Structural Fat Grafting for Craniofacial Trauma: Repeat Fat Grafting Injection-5 Subject Cohort: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Structural Fat Grafting for Craniofacial Trauma: Repeat Fat Grafting Injection-5 Subject Cohort (NCT01822301), a na na study. The primary outcome is Facial Volume Score.

2. Clinical Question

The clinical question is therefore primarily about change over time in a facial appearance and volume score within a small treated cohort, rather than a comparison of treatment groups. Without reported outcome measurements, the record cannot establish the direction or size of any change, how consistent responses were, or whether the hypothesized durability was observed. A within-cohort description may help characterize what was recorded among these participants, but it does not by itself separate a treatment effect from other explanations for change.

3. Trial Design

This is a completed, single-group study sponsored by the University of Pittsburgh. The record lists enrollment of 5, a single center University of Pittsburgh site, allocation as NA, and masking as NONE. The phase is listed as NA. The start is recorded as 2013-04 and primary completion as 2015-05. The intervention is repeat fat grafting, classified as a procedure.

The study is described as enrolling subjects who had previously participated in an earlier study of facial deformities. The background says data from that prior study could be used as additional control data because treatment and evaluation methods were the same. However, the posted results do not describe an analysis combining cohorts or a like-for-like comparative analysis. The registry record flags that the arms are not a randomized comparison and are not a like-for-like control comparison. Accordingly, the design should be read as a single cohort rather than as a controlled treatment comparison.

The primary measure is a facial volume score assessed at baseline (pre-op), days 7-21 post-op, 3 months post-op, and 9 months post-op. Serial computed tomography imaging is listed among secondary outcomes, but details of its measures and results are not reported in the registry record. Although the study status is completed, completion does not establish that every planned measure was collected or that results were posted. The record does not report the rationale for the enrollment target, the eligibility criteria beyond previous enrollment, or the statistical plan used for analysis.

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

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 Facial Volume Score, measured over assessed at baseline (pre-op), days 7-21 post-op, 3 months post-op, and 9 months post-op.

The primary endpoint is the Facial Volume Score, described as the mean of a continuous measure and reported in units on a scale. The score evaluates facial volume and appearance by aesthetic region, using clinician assessment based on physical examination and 3D photography. The scale ranges from 1-3: 1 indicates an obvious contour defect; 2 indicates noticeable contour improvement that is not sufficient to impart a normal appearance; and 3 represents a normal appearance and/or close approximation with a normal uninjured contralateral structure.

The measure is intended to capture appearance and contour over time, with assessments at baseline (pre-op), days 7-21 post-op, 3 months post-op, and 9 months post-op. Repeated assessments can describe whether the recorded score changes after the procedure and whether a later score is maintained. That makes the measure relevant to the study’s stated interest in restoration and durability, but a score alone does not directly establish tissue volume by an imaging measurement, quality of life, or the cause of any observed change.

The registry record reports no primary outcome values, standard deviations, or analyses. Consequently, the observed mean at any assessment and the pattern of change are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the registered outcome measure?

The primary outcome is identified as a mean for a continuous measure, the Facial Volume Score. In general, a mean summarizes the center of a set of measurements. Its meaning depends on the score definition and the observations included. Here, the record describes a scale from 1-3 and assessments at baseline (pre-op), days 7-21 post-op, 3 months post-op, and 9 months post-op. The posted results do not give means at these assessments, so no change or trajectory can be interpreted.

The registry record names standard deviation as the measure of dispersion. In general, a standard deviation describes how spread out observations are around their mean. It is not a measure of uncertainty in the mean itself. An estimate of uncertainty would typically require an interval or another inferential result, neither of which is reported for the primary endpoint. Because no primary outcome summaries are posted, the amount of participant-to-participant variation cannot be evaluated.

What can repeated measurements tell readers?

Repeated measurement can describe how a score changes over time within a cohort. A baseline assessment gives a reference point, while later assessments can describe the score after the intervention and at later follow-up. This is useful for describing timing and persistence of observed measurements. However, a time pattern in a single group does not identify what would have happened without the intervention. Without an appropriate comparator and analysis, observed change cannot be attributed to treatment alone.

The listed scale is ordinal in its interpretation: its categories correspond to different descriptions of contour and appearance. The record nevertheless identifies the primary parameter as a mean. In general, means can be sensitive to how scale values are spaced and to the distribution of observations. Interpretation should therefore keep the scale anchors in view rather than treating a numerical average as a direct measure of anatomical volume. No observed score distribution is reported, so the suitability of the chosen summary cannot be assessed from the posted results.

How should uncertainty and significance be understood?

In general, a confidence interval communicates statistical uncertainty around an estimate: narrower intervals indicate more precision under the model used, while wider intervals indicate less precision. A p-value, when reported, addresses compatibility between data and a specified null hypothesis under assumptions; it does not measure the size or clinical importance of an effect. Neither a confidence interval nor a p-value for the primary endpoint is reported in the registry record. No significance test or adjusted analysis is listed.

A small cohort generally limits how precisely a study can characterize variation, and a single-group design limits causal interpretation. These are general statistical considerations, not findings about an unreported outcome. Because the primary measurements themselves are absent, there is no basis to estimate an effect or its precision from the posted record.

What is the status of the planning illustration?

The record describes a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the stated effect to detect is a fraction of the observed effect. It specifies that non-time-to-event illustrations refer to participants per arm, while time-to-event illustrations refer to the total number of events. These are planning assumptions, not the design description of this single-group study, and the sample-size illustrations are not observed power. The registry record does not report the trial’s own sample-size justification. Since no primary outcome effect is posted, the planning illustration should not be read as evidence about the cohort’s result.

What analyses are actually reported?

The registry record lists 0 analyses. That means there are no posted analysis results to interpret for the primary endpoint. The planned repeated assessments and the fact that the outcome is described as a mean do not establish which model, missing-data approach, or analysis population was used. Those details are not reported in the registry record. General explanations of means, dispersion, confidence intervals, and single-group interpretation cannot replace the missing outcome 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("Facial Volume Score at Baseline", "Facial Volume Score at 7-21 Day PO", "Facial Volume Score at 3 Month PO", "Facial Volume Score at 9 Months PO")
n   <- c(5, 5, 5, 5)
m   <- c(1.8, 2.2, 2.2, 2.6)
sp  <- c(0.4, 0.5, 0.4, 0.5)
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  Facial Volume Score at Baseline  5  1.800  0.400  1.303  2.297
CARM  Facial Volume Score at 7-21 Day PO  5  2.200  0.500  1.579  2.821
CARM  Facial Volume Score at 3 Month PO  5  2.200  0.400  1.703  2.697
CARM  Facial Volume Score at 9 Months PO  5  2.600  0.500  1.979  3.221

11. Multiplicity, Missing Data and Analysis Populations

The primary measure is scheduled at baseline (pre-op), days 7-21 post-op, 3 months post-op, and 9 months post-op. Repeated assessment creates several possible questions: change at each follow-up, change across all visits, or whether later values remain near an earlier value. When multiple comparisons are made, the chance of at least one apparently unusual finding can increase unless the analysis plan addresses multiplicity. This is a general statistical issue, not evidence that multiple testing occurred in this study.

The registry record lists 2 outcome measures and identifies serial computed tomography imaging as a secondary outcome, but does not give details for the other measure or report outcome analyses. The number of analyses listed is 0. A multiplicity adjustment, a hierarchy of outcomes, and a prespecified primary contrast are not reported in the registry record. It is therefore not possible to determine how the investigators intended to handle multiple time points or outcomes.

Missing-data methods and analysis populations are also not reported in the registry record. The enrollment count is 5, but the record does not state how many participants contributed primary outcome data at each visit, whether any measurements were missing, or how missing measurements were handled. A completed study status does not establish complete follow-up. The record does not specify whether analyses used all enrolled participants, participants with available measurements, or another population.

These omissions limit assessment of both the reliability and interpretability of any potential change. Without visit-level denominators, missing-data handling, and a defined analysis population, readers cannot judge whether the available observations represent the full cohort or whether missingness could affect the result. Since no outcome estimates are posted, the impact of these unanswered questions cannot be quantified.

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 non-serious adverse event terms

For Repeat Facial Fat Grafting, the registry record lists 5 participants at risk for serious adverse events and 0 affected. It lists 5 participants at risk for other adverse events and 5 affected. These are participant counts in the posted safety categories. They do not describe the number of event episodes, the event terms, when events occurred, their severity, or whether investigators considered them related to the procedure.

No serious adverse event terms are listed. Deaths are not reported in the registry record. A count of 0 serious adverse events means none were recorded in that category for the participants at risk; it does not show that a serious event is impossible or establish comparative safety. The “other adverse events” count should not be interpreted as a description of clinical importance without event details.

There is no randomized comparator group in this single-group study, so these figures do not support a controlled comparison of event frequency. The registry record also does not report additional context such as the method of event collection or follow-up duration for safety. The counts describe the posted safety record, while leaving those details unresolved.

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

The registry record is useful for understanding what the investigators intended to study: repeat facial fat grafting in a cohort of 5 previously enrolled subjects, with facial volume and appearance assessed over time. It also defines the score’s scale anchors and lists serial computed tomography imaging as a secondary outcome. Those details describe the study question and measurement approach, not its effectiveness.

The posted results do not include primary score values or analyses. As a result, they do not show whether average scores changed, how large any change was, how much participants varied, or whether a later assessment maintained an earlier result. They also do not report the quality-of-life outcome described as a hypothesis in the study summary. The study’s completed status cannot substitute for missing outcome data.

Even if a within-cohort score change were available, the single-group design would require cautious interpretation. Change over time could be associated with the procedure, but without a suitable comparator it could not be attributed to the procedure alone. The prior study is mentioned as possible additional control data, but the posted results do not show a comparison using that cohort. Thus, no controlled effect estimate is reported.

The safety counts show 0 serious adverse events among 5 at risk and 5 other adverse events among 5 at risk. They provide limited descriptive information because event types and further context are not reported. These figures neither answer the primary outcome question nor establish relative safety.

The appropriate conclusion is bounded: this is a completed, small, single-group study with a defined facial score and a stated follow-up schedule, but its primary outcome results and analyses are not reported in the registry record. Claims about the direction, magnitude, precision, durability, or cause of changes would go beyond the posted evidence.

14. Why This Trial Matters Statistically

This study illustrates why a registry record’s design and outcome definitions must be distinguished from reported results. The protocol description gives a concrete score, scale anchors, and assessment schedule. Those features help readers understand what investigators intended to measure. But without the observed means, dispersion, or analyses, the clinical question remains unanswered by the posted outcome data.

The single-group structure is also statistically important. It can describe measurements within the treated cohort, but it lacks a concurrent randomized comparison that would help distinguish intervention-associated change from other influences. The background mentions potential control data from an earlier study, yet no combined or comparative analysis is reported. The distinction between a proposed source of comparison and a posted comparison is essential when assessing evidence.

The record also shows why enrollment and completion do not convey precision. Enrollment is 5, but the registry record does not report the number contributing measurements at each visit, estimates of variability, or uncertainty intervals. Readers therefore cannot judge how precisely the primary outcome was characterized. Likewise, a sample-size planning illustration is not an observed result or a measure of study power after completion.

Finally, the safety record demonstrates the limits of counts without event details. The serious-event count is reported as 0, and other adverse events are reported for all 5 participants at risk, but terms and context are absent. Statistically, complete interpretation depends not only on a denominator and count but also on clear definitions, ascertainment, follow-up, and a relevant comparison. Those gaps make this record a useful example of why design, outcome reporting, and uncertainty all matter.

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 central limitation is that the registry record does not report primary outcome measurements or analyses. Without the Facial Volume Score results, readers cannot assess the observed mean, variation, change over time, or precision. The record also lists 0 analyses, leaving the statistical approach and any model assumptions unclear.

The cohort is small, with enrollment of 5, and there is no randomized comparator group. These features constrain both the precision of descriptive estimates and causal interpretation. The record mentions the possibility of using prior-study data as additional control data, but does not report a comparison with those data. The enrollment target’s justification is not reported in the registry record.

Further limitations include unreported baseline characteristics, eligibility details, visit-level numbers, missing-data handling, and analysis populations. The record does not explain how multiple assessment times or outcomes were handled statistically. Although serial computed tomography imaging is listed as a secondary outcome, its results and measurement details are not reported. Quality of life is mentioned as a hypothesis in the study description, but it is not included among the listed outcome details.

Safety information is also limited: event terms and context are absent, and deaths are not reported in the registry record. The study’s completed status does not establish complete follow-up or complete reporting. These limitations concern what can be concluded from the registry record and do not imply that unreported measurements were not collected.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Structural Fat Grafting for Craniofacial Trauma: Repeat Fat Grafting Injection-5 Subject Cohort — NCT01822301.
• Registry record last updated 2017-07-11; status last verified 2017-06.
• Results first posted 2017-05-12.
• 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

NCT01822301 is a completed, single-group study sponsored by the University of Pittsburgh, with enrollment of 5. The intervention is repeat facial fat grafting. Allocation is listed as NA, masking as NONE, and phase as NA. The record gives a start of 2013-04 and primary completion of 2015-05.

The primary outcome is the mean Facial Volume Score, assessed at baseline (pre-op), days 7-21 post-op, 3 months post-op, and 9 months post-op. Serial computed tomography imaging is listed as a secondary outcome. Primary outcome values and analyses are not reported in the registry record; the number of analyses listed is 0.

For safety, 0 serious adverse events are reported among 5 at risk, and 5 other adverse events among 5 at risk. Serious-event terms are not listed, and deaths are not reported in the registry record. The design and missing outcome reporting limit conclusions about change, precision, and causal effects.