Safety Study of Cosmetic Tissue Augmentation in People of Color: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Safety Study of Cosmetic Tissue Augmentation in People of Color (NCT01147172), a na na study. The primary outcome is Keloid Formation at Site of Injection.

2. Clinical Question

3. Trial Design

This was a post-approval, multicenter, open-label, longitudinal, uncontrolled safety study of ELEVESS in the treatment of nasolabial folds in people of color. The registry classifies the study as single-group. It lists enrollment as 100 and identifies the safety population as the population for the primary endpoint. The listed intervention is ELEVESS, a device; no separate treatment arm or control is described.

Open-label means masking was not used, consistent with the registry’s masking entry of NONE. The registry lists allocation as NA, which accords with the absence of a randomized comparison group. Phase is also recorded as NA. A phase designation or further explanation of these entries is not reported in the registry record.

The study began in 2009-03, had primary completion in 2009-12, and is listed as COMPLETED. Its focus was safety in people with Fitzpatrick skin types IV, V and VI who had elected to undergo treatment. The registry’s summary states that further study of soft tissue fillers in people of color was needed and describes evaluation of keloid formation, pigmentation changes and other potential adverse events.

The design can describe outcomes among participants who received the filler, but it cannot directly compare those outcomes with what would have occurred under another treatment or without treatment. The protocol details, including the follow-up schedule beyond the stated primary endpoint timeframe, are not reported in the registry record. The record also does not state how participants were recruited or how many were assessed for eligibility.

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: Elevess was injected into the mid to deep dermis of each nasolabial fold. Subjects were telephoned at 72 (±24) hours to assess the subjects for possible AEs and injection site reactions. All subjects returned 14 ± 3 days after initial treatment for evaluation of AEs and to assess whether a Touch-up was needed.

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.

Population: Subjects of Fitzpatrick Skin Type IV, V or VI seeking treatment of nasolabial folds with injectable hyaluronic acid gel (Elevess).

6. Primary Endpoint

The registry lists the primary outcome as Keloid Formation at Site of Injection, measured over 2 Weeks.

The primary endpoint is the percentage of participants in the safety population with keloid formation at the site of injection at 2 Weeks. It is a participant-level binary outcome: for each participant, the event is either recorded as present or absent by the endpoint definition. Reporting the percentage is a way to express how often the defined event occurred in the population being assessed.

Keloid formation was selected as a safety outcome in a study focused on people with Fitzpatrick skin types IV, V and VI. The registry summary specifically identifies keloid formation and pigmentation changes as safety concerns to be evaluated in this population. The endpoint is therefore relevant to the stated safety objective, but its definition alone does not establish how frequently the event occurred.

The registry record does not report the observed primary endpoint result, a confidence interval, or a statistical comparison. It also does not provide a detailed assessment procedure or explain how a keloid was classified. The listed timeframe is 2 Weeks; findings at that assessment would not, by themselves, describe outcomes at other follow-up times. The registry lists 8 outcome measures, but the registry entries available do not give the results for the other measures.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a single-group, uncontrolled study and lists no masking. Those features determine what the results can address. A single-group analysis describes outcomes among participants who received ELEVESS. Without a comparator, it cannot estimate a treatment contrast or distinguish outcomes associated with treatment from outcomes that might also occur for other reasons. General statistical interpretation of a single-group safety result should therefore emphasize observed counts and their uncertainty, rather than a claim of comparative effect.

What does a binary endpoint represent?

The primary outcome is a percentage of participants with keloid formation at the injection site at 2 Weeks. In general, a binary endpoint classifies each participant according to whether a defined event occurred. A count of participants with the event, together with the number assessed, can be used to describe the event frequency. The registry does not report the primary endpoint count or an estimated percentage, so neither can be interpreted from this record. The adverse-event counts are distinct outcomes and cannot substitute for the missing keloid endpoint result.

What would uncertainty measures add?

In general, a confidence interval gives a range of values compatible with the observed data under a specified statistical procedure. It helps readers assess the precision of an estimate; it does not guarantee that the true value lies in the interval. The registry record does not report a confidence interval for the primary endpoint or the adverse-event counts. It also does not report a statistical model or other inferential method for these outcomes. Without those details and the primary endpoint result, precision cannot be evaluated from the registry record.

Why does the absence of a control matter?

In general, random allocation to comparison groups can help make groups comparable with respect to measured and unmeasured factors, though it does not eliminate every source of uncertainty. This study is explicitly uncontrolled and single-group, with allocation listed as NA. It has no control group for a direct comparison. Descriptive event counts can document what was recorded among participants, but they do not provide the counterfactual information needed to determine what would have happened to those same participants under another condition.

How should planning illustrations be understood?

Any sample-size planning illustration is a hypothetical calculation, not an observed trial result and not observed power. The stated illustration assumptions are a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect to detect defined as a stated fraction of the observed effect. Those assumptions do not describe this study’s single-group design. The registry does not report a trial-specific sample-size justification or a planned comparative design. Any such illustration should therefore be read as a planning scenario rather than evidence about the study’s achieved power or its safety findings.

What does over-dispersion mean in general?

For count outcomes, over-dispersion means that observed variability is greater than a statistical model assumes. In general, ignoring over-dispersion can make uncertainty estimates too narrow and tests too optimistic. The primary endpoint in this record is a participant-level percentage, and no count model or analysis of over-dispersion is reported. It would be inappropriate to assume that such a model was used or needed for this endpoint. More generally, the choice of a statistical method should follow the outcome’s structure and the analysis plan; that plan is not reported in the registry record.

The record lists 8 outcome measures but gives no analysis entries. It does not describe estimation methods, handling of repeated observations, covariate adjustment, or sensitivity analyses. These omissions limit assessment of how the reported adverse-event counts were generated and how incomplete observations may have affected them. The registry record supports a basic descriptive reading of the posted safety counts, not reconstruction of a broader statistical analysis.

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("Elevess")
n      <- c(97)
events <- c(0)
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  Elevess  97  0  0.0  0.0  3.7  0.0  3.8  0.0  3.7

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 8 outcome measures, but the registry entries available detail the primary keloid endpoint and do not provide results for the other measures. A statistical analysis of several outcomes can raise multiplicity concerns: in general, the more separate tests or claims considered, the greater the chance that an apparently notable result arises by chance. Whether an adjustment, testing hierarchy, or other multiplicity strategy was planned is not reported in the registry record. No p-values or analyses are listed, so the record does not permit assessment of how multiplicity was handled.

Missing-data procedures are also not reported in the registry record. The registry entries available do not state how missing endpoint assessments were treated, whether participants lost to follow-up were included in particular analyses, or whether any imputation or sensitivity analysis was used. These details matter because a percentage based on observed assessments can be affected if outcome status is unavailable for some participants. The listed safety population and adverse-event denominators do not establish completeness for every outcome.

The primary endpoint identifies the safety population, but the definition of that population and the rules for including participants are not reported in the registry record. The record lists enrollment as 100, yet it does not give participant flow or analysis-specific denominators for the keloid endpoint. It lists no analyses. Thus, neither the handling of missing observations nor the relationship between enrollment and endpoint assessment can be evaluated beyond the denominators reported for adverse events.

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 1% reporting threshold.

Most frequent non-serious adverse event terms

The registry lists 0 participants with serious adverse events among 100 at risk in the safety population. It also lists 47 participants in the other adverse-event category among 100 at risk. These are counts in two distinct categories, not a comparison between study arms. The study had no control group.

The record does not list any terms under the serious adverse-event terms, so it gives no further description of serious events. The specific events included in the other category are also not reported in the registry record. The figures do not show the number of events per participant, their timing, or their duration. Deaths are recorded as null, so a death count is not reported in the registry record.

In general, a serious adverse event is a category defined by the applicable safety-reporting criteria; it should not be treated as interchangeable with every adverse event. The registry’s separate counts should therefore be read in their stated categories. The 0 serious-event count does not establish that no non-serious adverse events occurred, and the other-category count does not establish that those events were serious. The registry does not provide enough detail to characterize the events beyond the reported counts.

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

The posted results provide limited descriptive safety information for a single-group study of ELEVESS in people with Fitzpatrick skin types IV, V and VI. The safety population is listed as 100 at risk for each of the adverse-event categories reported. The registry records 0 participants with serious adverse events and 47 participants in the other adverse-event category.

The primary endpoint is keloid formation at the injection site at 2 Weeks, expressed as a percentage of participants. Its result is not reported in the registry record. Because that is the designated primary endpoint, its absence is a central limitation when interpreting the study’s stated safety objective. The record also does not give the specific terms in the other adverse-event category or the death count.

These findings do not establish whether ELEVESS caused any recorded event, because the study has no comparator. They also do not support a conclusion about how the observed event counts compare with another filler or with no treatment. In general, event frequency in a treated group is descriptive; a comparative design and suitable analyses are needed to estimate differences between treatment conditions.

The findings are specific to the participants and observation information represented in the registry. The registry does not report enough detail to assess representativeness, completeness of follow-up, or precision for the primary endpoint. The posted counts should not be extended to other populations, products, or follow-up periods without supporting evidence. They describe what the record reports, while leaving important questions about the primary outcome, event details, and uncertainty unanswered.

14. Why This Trial Matters Statistically

This trial addresses a statistical and reporting challenge in safety research: studying outcomes in a population for which the registry summary states that further study of soft tissue fillers was needed. It focuses on people with Fitzpatrick skin types IV, V and VI and specifies keloid formation and pigmentation changes as safety concerns. A clearly defined participant-level safety endpoint can make the intended observation explicit, even when the registry record does not include the resulting estimate.

The design also illustrates the distinction between describing events and estimating comparative effects. In a single-group, uncontrolled study, counts can describe what was recorded among treated participants. They cannot, by themselves, establish how those counts differ from outcomes under another treatment or no treatment. This distinction is especially important when a registry reports safety counts without detailed event terms, a primary endpoint result, or measures of statistical uncertainty.

The record lists 100 enrolled and identifies a safety population. Yet it does not provide the keloid result or explain missing-data handling and analysis methods. That gap makes it difficult to judge precision and completeness for the primary question. A result definition, denominator, observed count, and uncertainty measure together would support a more informative statistical interpretation; the registry record does not report all of these elements for the primary endpoint.

The study is therefore informative as an example of why population-specific safety questions, endpoint reporting, and design constraints must be read together. Its posted adverse-event counts offer descriptive information, while the uncontrolled design and missing primary endpoint result limit what can be inferred. These limitations do not make the study question unimportant; they define the boundaries of the evidence available from this registry record.

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 most consequential limitation is that the registry record does not report the result for the primary endpoint, keloid formation at the injection site at 2 Weeks. It also does not report the observed result for pigmentation changes, although the summary identifies them as a safety concern. Without those results, the stated safety questions cannot be answered from the posted information.

The study is uncontrolled and single-group. There is no comparator for separating outcomes observed after treatment from background events or other influences. The open-label design means masking was not used, and the registry does not describe outcome assessment procedures that could clarify how event classification was made.

Details needed to assess the adverse-event findings are limited. The record does not list serious-event terms, describe the other adverse events, or report a death count. It does not provide participant flow, endpoint-specific denominators, missing-data methods, or follow-up details beyond the primary endpoint timeframe. The safety-population definition is not reported in the registry record.

The record lists 8 outcome measures but no analyses. It does not describe multiplicity control, statistical methods, or a trial-specific sample-size justification. Phase and allocation are recorded as NA, without further explanation. These reporting gaps make it difficult to assess analytic choices, outcome completeness, and precision. The registry’s enrollment and adverse-event denominators do not resolve those uncertainties, and the reported counts should be interpreted as limited descriptive data rather than a comprehensive account of safety.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Safety Study of Cosmetic Tissue Augmentation in People of Color — NCT01147172.
• Registry record last updated 2017-10-17; status last verified 2017-09.
• Results first posted 2015-04-20.
• 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

NCT01147172 is listed as a completed, post-approval, multicenter, open-label, longitudinal, uncontrolled, single-group safety study of ELEVESS for nasolabial folds in people with Fitzpatrick skin types IV, V and VI. Enrollment is listed as 100; the study began in 2009-03 and had primary completion in 2009-12. The primary endpoint is the percentage of the safety population with keloid formation at the injection site at 2 Weeks.

The registry reports 0 participants with serious adverse events and 47 in the other adverse-event category, each among 100 at risk. It does not report the primary endpoint result, specific terms for the other adverse events, or a death count. No analyses are listed. The single-group design supports descriptive reporting but not a direct comparison with another treatment or with no treatment.