A Study to Evaluate Efficacy and Safety of Macrolane VRF30 for Volume Restoration and Contouring of the Buttocks: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study to Evaluate Efficacy and Safety of Macrolane VRF30 for Volume Restoration and Contouring of the Buttocks (NCT01331408), a na phase 4 study. The primary outcome is Percentage of Participants With Improvement on the Global Esthetic Improvement Scale (GEIS) at Month 6.

2. Clinical Question

3. Trial Design

This was an open, post-marketing, multicenter Phase 4 study of Macrolane VRF30. The registry describes the model as single group, with no masking and allocation listed as not applicable. The intervention was injection of Macrolane VRF30 in the buttocks. The record reports enrollment of 61 and a completed status. The recorded study start is 2008-09, and primary completion is 2009-10. Galderma R&D is listed as the sponsor.

The design addresses participants’ assessments after receiving the intervention, rather than comparing outcomes between randomized treatment groups. For the primary endpoint, the reference is each subject’s baseline assessment. This can describe change in perceived appearance over follow-up, but without a separate control group it cannot isolate the contribution of the intervention from other influences on ratings over time. An open design also means participants knew they were receiving the intervention; the registry does not describe masking of outcome assessment.

The primary endpoint was assessed at 6 Months. The secondary outcomes listed are the percentage of participants with improvement on the Global Esthetic Improvement Scale at Month 1 and Month 12. The record names three outcome measures, but provides no outcome estimates for the primary or secondary endpoints. It also lists no analyses. Thus the design and intended measurements can be described, but the registry record does not support an assessment of the magnitude or precision of the reported efficacy outcome.

The registry does not report a separate control intervention, a randomized allocation procedure, detailed eligibility criteria, injection protocol, or statistical analysis plan. Those omissions limit how fully the study conduct and interpretation can be reconstructed from 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.

Overall Study

Analysis population for the primary outcome, as defined in the registry: Intention to treat, subjects with available 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: Intention To Treat

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Participants With Improvement on the Global Esthetic Improvement Scale (GEIS) at Month 6, measured over 6 Months.

The primary endpoint is the percentage of subjects whose own Global Esthetic Improvement Scale rating at 6 Months indicates that their buttock appearance is improved, much improved, or very much improved compared with baseline. It is a binary summary: the specified ratings count as improvement, while ratings outside those categories do not meet the endpoint definition. The registry describes the analysis population as intention to treat, subjects with available data, and identifies the dispersion measure as a 95% confidence interval.

A global aesthetic rating is useful for capturing a participant’s overall perception of change rather than relying only on a technical measurement of volume or contour. Perceived improvement may incorporate multiple aspects of appearance into a single assessment. That makes the endpoint relevant to a study whose stated purpose includes shaping and volume restoration, while also making clear that it is a subjective rating rather than an objective anatomical measurement.

The registry record does not report the observed percentage or its confidence interval. Consequently, the endpoint definition alone cannot show how often participants met the improvement criterion or how precise an estimate would be. It also does not specify the exact scale response options, the method for handling missing Month 6 ratings, or how the confidence interval was calculated.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The methods information in the registry record is limited. It specifies a single-group study, an open design, a subject-rated binary primary endpoint, a 95% confidence interval as the dispersion measure, and an intention-to-treat population described as subjects with available data. It does not report the statistical method used to estimate the percentage or interval, any hypothesis test, an adjustment strategy, or a detailed analysis plan. No analyses are listed in the record. Statistical concepts can help explain what such methods would mean in general, but they cannot fill in those missing details.

What does a percentage endpoint represent?

In general, a percentage for a binary endpoint expresses the share of evaluated participants who meet a defined criterion. In this study, the criterion is a subject rating of improved, much improved, or very much improved on the Global Esthetic Improvement Scale at 6 Months compared with baseline. The percentage would describe the observed frequency of those ratings among participants included in the relevant analysis. The registry record does not report that percentage, and it does not state the number with available Month 6 data.

Binary endpoints simplify a range of possible ratings into whether a specified threshold was met. This can make the result straightforward to communicate, but it also discards detail about differences among ratings within the improvement category and among ratings that do not meet it. Interpretation depends on the scale definition and on how participants without an assessment are handled. The scale categories are partly described in the registry, but its full response structure and missing-data rules are not reported.

What does a confidence interval add?

In general, a confidence interval communicates the statistical uncertainty around an estimated quantity. For a percentage, it helps readers judge how precisely the observed proportion has been estimated, alongside the estimate itself. A wider interval indicates less precision than a narrower interval, all else being equal. The registry identifies a 95% confidence interval for the primary endpoint, but does not report its limits, the estimate it accompanies, or the formula used to calculate it. Therefore, no judgment about the precision of the primary result is possible from the recorded information.

The interval method matters, particularly for a percentage, because methods can behave differently depending on the amount of information and the observed response pattern. The record does not identify whether the interval was based on a normal approximation or another approach. It would be inappropriate to infer the method from the endpoint format alone.

What can a single-group baseline comparison establish?

In general, a within-participant comparison asks whether assessments differ over time for the participants observed. It can describe change from baseline, but it does not by itself estimate what would have happened over the same period without the intervention. A concurrent comparator can help address that question by providing a reference group, although the quality of the comparison depends on the design and analysis. This study is listed as single group, with allocation not applicable; no randomized control group is reported.

The endpoint is also subjective. In general, an open study can be vulnerable to expectation or assessment effects when participants know they received an intervention. Such considerations do not show that ratings were biased in this study; they explain why design context is important when interpreting a subject-reported change. The registry does not report masked outcome assessment.

How should planning calculations be understood?

The stated planning illustration uses a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect to detect expressed as a fraction of the observed effect. These are assumptions for a planning calculation, not a description of this trial’s single-group design. The illustration is not the trial’s own documented sample-size justification, and it is not observed power. The record does not report the protocol’s sample-size justification or the statistical plan used to design the study. It also does not provide enough reported outcome information to interpret an observed effect from the primary endpoint.

In general, a planning sample size depends on the outcome, the target effect, variability or event frequency, the chosen significance level, the desired power, and the design assumptions. Changing an assumed effect changes the resulting planning requirement. Such calculations are conditional illustrations rather than guarantees about what a study will find. Since the registry’s stated illustration assumes two arms while the trial is single group, it should not be mistaken for a record of the study’s actual enrollment rationale.

What is not specified?

The registry does not state the test or estimator used for the primary endpoint, the method for constructing the 95% confidence interval, how missing observations were treated, or whether any covariate adjustment was performed. It does not report interim analyses or a detailed statistical plan. These details are needed to reproduce or fully evaluate an analysis. The absence of a listed analysis means the intended endpoint can be described, but no inferential result can be independently assessed from the registry record.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Macrolane VRF30")
n      <- c(56)
events <- c(45)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Macrolane VRF30  56  45  80.4  67.6  89.8  68.2  88.7  68.1  88.6

11. Multiplicity, Missing Data and Analysis Populations

The registry identifies the Month 6 Global Esthetic Improvement Scale assessment as the primary outcome and lists improvement at Month 1 and Month 12 as secondary outcomes. Considering multiple time points can provide a broader view of the course of subject-rated improvement, but repeated outcome testing raises a general multiplicity question: when multiple findings are examined, the chance of at least one apparently notable result can increase. Statistical plans sometimes address this through a hierarchy, adjustment, or a clearly stated distinction between confirmatory and exploratory outcomes.

The registry record does not report whether the outcomes were tested under a hierarchy or whether any multiplicity adjustment was planned. It gives no analyses, estimates, or hypothesis-test results for these outcomes. Therefore, the relation between the primary and secondary outcomes cannot be evaluated as an analysis strategy, and no claim of statistical significance can be drawn from the endpoint listings alone.

For the primary outcome, the analysis population is described as intention to treat, subjects with available data. This wording indicates that the endpoint analysis is limited to subjects with an available assessment, but the registry does not report how many had data at Month 6 or how missing values were handled. It does not say whether missing outcomes were imputed, excluded, or addressed in a sensitivity analysis. Missingness can matter if participants with and without observed ratings differ in ways related to the outcome; this is a general concern and not evidence that such a pattern occurred in this study.

The record also does not describe the population used for the secondary outcomes or report a participant flow. No interim-analysis plan is listed. With no analysis estimates and no missing-data methods, the robustness of any outcome conclusion cannot be assessed from the registry record.

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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: lipectomy (1.6%), ectopic pregnancy (1.6%).

The adverse-event record lists 2 participants affected by serious events among 61 at risk, and 13 participants affected by other events among 61 at risk. These are registry counts, not comparative estimates. Because the study has a single group and no control arm, the counts do not establish whether the intervention changed the risk of an event relative to another treatment or to no intervention.

Lipectomy and Ectopic pregnancy are listed among the serious adverse-event terms, each at 1.6%. The registry record does not provide further detail about timing, participant circumstances, severity beyond the serious classification, or a causal relationship to Macrolane VRF30. The listed terms should not be used to infer that the events were caused by the intervention. The figures also do not establish whether participants in the serious and other-event categories were distinct; the counts should not be added to estimate a total number of affected participants.

The death field is not populated with a count, so deaths are not reported in the registry record; that is not evidence of zero deaths. More generally, these safety figures summarize what is recorded, but do not provide a full clinical account or a controlled safety comparison.

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

The registry record establishes that this completed Phase 4 study evaluated Macrolane VRF30 injection for buttock volume restoration and shaping. It describes an open, multicenter, single-group design and a subject-rated primary endpoint at 6 Months. The endpoint asks whether participants perceived improvement compared with baseline, using the specified Global Esthetic Improvement Scale categories.

However, the record does not report the primary endpoint percentage or its 95% confidence interval. It also does not report the Month 1 or Month 12 improvement results. Without these values, the extent and precision of perceived improvement cannot be described from the registry record. The endpoint definition is not itself an outcome finding.

Even if an improvement percentage were reported, the single-group baseline comparison would describe ratings over time rather than provide a randomized estimate against a control group. An open study and a subject-rated endpoint are important context: expectations and other influences may affect ratings, although the record does not establish that they did. The endpoint also measures perceived overall change, not a direct measurement of anatomical volume or contour.

The safety record provides counts of participants affected by serious and other events, and names two serious-event terms with percentages. These figures do not establish causality or comparative risk. The death count is not reported in the registry record, and the available event details are limited.

Accordingly, the record supports a description of what the study set out to measure and some recorded safety counts. It does not support a conclusion about the magnitude or precision of the primary efficacy outcome, a causal treatment effect, or a comparison with another intervention. No medical conclusion should be inferred from the design description alone.

14. Why This Trial Matters Statistically

This trial illustrates why a clearly named outcome is not enough to assess a clinical result. The registry defines a patient-relevant question—whether subjects perceived improvement at 6 Months—but does not report the percentage meeting the criterion or its 95% confidence interval. Without the estimate and its uncertainty, readers cannot determine either the observed frequency of improvement or how precisely it was estimated.

The design also matters to the statistical question. A single-group study can describe participants’ ratings relative to baseline, but it does not provide a randomized comparator for estimating what would have occurred without the intervention. This distinction separates a descriptive change over time from a controlled treatment effect. The open design and subjective rating further make the outcome dependent on participants’ perception and awareness of treatment.

The record also shows why outcome timing and multiplicity need transparent planning. A primary assessment at Month 6 sits alongside secondary assessments at Month 1 and Month 12. Without a reported hierarchy or multiplicity strategy, readers cannot tell how the different time points were intended to contribute to confirmatory interpretation. No analyses are listed, so their statistical relationship remains unknown.

Finally, the registry distinguishes between design details and analysis evidence. It describes the study as completed and reports safety counts, but completion status does not substitute for outcome estimates. Planning calculations are not observed power, and planning assumptions for a hypothetical two-arm calculation do not describe the single-group trial’s actual design. The case underscores the value of complete outcome reporting, explicit missing-data handling, and a prespecified analysis strategy for interpreting clinical evidence.

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.

The main limitation for interpretation is the absence of the primary and secondary outcome results in the registry record. Although the primary endpoint and its 95% confidence interval are specified, neither the estimated percentage nor interval limits are reported. This prevents assessment of the result’s magnitude and precision.

The design is single group, open, and has no separate comparator. Baseline serves as a reference for the subject-rated endpoint, but cannot replace a concurrent control group for estimating what would have happened without the intervention. The open design and subjective nature of the Global Esthetic Improvement Scale also leave potential for expectation and assessment effects; the registry does not report masked assessment.

The primary population is described as intention to treat, subjects with available data, but the number with endpoint data and the handling of missing assessments are not reported. The registry does not provide a detailed analysis plan, confidence-interval method, multiplicity strategy, interim-analysis information, or sample-size justification. It lists no analyses, which further limits review of the statistical approach.

Safety reporting is also limited. The record gives affected counts and selected serious-event terms but does not provide detailed timing, clinical descriptions, or causal assessments. The death count is not reported in the registry record. Because the study has no comparator, its safety counts cannot establish comparative risk. These limitations restrict conclusions to the study’s design and the information explicitly recorded, rather than supporting a full evaluation of efficacy or safety.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: A Study to Evaluate Efficacy and Safety of Macrolane VRF30 for Volume Restoration and Contouring of the Buttocks — NCT01331408.
• Registry record last updated 2022-09-28; status last verified 2019-06.
• Results first posted 2019-02-28.
• 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

NCT01331408 is a completed, open, multicenter, single-group Phase 4 post-marketing study sponsored by Galderma R&D. It evaluated injection of Macrolane VRF30 in the buttocks for volume restoration and shaping. The registry reports enrollment of 61, a start date of 2008-09, and primary completion in 2009-10.

The primary outcome was the percentage of subjects reporting improvement, much improvement, or very much improvement on the Global Esthetic Improvement Scale at 6 Months compared with baseline. Month 1 and Month 12 improvement were listed as secondary outcomes. The primary endpoint was intended for an intention-to-treat population with available data and was associated with a 95% confidence interval. No outcome estimates or analyses are reported in the registry record.

Safety reporting lists 2 participants affected by serious events and 13 affected by other events among 61 at risk. Lipectomy and Ectopic pregnancy are each listed at 1.6% among serious terms. The death count is not reported in the registry record.