The Utility of Peri-operative Arnica Montana for Reduction of Ecchymosis in Rhinoplasty Surgery: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for The Utility of Peri-operative Arnica Montana for Reduction of Ecchymosis in Rhinoplasty Surgery (NCT01164644), a randomized na study. The primary outcome is Assess Extent of Bruising.

2. Clinical Question

The trial asked whether peri-operative Arnica montana was associated with a different amount of facial bruising after rhinoplasty than placebo. Bruising was assessed from photographs taken after surgery, with the primary assessment scheduled for post-operative day 3. The registry describes the study as a randomized, quadruple-masked, parallel-group trial.

The outcome was not a subjective rating of bruising severity: it was a ratio based on photographed pixel areas. The comparison therefore concerns this particular image-derived measure at the specified assessment time. The registry record does not report additional details about eligibility, the surgical procedures, or the people who assessed the photographs.

3. Trial Design

The registry classifies this study as randomized, quadruple-masked, and parallel-group. Random allocation means participants were assigned to one of the two study arms rather than choosing their group. The masking designation indicates that the record describes four categories of people as masked, but it does not identify those categories or describe how masking was maintained.

The two arms were Arnica montana and placebo. Both arm descriptions specify twelve pills by mouth three times a day over four days. The study summary describes the placebo as a sugar pill. The registry lists an enrollment of 28. The primary outcome results list 9 participants in the Arnica Montana arm and 13 in the Placebo arm; the safety results use different at-risk counts. The registry record does not explain the differences among these counts, and they should not be treated as interchangeable denominators.

The primary completion date is listed as 2012-12, and the overall status is COMPLETED. The phase is listed as NA. The sponsor is University of Wisconsin, Madison. These registry entries describe the trial record and do not establish that every enrolled participant contributed to every reported result.

The primary outcome was measured on post-operative day 3 using photographs and a standardized pixel-area ratio. The study summary says photographs were used to assess bruising in both groups. The record lists three outcome measures, but no secondary results are posted. Further details about randomization procedures, allocation concealment, masking roles, adherence, and the analysis population are not reported in the registry record.

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: 28 subjects were recruited, 22 completed the study. One elected to leave the study prior to surgery, 2 attended only one post-operative visit; 2 did not undergo surgery (loss of health insurance \[1\] and thrombocytopenia \[1\]); and 1 subject elected to leave the study for laser treatments for ecchymosis on post-operative day 3

Overall Study

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 Assess Extent of Bruising, measured over Post-operative day 3.

The primary outcome, titled “Assess Extent of Bruising,” measures the photographed area of bruising relative to a standard area marker. A card with a marker of known size was held in front of each subject’s face. The marker’s pixel area was compared with its known area, and the bruised area was measured in pixels. The outcome is the ratio of bruised-area pixels to standard-area pixels.

The scheduled measurement was post-operative day 3. In general, using a reference marker can standardize image measurements when photographs may differ in scale. A ratio expresses the bruised area relative to that reference rather than reporting a raw pixel count alone. By the endpoint’s definition, a lower ratio corresponds to less measured bruised area relative to the standard-area marker.

The registry reports the outcome as a mean with standard error for each arm. It does not report confidence limits for the arm means, a between-group estimate, or a statistical test. Details such as how the bruised region was outlined, whether multiple assessors measured photographs, and how measurement consistency was evaluated are not reported in the registry record.

This endpoint captures an image-based measure at one specified time. It is not, by itself, a measure of other aspects of recovery, patient experience, or bruising at other times. The registry record does not provide results for additional assessment times.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a randomized, quadruple-masked, parallel-group trial. Randomization is intended, in general, to make assignment independent of participants’ characteristics, reducing systematic differences between groups on average. Masking can reduce the influence of expectations on behavior, outcome assessment, or other trial processes. These are general methodological purposes; the registry record does not describe its randomization procedure, the roles included in quadruple masking, or how masking was maintained.

What do the reported means represent?

The primary measure is continuous: it is a numeric ratio based on the photographed bruised area and a standard-area marker. The registry reports a mean for each arm. A mean gives a summary of the observed values in that arm; it does not show the full distribution of individual measurements. The record does not provide individual observations, a standard deviation, or other information describing the shape or spread of those distributions.

The reported standard error is an estimate of the sampling uncertainty in an arm mean. In general, it is not the same as the standard deviation: standard deviation describes variability among observations, while standard error describes uncertainty in an estimated mean. The standard errors reported are 0.091 for Arnica Montana and 0.118 for Placebo. They do not, on their own, provide a confidence interval or a test of the difference between the arm means.

Why is a between-group estimate important?

The trial question is comparative. It asks how the primary outcome differs between the Arnica montana and placebo groups. An analysis designed for that question would ordinarily report a contrast between groups together with an uncertainty measure, such as a confidence interval, and possibly a test result. In general, a confidence interval gives a range of values compatible with the data and the method’s assumptions. Its width conveys precision, while its location conveys the direction and scale of the estimated contrast.

The registry record lists no analyses and posts no comparative estimate, confidence interval, or p-value for the primary endpoint. The available arm means and standard errors cannot be substituted for a sponsor-reported comparison. No recalculated comparison is reported in this discussion. The registry record does not report whether an adjusted or unadjusted method was planned or used.

What can masking and randomization establish?

In general, randomization and masking can support a fair comparison by limiting some sources of bias. They do not guarantee that all participants contribute complete data, that the endpoint is measured without error, or that a particular statistical analysis is appropriate. Interpretation also depends on how participants were analyzed, how missing measurements were handled, and whether the analysis followed a plan. Those details are not reported in the registry record.

The record identifies the study as quadruple-masked but does not name the masked groups of people. It also does not describe allocation concealment or the generation of the random sequence. These specific operational details should not be inferred from the masking or allocation labels.

How should planning calculations be read?

In general, sample-size calculations estimate how many participants a future study might need under stated assumptions about an effect, variability, significance level, allocation, and statistical method. They are planning illustrations, not evidence about the probability that the completed trial found an effect. The registry’s planning assumptions describe a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the effect framed as a stated fraction of the observed effect. The stated approach is a planning illustration based on the observed effect, not the trial’s own design justification.

Any sample-size illustration should be interpreted as conditional on its assumptions. It is not observed power, and it cannot replace an estimate and uncertainty interval from the completed study. The registry record does not report a sample-size justification for the original trial or a statistical analysis plan. No numerical planning estimate is stated in the results.

Finally, the outcome is derived from photographic pixel measurements. As a general matter, statistical summaries cannot remove measurement error or address systematic differences in image capture or assessment. The registry describes a standard marker, but does not report technical details about image processing, measurement reliability, assessor agreement, or quality-control procedures. Those omissions limit how fully the precision and reproducibility of the endpoint can be assessed.

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("Arnica Montana", "Placebo")
n   <- c(9, 13)
m   <- c(0.617, 0.736)
sp  <- c(0.091, 0.118)
sd  <- sp * sqrt(n)      # standard errors converted to SDs
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  Arnica Montana  9  0.617  0.273  0.407  0.827
CARM  Placebo  13  0.736  0.425  0.479  0.993

11. Multiplicity, Missing Data and Analysis Populations

The registry lists three outcome measures, while no secondary results are posted. It lists no analyses. The registry record does not report a statistical analysis plan, a hierarchy among outcomes, or a method for addressing multiplicity. In general, when several outcomes or statistical tests are considered, the chance of a false-positive result can increase unless the analysis accounts for the number and structure of the tests. The available record does not establish whether or how that issue was addressed.

Missing-data methods are not reported in the registry record. The primary outcome results list 9 participants in the Arnica Montana arm and 13 in the Placebo arm, whereas the safety record gives at-risk counts of 12 and 14. These are different reported denominators for different outcomes. The record does not explain the difference, identify the reasons for missing primary measurements, or state whether any measurements were excluded.

The analysis population is also not reported in the registry record. It is not stated whether the primary analysis included all randomized participants, only participants with usable photographs, or another defined group. No information is given about imputation, sensitivity analyses, protocol deviations, or handling of participants who did not complete the assigned regimen. These omissions mean that the implications of missingness and the exact population represented by the primary outcome summaries cannot be determined from the registry entry.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

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

Serious events with the highest arm-level rate: thrombocytopenia (8.3%).

The safety record reports serious adverse events for groups with 12 participants at risk in Arnica Montana and 14 in Placebo. It records one serious adverse event in the Arnica Montana group and zero in the Placebo group. The record reports zero other adverse events in each group. Death counts are not reported in the registry record.

The registry lists thrombocytopenia, with 8.3%, among the top serious adverse event terms. The record does not provide enough detail to establish the event’s timing, clinical course, or relationship to study treatment. The listed term should be read as a safety-record entry, not as evidence of causation.

These counts are descriptive. The at-risk denominators are not the same as the counts listed for the primary outcome, and the registry record does not explain the difference. With the information posted, the event counts do not provide a complete account of how adverse events were collected, classified, monitored, or attributed. Zero recorded events in a category does not establish that no event could occur; it means that none was reported in that category for the listed group in this record.

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

The posted results describe the primary photographic bruising measure on post-operative day 3. The Arnica Montana mean was 0.617, with a standard error of 0.091; the Placebo mean was 0.736, with a standard error of 0.118. Since the endpoint is bruised-area pixels divided by standard-area pixels, the arm means can be read as summaries of the measured ratios. The Arnica Montana mean is numerically lower, but the registry does not report a formal estimate of the difference between groups.

That distinction matters. A comparison of two group means is not fully characterized by the means alone. A comparative estimate and its uncertainty would indicate how precise the observed contrast is under the analysis method. The record provides neither a confidence interval nor a p-value for the primary comparison, and no analysis is listed. It therefore does not establish whether the observed difference is compatible with a range of effects that includes no difference, or how much uncertainty surrounds the comparison.

The results concern one image-derived measure at one assessment time. They do not establish a pattern at other times or address other outcomes. The record does not report secondary results, analysis populations, missing-data handling, or detailed procedures for measuring photographs. Those limitations leave important questions about the completeness and reproducibility of the endpoint summaries unanswered.

The serious adverse event record lists one event in Arnica Montana and zero in Placebo, with different at-risk counts. These are descriptive safety figures, not a comparative safety analysis. The record does not provide enough information to infer a causal relationship or to characterize all aspects of safety.

Accordingly, the posted data support a limited description of the reported arm summaries and safety counts. They do not, on their own, provide a complete inferential answer to the trial’s comparative question. No conclusion about whether either study regimen works or does not work follows from these registry summaries alone.

14. Why This Trial Matters Statistically

This trial illustrates why a clinical result needs more than an outcome measure and a pair of group summaries. The registry defines a specific photographic endpoint and reports a mean and standard error for each arm. Those values describe the observed arm-level results, but the clinical question is comparative. Without a reported between-group estimate and its uncertainty, readers cannot assess the precision of the comparison from the registry record.

The distinction between an endpoint summary and an inferential analysis is central to biostatistics. A mean describes the center of observed measurements; a standard error describes uncertainty in that mean under statistical assumptions. Neither alone gives the uncertainty around a contrast between groups. Reporting the comparative estimate, the method used, and a confidence interval would make the analysis more directly interpretable.

The record also shows why analysis populations and denominators matter. The primary outcome and safety summaries use different participant counts, and the registry does not explain why. A reader needs to know which participants contributed to each analysis and how missing outcome data were handled to judge what population each result represents.

Finally, the endpoint is based on image processing and a standardized marker. This offers a defined way to quantify bruising, while also making measurement procedures and reproducibility relevant to interpretation. The registry describes the ratio calculation but does not report assessor agreement or other measurement-quality details. Together, these features make the trial a useful example of the difference between descriptive results and a complete, transparent statistical account.

15. 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 trial-specific details needed to interpret the results are not reported in the registry record. The primary endpoint is derived from photographs, but the record does not explain who outlined the bruised area, whether assessors were masked to group assignment, or how measurement consistency was evaluated. Although the trial is labelled quadruple-masked, the masked roles are not identified. The use of a size marker is described, but procedures for photograph capture, image processing, and quality control are not detailed.

The primary outcome results list 9 participants for Arnica Montana and 13 for Placebo, while the safety results list 12 and 14 at risk. The registry record does not explain these different counts or identify the analysis population. Missing measurements, exclusions, adherence, and handling of incomplete follow-up are not described. This makes it difficult to determine how representative the reported outcome summaries are of the enrolled participants.

The record lists three outcome measures but posts no secondary results and no analyses. It does not report a statistical analysis plan, a sample-size justification, a between-group estimate, a confidence interval, or a p-value for the primary endpoint. It also does not report adjustment for multiplicity. Therefore, the posted arm summaries cannot be used to reconstruct the planned inferential framework.

The record gives the primary assessment time as post-operative day 3 and does not report results for other assessment times. Further eligibility criteria and details about the surgical procedures are also not reported. These limits constrain interpretation to the specific registered endpoint and summaries rather than a broader account of outcomes or the study population.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: The Utility of Peri-operative Arnica Montana for Reduction of Ecchymosis in Rhinoplasty Surgery — NCT01164644.
• Registry record last updated 2017-05-17; status last verified 2017-04.
• Results first posted 2013-05-03.
• 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.

19. Record Summary

NCT01164644 is a completed, randomized, quadruple-masked, parallel-group trial sponsored by University of Wisconsin, Madison. The registry lists enrollment of 28 and compares Arnica montana with placebo in subjects undergoing rhinoplasty. Both arm descriptions specify twelve pills by mouth three times a day over four days.

The primary endpoint is a photograph-based ratio of bruised-area pixels to standard-area pixels, assessed on post-operative day 3. The reported means are 0.617 for Arnica Montana and 0.736 for Placebo, with standard errors of 0.091 and 0.118. The registry record lists no analyses and does not report a comparative estimate, confidence interval, or p-value.

The safety record reports one serious adverse event in Arnica Montana and zero in Placebo, with at-risk counts of 12 and 14. Other adverse events are reported as zero in each group. The registry record does not report an analysis population or missing-data methods.