader feasibility work. The registry record does not give enough detail to assess the interview methods or findings.

The primary endpoint was recruitment, not a treatment-effect measure. Secondary outcomes listed in the registry include participant retention and satisfaction measures, as well as provider satisfaction. The posted results include three patient-satisfaction comparisons; the record does not report sponsor analyses for those comparisons. The randomized design makes an intervention comparison possible, but the posted results and analysis information do not establish that a definitive clinical-effect analysis was conducted.

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: At the moment of consent,165 patients were randomized to group. However, 14 (7 per group) did not provide outcomes as detailed below. Complete participants were 151 at Post-Treatment. A sample of ED providers at the sites answered 2 questions on the appropriateness and helpfulness of acupuncture being provided in the Emergency Department. Individuals with direct exposure to ACUITY answered 2 more questions on satisfaction and burden of conducting ACUITY in their ED.

Participants in the RCT (Overall Study)

Reasons for not completing this period:

ED Staff/Providers 6 Month Assessment

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Patients who were eligible AND approached.

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: Demographics and initial conditions of participants providing pre and post pain scores in part of the RCT. Or the demographics of the ED Staff/Providers who answered several questions at the 6 month point after recruitment in their ED was complete.

6. Primary Endpoint

The registry lists the primary outcome as Successful Recruitment of Participants Into the Study., measured over At Enrollment.

The primary endpoint measures recruitment into the study. The registry defines the recruitment rate as the number enrolled divided by the number approached, assessed overall and separately by site. The result is intended to describe whether eligible patients who were approached could be recruited, an operational question central to a feasibility study.

The posted overall recruitment rate is 26.1% among 632 approached. The site-specific values are 27.7% at University Hospitals/Case Western among 220 approached, 16.3% at VUMC among 300 approached, and 49.1% at UCSD among 112 approached. These are descriptive recruitment results, not randomized treatment comparisons. No confidence intervals or formal site-comparison analyses are reported in the registry record.

Recruitment is used in feasibility research because it indicates how well a study can enroll participants under its recruitment procedures and across its settings. A multisite average can conceal variation among sites, so the site-specific rates provide useful context for implementation. These results do not, by themselves, show whether acupuncture improves pain, changes medication use, or affects anxiety. Those are different outcomes and require their own reported data and analyses.

The registry’s primary endpoint is expressed as a percentage, but the record does not provide a target recruitment rate against which to judge success. It also does not explain whether the endpoint was compared with a prespecified feasibility threshold. The recruitment numbers should therefore be read as observed descriptive rates, rather than as a pass-or-fail test of feasibility.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a recruitment rate describe?

In general, a recruitment rate relates the number of people enrolled to the number approached. It describes a study process, not an outcome caused by the assigned intervention. This registry defines the measure that way and gives an overall value and separate site values. The site figures help readers see that recruitment differed across the participating settings. They do not show why it differed: information about site-level recruitment procedures, patient characteristics, or reasons for declining is not reported in the registry record.

The record presents recruitment percentages without confidence intervals. In general, a confidence interval communicates the uncertainty around an estimate under a specified statistical model. Without intervals or a reported comparison analysis, the observed site rates can be compared descriptively, but the precision of each rate and the evidence for differences between sites cannot be assessed from the posted result alone. The registry also does not report a target rate or threshold, so no formal feasibility criterion can be evaluated.

How should the satisfaction comparisons be read?

The satisfaction outcomes are reported as means and standard deviations, with separate arm summaries at each assessment. A mean is the arithmetic average of the recorded scale responses. A standard deviation describes the spread of individual responses around that average; it is not the uncertainty interval for the mean. The scale units are reported, but scale anchors and the full scoring interpretation are not reported in the registry record.

The mean difference compares the reported acupuncture and usual-care means. A positive estimate in these results means the reported acupuncture mean is numerically higher. The confidence interval gives a range of values compatible with the observed data under the calculation’s assumptions. A wide interval indicates less precision about the size of the difference; an interval close to zero indicates that small differences remain compatible with the data. Neither an interval nor a p-value establishes clinical importance. The registry does not report a threshold for a meaningful difference on these satisfaction measures.

The displayed comparisons are simple unadjusted recalculations from posted summary statistics, and the registry reports no sponsor analyses for them. They do not incorporate any unreported covariate adjustment or other modeling. The record indicates no discrepancy for these recalculations. If a discrepancy between a recalculation and a sponsor analysis were present, the sponsor’s own analysis would take precedence; no such discrepancy is indicated for these results.

An unadjusted p-value measures how incompatible the observed data are with a specified null model, under the assumptions of the calculation. It is not the probability that the null hypothesis is true, and it does not measure the size or importance of a difference. The two post-treatment p-values are reported as p < 0.001, while the one-week p-value is 0.049. Because the record includes multiple secondary outcomes and does not report a multiplicity plan, these values should be understood as unadjusted and interpreted cautiously.

What do the planning illustrations mean?

The sample-size illustrations use the observed satisfaction effects as planning inputs; they are not the trial’s original design calculation and are not observed power. They assume a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The rows illustrate planning for 100%, 75%, and 50% of the observed effect. The resulting values are participants per arm for 80% power and participants per arm for 90% power. These are hypothetical planning estimates conditional on the assumptions, not evidence that the completed study had a particular probability of detecting an effect.

Using an observed effect as the basis for future planning can be optimistic, especially when an estimate is uncertain or comes from a feasibility study. Considering smaller fractions of the observed effect is one way to illustrate how required sample size changes if the effect targeted in a later study is more modest. In general, smaller target effects require more participants to detect reliably, all else equal. The posted illustrations do not establish the appropriate target effect for a future trial; that choice requires substantive justification that is not reported in the registry record.

Why does variation matter?

In general, greater variability in responses makes a mean difference harder to estimate precisely. The standard deviations in the posted satisfaction summaries describe observed spread and inform the recalculations. The standardized effect-size values in the calculations express the mean differences relative to pooled variability. Such standardization can help compare effects measured on different scales, but it does not establish clinical importance and does not remove uncertainty in a small or incomplete dataset.

These satisfaction measures are continuous summaries. The registry does not report whether the scale responses were treated as approximately normally distributed in a sponsor analysis, whether robust methods were used, or whether any adjustment was made for site. The normal approximation is stated for the planning illustrations, but that assumption should not be extended to other analyses without evidence. The analysis plan, model specifications, handling of site effects, and any interim analyses are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists multiple secondary outcomes, including retention, patient satisfaction, and provider satisfaction. It posts ten secondary outcomes, but comparative numerical results are available for only three satisfaction measures in the record. No sponsor-reported analyses are listed for those comparisons. A multiplicity adjustment, prespecified outcome hierarchy, or strategy for controlling false-positive findings is not reported in the registry record.

In general, when several outcomes or comparisons are tested, unadjusted p-values do not account for the number of opportunities to find a result that appears statistically unusual. This does not make the individual estimates unusable, but it means the p-values should be considered exploratory unless an appropriate analysis plan supports a confirmatory interpretation. The one-week result, in particular, should not be treated as decisive merely because its unadjusted p-value is 0.049.

Missing-data methods are not reported. The registry does not describe how incomplete satisfaction responses or missed follow-up were handled, whether any imputation was used, or whether sensitivity analyses were performed. The numbers contributing to the posted summaries vary by measure and time point, but the record does not state why. It is therefore not possible to determine whether the observed responses represent all participants as intended or whether missingness could affect the comparisons.

The analysis population is also not reported. Although the trial is randomized, the registry does not say whether analyses followed intention-to-treat principles, used a per-protocol population, or applied another definition. The handling of protocol deviations, treatment received, site, and other covariates is not described. Interim analyses and stopping rules are not reported either. These omissions limit assessment of the analysis choices and of how closely the posted findings correspond to the randomized design.

For recruitment, the registry reports an overall rate and rates by site but no uncertainty intervals or inferential comparison. It does not report a prespecified benchmark or decision rule for judging feasibility. These missing details matter because a feasibility conclusion often depends not only on the observed rate but also on the target, precision, and operational criteria defined in advance.

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 5% reporting threshold.

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: hospitalization for suspected stroke (1.2%), death (1.2%).

The posted serious adverse event figures list one serious event among 83 participants at risk in the acupuncture group and one among 82 participants at risk in the usual-care group. The ED staff/providers group has zero serious events among 125 at risk. The registry lists one death in the acupuncture group and zero in the other two groups. It does not provide details connecting the death to the serious-event term, treatment, or cause; no causal conclusion can be drawn from these counts alone.

The serious-event terms listed among the top entries are hospitalization for suspected stroke and death, each reported as 1.2%. These entries describe the posted registry terms and percentages; the record does not establish that either event was caused by acupuncture or by usual care. The posted counts for other adverse events are zero in each group.

These figures are descriptive and sparse. They do not provide a precise comparison of safety between arms, and the risk sets are not a substitute for a full account of event timing, severity, relatedness, or follow-up. The registry record does not report further narrative detail or an adjusted safety analysis. The figures should therefore be read as the adverse-event information posted, not as proof of either harm or safety.

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

The primary result shows that recruitment was achieved at different observed rates across the participating sites. Overall recruitment was 26.1%, while the site-specific rates varied from 16.3% to 49.1%. This is relevant to the practical question of whether a future multisite study can enroll participants under comparable procedures. Because the record gives no recruitment target, confidence intervals, or formal feasibility decision rule, it does not establish whether the observed rates met a prespecified standard.

The secondary satisfaction comparisons show numerically higher reported means in the acupuncture arm for the posted questions. Their confidence intervals and unadjusted p-values describe the precision and statistical compatibility of the comparisons under their calculation assumptions. They do not establish that acupuncture changes pain or other clinical outcomes. Results for pain intensity, state anxiety, and pain medication utilization are not reported in the registry record.

The randomized design is relevant to treatment comparisons, but design alone does not determine how the analysis was conducted or whether all randomized participants contributed to each result. The registry does not report the analysis population, handling of missing data, multiplicity strategy, or sponsor analyses for the posted satisfaction comparisons. That limits the strength and completeness of interpretation.

This feasibility study should not be treated as a definitive efficacy trial. Its stated purpose was to refine procedures for a future fully powered multisite trial. The planning illustrations based on observed satisfaction effects are not observed power and do not establish a sample-size target without further justification. They are conditional examples under specified assumptions.

Overall, the record provides useful descriptive information about recruitment and selected satisfaction summaries, as well as sparse adverse-event counts. It does not provide a complete clinical-outcome assessment or enough analysis detail to determine the robustness of the secondary comparisons. No medical decision should be inferred from these registry results alone.

13. Why This Trial Matters Statistically

Feasibility studies address questions that must be answered before a larger trial can be designed and conducted well. Recruitment is one such question: the overall rate communicates the broad enrollment experience, while site-specific rates reveal that performance varied across settings. That variation can inform planning for recruitment procedures and coordination in a future multisite study, although the record does not identify its causes or define a target rate.

The study also illustrates why feasibility and efficacy should be kept distinct. Recruitment is a process measure; satisfaction is a participant-reported outcome; pain intensity, anxiety, and medication use are separate clinical outcomes. A favorable pattern in one domain cannot be used to fill in missing results in another. The registry’s primary result therefore contributes to implementation understanding without settling the treatment-effect question.

Statistically, the record highlights the need to interpret effect estimates alongside their uncertainty and analysis context. The post-treatment satisfaction comparisons have confidence intervals and unadjusted p-values, but the analyses are recalculations from summary statistics rather than sponsor-reported analyses. The one-week interval is close to zero at its lower end, and multiple secondary outcomes are listed without a reported multiplicity plan. These features argue for cautious, exploratory interpretation rather than a single definitive reading of the p-values.

The planning illustrations also demonstrate a useful distinction: sample-size calculations describe what a future study might need under stated assumptions; they do not measure the power that the completed study actually had. Using fractions of the observed effect gives alternative scenarios, but a future trial’s target effect and design require independent justification.

Finally, the record shows how missing methods information can constrain interpretation even when numerical summaries are available. Analysis populations, missing-data procedures, and a recruitment benchmark are not reported. A future study can make these decisions explicit in advance, making feasibility judgments and treatment estimates easier to evaluate.

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 primary endpoint is descriptive, and the registry does not report a target recruitment rate, confidence intervals, or a formal comparison among sites. The observed site variation cannot be attributed to any particular cause because site-level processes and reasons for non-enrollment are not described. Without a prespecified criterion, the recruitment result alone cannot establish that feasibility objectives were met.

The registry enrollment field reports 290, whereas the brief study description says 165 participants would be enrolled. The record does not explain this difference, so the enrollment field and planned number should not be treated as interchangeable or reconciled by assumption. The posted randomized-arm safety risk sets are also reported separately from the recruitment endpoint.

There are limited posted comparative results. The record does not report the described pain-intensity, anxiety, or pain-medication outcomes, and it does not include sponsor analyses for the satisfaction comparisons. Those comparisons are simple unadjusted recalculations from summary statistics, with no reported adjustment for site or other covariates. The registry does not describe the satisfaction scale anchors or a threshold for an important difference.

Additional limitations are missing information about analysis populations, missing-data handling, follow-up completeness, multiplicity, and prespecified hypotheses. The numbers contributing to the satisfaction summaries vary across measures and time points, but reasons for that variation are not reported. The registry also does not give details about the double-masking procedures, usual-care practices, or the association and timing of adverse events.

These limitations do not invalidate the posted descriptive results, but they narrow what can be concluded from them. In particular, the record cannot establish a definitive treatment effect or a complete benefit-risk assessment. The study’s stated feasibility purpose should guide interpretation of the available recruitment information.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Acupuncture in the Emergency Department for Pain Management — NCT04880733.
• Registry record last updated 2026-01-05; status last verified 2025-12.
• Results first posted 2024-02-20.
• 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

NCT04880733 is a completed randomized, double-masked, parallel-group feasibility study of acupuncture versus usual care for pain management in the emergency department. The study description names three participating sites and describes the goal of refining procedures for a future fully powered multisite trial. The registry lists enrollment as 290; the brief description states a planned enrollment of 165, and the record does not explain the difference.

The primary posted endpoint is recruitment among eligible patients approached. The overall rate is 26.1%, with site-specific rates of 27.7% at University Hospitals/Case Western, 16.3% at VUMC, and 49.1% at UCSD. Posted secondary results include three patient-satisfaction comparisons, all recalculated without adjustment from summary statistics. The registry reports no sponsor analyses for those comparisons.

Recruitment and satisfaction results do not establish effects on pain intensity, anxiety, or medication use; those outcomes are not reported in the registry record. Multiplicity handling, missing-data methods, and analysis populations are also not reported.