Clinical Efficacy of Cryolipolysis on the Fat of Thigh in Korean Women: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Clinical Efficacy of Cryolipolysis on the Fat of Thigh in Korean Women (NCT01177787), a non-randomized na study. The primary outcome is Change in Cross Sectional Area of Fat in Both Thighs.

2. Clinical Question

The study’s stated aim was to evaluate local fat reduction after cryolipolysis and to compare it with the contralateral thigh treated with electrical stimulation. The primary endpoint concerns a measured anatomical quantity, rather than a participant’s subjective assessment. The registry also lists secondary outcomes concerning fat amount at 12 weeks, thigh girths over 12 weeks, and weight change over 12 weeks. These listed outcomes describe planned areas of assessment, but the corresponding numerical results are not reported in the registry record.

The key statistical question is not simply whether measurements changed after treatment. It is whether the reported measurements support a reliable comparison between the two treatment conditions. The registry identifies the study as nonrandomized and single-group, and notes that the arms are not a like-for-like control comparison. Details of how treatment assignment was determined and how differences between thighs were addressed are not reported in the registry record. Without the endpoint results and analysis details, the magnitude and precision of any comparison cannot be assessed.

3. Trial Design

This was a completed, nonrandomized, single-group device study with no masking. The registry lists an enrollment of 28 and identifies the interventions as Zeltiq cryolipolysis and electrical stimulation. The study dates are listed as starting on 2010-07-01, with primary completion on 2010-09-30. Its phase is recorded as NA. The sponsor is Wonik Trade Company, Korea.

The study description places the two treatments on opposite thighs: cryolipolysis for 1 hour on one thigh and electrical stimulation for 30 minutes on the contralateral thigh. This creates a within-participant structure in the treatment descriptions, since each participant’s two thighs are related observations. However, the registry identifies the model as single-group and explicitly notes that this is not a randomized comparison and that the arms are not a like-for-like control comparison. The method used to assign treatment to a particular thigh is not reported in the registry record.

Nonrandomized treatment assignment matters because differences between treatment conditions may reflect more than the treatments themselves. General statistical context: random assignment is one way to reduce systematic differences between groups; without it, design and analysis must address possible imbalances and other sources of bias. The registry record does not report how such issues were handled. It also does not report a masking procedure, consistent with the listed masking status of none.

The primary endpoint was change in cross-sectional area of fat in both thighs at 4 weeks. The registry describes computerized tomography as the measurement method and the endpoint summary as a mean with standard deviation. Listed secondary outcomes concern fat amount, thigh girths, and weight over 12 weeks. The protocol, sample-size justification, detailed statistical analysis plan, and analysis population are not reported in the registry record. The study’s completed status indicates that it is recorded as completed, but does not by itself establish that all planned outcomes were measured or reported.

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: Two arm, but same group. Electrical Stimulation on Rt thigh versus Zeltiq Application on Left thigh.

Clinical Efficacy of Cryolipolysis

Cryolipolysis on Thigh

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Cross sectional areas of both thighs at initial visit

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: A total of 14 subjects were completed this study.

6. Primary Endpoint

The registry lists the primary outcome as Change in Cross Sectional Area of Fat in Both Thighs, measured over 4 weeks.

The primary endpoint is change in the cross-sectional area of fat in both thighs, assessed at 4 weeks. The registry describes the measurement as being made by computerized tomography and gives the unit as millimeters squares. It identifies the endpoint summary as a mean with standard deviation and describes the population as cross-sectional areas of both thighs at the initial visit.

Cross-sectional area is an anatomical measure: it quantifies the area of fat visible in a selected cross-section of the thigh. General statistical context: an objective imaging measure can provide a standardized way to quantify an anatomical feature, while the result still depends on how images are acquired, selected, and measured. Those operational details are not reported in the registry record.

The endpoint is framed as change from the initial visit, so interpretation would ordinarily depend on both the starting measurement and the follow-up measurement, as well as the definition of change used in the analysis. The registry does not report the numerical mean change for either thigh, a between-treatment contrast, a confidence interval, or a p-value. It also does not report whether the analysis used paired observations, adjusted for baseline measurements, or followed another approach.

The registry lists additional outcomes at 12 weeks, including fat amount, thigh girths, and weight change. Those outcomes have different measurement meanings and timeframes from the primary 4-week imaging endpoint. Their results are not reported in the registry record. Thus, the endpoint definition identifies what was intended to be measured, but does not establish the size or precision of any observed change.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the endpoint summary mean? The registry identifies the primary endpoint as a continuous measurement summarized by a mean and standard deviation. General statistical context: a mean describes the average measured value or change in a group, while the standard deviation describes how spread out individual measurements are around that average. They answer different questions. A standard deviation is not an estimate of how precisely the mean is known; precision of a mean is commonly described using a standard error or a confidence interval.

A confidence interval, in general, gives a range of values compatible with the data and the statistical method used, while expressing uncertainty in an estimate. Its interpretation depends on the analysis assumptions and study design. No confidence interval for the primary endpoint is reported in the registry record, so the precision of any estimated change or contrast cannot be assessed. The record also does not report the actual means or standard deviations.

How should the two-thigh structure be considered?

The treatment descriptions place the procedures on opposite thighs. General statistical context: two measurements from the same participant are often correlated because they share participant-level characteristics. A paired analysis can account for that relationship by focusing on within-participant differences, whereas an analysis that treats the two measurements as unrelated may not represent the data structure appropriately. The registry does not report whether a paired method was used, how treatment side was assigned, or whether baseline differences between thighs were incorporated into the analysis. No particular method should be inferred from the endpoint description alone.

The record also describes a nonrandomized comparison and explicitly says the arms are not a like-for-like control comparison. General statistical context: nonrandom assignment can leave systematic differences between treatment conditions, and statistical adjustment cannot necessarily remove bias from unmeasured or unrecorded factors. The registry record does not report an adjustment strategy or enough detail to assess whether potential differences between sides were addressed.

What can a significance test establish?

General statistical context: a p-value evaluates how compatible observed data are with a specified null hypothesis under a statistical model. It does not measure the size or practical importance of an effect, and it does not give the probability that the null hypothesis is true. Interpretation depends on the test, assumptions, and analysis plan. The registry record does not report a p-value or specify the test used for the primary endpoint. It is therefore not possible to infer statistical significance from the study aim, endpoint definition, or adverse-event counts.

A treatment comparison is generally more informative when it reports an estimated contrast with uncertainty, rather than relying only on whether a significance threshold was crossed. For this study, neither the numerical contrast nor its uncertainty is reported in the registry record. The sponsor’s analysis details are also not reported, so the analysis cannot be independently appraised from the registry information.

What do the planning assumptions represent?

The sample-size assumptions describe planning illustrations computed from an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. They describe the effect to detect as a stated fraction of the observed effect. General statistical context: such calculations explore how a future study’s planned size might relate to a chosen effect and statistical assumptions. They are not evidence that the present study had a particular probability of detecting an effect, and planning illustrations are never observed power.

The assumptions distinguish participants per arm for ordinary outcomes from total event counts for time-to-event outcomes. The primary endpoint is continuous, not time-to-event. The registry record does not report the observed primary effect or the resulting planning figures in the registry record for interpretation. The trial’s own sample-size justification is not reported in the registry record, so the planning assumptions should not be mistaken for the trial’s original design rationale.

What assumptions remain unknown?

The statistical analysis plan is not reported in the registry record. That includes the particular model or test, handling of baseline values, missing observations, multiplicity, and analysis population. General statistical context: conclusions from an analysis depend not only on the outcome measure but also on these decisions. Without them and without numerical outcome estimates, the primary endpoint’s magnitude, uncertainty, and robustness cannot be evaluated.

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("Cross Sectional Area on Left Thigh", "Cross Sectional Area on Right Thigh")
n   <- c(14, 14)
m   <- c(-420.25, -28.53)
sp  <- c(3099.55, 3526.21)
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  Cross Sectional Area on Left Thigh  14  -420.250  3099.550  -2209.877  1369.377
CARM  Cross Sectional Area on Right Thigh  14  -28.530  3526.210  -2064.503  2007.443

11. Multiplicity, Missing Data and Analysis Populations

The registry lists five outcome measures, including the primary change in cross-sectional area at 4 weeks and secondary outcomes concerning fat amount, thigh girths, and weight over 12 weeks. It lists one analysis. The detailed analysis plan, the number of statistical tests performed, and any procedure for handling multiple outcomes are not reported in the registry record.

General statistical context: when several outcomes or comparisons are examined, the chance of finding an apparently noteworthy result by chance can increase. Prespecifying a primary endpoint and an approach to multiple testing helps readers distinguish the main confirmatory question from additional analyses. Although the registry identifies a primary endpoint, it does not report how multiplicity was addressed or whether all listed outcomes were analyzed.

Missing-data handling is also not reported in the registry record. The record lists enrollment of 28, but does not state how many participants contributed endpoint measurements, whether all follow-up measurements were available, or how missing observations were handled. The analysis population and any exclusions are not reported. General statistical context: the consequences of missing data depend on why values are missing and on the method used to handle them; a complete-case result may differ from an analysis that makes explicit assumptions about unobserved measurements.

These gaps limit assessment of both selective reporting and possible bias. The registry record does not report a protocol-based comparison of planned and reported analyses, reasons for missing measurements, or sensitivity analyses. Numerical results and their uncertainty are also not reported, so the influence of multiplicity or missing data cannot be judged from the record.

12. 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 5% reporting threshold.

Most frequent non-serious adverse event terms

The adverse-event record lists serious adverse events in 0 of 14 participants at risk in the Zeltiq group and 0 of 14 participants at risk in the electrical stimulation group. Deaths are recorded as 0 in both groups. The record also lists other adverse events in 4 of 14 participants at risk in the Zeltiq group and 0 of 14 in the electrical stimulation group.

These figures are descriptive counts as recorded, not estimates of a causal treatment effect. The registry does not identify the four other adverse events by term, and it lists no top serious adverse-event terms. The record also does not report event timing, severity details for the other events, how events were collected, or a statistical comparison between groups. A zero count in this record means no event was recorded in that category for the listed group; it does not establish that an event is impossible.

Interpretation also needs to account for the study design. The comparison is nonrandomized, unmasked, and explicitly not a like-for-like control comparison. The adverse-event groups each list 14 participants at risk, but the registry record does not explain the relationship between these group counts and the full enrollment or provide participant-level exposure details. The counts therefore describe the posted safety record, without establishing that any difference arose from treatment.

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

The registry record establishes that a completed, nonrandomized study was designed to assess thigh fat measurements after cryolipolysis and electrical stimulation. It identifies the primary measure as change in cross-sectional area at 4 weeks, assessed by computerized tomography, and lists secondary outcomes at 12 weeks. It also records adverse-event counts for the two treatment groups.

Those design and outcome details do not answer whether a measurable difference was observed. The numerical results for the primary endpoint are not reported in the registry record, nor are confidence intervals or p-values. The listed secondary outcomes likewise have no numerical results in the registry record. Thus, the magnitude, direction, and precision of the outcome estimates cannot be described from these registry entries. The absence of reported numerical results is not evidence that there was no change or no difference.

The study’s nonrandomized design further limits interpretation of any comparison. The record explicitly states that the arms are not a like-for-like control comparison. The opposite-thigh treatment description may permit within-participant comparisons, but the method of treatment-side assignment and the statistical handling of paired measurements are not reported. Potential confounding and the precision of a comparison therefore cannot be evaluated.

The safety figures report zero serious adverse events and deaths in both groups, and other adverse events in the Zeltiq group but none in the electrical stimulation group. The event details and comparative analysis are not reported, so these counts should be read descriptively rather than as evidence that one treatment caused more or fewer events.

In short, the registry record conveys the study question, design, endpoint definitions, and selected safety counts. It does not provide enough outcome or analysis information to quantify efficacy, establish a treatment difference, assess its statistical uncertainty, or draw a causal conclusion.

14. Why This Trial Matters Statistically

This study is statistically notable because its treatment descriptions involve two thighs from the same participant, while the registry classifies the study as single-group and nonrandomized. That distinction matters: a comparison between two sites within a person is not automatically equivalent to a randomized comparison. Treatment-side assignment, baseline differences between thighs, and within-person correlation can all affect the interpretation of estimated differences. The registry does not report how these considerations were addressed.

General statistical context: choosing an analysis that matches the design is essential. Measurements from the same participant are typically related, and uncertainty estimates should reflect that relationship. In a nonrandomized design, even a correctly calculated estimate can remain vulnerable to systematic differences between treatment conditions. Readers need the treatment assignment process and the analysis method to judge the strength of a comparison.

The record also illustrates the difference between a well-defined endpoint and a reportable result. It specifies an imaging-based primary outcome, a timeframe, and a mean-with-standard-deviation summary, but does not report numerical endpoint estimates. Without those estimates and measures of uncertainty, readers cannot assess effect magnitude, precision, or consistency. The listed secondary outcomes and adverse-event counts add descriptive context but do not replace the missing primary results.

Finally, the registry lists planning assumptions for sample-size illustrations, but those are not observed power and are not the trial’s own design justification. The protocol and original sample-size rationale are not reported in the registry record. Separating planning calculations from observed evidence is important: a calculation based on an assumed or observed effect does not establish what the study found or how reliably it found it. These limitations make transparent reporting of design, analysis, and outcome estimates particularly important for evaluating this comparison.

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 statistical interpretation is that the registry record does not report numerical results for the primary endpoint. Without estimates of change and uncertainty, the outcome cannot be quantified or compared. The registry also does not report numerical results for the listed secondary outcomes.

The design is nonrandomized, unmasked, and single-group, and the record explicitly warns that the treatment conditions are not a like-for-like control comparison. Although the descriptions place treatment on opposite thighs, the process used to determine which thigh received which treatment is not reported. Nor is it reported whether analysis accounted for within-participant dependence, baseline differences between thighs, or other potential confounding.

The record does not report the statistical analysis plan, endpoint calculation details, analysis population, missing-data approach, or multiplicity strategy. It lists an enrollment of 28, but does not report the number with observed primary endpoint data or any reasons for missing measurements. The sample-size justification for the trial is not reported in the registry record.

Other design and measurement details are also not reported, including the eligibility criteria, measurement procedures beyond computerized tomography, and the handling of deviations from the treatment descriptions. The safety record does not provide terms for the other adverse events or details of their timing and ascertainment. These omissions prevent a full assessment of outcome quality, possible bias, and the reliability of the treatment comparison.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Clinical Efficacy of Cryolipolysis on the Fat of Thigh in Korean Women — NCT01177787.
• Registry record last updated 2021-05-14; status last verified 2021-04.
• Results first posted 2021-05-14.
• 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

The registry record describes a completed, nonrandomized, unmasked, single-group study of cryolipolysis and electrical stimulation for local thigh fat reduction in Korean women. It lists an enrollment of 28. Cryolipolysis with the Zeltiq machine was described as treatment on one thigh for 1 hour; electrical stimulation using amplitude modulated frequency was described on the contralateral thigh for 30 minutes.

The primary endpoint was change in cross-sectional area of fat in both thighs at 4 weeks, measured by computerized tomography and summarized as a mean with standard deviation. Secondary outcomes concern fat amount, thigh girths, and weight change over 12 weeks. Numerical outcome estimates and the detailed analysis plan are not reported in the registry record.

The record lists 0 serious adverse events and 0 deaths in each group, with other adverse events recorded for 4 of 14 in the Zeltiq group and 0 of 14 in the electrical stimulation group. It cautions that the nonrandomized arms are not a like-for-like control comparison.