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 Retrospective Data Collection Study in Patients With Macular Oedema Receiving OZURDEX® (NCT02181530), a registered phase not stated study. The primary outcome is Change From Baseline in Best Corrected Visual Acuity (BCVA) in the Study Eye.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02181530 |
| Phase | Phase not stated |
| Condition | Macular Edema, Retinal Vein Occlusion |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 43 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Allergan |
| Results posted | Yes |
2. Clinical Question
Population
Patients with macular oedema due to retinal vein occlusion who had received OZURDEX® in routine clinical practice. The registry lists 43 enrolled participants and identifies macular edema and retinal vein occlusion as conditions. Specific eligibility criteria and the number of participants contributing data to the primary endpoint are not reported in the registry record.
Intervention
The study concerns OZURDEX® (dexamethasone intravitreal implant 0.7 mg), administered at least once in accordance with routine clinical practice. The registry describes retrospective data collection and states that no intervention was administered as part of the study.
Comparator
No concurrent control group or comparator is described. The record identifies a retrospective OZURDEX® cohort, not a comparison between randomized treatment groups. Consequently, the study does not establish a like-for-like treatment contrast.
Primary question
What was the change from baseline in best corrected visual acuity (BCVA) in the study eye at 7 to 12 weeks following the first OZURDEX® injection? The endpoint is defined as a mean change on a decimal visual-acuity scale, with standard deviation as the stated measure of dispersion. The registry record does not report the observed change or its uncertainty.
This question describes visual acuity over a specified follow-up period among participants with data available at the time-point. It is a descriptive question about recorded outcomes after routine treatment, rather than a randomized comparison of treatment strategies. The record also lists secondary outcomes concerning BCVA improvements, retinal thickness measured by optical coherence tomography, and time to improvement or reinjection. Those outcomes give additional aspects of follow-up, but their numerical results are not reported in the registry record.
3. Trial Design
The registry describes a completed retrospective data collection study sponsored by Allergan. It lists a start of 2014-07 and primary completion of 2014-10, with enrollment of 43 participants. The study concerns OZURDEX® use among patients with macular oedema due to retinal vein occlusion in clinical practice. The description specifies that participants had received the implant at least once according to routine practice and that no treatment intervention was administered as part of the study.
This distinction matters for interpretation. Researchers collected data about treatment that had already occurred; the record does not describe assignment by the study team. Randomization, allocation procedures, masking, and a concurrent control group are not reported in the registry record. The listed arm is OZURDEX®, with no like-for-like control comparison. It is therefore not appropriate to interpret the design as a randomized efficacy trial or to attribute changes solely to treatment on the basis of this record.
The primary outcome is change from baseline in BCVA in the study eye, assessed at baseline and 7 to 12 weeks following the first injection. The record states that the primary endpoint population consists of participants with data available at the time-point. It also lists six secondary outcomes: BCVA improvement thresholds, change in retinal thickness, times to BCVA improvement, and time to OZURDEX® reinjection. The registry lists seven outcome measures in total, but reports no analyses. Eligibility details, the data collection process, the handling of repeated injections, and the statistical analysis plan are 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
| Stage | OZURDEX® |
|---|---|
| STARTED | 43 |
| COMPLETED | 43 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: All participants with data available at the time-point.
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 | OZURDEX® |
|---|---|---|
| Participants analysed | 43 | |
| Age, Continuous | years | 59.02 (SD 13.58) |
| Sex: Female, Male: Female | Participants | 17 |
| Sex: Female, Male: Male | Participants | 26 |
6. Primary Endpoint
The registry lists the primary outcome as Change From Baseline in Best Corrected Visual Acuity (BCVA) in the Study Eye, measured over Baseline, 7 to 12 weeks following the first OZURDEX® injection.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | units on a scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is change from baseline in best corrected visual acuity (BCVA) in the study eye, measured at baseline and 7 to 12 weeks following the first OZURDEX® injection. BCVA is assessed using an eye chart. The registry describes converting the number of letters read correctly, expressed as a Snellen fraction, to a decimal scale. On that scale, 20/20 corresponds to 1.0; the described range runs from 0.1 (20/200) at worst to 2.0 (20/10) at best. Higher values represent better visual acuity, and a positive change means improvement.
Change from baseline is used to express how the recorded visual-acuity score differs from the participant’s baseline score over follow-up. A mean summarizes the average change across participants with available data, while the standard deviation describes the spread of individual changes around that mean. These summaries can help characterize the direction and variability of the observed outcome. They do not, by themselves, show whether a change was caused by treatment or whether it is clinically important.
The endpoint population is defined as participants with data available at the time-point. The number with available endpoint data, the observed mean change, its standard deviation, and any uncertainty interval are not reported in the registry record. The primary outcome therefore cannot be interpreted quantitatively from the registry information described.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a clinically relevant descriptive outcome: change in BCVA in the study eye after routine OZURDEX® use. It also specifies the follow-up window and the scale direction, so the intended meaning of a positive change is clear. However, the numerical primary-outcome result is not reported in the registry record. There is no posted mean change, standard deviation, confidence interval, or inferential test to characterize the size or precision of the observed change.
The record lists 43 enrolled participants, but enrollment does not establish how many had usable BCVA measurements at the required time-point. The endpoint population is described as participants with data available at the time-point, and the count with such data is not reported in the registry record. As a result, the amount of missing primary-outcome data and the possible consequences of missingness cannot be assessed from the listed information.
The design is retrospective and has no concurrent comparator described. Changes between baseline and follow-up may be described if results are available, but a within-person change does not isolate the effect of treatment. Other influences, including the course of the condition and routine-care decisions, cannot be separated from treatment effects using the information in this record. The registry does not report details that would allow those influences to be evaluated or adjusted for.
Seven outcome measures are listed, covering visual acuity, retinal thickness, and timing of improvements or reinjection. The registry reports zero analyses. This means no analysis results are available in the record for evaluating the primary or secondary outcomes. It is not possible to determine whether the outcomes were analyzed using prespecified methods, whether estimates were adjusted, or how uncertainty was quantified.
The posted safety figures list 0 serious adverse events among 43 participants at risk and 29 other adverse events among 43 participants at risk. These are recorded event counts, not a treatment comparison, and the registry does not provide event descriptions for the serious-event category. The count of deaths is not reported in the registry record. These safety entries should be read separately from the unreported visual-acuity outcome; they do not fill the gap in the primary efficacy result.
Any sample-size figures associated with the posted planning material are illustrations based on the observed effect under specified assumptions, not evidence of the study’s original design or its achieved power. The registry does not report a protocol sample-size justification. No conclusion about treatment effect, statistical significance, or precision of the primary endpoint can be drawn without its outcome estimates and analysis details.
9. Statistical Methods Explained
The primary endpoint is a continuous outcome: change in BCVA from baseline. The registry specifies a mean as the summary parameter and standard deviation as the measure of dispersion. Those choices describe the average change and the variation in participant-level changes. They do not communicate the same information: the mean describes the center of the observed changes, whereas the standard deviation describes how spread out those changes are.
What does a change score represent?
In general, a change score compares a participant’s follow-up measurement with that participant’s baseline measurement. For this outcome, positive change is defined as improved visual acuity, and the decimal scale is oriented so that higher values indicate better acuity. A mean change can be useful for summarizing the cohort’s direction and average magnitude of change. It can also obscure variation: individual participants may have changes that differ from the average. The registry does not report the mean change or standard deviation, so neither the average nor the spread can be judged from the record.
What does a confidence interval add?
In general, a confidence interval gives a range of values compatible with the data and the statistical method used, expressing uncertainty in an estimate. It is distinct from a standard deviation, which describes variability among observations. A narrow interval indicates greater precision under the method’s assumptions; a wide interval indicates less precision. No confidence interval for the primary outcome is reported in the registry record. Without an estimate and an uncertainty measure, the size and precision of the BCVA change cannot be evaluated.
Why does the retrospective design matter?
In general, retrospective data collection uses records of care that has already occurred. It can describe outcomes observed in clinical practice, but it does not by itself create a randomized treatment contrast. In this study, the registry says no intervention was administered and does not describe a concurrent control group. Thus, any recorded change from baseline would be a before-and-after description within the treated cohort. Such a change cannot alone distinguish a treatment effect from other changes over time or differences in care and measurement.
The registry does not report whether the analysis accounted for baseline characteristics, repeated injections, or other factors. It also does not report the model used, assumptions checked, or any adjustment strategy. These methods cannot be inferred from the endpoint definition. If repeated measurements were included in an analysis, their dependence would be relevant; whether that occurred is not reported in the registry record.
How should the sample-size illustrations be understood?
In general, a sample-size calculation estimates the number of observations needed under chosen assumptions to detect a specified effect with a chosen error rate and power. The planning assumptions described for this material use a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and a stated fraction of the observed effect. For time-to-event outcomes, the stated calculation concerns the total number of events; for other outcomes, it concerns participants per arm. These are planning illustrations based on an observed effect, not the study’s own design or observed power.
Those assumptions do not match the registry’s description of a retrospective cohort without a like-for-like control group. The registry does not report a protocol sample-size justification, the effect used for planning, or an original randomized two-arm design. Any calculated sample-size illustrations should therefore be interpreted as hypothetical planning scenarios rather than evidence about the adequacy of enrollment or the certainty of the study findings. The illustrated values cannot replace a reported estimate and its uncertainty.
What do the reported analysis counts establish?
The registry lists seven outcome measures and zero analyses. In general, listing an outcome identifies a measure that was intended for collection or reporting; an analysis result requires an estimate or other statistical output. The outcome list alone does not establish that data were complete, that every endpoint was analyzed, or that a planned statistical method was followed. The registry record does not report model details, tests, confidence intervals, or the handling of repeated measures and missing observations. Consequently, the analytical approach and the numerical evidence for the outcomes remain unavailable.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists seven outcome measures: the primary BCVA change outcome and secondary measures concerning BCVA improvement, retinal thickness, and timing of improvement or reinjection. When several outcomes are examined, multiplicity can matter because repeated statistical tests may increase the chance of finding an apparently unusual result by chance. In general, prespecifying a primary outcome and an approach to multiple comparisons helps readers understand which results are confirmatory and how secondary findings should be interpreted. The registry record does not report a multiplicity adjustment or a statistical plan explaining how the outcomes were prioritized.
The record reports zero analyses, so it does not provide outcome estimates or tests from which multiplicity handling could be assessed. Whether any adjustment was planned or performed is not reported in the registry record. It would be inappropriate to infer a testing strategy from the outcome list alone.
For the primary endpoint, the analysis population is described as participants with data available at the time-point. This defines an available-data population rather than identifying a count or explaining how missing measurements were handled. The number with available baseline and follow-up BCVA data is not reported in the registry record. Reasons for missing data, differences between participants with and without measurements, and any imputation or sensitivity analyses are also not reported. These omissions limit assessment of selection and missing-data bias. No intention-to-treat population is described, and the record does not report a protocol defining analysis populations.
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 |
|---|---|---|---|
| OZURDEX® | 0 | 43 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| OZURDEX® | 29 of 43 |
Most frequent non-serious adverse event terms
| Event term | Organ system | OZURDEX® |
|---|---|---|
| Increased intraocular pressure | Investigations | 12 of 43 |
| Conjunctival haemorrhage | Eye disorders | 11 of 43 |
| Conjunctival hyperaemia | Eye disorders | 10 of 43 |
| Ocular hypertension | Eye disorders | 5 of 43 |
| Chemosis | Eye disorders | 4 of 43 |
| Cortical/nuclear cataract | Eye disorders | 4 of 43 |
| Eye pain | Eye disorders | 3 of 43 |
| Subcapsular cataract | Eye disorders | 2 of 43 |
| Vitreous floaters | Eye disorders | 2 of 43 |
The registry lists 43 participants at risk for serious adverse events and 0 participants affected. It lists 43 participants at risk for other adverse events and 29 affected. These are counts attached to the OZURDEX® group in the retrospective record. The registry provides no serious adverse-event terms, and the death count is not reported in the registry record.
In general, an at-risk count identifies the group used as the denominator for the event summary, while the affected count records how many participants were listed with an event in that category. These figures do not provide event timing, severity detail beyond the serious-versus-other classification, duration, or a comparison with an untreated group. The record does not report how adverse events were collected or classified, or whether the counts refer to unique participants or event episodes. Therefore, the figures describe the registry entries but do not establish a comparative safety effect or capture information not recorded in the registry.
12. What the Result Does, and Does Not, Mean
The registry record establishes that this was a completed retrospective data collection study of routine OZURDEX® use, with enrollment of 43 participants and a primary outcome defined as BCVA change from baseline at 7 to 12 weeks following the first injection. It also records safety counts and lists secondary outcomes. These details describe the study’s scope and the outcomes of interest.
The record does not report the primary outcome estimate, its standard deviation, or an uncertainty interval. It also reports zero analyses. The posted registry information therefore does not show the magnitude or precision of any BCVA change, nor does it provide an inferential result for the primary or secondary outcomes. No conclusion about statistical significance can be drawn from an outcome title or endpoint definition.
Even if a numerical before-and-after change were available, a retrospective cohort without a concurrent control group would not, on its own, establish that treatment caused the change. The absence of a like-for-like comparison prevents separating treatment-related changes from other influences using this record. The registry also does not provide enough detail to assess missing outcome data or the statistical methods used.
The safety figures report no participants affected by a serious adverse event in the listed group, and 29 participants affected by other adverse events. These entries describe what is recorded; they do not establish that no unrecorded events occurred or provide a comparison with another treatment group. The overall meaning is therefore limited to the study description and posted counts. The clinical effect and its precision are not reported in the registry record.
13. Why This Trial Matters Statistically
This record illustrates a distinction that matters in biostatistics: a clearly defined outcome is not the same as a reported result. The registry specifies the BCVA measure, its direction, the summary parameter, and the follow-up window. Those details help readers understand what an analysis would describe. Yet the record reports zero analyses, so the effect estimate and its uncertainty are unavailable. Statistical interpretation depends on results as well as design and endpoint definitions.
The study also highlights the difference between routine-care data and randomized comparisons. Retrospective collection can describe what was recorded after treatment in clinical practice. Without a concurrent comparator described in the record, a change over time cannot be treated as a controlled estimate of treatment effect. This is a design limitation, not a conclusion about whether the observed clinical course was favorable or unfavorable.
The endpoint population is defined by data availability, but the count with endpoint data and the handling of missing observations are not reported. This matters because the analyzed participants may not represent everyone enrolled. The listed safety counts likewise need context about collection and event definitions to support comparisons. Together, these features show why statistical reading should consider how data were gathered, who contributed measurements, what analyses were reported, and how precisely results were estimated. Here, the registry record offers the study framework and event counts, but not the primary outcome analysis.
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.
Several trial-specific limitations arise from the registry description. The study is retrospective, and no concurrent control group is described. The listed OZURDEX® cohort therefore does not provide a like-for-like comparison. Any within-person change in BCVA, if reported elsewhere, would not alone identify a causal treatment effect.
The primary endpoint is defined for participants with data available at the time-point, but the number contributing data is not reported in the registry record. The record also does not report the amount or reasons for missing data, or how missing measurements were handled. This prevents assessment of whether the endpoint population differed from the enrolled group in ways relevant to the outcome.
The primary outcome result and all analysis results are absent from the registry record, which lists zero analyses. No statistical analysis plan, model, adjustment strategy, or multiplicity approach is reported. The registry also does not report eligibility criteria, the data collection process, or details about repeated injections and their relationship to follow-up measurements.
For safety, the record gives participant counts but does not report event terms for serious adverse events, methods of event collection, or the death count. The listed counts cannot be used as a comparative safety estimate. These limitations concern what the registry record reports; they do not establish that other analyses or information were absent from the study’s underlying records.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Retrospective Data Collection Study in Patients With Macular Oedema Receiving OZURDEX® — NCT02181530.
- Registry record last updated 2015-05-25; status last verified 2015-05.
- Results first posted 2015-05-25.
- 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
NCT02181530 is a completed retrospective data collection study sponsored by Allergan, with enrollment of 43 participants. It concerns routine OZURDEX® (dexamethasone intravitreal implant 0.7 mg) use for macular oedema due to retinal vein occlusion and states that no intervention was administered as part of the study.
The primary outcome is mean change from baseline in BCVA in the study eye at 7 to 12 weeks following the first injection, with standard deviation as the stated dispersion measure. Six secondary outcomes are listed. The registry reports zero analyses, and the primary and secondary outcome results are not reported in the registry record. Safety entries list 0 serious adverse events among 43 at risk and 29 other adverse events among 43 at risk. The record does not describe a concurrent comparator or a like-for-like control comparison.