Study of Low Level Laser Light Therapy on Circumference Reduction: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study of Low Level Laser Light Therapy on Circumference Reduction (NCT02109107), a na na study. The primary outcome is Change in Combined Circumference Measurements.

2. Clinical Question

The study is framed as an evaluation of change during treatment, rather than a randomized comparison of the device with another intervention or with no intervention. That distinction shapes what can be learned. A before-and-after change can describe what happened to the measured group during the evaluation period, but without a comparison group it cannot distinguish the intervention’s contribution from other influences on measurements over time.

The registry record does not report numerical primary outcome results. It therefore does not establish whether the group’s mean change was a reduction, whether it met the protocol’s stated threshold, or how precisely the change was estimated. The clinical question is identifiable from the protocol description, but the posted record does not contain the outcome information needed to answer it statistically.

3. Trial Design

This was a completed, single-group device study sponsored by Erchonia Corporation. The registry lists the study start as 2013-10 and primary completion as 2014-11. It identifies the intervention as the Erchonia EZ6 Laser and lists enrollment of 54. Enrollment is not evidence that every enrolled participant contributed data to every outcome; the analysis population and outcome-specific denominators are not reported in the registry record.

The study was not a randomized comparison: allocation is listed as NA, the model is SINGLE GROUP, and the registry lists masking as NONE. Consequently, there is no concurrent control group in the design. The study purpose was to evaluate circumference reduction over a 6 week period, and the primary outcome timeframe is baseline and 6 weeks. The record does not report additional details about visit scheduling or how measurements were taken beyond the description of the circumference measure.

The intervention description identifies a six-headed scanner composed of six independent 17 milliWatts (mW), 635 nanometer (nm) red laser diodes mounted in scanner devices. It is described as a variable frequency, pulsed wave laser device. Those details characterize the recorded device; they do not supply information about adherence, treatment delivery for individual participants, or any deviations from the intended procedure. Such information is not reported in the registry record.

The primary outcome is a continuous measure, summarized in the protocol as a mean, with standard deviation specified as the dispersion measure. Secondary outcomes listed are change in body weight, change in Body Mass Index (BMI), and a subject satisfaction with study outcome rating. The registry lists four outcome measures and three analyses, but the numerical results and detailed analysis methods are not reported in the registry record.

The record describes planning assumptions for an illustration based on an observed effect, including a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. Those assumptions describe a planning illustration, not the single-group trial design; they do not establish that the study itself used a two-arm design or that the illustration was the trial’s sample-size justification. The trial’s own sample-size justification is 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.

Overall Study

Reasons for not completing this period:

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 Change in Combined Circumference Measurements, measured over Baseline and 6 weeks.

The primary endpoint is change in combined circumference measurements, expressed in inches, from baseline to 6 weeks. The combined measure is calculated as the sum of measurements for the individual body areas of the right and left thighs, hips, waist and upper abdomen. The protocol defines change as the difference between baseline and measurement after completion of the 6-week procedure administration period. It defines a negative change as a reduction and a positive change as an increase.

Combining several anatomical measurements gives a single continuous summary of change across the specified areas. A mean can describe the average change for the measured group, while the standard deviation describes how dispersed individual measurements are around that mean. These summaries answer different questions: the mean describes the group’s average direction and magnitude, whereas the standard deviation describes variability among measured participants. Neither is reported numerically in the registry record for this endpoint.

The protocol description states that a group mean change of -3.0 inches or more would be considered clinically meaningful and statistically significant. This is a stated criterion, not evidence that the observed result met it. Clinical relevance and statistical evidence are also distinct ideas: a threshold describes a judgment about the size of a change, while statistical uncertainty concerns how compatible the estimate is with a range of possible underlying changes. Without the result and its uncertainty, the endpoint cannot be evaluated against either idea.

The composite measure also has a trade-off. It summarizes the specified areas together, but a combined value alone would not show how each area changed or whether changes differed across body sites. Site-specific numerical findings are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a mean change describe?

The primary endpoint is a continuous quantity: change in combined circumference measurements, measured in inches. A mean change summarizes the average of the participant-level changes included in an analysis. It retains direction: under the registry’s definition, a negative value indicates a reduction and a positive value indicates an increase. A group mean does not imply that each participant had the same change, or even that all individual changes had the same direction.

The standard deviation is the stated measure of dispersion. As a general statistical explanation, it describes how spread out individual observations are around their mean. A small standard deviation indicates that observations are relatively clustered around the mean, while a larger standard deviation indicates greater spread. It is not the same as the standard error, which concerns the sampling uncertainty of an estimated mean. The registry record does not report the endpoint’s mean change or standard deviation, so neither the average nor the observed spread can be assessed.

How should a change score be understood?

A change score compares measurements taken at different times for the same outcome. Here, the record defines the primary change using baseline and the measurement after the 6-week procedure administration period. The resulting score is a within-participant difference, and the group mean summarizes those differences. Its meaning depends on consistent measurement and on having outcome data available at the relevant time points.

General statistical principle: change scores can be affected by measurement error at either time point. When a score is made by combining several body areas, errors or variation in the component measurements can contribute to the combined score as well. The record describes which areas enter the combined measure, but measurement procedures, repeatability, assessor training, and quality-control methods are not reported in the registry record.

What would uncertainty measures add?

A confidence interval is a range of values produced by a statistical procedure to represent uncertainty around an estimate. In general, a narrower interval indicates greater precision under the assumptions of that procedure; a wider interval indicates less precision. An interval also helps readers assess whether plausible values include no change or values on either side of a stated threshold. No confidence interval for the primary result is reported in the registry record.

A p-value, when calculated under a specified statistical model, measures how unusual results at least as extreme as the observed result would be if a defined null hypothesis and model assumptions held. It does not measure the probability that the null hypothesis is true, and it does not by itself describe the size or clinical importance of an effect. The registry record does not report a primary endpoint p-value or the statistical test used. The protocol’s stated criterion should therefore not be mistaken for a reported statistical test result.

What does the design permit statistically?

In a single-group study, the primary summary can describe the group’s change over time. A comparison of that change with a control group would address a different question: whether the change differs between conditions. No control group is listed in this record. General statistical principle: paired observations can account for the fact that measurements at different times come from the same person, but pairing does not control for other time-related influences. Neither a paired analysis nor a mean change alone creates the missing counterfactual comparison.

The registry record does not report whether the analysis used a paired test, a model, covariate adjustment, or another approach. It also does not report assumptions checks, handling of unusual observations, or whether any transformation or robust method was considered. These details matter because statistical procedures rely on assumptions about the outcome and its variability. For example, general statistical principle: over-dispersion means that observed variability is greater than a model assumes, which can make standard errors and inferential conclusions unreliable if not addressed. The record does not indicate whether over-dispersion was relevant to any analysis.

What do the planning assumptions mean?

The registry describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It describes the effect to detect as a stated fraction of the observed effect. These are assumptions for an illustrative planning exercise, not evidence about the trial’s actual design or its observed statistical power. In particular, the listed trial model is single-group, whereas the illustration assumes equal allocation between two arms. The illustration’s calculated sample-size values are not reported in the registry record.

General statistical principle: a sample-size calculation depends on its assumptions, including the target effect, variability, significance level, allocation, and statistical model. A planning calculation describes a design scenario; it does not establish that the trial was designed that way, nor does it show the probability that the completed study detected an effect. The record’s trial-specific sample-size justification and any observed-power analysis are not reported in the registry record.

What statistical details remain unknown?

The registry record does not report the full statistical analysis plan, the analysis population, outcome-specific denominators, treatment of missing measurements, or the method used to calculate uncertainty. It also does not report whether analyses were prespecified, whether any interim analyses occurred, or whether there were deviations from the planned analyses. These omissions prevent readers from reproducing or fully evaluating the analysis. They should not be filled in by assuming a conventional method, because different reasonable choices can yield different estimates or uncertainty.

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("Erchonia EZ6 Laser")
n   <- c(54)
m   <- c(-5.36)
sp  <- c(1.85)
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  Erchonia EZ6 Laser  54  -5.360  1.850  -5.865  -4.855

11. Multiplicity, Missing Data and Analysis Populations

The registry lists four outcome measures and three analyses. It identifies the combined circumference change as the primary outcome and lists change in body weight, change in BMI, and subject satisfaction with study outcome rating as secondary outcomes. Multiple outcomes create a multiplicity question: when several outcomes or comparisons are examined, the chance of at least one apparently notable finding can increase. This is a general statistical concern, not a claim about what happened in this study.

Whether the analyses were adjusted for multiplicity, and what family of outcomes or tests such an adjustment would cover, is not reported in the registry record. The record also does not provide enough analysis details to determine which tests corresponded to the three listed analyses. Without those details and numerical results, no multiplicity-adjusted interpretation can be reconstructed. The primary-outcome designation helps identify the principal question, but it does not by itself establish how other outcomes were handled statistically.

Missing-data methods are also not reported in the registry record. The enrollment figure of 54 does not establish how many participants had a valid baseline and follow-up measurement, or how many contributed to each secondary outcome. The record does not say whether missing measurements were excluded, imputed, or handled by a model, nor does it explain reasons for missingness. General statistical principle: missingness can affect an estimate when the people with observed outcomes differ systematically from those without them. Without denominators and a missing-data account, the possible effect cannot be assessed.

The analysis populations are not reported in the registry record. It is therefore unclear which participants were included in each analysis and whether the analysis population matched enrollment. No assumptions about intention-to-treat, per-protocol, or other populations should be inferred from the registry entry. These gaps limit assessment of both the primary endpoint and the secondary outcomes.

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.

The registry’s adverse-event entry for the Erchonia EZ6 Laser lists 54 at risk and 0 affected for serious adverse events. It also lists 54 at risk and 0 affected for other adverse events. The death count is recorded as null. These are the figures recorded in the adverse-event fields; null is not a numerical count and should not be read as a reported zero.

The affected counts describe what the registry entry reports, but the record does not provide event descriptions, observation details, or an explanation of how adverse events were collected and coded. It also does not report the timing or duration of safety monitoring. The at-risk figures do not establish that all participants completed follow-up or had the same amount of observation time.

General statistical principle: an observed count of zero does not prove that an event is impossible, and the interpretation of a zero depends on the size and completeness of the safety follow-up, event definitions, and ascertainment. Those details are not reported in the registry record. The listed figures should therefore be read narrowly as registry-reported counts, not as evidence that the device has no safety risks or as a complete characterization of safety.

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

The registry record documents a completed single-group evaluation of the Erchonia EZ6 Laser, with a primary question about change in combined circumference measurements from baseline to 6 weeks. It defines how the composite is constructed and how the direction of change is interpreted. It also states a criterion of -3.0 inches or more for a group mean change to be considered clinically meaningful and statistically significant under the protocol description.

The record does not report the numerical primary outcome result. It therefore cannot show whether the mean change was negative or positive, how large it was, how much participants varied, or whether the stated criterion was reached. No confidence interval or p-value is reported for the primary outcome, so the precision and statistical evidence cannot be evaluated from this record. Results for the listed secondary outcomes are also not reported in the registry record.

Even a reported before-and-after change would answer a limited question: what change was observed in the measured group over the study interval. Because the design is single-group and has no concurrent comparator, it would not alone establish that the intervention caused the change. Other influences over time and measurement variability would remain possible explanations. The record does not report a control condition that could help distinguish these explanations.

The combined measure can summarize change across the specified areas, but it does not reveal the pattern for each body area without separate results. The registry does not report site-specific outcome estimates. Nor does the record’s enrollment figure establish the number of participants with complete primary outcome data.

In statistical terms, the record is informative about the research question, design, endpoint definition, and recorded adverse-event counts. It is not sufficient to estimate an intervention effect, assess its uncertainty, or draw a comparative conclusion. This distinction matters: defining a question and a success criterion is not the same as reporting data that answer the question. No medical conclusion should be inferred from the registry entry alone.

14. Why This Trial Matters Statistically

This study illustrates why a clearly defined endpoint and a clearly defined comparison are separate parts of trial interpretation. The endpoint is described in detail: it is a continuous change measure, combines specified circumference sites, has a stated direction, and is paired with a protocol threshold. Yet those details cannot establish what happened when the numerical results are absent.

The single-group structure is statistically important. Measuring a group before and after an intervention can describe temporal change, but it does not distinguish intervention-associated change from other causes of change. This is not a flaw unique to this study; it is a general limit of interpreting uncontrolled before-and-after data. Readers need to match the strength of a conclusion to the comparison the design actually provides.

The composite outcome also raises a useful interpretive point. A single summary can be convenient and may represent an overall question, but it can conceal variation among its components. For circumference, changes in different body areas could contribute differently to the combined measure. Without site-specific estimates, the composite alone cannot describe those patterns.

Finally, statistical claims require both an estimate and information about uncertainty. A threshold named in a protocol does not show that a result crossed it, while a mean without a measure of precision would not fully describe the evidence. The missing numerical results, analysis details, and missing-data information leave those questions unresolved. The record thus demonstrates why outcome definitions, design, reporting completeness, and inferential precision all matter when assessing a clinical study.

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 limitations are specific to the information recorded for this study. The single-group design has no concurrent control, so observed change over time cannot be separated from changes that might have occurred for other reasons. Allocation is listed as NA and masking as NONE. The record therefore offers no randomized or masked comparison to reduce concerns about group differences or measurement expectations.

The primary endpoint combines measurements from the right and left thighs, hips, waist and upper abdomen. That composite can summarize the areas together, but it cannot show whether each area changed in the same direction or to a similar extent. The registry record does not report site-specific results. It also does not describe measurement repeatability or provide enough detail to assess how consistently the measurements were obtained.

Numerical results for the primary and secondary outcomes are not reported in the registry record. Consequently, the effect estimate, its variability and precision, and the relationship between the result and the stated -3.0 inches threshold cannot be evaluated. Outcome-specific denominators, analysis populations, missing-data handling, and reasons for missing measurements are also not reported. Enrollment of 54 should not be treated as proof that all enrolled participants contributed to the endpoint analysis.

The registry record does not report the full statistical plan, any multiplicity adjustment, or whether interim analyses occurred. It also does not report a trial-specific sample-size justification. The planning assumptions described for an illustration do not establish the design or analysis used in this single-group study. Finally, the adverse-event entry gives recorded affected counts but lacks detailed ascertainment and follow-up information. These limitations constrain interpretation of efficacy-related outcomes and safety alike.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Study of Low Level Laser Light Therapy on Circumference Reduction — NCT02109107.
• Registry record last updated 2016-02-02; status last verified 2015-12.
• Results first posted 2016-02-02.
• 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 NCT02109107, titled “Study of Low Level Laser Light Therapy on Circumference Reduction.” It lists Erchonia Corporation as sponsor, a completed status, and enrollment of 54. The study is identified as a single-group device study with allocation listed as NA and masking as NONE.

The intervention is the Erchonia EZ6 Laser. The primary endpoint is change in combined circumference measurements, in inches, from baseline to 6 weeks. The measure combines the right and left thighs, hips, waist and upper abdomen. Secondary outcomes listed are change in body weight, change in BMI, and subject satisfaction with study outcome rating.

Numerical outcome results and detailed analysis methods are not reported in the registry record. The adverse-event entry lists 0 affected for serious events and 0 affected for other events, with deaths recorded as null. The design and missing results prevent estimation of a comparative treatment effect from this record.