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 IPL and Meibomian Gland Expression to Treat Ocular Rosacea Ocular GVHD (NCT02066051), a na na study. The primary outcome is Number of Participants Who Responded to Intense Pulsed Light (IPL).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02066051 |
| Phase | NA |
| Condition | GVHD, Ocular Rosacea, Dry Eye Syndrome |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 8 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Mayo Clinic |
| Results posted | Yes |
2. Clinical Question
Population
Participants had inactive chronic graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation, severe dry eye symptoms related to ocular rosacea, and symptoms unresponsive to conventional management. The registry record reports 8 enrolled participants.
Intervention
The listed interventions were intense pulsed light (IPL) and meibomian gland expression. The outcome description says participants received treatment over 4 months. The registry record does not report further procedural details for meibomian gland expression.
Comparator
This was a single-group study, not a randomized comparison. No control or comparison group is described in the registry record, so the posted results cannot directly compare treatment with an alternative intervention or with no treatment.
Primary question
The primary question was how many participants responded to IPL, with response defined as over a 30% improvement in the Standard Patient Evaluation of Eye Dryness (SPEED2) score. The primary outcome result is not reported in the registry record.
The clinical context in the registry record is dry eye symptoms associated with ocular rosacea after inactive chronic GVHD. Its brief summary describes the study purpose as assessing whether IPL could be used safely and effectively for these symptoms, where treatment options were described as limited. That statement describes the study’s purpose; it is not evidence of a treatment effect.
The outcome description says symptoms were assessed using the SPEED2 questionnaire. The response threshold was based on change in that score, rather than on a complete resolution of symptoms. The registry record notes that participants were not expected to have a complete response because of ocular-surface damage from GVHD.
3. Trial Design
The registry record identifies this as a completed, single-group study sponsored by Mayo Clinic. It lists 8 participants as enrolled. The start is recorded as 2013-10 and the primary completion as 2014-11. The phase is listed as NA. Allocation is also listed as NA, and masking is listed as none.
The intervention list includes IPL, classified as a device, and meibomian gland expression, classified as a procedure. The primary outcome description says participants received treatment over 4 months and were monitored for safety and response for an additional 8 months, for a stated outcome timeframe of 12 months. The brief description of the treatment regimen is incomplete in the registry record, so further details about how the interventions were delivered are not reported in the registry record.
A single-group design can describe outcomes observed among participants who received the interventions, but it does not by itself distinguish intervention effects from other explanations for changes over time. Without a concurrent control group, the results cannot provide a like-for-like estimate of what would have happened to comparable participants under another treatment or without the study interventions. The registry record does not describe randomization or a control arm.
The record lists a primary outcome of the number of participants who responded to IPL and a secondary outcome concerning participants who experienced adverse events. It contains no listed analysis results. Details such as a prespecified statistical analysis plan, sample-size justification, and interim analyses are not reported in the registry record. The design and outcome definitions can therefore be described, but the record does not permit a full assessment of how the investigators planned to analyze or interpret the primary outcome.
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
| Stage | IPL Treatment |
|---|---|
| STARTED | 8 |
| COMPLETED | 7 |
| NOT COMPLETED | 1 |
Reasons for not completing this period:
| Reason | IPL Treatment |
|---|---|
| Subject developed active GVHD | 1 |
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 | IPL Treatment |
|---|---|---|
| Participants analysed | 8 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 8 |
| Age, Categorical: >=65 years | Participants | 0 |
| Sex: Female, Male: Female | Participants | 5 |
| Sex: Female, Male: Male | Participants | 3 |
| Region of Enrollment: United States | participants | 8 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants Who Responded to Intense Pulsed Light (IPL), measured over 12 months.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants who responded to IPL. Response was defined as over a 30% improvement in the SPEED2 score. The score captures reported dry eye symptoms: the questionnaire asks about four commonly experienced symptom groups, with frequency and severity ratings contributing to a total score that ranges from 0, indicating no problem, to 28, indicating severe problems.
A defined response threshold turns symptom-score change into a participant count. This can be easier to interpret as a description of how many participants crossed a prespecified level of improvement than a score change alone. However, the registry record does not report the number who met the response definition, so the primary endpoint’s observed result cannot be evaluated from the posted record.
The registry record states that participants were not expected to have a complete response because of the nature of the ocular-surface damage from GVHD. This provides context for using a threshold of improvement rather than requiring symptoms to disappear. It does not establish that the threshold was met or that any observed change was caused by the interventions.
The stated timeframe is 12 months: treatment occurred over 4 months, followed by 8 additional months of safety and response monitoring. The primary outcome is therefore a count of responders within a study with that stated treatment and monitoring schedule. The registry record does not report details about how missing questionnaire assessments, if any, were handled.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record does not report a numerical result for the primary endpoint. It defines response as over a 30% improvement in SPEED2 score and gives a 12-month timeframe, but it does not state how many participants met that definition. Consequently, no conclusion about the observed frequency of response can be drawn from the primary outcome record. The absence of a posted count should not be interpreted as zero responders.
The study enrolled 8 participants, but the record does not report the number included in the primary outcome analysis. Enrollment is not necessarily the same as the number with evaluable follow-up or the number analyzed. No analysis results are listed in the registry record. An effect estimate, uncertainty interval, or statistical test for the primary outcome is therefore not reported in the registry record.
Even if a response count were available, this single-group design would describe outcomes in the treated group rather than establish a controlled treatment effect. Changes in symptoms over time could have explanations other than the intervention. The registry record does not include a randomized comparator that would support a direct comparison, and it does not describe an adjusted analysis that could address this limitation.
The safety record reports 0 participants affected among 7 at risk for serious adverse events and 0 among 7 at risk for other adverse events in the IPL Treatment group. These are the recorded counts, not evidence that the risks are absent. The safety denominators differ from total enrollment, and the registry record does not explain that difference. Deaths are not reported in the registry record. No serious adverse-event terms are listed.
The record’s sample-size-planning assumptions are described as an illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. Those assumptions describe planning calculations, not the design of this single-group study. The planning values and the observed effect estimate are not reported in the registry record. Such planning illustrations are not observed power and do not add evidence about the study outcome.
Overall, the registry record gives useful information about the population, outcome definition, follow-up schedule, and reported safety counts, but it does not provide the primary endpoint result or analysis details needed to quantify the study’s findings. The missing result prevents assessment of the size and precision of any observed symptom response.
9. Statistical Methods Explained
What does a participant-count endpoint mean?
The primary endpoint is a count: the number of participants who met the response definition. A count differs from a continuous score outcome. It classifies each participant according to whether their score change crossed the stated threshold, then counts those classified as responders. This offers an interpretable summary, but it also discards information about the amount of change among participants who fall on either side of the threshold. The registry record does not report the count or the number analyzed, so neither the observed response frequency nor its precision can be assessed.
What does the response definition capture?
Response was defined as over a 30% improvement in SPEED2 score. The questionnaire asks about symptom frequency and severity across four commonly experienced dry eye symptom groups. Frequency ratings range from 0 (never) to 3 (constant), and severity ratings range from 0 (no problems) to 4 (intolerable); the total score ranges from 0 (no problem) to 28 (severe problems). The threshold translates score change into a binary responder classification. In general, a threshold can make a result easier to communicate, but it does not show the full distribution of individual score changes. The registry record does not provide the underlying score data or a primary response count.
Why does study design matter for interpretation?
In a single-group study, outcomes are observed among participants receiving the intervention or interventions, without a concurrent comparison group. General statistical interpretation distinguishes a change observed after treatment from a treatment effect attributable to treatment. A control group can help estimate what would have occurred under a comparison condition; without one, other explanations for change cannot be separated in the same way. This is a design limitation, not a calculation problem. The registry record describes no randomized comparison, and its own listed design is single group.
What does statistical precision mean?
In general, a confidence interval expresses the range of values compatible with an estimate under the analysis assumptions. A narrow interval indicates greater precision than a wide interval, while neither alone establishes that an effect is important or caused by treatment. For a participant-count outcome, precision depends on the observed count and the number analyzed, among other assumptions. The registry record does not report a primary outcome estimate, confidence interval, or analysis population, so no statement about precision for the primary result is possible.
How should planning calculations be understood?
The registry record describes sample-size illustrations using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It also describes the target effect in relation to the observed effect. These are planning assumptions, not a report of the study’s actual single-group design, which is listed as single group. Any sample size calculated under hypothetical assumptions is a planning illustration; it does not show the power actually achieved by the completed study. The numerical planning results and the observed effect estimate are not reported in the registry record.
Why can event counts be difficult to interpret?
For a binary safety outcome, the affected count should be read alongside the number at risk. The registry record lists 0 affected among 7 at risk for serious adverse events and 0 affected among 7 at risk for other adverse events. These counts describe the recorded experience in the stated group. In general, a zero count in a small group does not establish that an event cannot occur, and it does not precisely estimate the event risk. The record does not provide an uncertainty interval or additional event-level detail.
Over-dispersion is a general statistical concept relevant to some count outcomes: it occurs when observed variability is greater than a model assumes. It can make model-based uncertainty too small if the extra variability is ignored. The primary outcome in this study is described as a participant count, but no statistical model or analysis results are listed in the registry record. There is therefore no basis to say that over-dispersion was assessed or that a particular model was used.
More broadly, analysis choices affect which participants contribute to an estimate, how uncertainty is calculated, and how missing observations are treated. Those choices, along with any covariate adjustment, are not reported in the registry record. Statistical concepts can clarify what would be needed to interpret a numerical estimate, but they cannot replace the unreported primary result or analysis details.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists a primary outcome for the number of participants responding to IPL and a secondary outcome for the number experiencing adverse events. Assessing multiple outcomes can raise a multiplicity question: when several hypotheses are tested, the chance of at least one apparently notable result can increase. In general, investigators may specify a hierarchy or use an adjustment, depending on the goals and analysis plan. A multiplicity strategy is not reported in the registry record. No statistical tests or outcome analyses are listed, so it is not possible to determine whether multiplicity was addressed.
Information about missing data is also not reported in the registry record. The record does not state whether any SPEED2 assessments were missing, how missing scores were handled, or whether participants without an endpoint assessment were counted as responders, nonresponders, or excluded. These details matter because the analyzed participants may differ from the enrolled group, and the handling of incomplete observations can affect the estimate.
The registry record reports 8 enrolled participants, while the adverse-event group lists 7 at risk. It does not explain this difference. The number included in the primary endpoint analysis and the analysis population definition are not reported in the registry record. It is therefore not possible to determine whether the primary result, if available elsewhere, would represent all enrolled participants or a subset.
In general, an analysis population definition specifies which participants contribute to an outcome analysis. Common approaches can differ in how they handle nonadherence, withdrawals, and missing measurements; the registry record does not identify an approach. No assumptions about missingness, sensitivity analyses, or imputation methods are 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 |
|---|---|---|---|
| IPL Treatment | 0 | 7 | 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 |
|---|---|
| IPL Treatment | 0 of 7 |
The registry record reports no serious adverse events among 7 participants at risk in the IPL Treatment group, and no other adverse events among 7 at risk in that group. These are separate recorded categories, each with 0 affected and 7 at risk. No serious adverse-event terms are listed.
The safety denominator is 7, whereas the enrollment count is 8. The reason is not reported in the registry record. The record also does not give the duration of each participant’s safety observation beyond stating that safety and response were monitored for an additional 8 months after treatment. Deaths are not reported in the registry record; the death field is not a reported zero count.
In general, zero recorded events in a small group do not prove that the event risk is zero. Such counts describe what was recorded among those at risk, while the underlying risk remains uncertain. The registry record does not provide confidence intervals, detailed event narratives, or a comparison group for safety. The counts therefore should be read as descriptive observations, not as evidence that an intervention is free of adverse events.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a completed, single-group study enrolled 8 participants with inactive chronic GVHD after allogeneic bone marrow transplantation and severe dry eye symptoms related to ocular rosacea that had not responded to conventional management. It lists IPL and meibomian gland expression as interventions and describes a 12-month outcome timeframe, including treatment over 4 months and an additional 8 months of monitoring.
The primary endpoint is clearly defined as the number of participants whose SPEED2 score improved by over 30%. However, the primary outcome result is not reported in the registry record. The record therefore does not show how many participants met the response definition, how variable their outcomes were, or how precisely any response rate was estimated. A missing result is not equivalent to a finding of no response.
The safety counts report 0 serious adverse events among 7 at risk and 0 other adverse events among 7 at risk. Those counts provide a limited descriptive account of recorded events. They do not demonstrate that adverse events cannot occur, and no comparison group is available to assess relative safety.
The single-group design also limits causal interpretation. In general, an observed change after treatment cannot be attributed to the intervention alone when there is no concurrent comparison. The registry record does not supply evidence that separates treatment effects from other possible influences on symptoms. The purpose statement in the record is not a result.
Accordingly, the record supports a description of the study design, target population, response definition, follow-up schedule, and reported adverse-event counts. It does not support a quantitative conclusion about the primary response outcome or a controlled estimate of treatment effect. Further interpretation would require primary outcome results and analysis details that are not reported in the registry record.
13. Why This Trial Matters Statistically
This study is statistically notable because it combines a small enrolled group with a participant-count endpoint and a single-group design. Those features shape what can be learned from any observed outcome. A count of participants crossing a symptom-improvement threshold can be understandable to readers, but it does not retain the full range of score changes. The threshold also means that participants with similar changes near the cutoff may be classified differently.
The single-group design makes the distinction between observed outcomes and causal effects especially important. A treated group’s outcomes can be described, but without a comparison group the study cannot directly estimate how those outcomes differ from a concurrent alternative. This limitation remains even if a numerical response count is eventually available.
The record also illustrates why outcome reporting is essential to statistical interpretation. It specifies the primary endpoint and its threshold, but does not report the primary result, an uncertainty interval, or an analysis population. Without those details, readers cannot evaluate either the magnitude or the precision of the primary outcome.
Finally, safety counts need their denominators and context. The record lists 0 affected among 7 at risk for each of the serious and other adverse-event categories, while enrollment is 8. The reason for the denominator difference is not reported. These counts are descriptive and do not establish absence of risk. Together, these features make transparent reporting of outcomes, analysis methods, and participant flow important for evaluating this study.
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 registry record identifies a single-group study with 8 participants enrolled. The lack of a randomized comparison limits the ability to distinguish changes associated with treatment from other possible explanations. The record also lists no masking, so it does not describe masking that might reduce awareness of treatment assignment or assessment. With no comparator described, the study cannot provide a like-for-like contrast.
The most important interpretive limitation is that the primary outcome result is not reported in the registry record. The record defines the responder threshold and timeframe, but does not report the number of responders or the number analyzed. No primary effect estimate, uncertainty interval, or analysis result is listed. These omissions prevent assessment of the observed response and its precision.
The safety group lists 7 participants at risk, while total enrollment is 8; the reason for this difference is not reported in the registry record. The record does not describe participant flow, missing questionnaire data, or how incomplete follow-up was handled. The analysis population and missing-data methods are also not reported in the registry record.
The treatment description is incomplete: the arm description ends before all regimen details are stated. Although the outcome description gives treatment over 4 months and the intervention list includes both IPL and meibomian gland expression, further procedural detail is not reported in the registry record. Sample-size justification, interim analyses, and a statistical analysis plan are not reported in the registry record either. These limits mean that the protocol-level rationale and the conduct of the outcome analysis cannot be fully assessed.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: IPL and Meibomian Gland Expression to Treat Ocular Rosacea Ocular GVHD — NCT02066051.
- Registry record last updated 2015-11-25; status last verified 2015-10.
- Results first posted 2015-11-25.
- 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
NCT02066051 is a completed Mayo Clinic study titled “IPL and Meibomian Gland Expression to Treat Ocular Rosacea Ocular GVHD.” The official title describes intense pulsed light and meibomian gland expression for ocular rosacea secondary to inactive chronic ocular GVHD. The registry record lists 8 enrolled participants, a single-group design, no masking, and phase NA.
The primary outcome was the number of participants responding to IPL, defined as over a 30% improvement in SPEED2 score, with a 12-month timeframe. The record describes treatment over 4 months and an additional 8 months of safety and response monitoring. The primary result and analysis details are not reported in the registry record.
For the IPL Treatment group, the safety record lists 0 serious adverse events among 7 at risk and 0 other adverse events among 7 at risk. The reason the safety denominator differs from enrollment is not reported in the registry record. No serious adverse-event terms are listed, and deaths are not reported in the registry record.