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 Fluoxetine for Visual Recovery After Ischemic Stroke (NCT02737930), a randomized phase 2 study. The primary outcome is Percent Change in the Bionocularly Averaged Perimetric Mean Deviation.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02737930 |
| Phase | Phase 2 |
| Condition | Acute Stroke, Visual Field Loss |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 17 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Bogachan Sahin |
| Results posted | Yes |
2. Clinical Question
Population
People with acute ischemic stroke and visual field loss were the focus of the study. The registry record lists 17 participants enrolled. Eligibility criteria and further details about the population are not reported in the registry record.
Intervention
Participants assigned to the fluoxetine arm received a 20 mg capsule by mouth once daily for 90 days.
Comparator
Participants assigned to the placebo arm received matching placebo. Further details about the placebo regimen are not reported in the registry record.
Primary question
The study asked whether fluoxetine was associated with change in visual field function after stroke, measured by percent change in binocularly averaged perimetric mean deviation from baseline to 6 months. The posted results give a mean and a 95% confidence interval for each arm. They do not give an estimable between-arm comparison for this continuous outcome, so the arm summaries alone do not answer the comparative question.
The brief study description frames fluoxetine as a selective serotonin reuptake inhibitor commonly used for depression and states that the study purpose was to determine whether it enhances visual recovery after acute ischemic stroke. That statement describes the research question, not a conclusion. The posted endpoint estimates should therefore be read as descriptive arm results rather than as evidence that one assignment produced a larger change than the other.
3. Trial Design
This was a phase 2, randomized, quadruple-masked, parallel-group study comparing fluoxetine with placebo. The registry lists 17 participants enrolled and identifies the trial status as terminated. The recorded start was 2016-05, and primary completion was recorded as 2020-08. The reason for termination and the timing or circumstances of that decision are not reported in the registry record.
The intervention description specifies fluoxetine 20 mg by mouth once daily for 90 days. The comparator is described as matching placebo. The registry lists five participants in the fluoxetine arm and seven in the placebo arm for the primary outcome. These are the outcome-specific arm counts, and they should not be mistaken for the overall enrollment figure. The primary-outcome description also notes that one participant in the placebo arm withdrew after month 1 but was included in the analysis. Other details of the analysis population are not reported in the registry record.
The primary outcome was a continuous measure of percent change in binocularly averaged perimetric mean deviation from baseline to 6 months. The record also lists eight secondary outcomes, covering visual field measures, functional measures, questionnaires, stroke-related function, imaging, and retinal nerve fiber layer thickness. Values for those secondary outcomes are not included in the posted results summarized for this analysis. The registry reports nine outcome measures overall and zero analysis entries. Random allocation and masking are reported, but the method of sequence generation, allocation concealment, and details about who was masked 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.
Before assignment: 5 participants were consented but 1 screen failed and 4 withdrew from the study before being randomized to an arm, received the intervention and before any data was collected.
Overall Study
| Stage | Fluoxetine | Placebo |
|---|---|---|
| STARTED | 5 | 7 |
| COMPLETED | 5 | 6 |
| NOT COMPLETED | 0 | 1 |
Reasons for not completing this period:
| Reason | Fluoxetine | Placebo |
|---|---|---|
| Withdrawal by Subject | 0 | 1 |
Analysis population for the primary outcome, as defined in the registry: One participant in the placebo arm withdrew from the study after month 1 but was included in the analysis.
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 | Fluoxetine | Placebo | Total |
|---|---|---|---|---|
| Participants analysed | 5 | 7 | 12 | |
| Age, Continuous | years | 71 (70 to 79) | 61 (45 to 70) | 66 (61 to 79) |
| Sex: Female, Male: Female | Participants | 1 | 1 | 2 |
| Sex: Female, Male: Male | Participants | 4 | 6 | 10 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 | 0 | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 5 | 7 | 12 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): White | Participants | 5 | 7 | 12 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Region of Enrollment: United States | participants | 5 | 7 | 12 |
| Number of participants who received tissue plasminogen activator | participants | 0 | 1 | 1 |
| Number of participants with diabetes | participants | 3 | 2 | 5 |
| Number of participants with hypertension | participants | 5 | 5 | 10 |
6. Primary Endpoint
The registry lists the primary outcome as Percent Change in the Bionocularly Averaged Perimetric Mean Deviation, measured over baseline to 6 months.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | percent change in dB |
| Endpoint classification | Continuous Endpoint |
The primary endpoint was percent change in binocularly averaged perimetric mean deviation from baseline to 6 months. Perimetric mean deviation summarizes how measured visual-field sensitivity at test locations differs from expected threshold values, averaging those deviations into one measure. The registry describes testing with 24-2 Humphrey perimetry for each eye, using the Swedish Interactive Threshold Algorithm Standard, a size III white target, enforced fixation, and near-vision correction. A sensitivity cutoff of 10 dB was selected to classify test locations as sighted or blind. The described measure can range from +2 to -32 dB.
A summary measure can make visual-field results easier to compare over time than a collection of point-by-point test values. Mean deviation captures an overall pattern, but it does not show where changes occurred within the visual field. The endpoint is expressed as a percent change in the binocularly averaged measure, so it is intended to describe change relative to baseline rather than simply reporting a single follow-up score.
The registry reports the endpoint as a mean with a 95% confidence interval for each arm. Those intervals describe uncertainty around each arm’s reported mean under the analysis used. They are not a confidence interval for the difference between fluoxetine and placebo. The registry record does not report an estimable comparison between arms for this endpoint, so the endpoint summaries do not establish the size or precision of a treatment contrast.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted primary-outcome estimates are a mean percent change of 64.4 for fluoxetine, with a 95% confidence interval from 30.2 to 98.6, and a mean percent change of 26.0 for placebo, with a 95% confidence interval from 0.2 to 51.7. These are separate arm summaries. The registry record indicates that values were missing or not estimable for a two-arm comparison of this continuous endpoint. Consequently, the estimates do not provide a reported treatment-effect estimate or its uncertainty.
A mean within an arm describes the observed outcome summary for participants included in that arm’s analysis. It is not, by itself, an estimate of the difference attributable to assignment. A randomized comparison is interpreted through a contrast between assigned groups, ideally accompanied by its uncertainty and the analysis details needed to understand how it was obtained. Here, the arm-level means and confidence intervals do not substitute for that contrast. No p-value or confidence interval for the between-arm difference is reported in the registry record.
The confidence intervals are broad, particularly in light of the small outcome-specific arm counts: five for fluoxetine and seven for placebo. In general, a confidence interval communicates the uncertainty around an estimated quantity, given the statistical method and data. The intervals concern each arm’s mean, not the randomized contrast. They should not be compared as a shortcut for testing whether the arms differ. In particular, overlap or non-overlap of separate arm intervals is not a replacement for a directly estimated between-arm effect.
The observed arm means are numerically different, but that descriptive observation does not establish a reliable difference between assignments. The record does not provide the information needed to quantify the uncertainty of such a difference. Nor does it provide a reported result for the secondary outcomes that could broaden interpretation across other measures of vision, function, mood, imaging, or retinal structure. The registry lists the study as terminated, but does not report the reason. That status is relevant context, but it does not explain why the two-arm endpoint comparison is unavailable.
These results are therefore best read as limited descriptive evidence from a small randomized study, not as a conclusive comparative finding. The reported means and intervals show the arm-specific estimates as posted; the missing between-arm estimate leaves the central comparative question unanswered in the registry results. The registry record does not report a conclusion about benefit, lack of benefit, or clinical importance.
9. Statistical Methods Explained
The primary outcome is a continuous measure summarized by a mean. The posted results give an arm-specific mean and a 95% confidence interval for fluoxetine and for placebo. The record does not report a between-arm estimate for this endpoint because values were missing or not estimable for a two-arm comparison. That limitation determines what can be inferred: the available numbers describe each group separately, but do not quantify the randomized contrast.
What does a confidence interval describe?
General statistical explanation: A confidence interval expresses uncertainty around an estimate under a specified statistical procedure. A narrower interval generally indicates greater precision than a wider interval, all else being comparable. It does not show the range of individual participants’ outcomes, and it does not mean that the true value has a particular probability of being inside the calculated interval after the data have been observed. The intervals in this trial are reported for each arm’s mean. They should not be interpreted as intervals for the difference between the arms.
For the fluoxetine arm, the posted mean is 64.4 and the 95% confidence interval is 30.2 to 98.6. For the placebo arm, the posted mean is 26.0 and the 95% confidence interval is 0.2 to 51.7. The record does not state the method used to construct these intervals. It also does not report an adjusted or unadjusted estimate for the between-arm effect. Without that contrast and its uncertainty, no comparative confidence interval can be interpreted from the posted primary results.
Why is the arm-level mean not the treatment effect?
General statistical explanation: A treatment effect in a randomized comparison is commonly expressed as a contrast between the outcome distributions or summaries in the assigned groups. The contrast addresses how the groups differ, while an arm mean describes only one group. A contrast also needs an uncertainty estimate to indicate how precisely the observed difference is estimated. Randomization supports a comparative design, but it does not make separate descriptive summaries equivalent to a reported comparative analysis.
The primary endpoint is a percent change in a continuous measurement. A mean is a way to summarize the central tendency of such values, but the mean can be influenced by extreme observations, especially in a small group. The registry does not report participant-level outcomes or a measure of spread other than confidence intervals around the arm means. It is therefore not possible to assess the distribution’s shape, identify influential observations, or evaluate whether the mean is a complete description of the observed values.
What do the outcome-specific counts mean?
The registry reports five participants in the fluoxetine arm and seven in the placebo arm for the primary outcome. These counts are smaller than the total enrollment of 17. The record does not explain the full relationship between enrollment and these outcome-specific counts. It does state that one participant in the placebo arm withdrew after month 1 and was included in the analysis. That inclusion detail should be retained when reading the reported placebo summary, but the registry does not give enough information to determine how other participants were handled or why the endpoint counts differ from enrollment.
How should sample-size planning illustrations be read?
General statistical explanation: Planning calculations translate assumptions about an effect, variability, allocation, and a statistical threshold into an illustrative sample size. They are not evidence that a study had a particular probability of detecting an effect after it was conducted. In this record, any planning illustration is based on the observed effect and uses a two-sided significance level of 0.05, equal allocation, and a normal approximation; the target effect is expressed as a fraction of the observed effect. Such calculations are explicitly illustrations, not the trial’s own design justification, and should not be described as observed power. The registry record does not report the original sample-size justification or the assumptions used in the trial’s planning.
For continuous outcomes, planning estimates are expressed as participants per arm. General statistical explanation: These estimates depend strongly on the effect size and variability assumptions. If an assumed effect is smaller, more participants may be needed to detect it under otherwise comparable conditions. That general relationship does not establish what sample size would have been appropriate for this study, because the registry record does not report the original design assumptions. No additional planning figures are needed to interpret the posted primary outcome: the central issue remains that the randomized comparison itself is not estimable in the registry results.
What can be said about the statistical plan?
The registry reports zero analysis entries. This is a description of what is recorded, not proof that no analysis was conducted. The statistical model, covariate adjustment, handling of repeated measurements, missing-data procedures, and analysis population definitions are not reported in the registry record. The record also does not report whether any interim analyses were planned or conducted. These omissions limit the ability to evaluate the analysis choices and to determine whether the posted summaries correspond to a prespecified analysis.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists nine outcome measures overall, including the primary endpoint and eight secondary outcomes. Those secondary outcomes include other visual-field measures, the number of participants with >95% recovery, a functional field score, questionnaire measures, a modified Rankin Scale score, functional magnetic resonance imaging, and retinal nerve fiber layer thickness. The registry results summarized for this analysis do not include values for the secondary outcomes. Their estimates, uncertainty, and any associated comparisons are therefore not available for interpretation.
When a study examines multiple outcomes or multiple comparisons, the chance of obtaining at least one apparently notable result can increase. General statistical explanation: Multiplicity refers to the consequences of making multiple statistical tests or estimates, and strategies such as prioritizing a primary endpoint or adjusting thresholds can help control the interpretation of those results. The registry record does not report a multiplicity strategy, a hierarchy among secondary outcomes, or how secondary analyses were intended to affect conclusions. It would therefore be inappropriate to assume that an adjustment was or was not used.
The record notes that one placebo participant withdrew after month 1 but was included in the primary analysis. It does not report the missing-data method, the reasons for missing endpoint values, or the analysis population definition. The enrolled total and the outcome-specific arm counts are not the same, but the registry does not give a complete account of participant flow or explain all exclusions from the endpoint summaries. It also does not report whether sensitivity analyses were performed to assess the effect of missing observations.
These gaps matter because outcome availability and analysis choices can affect estimates and their precision. The posted arm means should be read in the context of the reported inclusion of the withdrawing participant and the limited information about other missing data. The record does not provide enough detail to assess whether missingness could have influenced the results or whether the primary analysis followed a prespecified plan.
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 |
|---|---|---|---|
| Fluoxetine | 3 | 5 | 60.0% |
| Placebo | 3 | 7 | 42.9% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Fluoxetine | 0 of 5 |
| Placebo | 0 of 7 |
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 |
|---|---|
| Fluoxetine | 0 of 5 |
| Placebo | 0 of 7 |
Most frequent serious adverse event terms
| Event term | Organ system | Fluoxetine | Placebo |
|---|---|---|---|
| seizure | Nervous system disorders | 2 of 5 | 0 of 7 |
| hemorrhagic transformation | Vascular disorders | 0 of 5 | 1 of 7 |
| stroke | Vascular disorders | 0 of 5 | 1 of 7 |
| transient ischemic attack | Vascular disorders | 1 of 5 | 0 of 7 |
| rash | Skin and subcutaneous tissue disorders | 0 of 5 | 1 of 7 |
Serious events with the highest arm-level rate: seizure (40.0%), transient ischemic attack (20.0%), hemorrhagic transformation (14.3%), stroke (14.3%), rash (14.3%).
The registry reports serious adverse events among five participants at risk in the fluoxetine arm and seven participants at risk in the placebo arm. Three participants in each arm were reported as affected by serious adverse events. For other adverse events, zero participants were reported as affected among five at risk in the fluoxetine arm and among seven at risk in the placebo arm. Deaths were reported as zero in both arms.
The registry also lists seizure at 40.0%, transient ischemic attack at 20.0%, hemorrhagic transformation at 14.3%, stroke at 14.3%, and rash at 14.3% among the top serious-event terms. The record does not make the denominator or the relationship of these percentages to the arm-level affected counts clear enough to attribute each term to a particular arm or to calculate an arm-specific risk. These percentages should therefore be read as listed event-term summaries, not as direct comparative rates.
In general, adverse-event counts describe events reported under the registry’s definitions and collection procedures; they do not, by themselves, establish that an event was caused by an assigned intervention. The record does not report event timing, severity beyond the serious classification, attribution, or a comparative statistical analysis. The small numbers at risk also mean that the posted counts provide limited information about uncommon events. The registry’s safety figures are descriptive and should not be interpreted as a definitive comparison of safety between assignments.
12. What the Result Does, and Does Not, Mean
The trial is a randomized comparison addressing a clinically relevant research question: whether fluoxetine is associated with visual recovery after acute ischemic stroke. Its primary endpoint uses perimetry to summarize visual-field sensitivity, and the registry reports mean percent change from baseline to 6 months for each arm. Those details establish what was measured and when. They do not establish a comparative effect in the absence of an estimable between-arm result.
The fluoxetine arm’s reported mean was 64.4, with a 95% confidence interval from 30.2 to 98.6; the placebo arm’s reported mean was 26.0, with a 95% confidence interval from 0.2 to 51.7. These are observed arm summaries, not a reported estimate of how much the assignments differed. The registry explicitly indicates that values for a two-arm comparison of the continuous endpoint were missing or not estimable. The result therefore cannot be used to quantify the size or precision of a treatment contrast.
It also does not establish that fluoxetine did or did not improve visual recovery. A descriptive difference between group means is not enough to draw that conclusion. The registry does not provide a comparative confidence interval, a p-value, or a stated statistical conclusion for the primary outcome. The fact that the trial was randomized is important design information, but it does not replace the missing comparative result.
The record’s termination status, the gap between enrollment and outcome-specific counts, and the absence of posted secondary-outcome results add context but do not explain the primary comparison’s unavailability. The reason for termination, full participant flow, missing-data procedures, and analysis details are not reported in the registry record. Those limitations make it difficult to assess how representative the analyzed groups were of those enrolled and how the endpoint summaries were produced.
The appropriate takeaway is narrow: the registry reports arm-specific estimates with uncertainty, while the randomized comparison of the primary endpoint is not available. The results should be treated as descriptive and imprecise rather than as a definitive finding about comparative efficacy. They also do not settle questions about the other visual, functional, questionnaire, imaging, or retinal outcomes listed in the study record.
13. Why This Trial Matters Statistically
This study illustrates why a randomized design and a reported treatment comparison are both important. Randomization is intended to support fair comparison between assigned groups, but the key result for a clinical question is usually the estimated contrast between those groups, together with its uncertainty. In this record, the primary outcome is described and arm-level means are posted, yet the two-arm comparison is not estimable. Readers therefore cannot use the primary result to quantify the comparative effect.
The difference between enrollment and the outcome-specific counts also highlights the value of transparent participant flow. The registry lists 17 enrolled, while the primary-outcome summaries include five participants in the fluoxetine arm and seven in the placebo arm. One placebo participant who withdrew after month 1 was included in the analysis. The record does not explain the remaining details of participant disposition or the analysis population. Without that information, it is harder to judge how missing outcome data and inclusion decisions may have shaped the results.
The trial also shows why confidence intervals need to be interpreted according to the quantity they describe. The posted intervals concern each arm’s mean, not the difference between assignments. Looking at separate intervals cannot provide the same information as a confidence interval for the randomized contrast. This distinction is especially important when the outcome-specific groups are small and uncertainty is substantial.
Finally, the registry lists multiple secondary outcomes but does not post their results in the summarized record. Multiple outcomes can raise interpretive issues, and the statistical plan for handling multiplicity is not reported. Together, these features make the trial statistically instructive: the record contains useful information about design, measurement, and arm summaries, but the missing comparative estimate and limited reporting constrain what can be concluded.
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 limitations specific to this trial restrict interpretation of the primary result. The most consequential is that the registry reports no estimable two-arm comparison for the continuous primary endpoint. Although arm means and confidence intervals are available, a treatment contrast and its uncertainty are not. The comparative research question is therefore not answered by the posted primary results.
The overall enrollment was 17, while the primary-outcome summaries include five participants in the fluoxetine arm and seven in the placebo arm. The registry record does not fully explain participant flow or the reasons the outcome-specific counts differ from total enrollment. It notes that one placebo participant withdrew after month 1 and was included in the analysis, but does not describe the handling of other participants or missing endpoint data. This leaves uncertainty about the analyzed population and the potential influence of missing observations.
The record identifies the trial as terminated but does not state why. It also does not report the original sample-size justification, the detailed statistical analysis plan, any interim analyses, or the methods used to construct the reported confidence intervals. The registry lists eight secondary outcomes, but their results are not posted in the summarized results. A multiplicity strategy is not reported, so the planned interpretation of multiple outcomes cannot be evaluated.
The primary measurement is a summary of visual-field sensitivity. As with any summary measure, it may not capture all aspects of visual function or the location of changes across the field. The registry describes the perimetry procedure and the measure’s possible range, but does not provide participant-level results or a fuller account of measurement variability. The results are consequently limited both by the unavailable between-arm estimate and by gaps in reporting about analysis and data completeness.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Fluoxetine for Visual Recovery After Ischemic Stroke — NCT02737930.
- Registry record last updated 2021-10-13; status last verified 2021-09.
- Results first posted 2021-10-13.
- 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 record describes a phase 2, randomized, quadruple-masked, parallel-group study of fluoxetine versus matching placebo for visual recovery after acute ischemic stroke. It lists 17 participants enrolled and records the study as terminated. Fluoxetine was described as a 20 mg capsule taken by mouth once daily for 90 days. The primary endpoint was percent change in binocularly averaged perimetric mean deviation from baseline to 6 months.
The posted primary results report a mean of 64.4 for fluoxetine, with a 95% confidence interval from 30.2 to 98.6, and a mean of 26.0 for placebo, with a 95% confidence interval from 0.2 to 51.7. The registry indicates that a two-arm comparison for this continuous endpoint was missing or not estimable. It also lists eight secondary outcomes without results in the summarized record. The reason for termination, full participant flow, and important analysis details are not reported in the registry record. Accordingly, the primary findings are descriptive arm summaries rather than a reported comparative treatment effect.