Efficiency And Quality In Post-Surgical Pain Therapy After Discharge: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Efficiency And Quality In Post-Surgical Pain Therapy After Discharge (NCT05221866), a randomized na study. The primary outcome is Cumulative Weekly Opioid Intake After Discharge.

2. Clinical Question

3. Trial Design

The registry describes a randomized, single-masked, factorial study sponsored by the University of Nebraska. Enrollment was 711. The trial status is completed. Its recorded start date is 2022-05-02, and its primary completion date is 2023-12-10. The phase is listed as not applicable. The registry record does not report further details about sequence generation, concealment of allocation, or the identity of the masked parties beyond the statement that participants were masked to when the provider-facing tool was activated.

The four arms distinguish app content and provider-tool use. They include an educational app without the provider tool, an app with only data collection and no provider tool, an educational app with the provider tool, and an app with only data collection plus the provider tool. The provider-facing tool was to be turned on once half of the subjects were enrolled in the two arms that included it. The registry describes this timing feature but does not report how its effect was handled in the analysis.

The study’s stated aim was to assess whether a provider-facing decision-support tool and a participant-facing smartphone app could reduce opioids prescribed and taken after discharge while ensuring effective post-surgical pain treatment. The planned measurements included opioid intake, non-opioid analgesic use, opioid doses prescribed at discharge, pain intensity and interference, additional opioid prescriptions, and disposal of leftover medication. The registry record posts results for the primary intake measure and selected secondary outcomes, but does not report results for every planned measurement.

The record does not report a detailed statistical analysis plan, a sample-size justification, or a prespecified factorial model. Although randomization and a factorial structure are recorded, the posted results are arm-level summaries rather than reported estimates of the separate app and provider-tool effects or their interaction.

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: Participants who completed at least one week of surveys were included in the analysis.

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: A total of 711 participants consented to the trial, and 606 completed the research.

6. Primary Endpoint

The registry lists the primary outcome as Cumulative Weekly Opioid Intake After Discharge, measured over Baseline (discharge), weekly for four weeks.

The primary endpoint is cumulative weekly opioid intake after discharge, expressed in morphine milligram equivalents (MME). The registry describes recording opioid type, units, and total amount taken during the first 28 days after hospital discharge. Converting different opioids to a common MME scale is a general way to express their amounts on a shared scale, accounting for differences in opioid potency.

The endpoint is recorded at discharge and weekly for four weeks. The registry specifies the median and interquartile range as the summary measures. A median describes the middle of the observed distribution; the interquartile range describes the span from the lower quarter to the upper quarter of observations. These summaries are useful for an outcome that may be unevenly distributed, including one with many low or zero values and some larger values. The posted arm summaries show this pattern of a lower bound of 0.0 MME in each arm, with differing upper quartiles.

The analysis population was participants who completed at least one week of surveys. The registry does not report the number of otherwise eligible participants who lacked that minimum amount of survey data, the handling of partial follow-up, or an imputation method. Nor does it report a formal test or confidence interval for differences in the primary endpoint between groups. Consequently, the posted medians and interquartile ranges describe the analyzed participants but do not, by themselves, establish the precision of a between-group effect.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the design as randomized, single-masked, and factorial. Randomization is intended to make assigned groups comparable, on average, with respect to measured and unmeasured baseline characteristics. A factorial design can evaluate more than one intervention component within the same trial, and may allow estimation of each component’s effect and their combined effect. Those benefits depend on an analysis that reflects the factorial assignment and relevant design features. The registry record does not report the planned factorial contrasts or a model for the primary endpoint.

What do the primary summaries describe?

The reported primary measure is cumulative opioid intake in MME, summarized by arm using the median and interquartile range. A median is the central point of an ordered set of observations. Unlike a mean, it is less influenced by unusually large values. The interquartile range gives the interval between the lower and upper quartiles and describes the spread of the central half of the observations. It is a descriptive measure of variation, not a confidence interval for a group effect.

The posted summaries have a lower quartile of 0.0 MME in each arm and different medians and upper quartiles. This combination is consistent with distributions that include low or zero values and have variation among participants. It also illustrates why a single measure of location cannot convey the full outcome distribution. The registry does not post individual-level data, additional distributional summaries, or a formal comparison of the primary endpoint.

Why does the factorial structure matter?

The app content and provider-facing tool are distinct components in the four-arm arrangement. A factorial analysis might estimate the app component’s effect averaged across provider-tool status and the provider tool’s effect averaged across app status, while also considering whether the components act differently when combined. That last question is an interaction question. A comparison of one arm with the control answers a narrower question and does not automatically estimate all factorial effects. The registry record does not report whether these component effects or an interaction were analyzed.

The provider tool’s activation after half of enrollment adds a timing feature to the intervention. Participants were masked to when it was activated. The record does not report how calendar time, activation timing, or participants enrolled before versus after activation were considered in the analysis. No conclusion about the implications of this feature can be drawn from the arm-level summaries alone.

How should the secondary re-calculations be read?

For selected binary secondary outcomes, simple unadjusted re-calculations compare an intervention arm with the educational-app control. A risk difference is the difference between the two observed event proportions, expressed on an absolute scale. Its confidence interval describes a range of values compatible with the data under the calculation’s assumptions. When that interval includes zero, the observed data do not clearly distinguish the risk difference from no difference at the stated confidence level. These re-calculations are not registry-reported analyses, and they should not be mistaken for an adjusted factorial analysis.

The posted unadjusted p-values likewise address individual comparisons under their calculation assumptions. A p-value is a measure of how unusual data at least as discrepant as those observed would be under a specified null model; it is not the probability that the null hypothesis is true, nor a measure of clinical importance. Multiple outcomes and comparisons raise the general concern of multiplicity: if many tests are considered, the chance of at least one apparently unusual result can increase. The registry record does not report a multiplicity strategy, so these secondary calculations should be considered exploratory rather than confirmatory.

What do the planning illustrations mean?

The planning illustrations use observed effects as inputs and show participants per arm for stated power targets and effect fractions. They are not the trial’s original sample-size justification, which is not reported in the registry record. They are hypothetical planning calculations based on the posted observed effect, a two-sided significance level of 0.05, equal allocation, and a normal approximation. The rows for planning for 75% or 50% of the observed effect describe smaller target effects than planning for the full observed effect.

Such calculations are especially unstable when an observed difference is small or when few events occur. An effect estimated from a particular dataset is uncertain, and planning from it can yield very large or otherwise unreliable sample-size illustrations. These values do not describe the probability that this completed trial detected an effect. The sample sizes are planning illustrations, never observed power. The registry does not report the assumptions or target effect used for the trial’s original design.

What information is absent?

The registry record does not report a detailed primary analysis plan, confidence intervals or tests for the primary endpoint, adjustment for baseline characteristics, missing-data methods, or a full account of analysis populations. It also does not report how repeated weekly measurements were modeled, if they were modeled jointly. These details matter because the endpoint is measured over time and because survey completion determines inclusion in the primary analysis. Without them, the primary result is best interpreted as descriptive arm-level information, while the selected secondary re-calculations remain unadjusted comparisons.

10. Multiplicity, Missing Data and Analysis Populations

The registry record does not report a multiplicity plan. The trial had several outcomes covering opioid intake, prescribing, pain intensity, pain interference, and disposal, and selected results include comparisons of the control with other arms. When many outcomes or comparisons are examined, some may appear noteworthy by chance even when there is no underlying effect. A prespecified hierarchy or adjustment can help control the interpretation of repeated testing. Without a reported strategy, individual unadjusted secondary p-values should not be treated as if they were the sole confirmatory test.

The record reports no formal analysis for the primary endpoint and no registry-reported analyses for the secondary outcomes. Selected binary comparisons are available as simple unadjusted re-calculations, but no adjusted factorial estimates are reported. The registry record does not state whether the trial’s original analysis plan specified covariate adjustment, treatment of repeated measures, or handling of the provider tool’s staged activation.

Missing-data details are also limited. The primary analysis included participants who completed at least one week of surveys. The record does not report the number of participants with missing surveys, how missing weeks were handled, whether partial survey histories contributed to cumulative intake, or whether any imputation was used. It does not report the number meeting the primary analysis criterion by arm. These omissions make it difficult to assess how representative the analyzed participants are of all randomized participants.

The record does not report a full intention-to-treat analysis population, a per-protocol population, or reasons for exclusion from analyses. As a result, the effect of any post-randomization exclusions cannot be evaluated. These are reporting limitations; they do not establish that a particular analysis was or was not conducted outside the registry. The registry record alone does not provide enough detail to determine how missingness, multiplicity, or analysis-population choices affect the 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.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: re-hospitalization (any reason) (7.9%).

Serious adverse events were reported in all four groups: 11 of 148 participants in the educational-app group, 12 of 152 in the data-collection-only app group, 8 of 155 in the educational-app plus provider-tool group, and 11 of 151 in the data-collection app plus provider-tool group. The registry lists re-hospitalization for any reason as the leading serious-event term, at 7.9%. These are reported event counts and a listed event term; the registry record does not provide a causal assessment linking events to an intervention.

Other adverse events were reported as 2, 1, 0, and 0 across those groups, respectively. Death counts were 0, 1, 0, and 0, respectively. These categories should be read as separate safety summaries as recorded, not combined into a new total. The registry record does not provide additional details about event timing, severity beyond the serious-event classification, or attribution. Arm-level counts alone do not establish whether differences reflect an intervention effect, chance variation, or other factors.

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

The results describe reported opioid intake among participants who completed at least one week of surveys and provide selected counts for additional prescriptions, disposal, and safety outcomes. The primary arm summaries show differing medians, with the same reported lower quartile in each arm and a broad range across the middle half of observations. This is a useful description of what was observed, but it is not a formal estimate of the causal effect of either intervention component.

The registry does not report a primary-outcome hypothesis test, confidence interval, or factorial analysis. Therefore, it does not establish the precision of differences between groups or whether the observed differences are distinguishable from sampling variation. Nor does it establish that the app, provider tool, or their combination caused the observed arm-level patterns. Random assignment is an important design feature, but interpretation still depends on the analysis, missing-data handling, and reporting details available.

The planned aim included reducing post-discharge opioid prescribing and use while ensuring effective pain treatment. The posted primary results address opioid intake, but registry results for pain intensity and interference are not reported in the registry record. Without those results, the posted information cannot establish how opioid intake patterns related to pain outcomes. The secondary prescription and disposal counts address related questions but do not fill that gap.

These results should not be read as an individual treatment recommendation or as evidence that a particular approach is beneficial or ineffective. They are a registry record of a completed randomized study, with descriptive primary summaries and limited secondary analyses. A fuller assessment would require the prespecified analysis plan, complete outcome reporting, and more information about survey completion and missing data; those details are not reported in the registry record.

13. Why This Trial Matters Statistically

This trial raises a statistically important question about how to evaluate interventions with multiple components. A patient-facing app and a provider-facing prescription aid could each contribute to outcomes, and their effects might differ when used together. A factorial design can be suited to separating those questions, but only when results are reported using contrasts that match the design. The registry provides four arm summaries but does not report estimates of component effects or their interaction.

The primary endpoint also illustrates the value of choosing summaries suited to the outcome’s distribution. Medians and interquartile ranges describe the center and spread without relying on a mean alone. The zero lower quartile in every group and the varying upper quartiles show why a single arm-level number cannot capture the full pattern of medication use. At the same time, descriptive summaries do not substitute for uncertainty estimates or a formal comparison.

Another key issue is outcome completeness. The primary analysis required at least one week of surveys, while the record does not report how many participants met that criterion by arm or how missing weekly data were handled. In longitudinal self-reported outcomes, the pattern of completion can affect how well the observed data represent all randomized participants. Transparent reporting of the analysis population and missingness is therefore central to interpreting the result.

Finally, several secondary outcomes and comparisons create a multiplicity challenge. Unadjusted re-calculations can be informative as exploratory descriptions, but without a reported analysis hierarchy or multiplicity plan they should not be treated as independent confirmation. The registry record illustrates how design, outcome definition, missingness, and multiplicity all shape what can be concluded from observed group summaries.

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 result is reported as arm-level medians and interquartile ranges without a registry-reported formal comparison or confidence interval. This limits assessment of the precision of differences and prevents direct evaluation of a primary hypothesis. The registry does not report the planned factorial contrasts, any interaction analysis, or whether the staged activation of the provider tool was incorporated into the analysis.

The primary analysis included participants who completed at least one week of surveys, but the number meeting that criterion by arm, the amount of missing weekly data, and the handling of partial follow-up are not reported in the registry record. The record also does not report a detailed account of analysis populations, exclusions, or imputation. Self-reported cumulative intake may be subject to incomplete recall or reporting, but the available record does not quantify or evaluate such measurement error.

Although pain intensity and interference were listed as outcomes, their results are not reported in the registry record. Their absence limits interpretation of the stated aim of reducing opioid use while ensuring effective pain treatment. Results for all planned measures are not available in the posted record, so the relationship among intake, pain, and other aspects of care cannot be fully assessed.

The selected binary comparisons are unadjusted re-calculations, and the registry does not report a multiplicity plan or a detailed statistical analysis plan. These comparisons do not account for the factorial design in the way a reported factorial model might. The sample-size illustrations are based on observed effects rather than the trial’s original design assumptions and should not be taken as evidence of the study’s planned power. Finally, the safety record gives arm-level counts and a leading serious-event term but does not report event attribution or detailed timing.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Efficiency And Quality In Post-Surgical Pain Therapy After Discharge — NCT05221866.
• Registry record last updated 2025-07-01; status last verified 2025-06.
• Results first posted 2025-07-01.
• 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

NCT05221866 is a completed randomized, single-masked factorial trial sponsored by the University of Nebraska, with enrollment of 711. It studied app and provider-tool approaches to post-surgical pain management after discharge. The primary outcome was cumulative opioid intake in MME during the first 28 days, reported by arm as a median and interquartile range among participants completing at least one week of surveys.

The registry posts descriptive primary results, selected secondary counts, and adverse-event counts. It does not report a formal primary comparison, a detailed statistical analysis plan, or results for every listed outcome. The posted summaries therefore describe observed outcomes but provide limited information about the precision of between-group effects.