Study in Subjects Undergoing Complete Abdominoplasty: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study in Subjects Undergoing Complete Abdominoplasty (NCT03789318), a randomized phase 2 study. The primary outcome is Pain Intensity Scores at 96 Hours at Rest Using Numerical Rating Scale (NRS).

2. Clinical Question

3. Trial Design

This was a Phase 2, randomized, parallel-group study of CA-008 and placebo in subjects undergoing complete abdominoplasty. The registry record lists the study as completed, with enrollment of 54. It identifies postsurgical pain as the condition under study and Concentric Analgesics as the sponsor. The study is described as single center in its brief summary.

The official title calls the study double-blind, while the registry masking entry specifies triple masking. Both descriptions indicate masking, but the record does not identify which participant, investigator, or other role corresponded to each masking designation. The allocation is listed as randomized. Further details about sequence generation, concealment, or randomization procedures are not reported in the registry record.

Participants were assigned within dose cohorts. The results list CA-008 5 mg and its Cohort 1 placebo, CA-008 10 mg, CA-008 15 mg, and a placebo group for Cohorts 2 and 3. The primary endpoint results are given separately for these five groups. The sponsor-reported inferential comparison concerns the 15 mg group and the placebo group for Cohorts 2 and 3; it is not a single reported test covering every dose group.

The study involved surgery under general anesthesia supplemented with a transverse abdominis plane block and local surgical-site infiltration. The arm descriptions specify bupivacaine hydrochloride for the block. The registry lists hydromorphone, fentanyl, acetaminophen, and oxycodone among the interventions, as well as CA-008, placebo, and bupivacaine hydrochloride. The exact use and timing of every listed drug are not reported in the registry record in the information available for this analysis.

The reported primary endpoint is pain intensity at rest at 96 hours, measured on a Numerical Rating Scale. The record identifies the safety population for this endpoint. It does not report the planned sample-size justification, detailed analysis plan, or procedures for handling missing endpoint observations.

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: Safety population

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 Pain Intensity Scores at 96 Hours at Rest Using Numerical Rating Scale (NRS), measured over 96 hours.

The primary endpoint is the mean pain-intensity score at rest at 96 hours, measured using a Numerical Rating Scale from 0 to 10. A score of 0 is defined as no pain and a score of 10 as the worst pain imaginable. The registry record reports the endpoint in the safety population and gives a mean and standard deviation for each posted treatment group.

A pain rating is a continuous measure in the sense that its values can be summarized with a mean and a measure of spread. The mean describes the group’s average score; the standard deviation describes how dispersed individual scores were around that average. These summaries do not show every participant’s rating or the shape of the score distribution.

A rating at a specified time point gives a focused description of pain at that point, rather than a record of pain across the entire postoperative period. The registry also lists a weighted sum of pain-intensity assessments, time to opioid cessation or freedom, the percentage of opioid-free subjects, and total opioid consumption as secondary outcomes. Those outcomes address other aspects of postoperative pain and analgesic use, but they do not replace the primary endpoint.

The endpoint description identifies the assessment as being at rest. It does not describe the exact assessment procedures, how a missing rating was handled, or whether any adjustments were made to the group means. Those details are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary measure is continuous, and the registry reports its mean and standard deviation in each group. A mean is a measure of the group’s central level. A standard deviation describes the spread of observations around the mean, but does not communicate uncertainty in the mean in the same way that a confidence interval does. The registry does not provide confidence intervals for the group means.

What does the reported ANOVA test address?

The sponsor-reported method is analysis of variance, or ANOVA, for the 15 mg group and the placebo group for Cohorts 2 and 3. In general, ANOVA is a method for assessing whether group means are compatible with a shared mean under a specified model. For this reported comparison, the registry gives p = 0.291. It does not report the model details, the estimated mean contrast, a confidence interval, or additional covariates. The method label alone does not supply those missing details.

A p-value describes how unusual data at least as incompatible with a null model as the observed data would be, if that null model and the analysis assumptions were correct. It is not the probability that the null hypothesis is true, and it does not quantify the magnitude or clinical importance of a difference. Interpretation also depends on the analysis plan and on how many outcomes or comparisons were examined; those details are not reported in the registry record.

What do the group summaries say about precision?

In general, a confidence interval gives a range of values compatible with the data and the method used to calculate it. Its width conveys precision: a wider interval indicates less precise estimation than a narrower interval. No confidence interval for the treatment contrast is reported, so the precision of that contrast cannot be read directly from the registry’s inferential result. The group sample sizes and standard deviations are available, but they do not substitute for a reported contrast and its interval.

In general, over-dispersion means that variation is greater than a statistical model expects. When present, it can make standard errors and tests based on a simpler variance model unreliable unless the analysis accounts for it. The posted group standard deviations show variability in the NRS scores, but the registry does not report an assessment of over-dispersion or describe a model that accounts for it. It would therefore be inappropriate to claim that over-dispersion was or was not present.

How should recalculations and planning illustrations be read?

A recalculation based on summary statistics is an unadjusted calculation and may not reproduce an analysis that used participant-level data, covariate adjustments, or other procedures. In this record, the reported comparison does not have a corresponding recalculated two-arm effect and interval available because the values are missing or not estimable for that comparison. The sponsor’s reported ANOVA result can be described, but the registry does not supply enough detail to independently reconstruct it from the posted group summaries.

In general, sample-size calculations use assumptions about the effect to be detected, variability, significance level, allocation, and statistical method. The planning illustration described for this study uses a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; its target effect is a stated fraction of the observed effect. Such illustrations are planning exercises, not observed power and not evidence that the trial was designed using those assumptions. The trial’s own sample-size justification is not reported in the registry record. No planning sample-size results are described in this interpretation.

For time-to-event outcomes, an event-based planning quantity can differ from a participant count; for other outcomes, the planning quantity is expressed as participants per arm. These are general distinctions in planning methods. They do not change the interpretation of the primary continuous endpoint, which is a group mean score at a fixed time point.

What information is absent from the statistical report?

The registry record does not report the full analysis plan, the handling of missing ratings, detailed assumptions for the ANOVA, or an adjustment strategy for multiple outcomes and comparisons. It also does not provide confidence intervals for the primary group summaries or the sponsor-reported comparison. Without those details, the posted results support a description of the recorded means, standard deviations, and reported p-value, but not a complete reconstruction of the inferential analysis.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("CA-008 5 mg (0.05 mg/mL) Cohort 1", "Placebo for Cohort 1", "CA-008 10 mg (0.1 mg/mL)", "CA-008 15 mg (0.15 mg/mL)", "Placebo for Cohorts 2 and 3")
n   <- c(9, 9, 12, 12, 12)
m   <- c(2.8, 2, 3, 2.8, 1.8)
sp  <- c(2.59, 2.12, 2.22, 3.1, 1.96)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  CA-008 5 mg (0.05 mg/mL) Cohort 1  9  2.800  2.590  0.809  4.791
CARM  Placebo for Cohort 1  9  2.000  2.120  0.370  3.630
CARM  CA-008 10 mg (0.1 mg/mL)  12  3.000  2.220  1.589  4.411
CARM  CA-008 15 mg (0.15 mg/mL)  12  2.800  3.100  0.830  4.770
CARM  Placebo for Cohorts 2 and 3  12  1.800  1.960  0.555  3.045

11. Analyses Reported by the Sponsor

The sponsor-reported inferential result is an ANOVA comparison of CA-008 15 mg with the placebo group for Cohorts 2 and 3. The registry reports p = 0.291 for that analysis. It does not report the estimated contrast, a confidence interval, or enough model details to reconstruct the sponsor’s analysis from the posted summaries.

The group-level means and standard deviations are available, but a recalculated two-arm effect and confidence interval are not available for this comparison because the values are missing or not estimable. Accordingly, there is no recalculated contrast to place alongside the sponsor’s result. The registry does not flag a discrepancy between a sponsor result and a recalculation.

In general, a recalculation from summary statistics is unadjusted and can differ from an analysis using participant-level data or other model details. Here, the available record permits the sponsor’s reported p-value to be stated, but not independently verified or fully interpreted in relation to an estimated effect and its precision. The reported p-value should not be treated as an effect-size estimate.

12. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary endpoint and four secondary outcomes: weighted sum of pain-intensity assessments, time to opioid cessation or freedom, percentage of opioid-free subjects, and total opioid consumption. It also reports several CA-008 dose groups and placebo groups. This creates multiple outcomes and potential comparisons to consider when interpreting the results.

Multiplicity refers, in general, to the statistical issue that arises when several hypotheses are tested. With more tests, the chance of at least one apparently notable result can increase if no adjustment or prespecified testing strategy is used. A prespecified hierarchy or multiplicity adjustment can help define how results should be interpreted. The registry record does not report whether such a strategy was planned or applied, nor does it describe which comparisons were primary for inference beyond naming the primary endpoint.

The sponsor-reported ANOVA result concerns the 15 mg group and the placebo group for Cohorts 2 and 3. The registry does not state whether this was the only inferential comparison, whether other comparisons were planned, or whether the reported p-value was adjusted. The record also does not provide inferential results for the secondary outcomes in the information available for this analysis. Their inclusion in the outcome list does not establish that they were tested or that results were favorable or unfavorable.

The endpoint population is described as the safety population. That label identifies the population for the posted primary endpoint, but the registry record does not define its membership or state whether it corresponds to an intention-to-treat or per-protocol population. The analysis populations for the sponsor-reported ANOVA and the secondary outcomes are not reported.

Missing-data handling is also not reported. The record does not say how absent 96-hour ratings were addressed, whether any imputation was used, or how missingness was assessed. These omissions limit evaluation of the analysis but do not establish that missing data occurred or that any particular method was used.

13. 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: abortion spontaneous (11.1%), deep vein thrombosis (11.1%), post procedural haemorrhage (8.3%).

The registry reports serious adverse events by group. In Cohort 1, 2 of 9 participants in the CA-008 5 mg group and 0 of 9 participants in its placebo group were reported as affected. In the 10 mg group, 1 of 12 was affected; in the 15 mg group, 1 of 12 was affected; and in the placebo group for Cohorts 2 and 3, 0 of 12 were affected. The record reports 0 deaths in every group.

For other adverse events, the reported affected counts were 9 of 9 in the 5 mg group, 8 of 9 in its placebo group, 11 of 12 in the 10 mg group, 10 of 12 in the 15 mg group, and 11 of 12 in the placebo group for Cohorts 2 and 3. These counts describe participants affected, not the number of separate event episodes.

The registry lists serious-event terms with percentages: Abortion spontaneous, 11.1%; Deep vein thrombosis, 11.1%; and Post procedural haemorrhage, 8.3%. The record does not provide the event counts or denominators associated with each listed percentage in the information available for this analysis, so they should not be assigned to a treatment group or interpreted as group-specific rates.

These figures are descriptive. They do not establish that an event was caused by a study drug, and the registry does not provide enough detail to assess timing, severity beyond the serious-event classification, or comparative risk.

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

The posted results describe pain-intensity scores at rest at 96 hours in five treatment groups. They report the group means, standard deviations, and sample sizes, alongside one sponsor-reported ANOVA p-value for the 15 mg group compared with the placebo group for Cohorts 2 and 3. This information allows readers to see the recorded group summaries and the scope of the reported inferential comparison.

The summaries do not, on their own, establish a causal effect of CA-008 or support a conclusion about whether any dose is clinically important. A group mean is not an individual participant’s experience, and the standard deviation is not a confidence interval for the treatment contrast. The registry does not report an estimated contrast or its confidence interval for the sponsor’s comparison. The p-value does not give the size of an effect or the probability that a treatment works.

The trial’s randomized design is relevant to the intended comparison, but the registry excerpt does not report the detailed randomization procedures, analysis plan, or missing-data methods needed for a full statistical appraisal. Results are reported for the safety population for the primary endpoint; the record does not define that population further. The study’s single-center description and enrollment of 54 also define the setting and scale of the study, but do not by themselves determine how precisely an effect was estimated.

The safety results give counts of participants affected by serious and other adverse events, and report no deaths in any group. They are descriptive counts and do not establish causation. The serious-event terms and percentages are not tied to specific groups in the available record.

Overall, the registry supports a careful account of the posted endpoint summaries, the one reported p-value, and the adverse-event counts. It does not provide a complete basis for determining the size, precision, multiplicity-adjusted significance, or clinical relevance of a treatment effect.

15. Why This Trial Matters Statistically

This study illustrates why a statistical interpretation should distinguish a group summary from a treatment-effect estimate. The registry reports means and standard deviations for each group, but does not report a contrast and confidence interval for the sponsor’s comparison. Readers can describe the observed scores, yet the precision of the between-group estimate cannot be assessed from a reported interval because none is given.

The cohort structure also matters. CA-008 was studied at 5 mg, 10 mg, and 15 mg, with separate placebo arrangements for Cohort 1 and Cohorts 2 and 3. The reported ANOVA concerns the 15 mg dose and the latter placebo group. It should not be generalized as a statistical test of every dose or as an overall comparison across all groups.

The record reports several secondary outcomes in addition to the primary pain score. In general, multiple outcomes and comparisons make the analysis plan important: a prespecified approach can clarify which tests are confirmatory and how multiplicity is handled. That approach is not reported in the registry record. Likewise, details about missing observations, model assumptions, and the analysis populations would help readers evaluate how the reported result was obtained.

The trial also shows the value of separating efficacy-related summaries from safety descriptions. The adverse-event counts are not treatment-effect estimates, and the listed serious-event terms are not assigned to groups in the available record. Statistical interpretation requires attention to what each number represents, its denominator, and the comparison it supports.

16. 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 registry record provides group means and standard deviations for the primary endpoint, but no confidence intervals for those means or for a treatment contrast. The sponsor-reported ANOVA result is accompanied by a p-value but not an estimated difference or interval. As a result, the magnitude and precision of that comparison cannot be fully assessed from the posted results.

The inferential result applies to the 15 mg group and the placebo group for Cohorts 2 and 3. The registry does not report an inferential comparison for the 5 mg or 10 mg groups. It also does not state whether the placebo groups were intended to be pooled for any analysis, or describe comparisons across all doses. The separate cohort and placebo structure therefore limits how broadly the one reported test can be interpreted.

The record does not report the sample-size justification, full statistical analysis plan, handling of missing endpoint data, or detailed model assumptions. It does not specify a multiplicity strategy or define the safety population beyond naming it as the population for the primary endpoint. The reported ANOVA cannot be independently reconstructed from the information.

The study is described as single center and has enrollment of 54. These registry entries describe the study’s scale and setting, but the registry does not provide enough detail to assess how enrollment related to the planned precision or power. The study’s own sample-size justification is not reported in the registry record.

For safety, the record gives affected-participant counts by group, but the listed serious-event terms and percentages are not linked to treatment groups in the available information. The registry excerpt does not provide the event timing or other detail needed to assess attribution. These limitations restrict interpretation of both efficacy and safety; they do not establish that unreported methods or analyses were absent from the study itself.

17. Related Tutorials

18. Related Statistical Calculators

19. Sources

• ClinicalTrials.gov: Study in Subjects Undergoing Complete Abdominoplasty — NCT03789318.
• Registry record last updated 2024-03-19; status last verified 2024-03.
• Results first posted 2022-01-13.
• 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.

20. Record Summary

NCT03789318 is a completed Phase 2, randomized, parallel-group, placebo-controlled study of CA-008 in subjects undergoing complete abdominoplasty. The registry describes the study as single center and lists enrollment of 54. The official title says double-blind, and the masking entry says triple masking.

The primary endpoint is mean pain intensity at rest at 96 hours on a 0-to-10 Numerical Rating Scale, reported for the safety population. The registry gives group means and standard deviations for CA-008 5 mg, 10 mg, and 15 mg and their corresponding placebo group arrangements. A sponsor-reported ANOVA compares the 15 mg group with the placebo group for Cohorts 2 and 3 and reports p = 0.291.

The record also lists four secondary outcomes and reports adverse-event counts by group. It reports 0 deaths in every group. Detailed sample-size justification, missing-data handling, multiplicity procedures, and the full statistical analysis plan are not reported in the registry record.