Nurse Initiated Acupressure for Pain Management: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Nurse Initiated Acupressure for Pain Management (NCT04044716), a randomized na study. The primary outcome is Visual Analogue Pain Scale.

2. Clinical Question

This is a comparison of group-level pain scores in a randomized, parallel-group pilot study. Its stated purpose was to test the feasibility of nurse-initiated postoperative bilateral auricular acupressure as an adjunct to medication. The registry record gives outcome results, but it does not report a separate measure of feasibility or describe criteria for deciding whether the intervention was feasible. The pain-score comparison therefore addresses the posted primary outcome, while the study’s stated pilot purpose should not be treated as a claim that the record establishes feasibility.

3. Trial Design

The registry record describes a randomized, single-masked, parallel-group study with an enrollment of 65. The study is marked completed. It lists a start date of 2019-12-31 and a primary completion date of 2021-10-04. The record does not say who was masked, and it does not give more detail about how randomization was carried out or how allocation was concealed.

The intervention was auricular acupressure, described as a device, and the comparator was standard of care pain management. In the intervention group, nurses placed acupressure pellet pads on participants postoperatively. The record also states that nurse interventionists were trained to apply the pads or pellets in the holding room prior to surgery. It does not explain the timing difference between that training description and the postoperative placement described for the intervention group. Standard of care participants received pain management from the treating physician.

The listed phase is NA. The study’s brief description calls it a pilot study and says its purpose was to test the feasibility of nurse-initiated postoperative bilateral auricular acupressure as an adjunct to medication. The record does not report the original sample-size justification, the trial’s own design assumptions, or a detailed statistical analysis plan. It also does not report whether interim analyses were planned or conducted. Those omissions limit what can be inferred about the design decisions behind the study, even though the registry does identify the allocation, masking, model, enrollment, endpoints, and posted analyses.

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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: 1 in Treatment and 2 in Standard of Care (SOC) group with incomplete missing data.

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: No baseline demographic information was gathered on participants in the Nurses arm, so those participants are not included in this section.

6. Primary Endpoint

The registry lists the primary outcome as Visual Analogue Pain Scale, measured over Up to Post-operatively day 4, at rising approximately 6 am.

The primary endpoint is the average pain upon awakening, measured with a visual analogue pain scale from 0, meaning no pain, to 10, meaning the worst pain. The registry defines the outcome as the pain score averaged across postoperative days 1 through 4, with assessment up to postoperative day 4 at rising, approximately 6 am. It reports a mean and standard deviation for each group.

Averaging scores across the stated postoperative days produces a summary of pain upon awakening over that period, rather than a result for just one assessment. This makes the endpoint useful for comparing group-level pain scores over the specified postoperative interval. It does not, by itself, describe each participant’s day-to-day pattern, the maximum pain experienced, or pain at other times of day. The registry does not report a minimally important difference or another threshold for judging the clinical importance of a score difference.

The endpoint is a continuous measure. The posted results include group means and standard deviations, while the sponsor’s reported analysis is ANCOVA. The record describes the primary analysis population as participants in the treatment and Standard of Care groups with incomplete missing data, using the wording “1 in Treatment and 2 in Standard of Care group.” It does not clarify that description or provide further details about the handling of missing scores.

7. Results Posted in the Registry

• Auricular Acupressure Group: mean 3.03 versus 4.37 on control; difference -1.34 (95% CI -2.50 to -0.18), standardized effect d = -0.64; z-test p = 0.024.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Visual Analogue Pain Scale

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Auricular Acupressure Group: mean 2.30 versus 2.84 on control; difference -0.54 (95% CI -1.80 to 0.72), standardized effect d = -0.22; z-test p = 0.402.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Auricular Acupressure Group and the control. The interval gives the range of effects that remain compatible with the data.

Number of Participants Who Responded They Were Satisfied With Pain Management

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Auricular Acupressure Group: 100.0% (19/19) versus 95.5% (21/22) on control; risk difference 4.5 percentage points (95% CI -4.2 to 13.2), risk ratio 1.05 (0.96–1.15); unadjusted two-proportion z-test p = 0.347.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Auricular Acupressure Group and the control. The interval gives the range of effects that remain compatible with the data.

Number of Participants Who Responded "Yes, Would Definitely Consider Using in the Future."

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Auricular Acupressure Group: 90.5% (19/21) versus 59.1% (13/22) on control; risk difference 31.4 percentage points (95% CI 7.3 to 55.5), risk ratio 1.53 (1.05–2.23); unadjusted two-proportion z-test p = 0.018.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically higher for Auricular Acupressure Group than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

The secondary results cover different kinds of information: a baseline pain score, participant satisfaction with pain management, and stated willingness to consider using the intervention in the future. They should not be treated as interchangeable measures of the primary postoperative pain endpoint. Baseline pain describes participants before the postoperative intervention comparison, while satisfaction and future-use responses reflect participant-reported views. The record lists additional secondary outcomes, including repeated visual analogue pain measures, but the posted results represented in the registry do not provide a complete set of estimates for every listed outcome.

The pattern across the posted results is mixed. The baseline pain comparison does not show a clear group difference in the unadjusted analysis. The satisfaction comparison is also uncertain. The future-use response has an unadjusted result favoring the acupressure group, but it addresses acceptability rather than pain reduction. This pattern does not independently confirm the primary pain-score finding, and it does not establish that the intervention improves all relevant outcomes.

Unadjusted secondary results carry less weight as confirmatory evidence when multiple outcomes are examined and no multiplicity plan is reported. With multiple comparisons, an isolated nominal result can arise even when there is no consistent underlying difference across the outcomes. This is a general statistical concern, not a claim that the future-use finding is false. The registry does not report whether secondary outcomes were prespecified as confirmatory, whether a hierarchy was used, or whether any adjustment was made.

Interpretation is also affected by the response denominators recorded for these outcomes and by the lack of detail about missing responses. The registry does not report why participants did not contribute to each secondary result or whether missingness differed in ways relevant to interpretation. The different endpoint populations and response counts mean that the secondary results should be read individually and cautiously, rather than combined into a single overall conclusion about pain management or acceptability.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Visual Analogue Pain Scale
• Visual Analogue Pain Scale
• Visual Analogue Pain Scale
• Visual Analogue Pain Scale
• Visual Analogue Pain Scale
• Visual Analogue Pain Scale
• Visual Analogue Pain Scale
• Visual Analogue Pain Scale

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is continuous, so a mean difference is a natural way to describe the contrast between the groups. The recalculated estimate is -1.34, using the Auricular Acupressure group mean minus the Standard of Care group mean. A negative value means the observed mean score was lower in the acupressure group under that subtraction convention. The estimate is expressed in units on the visual analogue scale. It is an unadjusted comparison based on the posted summary statistics.

What does the mean difference represent?

A group mean condenses the observed scores into an average, and the mean difference compares those averages. It does not mean that every participant had a score equal to the group mean or experienced a change equal to the difference. The standard deviations describe the spread of individual scores around each group’s mean. The registry reports standard deviations of 2.04 in the Auricular Acupressure group and 2.18 in Standard of Care for the primary endpoint. These spreads are relevant because participants’ scores vary around their group averages.

The recalculation also reports a pooled standard deviation of 2.11. Pooling is a way to combine the within-group spread for a standardized comparison. A standardized effect can help express a difference relative to the variability, but it is less directly interpretable than the scale-unit difference. The standardized effect value has more than three decimal places in the record and is therefore not repeated. The registry does not report a clinical threshold that would translate either the raw or standardized contrast into a judgment about clinical importance.

What does the confidence interval add?

A confidence interval gives a range of values compatible with the data and the analysis used, under the method’s assumptions. For the unadjusted primary mean difference, the posted interval excludes zero and is below zero throughout. This indicates that the recalculated estimate is not equally compatible with a zero difference under that interval procedure. The interval is not a guarantee that the true effect lies within its limits, and it does not resolve uncertainties about missing data, design, or generalizability.

The registry separately reports ANCOVA with p = .048. ANCOVA is a regression-based method that can compare outcomes between groups while adjusting for covariates, if those covariates are included in the model. The registry does not identify the covariates, the adjusted effect estimate, or its confidence interval. It is therefore possible to describe the method and reported p-value, but not to reconstruct the adjusted contrast or assess which covariates were used. The unadjusted recalculation and reported ANCOVA should remain clearly distinguished.

How should the p-values be read?

A p-value measures how incompatible the observed data are with a specified null model, according to the statistical procedure. It is not the probability that the null hypothesis is true, nor does it measure the size or clinical importance of an effect. The unadjusted primary p-value is 0.024; the registry’s ANCOVA p-value is .048. Both are reported results, but they arise from different analyses. The registry’s planning illustration specifies a two-sided significance level of 0.05; the record does not state whether this was the original trial’s planned threshold.

The comparison of the primary result should emphasize the estimated difference and its confidence interval, alongside the sponsor’s own analysis, rather than relying on a p-value alone. This is especially relevant in a pilot study with incomplete endpoint data and an unreported detailed analysis plan. The study record does not report whether the ANCOVA was prespecified, which covariates were selected, or whether any sensitivity analyses were conducted.

What does the ANCOVA result establish?

The registry labels the reported analysis as a superiority analysis and identifies ANCOVA as its method. It reports a p-value but no ANCOVA effect estimate or confidence interval. Without those quantities, the reported analysis does not reveal the adjusted difference’s magnitude or precision. The posted p-value can be reported faithfully, but it cannot supply the missing effect estimate. The absent model details also mean readers cannot assess the adjustment choices from the registry record.

Statistical methods generally make assumptions about the data and the model. For a continuous outcome analyzed by ANCOVA, relevant considerations can include how covariates relate to the outcome and whether the model form is appropriate. Those are general statistical considerations, not evidence that any assumption was or was not met in this study. Model diagnostics and assumption checks are not reported in the registry record.

Why does variation matter?

Variation among participant scores affects the precision of a group comparison. When scores are more dispersed, a mean difference may be estimated less precisely than when scores are more tightly grouped, all else being equal. The posted standard deviations provide a description of the observed spread, while the confidence interval reflects uncertainty in the calculated contrast under its method. This general principle does not justify a new estimate beyond the values reported.

Over-dispersion is a general concern when a statistical model assumes less variability than the data contain: standard errors can then be too small and intervals too narrow. The primary endpoint is analyzed as a continuous measure, and the registry does not report an over-dispersion assessment. It would not be appropriate to claim that over-dispersion occurred or affected the result.

For binary secondary outcomes, a risk difference compares the observed proportions between groups. A risk ratio compares those proportions as a ratio. Those measures address participant responses, not mean pain scores, and their uncertainty can be substantial when the available response counts are limited. The registry’s secondary results include confidence intervals for binary comparisons, but no multiplicity adjustment is reported. The results should therefore be read as endpoint-specific, unadjusted evidence rather than as a single joint test of all outcomes.

11. Confidence Intervals and Precision

The primary recalculated mean difference is -1.34, with a confidence interval from -2.5 to -0.180 in the registry record. The lower and upper limits are both below zero, so the interval does not include no difference for this unadjusted comparison. The interval also shows that the estimate is not known with exact precision: a range of differences remains compatible with the data under the calculation’s assumptions. The interval is reported for the simple, unadjusted recalculation, not for the ANCOVA analysis.

Interval width is one way to assess precision: a narrower interval indicates less statistical uncertainty than a wider interval for the same kind of estimate. Precision is not the same as clinical importance. The registry does not identify a threshold for a meaningful pain-score difference, so the interval alone cannot determine whether values within it would be important to patients or clinicians. It also does not account for limitations that may arise from missing outcomes or unreported analysis choices.

The sponsor’s ANCOVA result has no posted effect estimate or confidence interval. Its p-value, .048, does not show the adjusted difference’s size or the range of adjusted values compatible with that analysis. It is therefore not possible to compare the precision of the adjusted estimate directly with the unadjusted interval.

Confidence intervals for secondary outcomes also vary in what they permit readers to conclude. Some include the null value for their respective contrast, while the interval for the future-use response does not. Those intervals are unadjusted, and the record does not report a plan for accounting for multiple secondary comparisons. Accordingly, their nominal precision does not remove the concern that examining several outcomes can make isolated results less persuasive as confirmatory evidence.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size figures are planning illustrations based on the observed effect, not the trial’s original design justification. In this record, the figures are participants per arm, not total events. The planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The assumed effect to detect is the stated fraction of the observed effect. The registry does not report the trial’s own original sample-size assumptions or justification.

The 80% power column describes the planned number of participants per arm for a design that would have an 80% chance of detecting the specified effect under the planning assumptions, if that effect and the assumptions were correct. The 90% power column represents a higher target chance of detection under the same type of assumptions and generally calls for more participants per arm. These percentages are planning targets, not probabilities that the observed result is true.

The rows use different fractions of the observed effect. Planning for 100% of the observed effect requires 39 participants per arm for 80% power and 53 participants per arm for 90% power. Planning for 75% of the observed effect requires 70 participants per arm for 80% power and 93 participants per arm for 90% power. Planning for 50% of the observed effect requires 156 participants per arm for 80% power and 209 participants per arm for 90% power. The pattern illustrates the general relationship that smaller effects are harder to detect and require more participants under otherwise unchanged assumptions.

These are planning illustrations computed from the observed result, not observed power. They should not be interpreted as evidence that the completed study had a particular probability of detecting an effect. The observed effect can be an unstable basis for planning, especially in a pilot study, and the registry does not report whether its original design used these assumptions. The figures also do not account for details not included in the stated planning assumptions, such as missing data or any departures from equal allocation.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -1.340; pooled standard deviation σ = 2.110.
2. n = 2 × (1.96 + 0.842)² × 2.110² / -1.340² = 38.9, rounded up to 39 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- -1.34                      # observed difference in means
sigma <- 2.10973254906195                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(4044716)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 39 (80% power), 53 (90% power)
 75% of observed effect: n per arm = 70 (80% power), 93 (90% power)
 50% of observed effect: n per arm = 156 (80% power), 209 (90% power)
power.t.test: 39.9 
Simulated power at n = 39 per arm: 0.790 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Analyses Reported by the Sponsor

The registry’s own primary analysis is ANCOVA, reported as a superiority analysis with p = .048. It does not provide the adjusted effect estimate, confidence interval, covariates, or additional model details. The recalculated result is an unadjusted comparison of the posted means: a mean difference of -1.34, with a confidence interval from -2.5 to -0.180 and p = 0.024. These are not two estimates from an identical analysis; one is the registry-reported adjusted method, and the other is a simple calculation from group summaries.

The discrepancy flag is false, so the record does not identify a discrepancy between the sponsor’s result and the recalculation. The sponsor’s analysis remains the trial-reported analysis, while the recalculation offers a transparent unadjusted comparison. Differences in p-values do not by themselves establish a contradiction, because model adjustment and analysis methods can affect uncertainty and inferential results. Without the ANCOVA estimate and model specification, the adjusted result’s magnitude and precision cannot be assessed or directly reconciled with the unadjusted estimate.

The record does not say whether the ANCOVA model was prespecified, which covariates were included, or whether robustness checks were performed. The reported p-value should therefore be presented as the sponsor’s posted inferential result, without implying more detail than the registry supplies.

15. Multiplicity, Missing Data and Analysis Populations

The registry record lists 19 outcome measures, five analyses, and 14 posted secondary outcomes. It does not report a multiplicity strategy, such as a prespecified primary-secondary hierarchy, adjustment of significance levels, or a plan to control the chance of false-positive findings across multiple comparisons. Without such information, secondary p-values are best understood as unadjusted endpoint-specific results. A nominal result should not be treated as confirmatory solely because its p-value is small.

Multiplicity is a general statistical issue: as more hypotheses are tested, the chance of at least one apparently notable result can increase if every test is interpreted separately. Adjustment or a clearly defined testing hierarchy can help control that issue, but the registry does not say whether either was used. It also does not report whether all planned outcomes and analyses are posted, so the relationship between the listed outcomes and the complete analysis plan is not clear.

Missing data are another important limitation. For the primary endpoint, the registry describes the population as “1 in Treatment and 2 in Standard of Care group with incomplete missing data.” The wording is not clarified, and the record does not report the number of missing pain measurements, their reasons, the method used to handle them, or sensitivity analyses. The endpoint is an average across postoperative days 1 through 4, but the record does not explain how partial sets of daily scores contributed to each participant’s average.

Analysis-population details are limited. The registry does not report whether the primary comparison followed an intention-to-treat principle, whether participants were analyzed as randomized, or how deviations from the assigned intervention were handled. The ANCOVA covariates and its missing-data method are also not reported. These omissions do not prove that the analyses were inappropriate; they restrict the ability to evaluate their assumptions and reproduce the reported result.

16. 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 non-serious adverse event terms

The registry lists serious adverse events for groups with 30 participants at risk in each group. It reports zero serious adverse events in the Auricular Acupressure group and zero in Standard of Care. Deaths are also listed as zero in both groups. For other adverse events, the record reports one event in the Auricular Acupressure group and zero in Standard of Care.

These figures are counts in the registry record and should be read as such. They do not establish that the intervention is free of risk, nor do they show that the groups have equivalent safety. The number of events is small, and the registry does not provide event descriptions for the non-serious event, the observation period for adverse events, or details about how events were collected and classified. No serious adverse-event terms are listed.

The reported at-risk groups for the adverse-event results differ from the primary endpoint populations. The record does not explain the relationship between those populations or whether adverse-event follow-up was complete. Accordingly, the posted counts provide a limited description of recorded events, not a comprehensive safety assessment.

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

The primary results describe lower mean pain scores upon awakening in the Auricular Acupressure group than in Standard of Care over the specified postoperative days. The unadjusted mean difference is -1.34, and its confidence interval lies below zero. The sponsor’s ANCOVA analysis reports p = .048, but its adjusted effect estimate and confidence interval are not reported. Together, these are evidence about the outcomes recorded in this study, not a definitive account of what would happen in every clinical setting.

The result does not establish the clinical importance of the difference because the registry does not report a threshold for meaningful change on the scale. Nor does the result show that every participant experienced a lower score or that pain was lower at all times. The endpoint is an average of scores upon awakening across postoperative days 1 through 4; it is not a measure of all pain experiences or other aspects of recovery.

The findings also do not establish that the intervention works or does not work. This study is described as a pilot whose purpose was to test feasibility, but the registry does not report a separate feasibility outcome or criteria. The primary endpoint population is noted as having incomplete missing data, and the missing-data details are not reported. These factors limit the certainty and scope of interpretation.

The secondary outcomes add information about baseline pain, satisfaction, and future-use responses, but they do not all measure the same construct as postoperative pain. The lack of a reported multiplicity strategy makes unadjusted secondary findings exploratory. The adverse-event counts are sparse and do not establish the absence of risk. The appropriate reading is therefore a description of the posted results and their uncertainty, with important design, analysis, and reporting details left unresolved by the registry record.

18. Why This Trial Matters Statistically

This study illustrates why a clinical result should be read through its estimand, analysis method, and uncertainty rather than through a single p-value. The primary outcome is an average of pain upon awakening across postoperative days 1 through 4. The registry provides group means and standard deviations, allowing an unadjusted mean difference and confidence interval to be recalculated. It also reports an ANCOVA p-value, but not the adjusted estimate or the model details. Seeing both kinds of information makes clear that the reported adjusted analysis and a summary-statistic recalculation answer related but not identical statistical questions.

The registry also shows how a pilot study can have a stated feasibility purpose while posting clinical outcome comparisons. Those comparisons are informative descriptions, but they do not automatically establish feasibility or provide a definitive estimate for future studies. Planning illustrations based on the observed effect can help readers understand how assumptions about effect size and power affect participant requirements, but they are not evidence of the completed study’s observed power or its original design rationale.

Finally, this record highlights the importance of reporting missing-data methods, analysis populations, model details, and multiplicity plans. Those details affect how confidently readers can interpret point estimates, intervals, and secondary results. Their absence does not negate the reported data; it defines the limits of what can be evaluated from the registry record.

19. 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.

Several limitations specific to this record constrain interpretation. Although the study is described as a pilot intended to test feasibility, a feasibility outcome and criteria for success are not reported in the registry record. The record provides an enrollment figure but does not report the original sample-size justification or the assumptions used to plan the study. The planning illustrations are based on observed effects and should not be confused with the trial’s original design.

The primary endpoint description notes incomplete missing data, but the wording about the endpoint population is unclear. The record does not report the extent or pattern of missing pain scores, reasons for missingness, the method used to form averages when daily scores were incomplete, or sensitivity analyses. It also does not state whether the analysis followed an intention-to-treat principle. These omissions make it difficult to evaluate how representative the analyzed endpoint data are of the randomized groups.

The registry reports ANCOVA but does not provide its covariates, adjusted effect estimate, or confidence interval. It does not report model diagnostics or whether the analysis was prespecified. The recalculated comparison is unadjusted and therefore cannot fill those gaps. The registry also does not report a multiplicity plan despite listing multiple outcomes and analyses, limiting the confirmatory interpretation of secondary findings.

Other details are also limited: the record does not identify who was masked, provide further information about randomization, or explain the timing descriptions for nurse training and postoperative pad placement. Adverse-event follow-up duration and event-collection details are not reported. These are limitations of the information in the registry record; they should not be taken as proof that procedures were not conducted or that unreported information does not exist.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Nurse Initiated Acupressure for Pain Management — NCT04044716.
• Registry record last updated 2022-12-07; status last verified 2022-12.
• Results first posted 2022-12-07.
• 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.

23. Record Summary

NCT04044716 is a completed, randomized, single-masked, parallel-group pilot study sponsored by Wake Forest University Health Sciences. It compares nurse-initiated auricular acupressure as an adjunct to standard pain management with standard of care after knee or hip arthroplasty. The registry lists an enrollment of 65 and identifies postoperative and acute pain as conditions.

The primary outcome is mean visual analogue pain score upon awakening, averaged across postoperative days 1 through 4. The recalculated unadjusted mean difference is -1.34, with a confidence interval below zero; the registry’s ANCOVA analysis reports p = .048 but no adjusted estimate or interval. The record also posts baseline pain, satisfaction, future-use, and adverse-event results. Missing-data handling, original sample-size assumptions, ANCOVA covariates, and a multiplicity plan are not reported in the registry record.