Doubleblinded RCT of the Omnilux on Lower Extremity Surgical Wounds Left to Heal by Second Intention: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Doubleblinded RCT of the Omnilux on Lower Extremity Surgical Wounds Left to Heal by Second Intention (NCT02383056), a randomized na study. The primary outcome is Number of Days Required for the Wound to Heal Completely.

2. Clinical Question

The clinical question is whether the posted wound-healing results differ between the Omnilux LED group and the sham group among people with lower-extremity surgical wounds left to heal by second intention. In this approach, the wound is allowed to heal without stitches, as described in the registry summary. Both groups were intended to receive standard wound care in addition to their assigned light procedure; the detailed standard-care regimen is not reported in the registry record.

The registry describes the study as randomized, double-blinded, and controlled. The sham procedure was intended to reduce bias associated with awareness of treatment assignment. The record does not explain who was blinded or how assignment concealment was implemented. It also does not report whether the primary outcome was assessed by reviewers unaware of group assignment.

The primary endpoint is a time measure: days until the physician assessed that the wound had closed. The posted results report group means and standard deviations. They do not include a posted inferential comparison or enough information to reconstruct one reliably from the registry record. The results therefore describe the recorded outcome in the reported groups, rather than establishing a precise treatment contrast.

3. Trial Design

The registry record identifies NCT02383056 as a randomized, double-blind, parallel-group trial sponsored by the University of Miami. The study is listed as terminated. Its recorded start is 2012-12, and its primary completion is 2017-11. The reason for termination is not reported in the registry record. The registered enrollment is 14; the number is a registry enrollment figure and should not be taken as the number contributing to every reported outcome.

Participants were assigned to a sham group or a treatment group. The sham group was scheduled to receive 4 sessions of Omnilux sham light, while the treatment group was scheduled to receive 4 sessions of Omnilux 633nm LED. In both descriptions, sessions began 1 week after surgery, occurred once each week (+/- 3 days), and lasted 20 minutes. The registry summary characterizes the sham as regular light from the same device, without anticipated effects on wound healing. Both groups were to receive standard wound care, but details of that care are not reported in the registry record.

The parallel design means the record presents separate groups rather than a within-person comparison. Random assignment can, in general, help make groups comparable at the start of a study, while masking can help limit some influences of treatment knowledge. Those design features do not by themselves establish that the posted comparison is unbiased: implementation details, baseline characteristics, adherence, and outcome-assessment procedures are not reported in the registry record.

The registry lists two secondary outcomes: change in relative area of the surgical wound remaining and change in total surface area of the surgical wound. The primary result reported is days required for complete healing. Detailed results for the secondary outcomes are not reported in the registry record. The phase is listed as NA.

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 Number of Days Required for the Wound to Heal Completely, measured over 84 days.

The primary endpoint is the number of days required for the wound to heal completely. The registry defines the assessment as a physician indication of wound closure and gives an outcome timeframe of 84 days. This is a time-to-event type of clinical measure in concept: the event is wound closure, and the recorded quantity is the time until that event. The registry reports it as a continuous outcome summarized by a mean and standard deviation.

Time to closure is relevant to the stated study question because the registry summary describes prolonged healing as a concern for lower-leg surgical wounds. A measure of days can convey how long healing took in the observed groups, while a physician assessment supplies the stated criterion for considering a wound closed. The record does not provide further operational detail about the closure assessment, such as whether confirmation was required or whether assessors used a standardized scale.

The 84-day timeframe matters when interpreting the endpoint. The registry record does not explain how wounds that had not closed by that point were handled in the analysis, whether follow-up continued beyond that timeframe, or how incomplete observations were treated. Those details affect the interpretation of a mean time-to-healing result, particularly if some participants did not reach closure during the specified period.

The posted summaries give the sham group a mean of 48.67 days with a standard deviation of 11.1, and the treatment group a mean of 63.2 days with a standard deviation of 12.2. These are descriptive summaries for the reported endpoint; they do not, on their own, quantify uncertainty in the difference between groups.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous: it records a quantity measured in days. The registry specifies a mean as the summary measure and a standard deviation as the measure of spread. A mean describes the arithmetic average of the observations included in a group summary. A standard deviation describes how spread out individual observations are around that mean. It is not the same as a confidence interval and does not directly express the uncertainty in a comparison between groups.

For the sham group, the registry reports a mean of 48.67 days and a standard deviation of 11.1, based on a listed outcome sample size of 6.0. For the treatment group, it reports a mean of 63.2 days and a standard deviation of 12.2, based on a listed outcome sample size of 5.0. The registry record does not report a confidence interval for either mean or for the difference between means. A standard deviation alone cannot establish how precisely the group contrast is estimated.

General statistical explanation: comparing group means usually requires an estimate of the between-group contrast together with an estimate of its uncertainty. Depending on the design and assumptions, an analysis might use a model-based or unadjusted method. The registry record does not identify a primary comparison method, covariate adjustment, model, or test for this endpoint. It therefore does not support attributing any particular inferential procedure to the trial.

The randomized, parallel design has two independent assigned groups rather than repeated treatment periods for each participant. In general, randomization aims to balance prognostic factors across groups on average, but a small realized sample may still have imbalances. The registry record does not provide baseline characteristics with which to assess group comparability. It also does not report allocation concealment procedures, the randomization sequence method, adherence, or details about masking implementation.

There is no posted inferential analysis for the primary result, and the registry identifies the two-arm continuous comparison as not estimable for recalculation from the available summary statistics. That limitation is important: the posted means and standard deviations permit descriptive reading, but they do not supply the ingredients needed for every valid comparative analysis. No recalculated p-value or interval should be inferred from those summaries. The record lists no analyses.

The endpoint concerns time until wound closure, but it is summarized as a mean and standard deviation. General statistical explanation: when an outcome is time to an event, some participants may not experience the event during follow-up or may have incomplete observation. Methods for such data can account for censoring and differences in follow-up. The registry record does not say whether any wounds remained unhealed at the 84-day timeframe, how such cases were handled, or whether a time-to-event method was used. It is therefore not appropriate to assume a specific analysis approach.

The record describes planning illustrations based on the observed effect, using a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation; the stated effect to detect is a fraction of the observed effect. Such figures are planning illustrations, not observed power and not evidence that the trial had a particular probability of detecting an effect. The specific planning figures are not reported in the registry record available for this analysis. General statistical explanation: planning calculations depend on assumptions about the target effect, variability, allocation, and analysis. They should not be mistaken for an outcome of the completed or terminated study.

General statistical explanation: a confidence interval is useful because it combines an estimated effect with a range reflecting sampling uncertainty under a statistical model. Wider intervals indicate less precision, while narrower intervals indicate greater precision under that model. Since no interval is reported for the primary comparison, the precision of a comparative effect cannot be evaluated from the registry record. A lack of a reported p-value also means there is no posted test result to interpret; it does not establish that there was no effect.

The endpoint sample sizes and safety denominators are not the same in the record. The primary outcome lists 6.0 participants in the sham group and 5.0 in the treatment group, whereas the adverse-event results list 7 at risk in each group. The registry record does not explain these different denominators. General statistical explanation: denominator differences can arise from outcome-specific availability or analysis populations, but no particular explanation can be assigned in this case without a participant flow account.

The registry lists two secondary wound-area outcomes, but numerical estimates and inferential results for them are not reported in the registry record. The primary endpoint therefore cannot be cross-checked against posted secondary outcome results. Nor does the record state how the analyses were ordered or whether any outcome was designated for confirmatory inference beyond its registry listing.

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("Sham Group (Group 1)", "Treatment Group (Group 2)")
n   <- c(6, 5)
m   <- c(48.67, 63.2)
sp  <- c(11.1, 12.2)
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  Sham Group (Group 1)  6  48.670  11.100  37.021  60.319
CARM  Treatment Group (Group 2)  5  63.200  12.200  48.052  78.348

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary endpoint and two secondary outcomes: change in relative area of the surgical wound remaining and change in total surface area of the surgical wound. The numerical results for the secondary outcomes are not reported in the registry record. No analysis results are posted, and the record does not describe a multiplicity adjustment, a hierarchy among outcomes, or a plan for interpreting multiple statistical tests. Without those details, it is not possible to assess how the study addressed the increased chance of false-positive findings that can arise when multiple outcomes or comparisons are tested.

The endpoint summaries report sample sizes of 6.0 for the sham group and 5.0 for the treatment group. Safety results use a denominator of 7 in each group. The registry record does not provide a participant flow account or explain the differing outcome-specific denominators. It also does not describe missing-data rates, reasons for missing observations, imputation, or sensitivity analyses. The handling of participants whose wounds had not closed by the 84-day timeframe is not reported in the registry record.

The record does not state whether the primary analysis followed an intention-to-treat principle, included only participants with observed outcomes, or used another analysis population. Randomization describes assignment, but it does not specify which participants were included in the reported endpoint summaries. The record also does not provide protocol deviations or treatment adherence information that could clarify the analysis population.

These omissions limit interpretation. Missingness can affect a group comparison when the availability of measurements is related to outcome or treatment assignment. General statistical explanation: sensitivity analyses can explore whether conclusions change under different reasonable assumptions about missing outcomes. No such analyses are reported in the registry record, so the effect of missing or incomplete data cannot be assessed.

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 0% reporting threshold.

Most frequent non-serious adverse event terms

The registry reports serious adverse events for the sham group as 0 affected among 7 at risk and for the treatment group as 0 affected among 7 at risk. It reports no deaths in either group. No serious adverse-event terms are listed. These are the posted serious-event figures and should be read with their group-specific denominators.

For other adverse events, the registry reports 3 affected among 7 at risk in the sham group and 5 affected among 7 at risk in the treatment group. The record does not list the event terms, describe how events were defined or collected, or explain whether an individual could contribute more than one event. The counts therefore do not describe the nature, timing, severity, or recurrence of those events.

General statistical explanation: an observed count of zero serious events does not establish that the underlying risk is zero. Small groups provide limited information about uncommon events, and safety estimates are imprecise when based on few observations. The registry record does not provide confidence intervals or a comparative safety analysis. The adverse-event denominators also differ from the primary endpoint sample sizes, and the reason is not reported. These figures should not be used to infer a definitive safety difference between groups.

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

The posted primary outcome results describe the mean number of days to physician-assessed wound closure in each group: 48.67 days for sham and 63.2 days for Omnilux treatment. The respective standard deviations are 11.1 and 12.2. The result is descriptive, and the registry record provides no inferential comparison or uncertainty interval for the group contrast. It therefore does not establish whether the observed group summaries reflect a reliable difference or sampling variation.

The record does not report detailed findings for the secondary wound-area outcomes. It also does not state how wounds that had not closed by the 84-day timeframe were handled, whether the endpoint assessment was blinded, or how missing observations were addressed. These gaps leave important uncertainties about how the posted endpoint summaries were produced and how representative they are of all enrolled participants.

The trial is listed as terminated, and no reason for termination is reported in the registry record. Termination alone does not explain whether it was related to recruitment, operational considerations, data availability, safety, or any other factor. It should not be treated as evidence for or against an effect.

The safety record reports no serious adverse events and no deaths in either group, alongside other adverse events in both groups. The small group-specific denominators and absence of event descriptions limit what can be inferred about safety. In general, the absence of recorded serious events in a small study cannot rule out uncommon harms.

These results do not demonstrate that either procedure works or fails to work. They give a limited descriptive account of the registered primary endpoint and adverse-event counts. A stronger interpretation would require a reported comparative analysis, information about missing observations and analysis populations, and fuller outcome and safety reporting. No medical decision should be based on these registry summaries alone.

14. Why This Trial Matters Statistically

This trial raises several statistical issues that are common in small clinical studies. The registered enrollment is 14, while the primary endpoint summaries list outcome sample sizes of 6.0 and 5.0. The adverse-event results instead list 7 at risk in each group. These distinctions matter because every estimate depends on the participants and observations included in its denominator. The registry record does not explain the differences.

The endpoint is time to wound closure, yet the reported summary is a group mean and standard deviation. This is straightforward to describe, but interpretation depends on knowing how observations were handled when closure was not documented within the 84-day timeframe. The registry record does not report that information. General statistical explanation: time-to-event methods can incorporate incomplete follow-up and participants who have not experienced the event by a specified time. Without analysis details, readers cannot know whether such methods were used or needed.

The record also illustrates why descriptive results and inferential results are different. Means and standard deviations show the observed group summaries, but they do not by themselves establish the precision of a treatment contrast. No confidence interval, p-value, or comparative analysis is posted. The absence of those quantities leaves the uncertainty around the primary comparison unresolved.

Finally, a randomized and double-blind label is useful design information, but it cannot substitute for reporting implementation and analysis details. Information about allocation procedures, participant flow, missing data, outcome assessment, and multiplicity would help readers judge the strength of the evidence. The record’s terminated status and unreported reason add context, but do not determine the direction or validity of the endpoint results.

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 registry record has important limitations for interpretation of this specific trial. Although it records enrollment of 14, the primary endpoint summaries use outcome sample sizes of 6.0 in the sham group and 5.0 in the treatment group. The safety results use 7 at risk in each group. No participant flow account explains these figures, so the relationship between enrolled participants, endpoint availability, and safety follow-up is unclear.

The study is listed as terminated, but the reason is not reported in the registry record. The record does not provide a detailed account of recruitment, follow-up completion, treatment adherence, protocol deviations, or the timing and completeness of outcome assessments. These omissions prevent assessment of whether the observed endpoint summaries represent all randomized participants or a subset.

The primary endpoint is defined as days to physician-indicated wound closure with an 84-day timeframe. The record does not explain how unhealed wounds, incomplete follow-up, or missing closure assessments were handled. It also does not provide more detail about the assessment procedure or whether the assessor was masked. These points are particularly relevant for interpreting a time-to-closure summary.

No primary comparative analysis, confidence interval, or p-value is posted. Results for the two listed secondary wound-area outcomes are also not reported in the registry record. The record does not state the analysis population, missing-data strategy, multiplicity approach, or statistical model. Finally, the safety event terms and collection definitions are absent. Together, these reporting gaps restrict assessment of precision, potential bias, and the completeness of both efficacy and safety findings.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Doubleblinded RCT of the Omnilux on Lower Extremity Surgical Wounds Left to Heal by Second Intention — NCT02383056.
• Registry record last updated 2019-05-23; status last verified 2019-05.
• Results first posted 2019-05-23.
• 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

NCT02383056 is a randomized, double-blind, parallel trial sponsored by the University of Miami, listed as terminated. The registered enrollment is 14. The study compared Omnilux 633nm LED with Omnilux sham light for lower-extremity surgical wounds left to heal by second intention. Both procedures were scheduled as 4 weekly sessions of 20 minutes, beginning 1 week after surgery.

The primary endpoint was days to physician-indicated complete wound closure, with an 84-day timeframe. The sham group mean was 48.67 days (standard deviation 11.1; outcome sample size 6.0), and the treatment group mean was 63.2 days (standard deviation 12.2; outcome sample size 5.0). No inferential comparison is posted. The registry lists two secondary wound-area outcomes without numerical results. Serious adverse events and deaths were recorded as 0 in both groups; other adverse events were reported in each group. The reason for termination, analysis population, missing-data handling, and explanation for the differing denominators are not reported in the registry record.