This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Light Therapy in the Treatment of Leg Pain (NCT00253981), a randomized na study. The primary outcome is Visual Analog Scale.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00253981 |
| Phase | NA |
| Condition | Tibial Fractures, Leg Injuries |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 30 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Samueli Institute for Information Biology |
| Results posted | Yes |
2. Clinical Question
Population
The study summary describes active duty soldiers with shin splints. The listed conditions are tibial fractures and leg injuries, and the official title refers to tibial stress reaction. The record does not report further eligibility details or a more specific description of the analyzed population.
Intervention
Monochromatic Near-Infrared Light Energy, described as infrared light therapy, was assigned three times a week for four weeks. The record identifies this as a device intervention.
Comparator
The comparator was standard of care, described as standard medical treatment that included medication. The record does not specify the medication or provide further detail about the comparator regimen.
Primary question
The stated endpoint was a participant-rated pain score on a numeric scale from 1 to 10, with higher values indicating more pain. The registry lists a 4-week timeframe. It does not report a numerical comparison of pain scores between the assigned groups, so the treatment contrast cannot be estimated from the registry results.
3. Trial Design
The registry describes a randomized, double-masked, parallel-group study. Random allocation is intended to reduce systematic differences between groups at assignment, while masking is intended to limit the influence of treatment knowledge on care or outcome assessment. The record does not say who was masked, how masking was maintained, or how the randomization sequence was generated. Those details are not reported in the registry record.
The enrollment is listed as 30. This is a registry enrollment figure; it does not establish how many participants completed treatment, contributed endpoint data, or were included in an analysis. The record does not give group-specific enrollment or a participant flow description. The study status is terminated. Its recorded start is 2005-11 and its primary completion is 2008-06. The phase is listed as NA.
The intervention arm received infrared light therapy assigned three times a week for four weeks. The control arm received standard medical treatment, including medication. The registry does not specify the exact treatment procedures, device settings, medication choices, adherence, or whether other care was permitted. The sponsor is Samueli Institute for Information Biology.
Although the study is randomized and has a stated endpoint, the record lists 0 analyses and does not provide an outcome estimate. It therefore does not support an estimate of the difference between the assigned groups. A design description identifies how a comparison was intended to be organized; it is not itself evidence about the size or precision of a treatment effect.
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: Some participants were excluded due to deployment, military training that required them to leave the post.
Overall Study
| Stage | Infrared Light Therapy | Standard of Care |
|---|---|---|
| STARTED | 16 | 14 |
| COMPLETED | 16 | 14 |
| NOT COMPLETED | 0 | 0 |
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.
| Characteristic | Unit | Experimental | Control | Total |
|---|---|---|---|---|
| Participants analysed | 16 | 14 | 30 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 16 | 14 | 30 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Female | Participants | 1 | 0 | 1 |
| Sex: Female, Male: Male | Participants | 15 | 14 | 29 |
| Region of Enrollment: United States | participants | 16 | 14 | 30 |
6. Primary Endpoint
The registry lists the primary outcome as Visual Analog Scale, measured over 4 weeks.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is titled Visual Analog Scale and is described as a numeric scale based on perceived pain level from 1 to 10. Higher values indicate higher pain, as perceived by the participant. The stated timeframe is 4 weeks. The record does not specify a unit beyond the scale values or give a more detailed description of the measurement procedure.
Pain ratings are patient-reported measures: they capture a participant’s own assessment rather than an external measurement of tissue healing. Such measures can be useful when the research question concerns a subjective experience, because the participant is the direct source of that experience. They may also vary with individual interpretation, circumstances at the time of rating, and how the scale is administered. These are general features of subjective rating measures, not findings about this trial.
The study summary mentions evaluating healing time and effectiveness, but the registry’s listed primary measure is the pain scale at 4 weeks. The record does not provide a healing-time endpoint or a numerical result for the pain endpoint. It also indicates that the primary outcome had several categories or time points and was not reduced to a single comparison. Without a reported group comparison, the direction, magnitude, and precision of any difference in pain scores cannot be assessed from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The record establishes that the trial was randomized, double-masked, and parallel, and that pain was to be assessed at 4 weeks. It does not report a numerical outcome comparison. In particular, there is no posted estimate of the difference in pain scores between the infrared light therapy group and the standard-of-care group, and no confidence interval or p-value is reported in the registry record. The listed count of 0 analyses reinforces that there is no analysis result to interpret.
Consequently, the registry does not show whether the groups’ pain ratings differed, how large any difference was, or how uncertain an estimated difference might be. The absence of a reported comparison is not evidence that the groups had equal outcomes. Nor does it establish that the intervention improved or worsened pain. These conclusions require outcome data and an analysis that are not reported in the record.
The registry lists enrollment of 30, but this does not indicate how many participants had usable endpoint measurements. It is not a substitute for an analyzed sample size, and it cannot be used to infer the precision of an unreported treatment estimate. The record also does not describe participant flow, missing endpoint values, or the population included in an analysis.
The endpoint itself is a subjective pain rating, with larger scale values indicating more pain. That direction helps interpret a numerical score if one is reported; it does not supply a treatment effect in the absence of results. The timeframe of 4 weeks identifies the intended assessment point, but no assessment values or changes are presented for that time.
The trial status is terminated. That status does not explain why the study ended, whether termination was planned, or whether it affected data collection. The reason for termination and any relationship between termination and the availability of results are not reported in the registry record. The appropriate statistical reading is therefore limited: the registry documents a study design and endpoint, but not an estimable treatment comparison.
9. Statistical Methods Explained
Statistical interpretation depends on both the design and the reported results. This record describes randomized allocation, double masking, and a parallel model. In general, randomization aims to make assigned groups comparable with respect to measured and unmeasured characteristics on average. It does not guarantee that groups are identical, especially in a small study, and it cannot replace reporting the observed group data and the analysis used. The registry does not describe the randomization method or allocation concealment.
What does masking contribute?
In general, masking can reduce the influence of expectations on treatment delivery, participant reports, and outcome assessment. Its value depends on who was masked and whether masking remained credible. The record labels the study double-masked but does not identify the masked roles or explain the procedures. No further inference about masking can be made from that label alone.
What would a treatment estimate show?
A group contrast would quantify how the endpoint differed between assigned groups at the stated assessment. For a pain scale, a complete report would identify the analyzed participants and describe the group results and the contrast between them. A confidence interval, in general, expresses the uncertainty around an estimated effect under the analysis assumptions. A narrow interval indicates greater precision than a wide interval; an interval spanning values that would imply different interpretations may leave the evidence inconclusive. The registry record does not report an effect estimate or confidence interval, so this kind of precision assessment is unavailable.
A p-value, in general, measures how compatible the observed data are with a specified statistical model under a null hypothesis. It is not the probability that the null hypothesis is true, and it does not describe the size or practical importance of an effect. Because no p-value is reported, the registry does not support a significance assessment. Even if a p-value were available, it would not replace the estimate and its uncertainty.
Why does the endpoint structure matter?
The registry indicates that the primary outcome had several categories or time points and was not reduced to one comparison. When outcomes include multiple categories, assessment times, or analyses, the choice of comparison affects what a result means. A prespecified primary comparison can help distinguish the main question from additional exploratory questions. Testing multiple comparisons can increase the chance of at least one apparently unusual result if no adjustment or interpretive plan is used. These are general statistical considerations; the registry does not report the endpoint structure in sufficient detail to identify the comparisons or any multiplicity strategy.
The primary outcome is described as a numeric pain scale, but the statistical method for analyzing it is not reported. Different approaches may target different quantities, such as a group difference at the assessment point or a difference in change from an earlier measurement. The record does not specify baseline measurements, a model, covariate adjustment, or whether the outcome was treated as continuous or otherwise. It would be inappropriate to assign an analysis method to the trial without documentation.
How should planning illustrations be read?
The planning note describes illustrative sample-size calculations based on a fraction of an observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. It specifies that the effect used for illustration is not the trial’s own design target. These are planning assumptions, not trial results and not observed power. An illustrative sample size answers a conditional question: how many participants per arm might be needed under the stated assumptions and effect scenario. It does not show that the trial enrolled that number per arm, nor does it establish the probability that this trial detected an effect. The effect estimate used for the illustration is not reported in the registry record, so the numerical basis for any such planning display cannot be checked from the record alone.
In general, over-dispersion occurs when data vary more than a model assumes. Ignoring it can make standard errors too small and uncertainty appear less than it is. No count model or over-dispersion assessment is identified in this record, and the endpoint is described as a pain scale rather than an event count. Thus, over-dispersion is a general methods concept, not a reported feature of this trial.
10. Multiplicity, Missing Data and Analysis Populations
The registry states that the primary outcome had several categories or time points and was not reduced to one comparison. It does not identify those categories or times in detail, explain which comparison was primary, or report an adjustment for multiple testing. When researchers assess multiple outcomes or multiple contrasts, chance alone can produce an apparently noteworthy result; a prespecified analysis plan and transparent reporting help readers understand how such results should be interpreted. This is a general concern, not a claim that a particular method was or was not used in the trial.
The registry lists 1 outcome measure and 0 analyses. The recorded outcome description names a pain scale at 4 weeks, but no numerical results or analysis population are reported. A count of outcome measures does not establish that every outcome or time point was fully reported, especially when the registry also notes multiple categories or times. The analysis plan, prespecified hierarchy, and any interim analyses are not reported in the registry record.
Missing-data handling is also not reported. The record does not state how many participants posted endpoint data, whether any measurements were missing, why values might be missing, or whether an imputation or sensitivity analysis was used. In general, missing data can affect an estimate if the likelihood of missingness is related to participant characteristics or outcomes. Without flow and missingness information, readers cannot assess that issue for this study.
The registry does not identify an analysis population, such as all randomized participants or only those who completed treatment. It also does not explain how deviations from assigned treatment were handled. Those details matter because the analysis population and handling of missing outcomes can influence both the estimated effect and its uncertainty. They are not reported in the registry record.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Experimental | 0 | 16 | 0.0% |
| Control | 0 | 14 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Experimental | 0 of 16 |
| Control | 0 of 14 |
The adverse-event record lists serious adverse events affecting 0 participants in the experimental group, with 16 at risk, and 0 participants in the control group, with 14 at risk. It also lists other adverse events affecting 0 participants in the experimental group, with 16 at risk, and 0 participants in the control group, with 14 at risk. These figures describe the entries in the registry; they do not provide event narratives or additional detail about how events were collected or classified.
Deaths are not reported in the registry record. The zero affected counts should not be interpreted as proof that no adverse event could occur, or that the intervention is safe. A recorded zero can reflect the observed reporting period and the completeness of event collection; the record does not give enough information to evaluate those aspects. The listed at-risk counts also do not establish how long participants were followed for safety. The safety information is therefore limited to the event counts entered in the registry and cannot support a broader comparative safety conclusion.
12. What the Result Does, and Does Not, Mean
The record supports a description of the trial’s planned comparison: randomized assignment to infrared light therapy or standard care, with a pain-scale endpoint specified at 4 weeks. It also reports the overall enrollment, terminated status, and limited adverse-event counts. These are details about the study record, not a treatment-effect estimate.
No numerical primary-outcome comparison is reported. As a result, the record cannot show the size or direction of a difference in pain ratings, or how precisely such a difference was estimated. It cannot establish that the groups were equivalent, that the intervention changed pain, or that there was no effect. A missing result is not the same as a result showing no difference.
The entry’s statement that the study was intended to evaluate healing time and effectiveness does not provide evidence about those outcomes. The listed primary measure is pain, and no healing-time result is given. The terminated status does not reveal why the study stopped or whether any available data were analyzed elsewhere; that information is not reported in the registry record.
The adverse-event entries report zero affected participants in both listed groups for serious and other adverse events. Those entries do not prove absence of risk and do not, by themselves, establish comparative safety. Follow-up duration, event definitions, and collection methods are not reported.
Overall, the registry record is informative about the design and the endpoint but insufficient for judging efficacy or estimating the precision of a treatment contrast. A numerical interpretation would require reported group outcomes, an analysis description, and information about the participants included and any missing data.
13. Why This Trial Matters Statistically
This trial illustrates an important distinction between a registered study design and a reportable statistical result. Randomization and masking describe safeguards intended to support a fair comparison, but they do not supply the outcome data needed to estimate an effect. Without a reported contrast and its uncertainty, readers cannot determine what the trial’s results imply about the pain endpoint.
It also demonstrates why endpoint definitions and analysis choices matter. The registry names a subjective pain scale, gives its direction, and states a 4-week timeframe. Yet it notes that the primary outcome had several categories or time points and was not reduced to one comparison. Without details about the planned comparison and the analysis, even a reported score could be difficult to interpret in context.
The record is also a reminder that enrollment is not the same as an analyzed sample. The listed enrollment does not reveal how many participants contributed endpoint data, and no analysis population or missing-data approach is reported. Those omissions limit assessment of precision and potential bias.
Finally, the safety entries are counts, not a complete safety evaluation. Zero recorded events in the listed categories should be read alongside the absence of follow-up and collection details. Taken together, these features show why statistical transparency requires more than a design label: readers need outcomes, analysis methods, participant flow, and uncertainty to evaluate what a trial contributes.
14. 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 the absence of a numerical outcome analysis. Although a primary pain measure and timeframe are identified, the registry lists 0 analyses and provides no group scores, treatment contrast, confidence interval, or p-value. The effect and its precision therefore cannot be assessed.
The record notes that the primary outcome had several categories or time points but does not specify them or reduce them to a single comparison. This leaves uncertainty about which endpoint contrast was intended to answer the primary question. The analysis plan and any approach to multiplicity are not reported in the registry record.
Participant flow and the analysis population are not described. Enrollment is listed as 30, but the number with endpoint measurements, the number completing assigned treatment, and the handling of missing outcomes are not reported. The reason for termination is also not reported, so the relationship between study status and the availability of results cannot be determined.
Important design details are absent, including the randomization procedure, who was masked, treatment adherence, device details, and specifics of standard care. The exact pain-scale administration and any baseline assessment are not described. These gaps restrict appraisal of how the comparison was conducted and what the endpoint estimate, if reported, would represent.
The safety record is limited to the listed affected and at-risk counts. Deaths, follow-up duration, event definitions, and collection procedures are not reported. These limitations are specific to the information available in the registry record; they do not establish that the underlying study lacked these procedures or data.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Light Therapy in the Treatment of Leg Pain — NCT00253981.
- Registry record last updated 2016-06-13; status last verified 2016-05.
- Results first posted 2014-06-19.
- 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.
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18. Record Summary
The registry describes NCT00253981, titled “Light Therapy in the Treatment of Leg Pain,” with an official title referring to monochromatic near-infrared light energy in tibial stress reaction. The study was randomized, double-masked, and parallel, with enrollment listed as 30. Its status is terminated; the recorded start is 2005-11 and primary completion is 2008-06.
The intervention was infrared light therapy assigned three times a week for four weeks, compared with standard medical treatment that included medication. The primary endpoint was a participant-rated pain scale from 1 to 10 at 4 weeks, with higher scores indicating more pain. The registry lists 1 outcome measure and 0 analyses. No numerical outcome comparison is reported. Safety entries list zero affected participants for serious and other adverse events in both groups; deaths are not reported in the registry record.