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 Evaluation of Visual Performance of Two Types of Cosmetic Contact Lenses (NCT04534764), a randomized na study. The primary outcome is Distance Monocular Visual Acuity (logMAR).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04534764 |
| Phase | NA |
| Condition | Visual Acuity |
| Allocation | Randomized |
| Design model | Crossover |
| Masking | Single |
| Enrollment | 35 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Johnson & Johnson Vision Care, Inc. |
| Results posted | Yes |
2. Clinical Question
Population
The study enrolled habitual soft contact lens wearers. The primary-outcome population is described as subjects who successfully completed all visits and did not substantially deviate from the protocol. The number in that analysis population and further participant characteristics are not reported in the registry record.
Intervention
One study lens was etafilcon A with a cosmetic pattern. The study was non-dispensing: participants were fitted with the study lenses for evaluation rather than receiving them as a dispensing intervention. Each participant wore both lens types over the study periods.
Comparator
The other lens was 1-Day Acuvue DEFINE Vivid Style. The randomized sequences were Test/Control and Control/Test, so the order of lens wear varied. The record labels the study brand-masked but does not identify who was masked.
Primary question
The primary endpoint was distance monocular visual acuity measured in logMAR 5 min after lens insertion. Measurements were described under high luminance with low contrast and low luminance with high contrast. The registry record does not report the numerical means, variability, or a direct comparison for either lighting condition, so the direction and size of any difference cannot be determined.
3. Trial Design
This was a randomized, single-masked, crossover study with a planned enrollment of 35. The registry lists its status as completed, its phase as NA, and its design as a crossover model. The study is described as a single visit, brand-masked, non-dispensing, 2×2 bilateral crossover evaluation. In a crossover design, participants receive each study intervention in sequence, allowing measurements from the same participant to be compared across interventions.
Participants were bilaterally fitted with one of the two test articles in each study period. The lens order was randomized to Test/Control or Control/Test, with a 5-minute washout period between study lenses. The descriptions identify eligible participants as habitual soft contact lens wearers. The meaning of the single-masked designation is not further specified; the identity of the masked party is not reported in the registry record.
Visual acuity was assessed 5 min post lens insertion. The endpoint description specifies distance testing at 4 meters, using ETDRS charts under high luminance low contrast and low luminance high contrast conditions. Letter-by-letter results were used to calculate a visual performance score for each chart read. Although the primary-outcome population is described as participants who completed all visits without substantial protocol deviations, the number meeting that definition is not reported in the registry record.
The record lists the study start as 2020-07-31 and primary completion as 2020-08-12. It does not report the allocation-concealment procedure, the order-generation method, details of participant flow, or the statistical model used for the crossover comparison. Those omissions prevent a fuller assessment of how sequence, within-participant measurements, or protocol deviations were handled.
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.
Period 1
| Stage | Test/Control | Control/Test |
|---|---|---|
| STARTED | 18 | 17 |
| COMPLETED | 18 | 17 |
| NOT COMPLETED | 0 | 0 |
Period 2
| Stage | Test/Control | Control/Test |
|---|---|---|
| STARTED | 18 | 17 |
| COMPLETED | 18 | 17 |
| NOT COMPLETED | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: All subjects who had successfully completed all visits and did not substantially deviate from the protocol.
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 | Total |
|---|---|---|
| Participants analysed | 35 | |
| Age, Continuous | years | 30.2 (SD 5.36) |
| Sex: Female, Male: Female | Participants | 31 |
| Sex: Female, Male: Male | Participants | 4 |
| Race/Ethnicity, Customized: Asian | participants | 1 |
| Race/Ethnicity, Customized: Black or African American | participants | 1 |
| Race/Ethnicity, Customized: White | participants | 32 |
| Race/Ethnicity, Customized: Other | participants | 1 |
| Region of Enrollment: United States | participants | 35 |
6. Primary Endpoint
The registry lists the primary outcome as Distance Monocular Visual Acuity (logMAR), measured over 5 min post lens insertion.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | logMAR |
| Endpoint classification | Continuous Endpoint |
The primary endpoint was distance monocular visual acuity expressed in logMAR, assessed 5 min after lens insertion. Visual acuity measures the ability to resolve detail. The endpoint description says testing took place at 4 meters and used ETDRS charts under high luminance low contrast and low luminance high contrast lighting conditions. Letter-by-letter chart results were converted into a visual performance score for each chart read.
The registry explains that logMAR scores closer to zero, or below zero, indicate better visual acuity. It also states that a logMAR score of 0.0 is equivalent to Snellen visual acuity of 20/20. These definitions help interpret the scale, but they do not establish the observed performance of either lens: the numerical endpoint values are not reported in the registry record.
Visual acuity is relevant to this comparison because it quantifies chart-reading performance under the specified testing conditions. The two lighting and contrast combinations represent distinct conditions, so results for one condition would not automatically describe the other. The registry record does not report the means or standard deviations by lens and condition, nor does it give a numerical contrast between lenses. As a result, neither the observed level of acuity nor the precision of any lens-to-lens difference can be assessed from the posted results.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies a continuous primary endpoint, reports that the analysis used a mean and standard deviation, and lists two analyses. It does not include the numerical visual-acuity results. In particular, group means, standard deviations, a lens-to-lens estimate, confidence intervals, and p-values are not reported in the registry record. The statistical evidence about the primary question therefore cannot be characterized as favoring either lens, showing similar results, or leaving a particular difference plausible.
The endpoint scale has a stated direction: logMAR values closer to zero or below zero indicate better visual acuity. That definition would help interpret reported values, but no lens-specific values are available. A difference between means would also need to be interpreted in its direction and magnitude on the logMAR scale. Without those numbers, the size of any observed difference and its practical meaning cannot be assessed.
Precision is also unknown. A confidence interval, if reported, would describe the range of values reasonably compatible with the data under the analysis assumptions. Its width would help distinguish a precise estimate from one that remains uncertain. No interval is reported, and the registry record does not give enough numerical detail to reconstruct one. The absence of reported p-values likewise means that statistical significance cannot be assessed. Even a p-value alone would not describe the size or precision of an effect.
The crossover structure is important to interpretation because each participant was assigned to wear both lens types in randomized order. A comparison that uses the paired observations can account for within-participant variation. The registry record does not describe the model or calculation used, so it is not possible to determine how the sequence, pairing, or any period effects were handled. This is an uncertainty about the reported analysis, not evidence that the analysis was necessarily inappropriate.
The enrollment was 35, but the primary-outcome population is defined by completion and protocol adherence. The number included in the endpoint analyses is not reported in the registry record. Consequently, the relationship between enrollment and the analyzed sample cannot be evaluated. The record does state that each adverse-event group had 35 participants at risk, but those safety figures do not establish the sample size used for the visual-acuity analyses.
Overall, the posted record supplies the endpoint definition and study structure, but not the primary outcome estimates. Statistical conclusions about the comparative visual performance of the two lenses should therefore not be inferred from the design description or from the absence of numerical results.
9. Statistical Methods Explained
The registry describes a continuous endpoint summarized by a mean and standard deviation. It does not report the statistical method used to compare the lenses. The explanations below are general statistical context, not a description of an analysis confirmed by the registry record.
What does a mean describe?
For a continuous measurement, a mean represents the central level of the observed values. Here, that value would summarize visual acuity scores for a lens under a specified lighting and contrast condition. A mean by itself does not show how varied individual scores were or how precisely the mean estimates performance in the study population. The registry record does not include the endpoint means for either lens.
Why report a standard deviation?
In general, a standard deviation describes the spread of participant measurements around the mean. It conveys variation among observed scores, rather than the precision of a comparison estimate. A standard deviation is not a confidence interval and should not be interpreted as a measure of uncertainty in the mean difference. The registry record identifies standard deviation as the dispersion measure but does not report its values.
Why does the crossover design matter?
In a crossover study, the same participant receives each intervention, so measurements can be paired. A paired comparison focuses on within-participant changes and can account for stable differences between participants. A method that treats all observations as independent may not represent that structure appropriately. The appropriate analysis also depends on design details, assumptions, and the available observations. The record does not state whether the reported comparison used a paired method, a repeated-measures model, or another approach, so no specific procedure should be attributed to the investigators.
Randomizing the order helps distribute possible sequence-related influences across the two sequences. In a crossover study, period and sequence can matter: measurements may vary according to when an intervention is received or the order of exposure. A washout period is intended to separate periods, but the registry record does not report an analysis of carryover or period effects. The stated 5-minute washout is a design feature; it does not, by itself, establish whether carryover was absent.
What would a confidence interval add?
In general, a confidence interval expresses the uncertainty around an estimated effect under a specified statistical model. It gives a range of values compatible with the data and assumptions, rather than a guarantee about the true value. An interval around a difference in visual-acuity means would help readers judge both precision and which effect sizes remain compatible with the study. No such interval is reported in the registry record. Without the contrast and its uncertainty, the comparative result cannot be evaluated.
What is the role of a p-value?
In general, a p-value assesses how unusual data at least as incompatible with a stated null hypothesis would be if that hypothesis and the analysis assumptions were correct. It is not the probability that the null hypothesis is true, and it does not measure the size or clinical importance of a difference. A p-value is most informative when considered alongside the estimated effect and its confidence interval. Neither a p-value nor an effect estimate for the primary endpoint is reported in the registry record.
What do the planning assumptions mean?
The registry describes planning illustrations based on an observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. Such illustrations are planning calculations, not observed power and not evidence that the study had a particular probability of detecting a true effect. They depend on the effect size and assumptions used. The registry record does not report a sample-size justification from the investigators, and no numerical illustration can be assessed from the information recorded.
General concerns about over-dispersion apply when observed variability is greater than a model assumes. In that situation, standard errors may be understated and intervals too narrow if the model does not account for the extra variability. Whether over-dispersion is relevant depends on the outcome and model; the continuous endpoint description alone does not establish that it occurred. The record does not report a diagnostic assessment or model details.
Finally, statistical interpretation depends on the population and handling of incomplete observations. The endpoint population is defined by completion and lack of substantial protocol deviation, but the analysis sample size and missing-data procedure are not reported in the registry record. Without those details, readers cannot assess whether exclusions or missing measurements influenced the estimates. These general considerations explain why study design, outcome summaries, and analysis details are all needed to interpret a comparative result.
10. Multiplicity, Missing Data and Analysis Populations
The primary endpoint description includes measurements under high luminance low contrast and low luminance high contrast conditions. The registry lists two analyses, but does not state which condition or comparison each analysis represents, whether the analyses were prespecified in detail, or whether any adjustment for multiple comparisons was used. The record says the primary outcome has several categories or time points and was not reduced to one comparison. The exact outcome results by category are not reported in the registry record.
Multiplicity arises when several conditions, outcomes, or comparisons are tested. In general, considering many tests can increase the chance of at least one apparently notable result if all tests are interpreted without accounting for their number. Whether an adjustment is appropriate depends on the inferential aims and analysis plan. Because the registry record does not give the analysis plan or the individual results, the consequences of multiplicity cannot be evaluated.
The primary-outcome population is described as all subjects who successfully completed all visits and did not substantially deviate from the protocol. The number who met that definition, the number with usable measurements in each condition, and any reasons for missing observations are not reported in the registry record. A missing-data method or sensitivity analysis is also not reported. Therefore, it is not possible to assess the extent of missingness or how it may have affected the endpoint analysis.
The record does not report whether all randomized participants were analyzed according to their assigned sequence or whether any participants were excluded from the primary analysis. Enrollment of 35 should not be assumed to equal the endpoint analysis population. These omissions limit assessment of analysis-population choices and the robustness of conclusions to missing data or exclusions.
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 |
|---|---|---|---|
| Test | 0 | 35 | 0.0% |
| Control | 0 | 35 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Test | 0 of 35 |
| Control | 0 of 35 |
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 |
|---|---|
| Test | 0 of 35 |
| Control | 0 of 35 |
The registry lists separate Test and Control safety groups. For each group, 35 participants were at risk for serious adverse events and 35 were at risk for other adverse events. The reported number affected was 0 for serious adverse events and 0 for other adverse events in each group. Deaths were 0 in both groups, and no top serious-event terms are listed.
These figures describe what was recorded for the stated groups; they should not be read as proof that adverse events are impossible or that the lenses are safe in every setting. The registry record does not provide event definitions, detailed monitoring methods, or a narrative describing how events were collected. It also does not report additional context about event timing or participant-level exposure beyond the at-risk counts.
The crossover design means participants wore both lenses in sequence, while the safety summary presents Test and Control groups separately. The registry record does not explain how those safety groups map to exposure periods or how events, if any, were assigned to a lens. No events are listed in either group, but the zero counts do not supply information about unrecorded events or risk beyond this study. The study enrolled 35 participants and is described as a single-visit evaluation; the safety figures should be interpreted within that limited context.
12. What the Result Does, and Does Not, Mean
This record establishes that a randomized crossover evaluation compared etafilcon A with a cosmetic pattern and 1-Day Acuvue DEFINE Vivid Style. It defines distance monocular visual acuity on the logMAR scale as the primary endpoint and specifies testing conditions. It also describes randomized lens order, bilateral fitting, and a 5-minute washout period. These details clarify what the study set out to measure and how participants experienced the two lens types.
The record does not report numerical visual-acuity outcomes. There are no reported means, standard deviations, between-lens estimates, confidence intervals, or p-values. As a result, it does not show the direction or size of a difference, the precision of an estimate, or whether the results were statistically distinguishable under a stated analysis. The absence of these results is not evidence that the lenses had equal performance, nor is it evidence that one performed better.
The outcome definition also does not support conclusions beyond the conditions described. The measurements concern distance monocular acuity at 5 min post lens insertion, tested at 4 meters under the specified lighting and contrast conditions. The record does not establish performance in other settings, at other times, or for outcomes that were not reported. The participant description is limited to habitual soft contact lens wearers, and additional population characteristics are not reported in the registry record.
The safety summary records 0 serious adverse events, 0 other adverse events, and 0 deaths in each listed group. Those observations describe the posted safety counts for this study, not a guarantee about other participants or circumstances. Taken together, the record supports a description of the design, endpoint, and posted safety counts, but it does not support a numerical conclusion about comparative visual acuity.
13. Why This Trial Matters Statistically
This study is statistically interesting because a randomized crossover design can compare two interventions within the same participants. Pairing can reduce the influence of stable differences between people, provided the analysis reflects the repeated measurements and the design assumptions are appropriate. The lens order was randomized, and the record describes a washout period between study lenses. These are central features when considering how the comparison was organized.
The endpoint also illustrates why measurement definition matters. The registry specifies logMAR, distance monocular acuity, the timing after insertion, the chart method, and two lighting and contrast conditions. A clear endpoint definition helps readers understand what the numerical result would represent. It does not replace the result itself: without means, variability, or a comparative estimate, the scientific question remains unanswered in the posted record.
Multiple conditions make transparent reporting especially important. If results are reported separately by condition, readers need to know which analyses were planned and how multiple comparisons were treated. The registry lists two analyses but does not explain their exact relationship to the conditions or describe multiplicity handling. Similarly, defining the analysis population is not enough to assess selection or missing-data effects unless the number analyzed and participant flow are stated.
The record therefore highlights the distinction between a design that can support a useful comparison and evidence that permits the comparison to be evaluated. Randomization, crossover allocation, and a defined endpoint describe the framework. Numerical estimates, uncertainty, analysis details, and clear reporting of the analyzed population are necessary to assess the result. In their absence, statistical interpretation should remain limited to the design and outcome definitions actually recorded.
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 principal limitation for interpreting this trial is that the numerical primary-outcome findings are not reported in the registry record. Without lens-specific means and standard deviations, or a direct estimate of the difference and its uncertainty, readers cannot assess the observed visual-acuity levels, comparative direction, magnitude, or precision.
The record identifies two analyses and describes two lighting and contrast conditions, but does not map the analyses to specific conditions or explain whether other comparisons were made. An analysis plan, multiplicity approach, and statistical model are not reported. Because the design is a crossover, missing information about pairing, period effects, sequence effects, and carryover limits assessment of whether the analysis reflected the design.
Enrollment was 35, while the primary-outcome population is defined by completion and no substantial protocol deviation. The number analyzed, participant flow, exclusions, and missing-data handling are not reported in the registry record. Consequently, it is not possible to determine whether the endpoint analysis included all enrolled participants or how incomplete data affected the comparison.
The record describes habitual soft contact lens wearers but does not report further participant characteristics. It also does not specify who was masked, provide details of allocation concealment, or describe procedures for assessing protocol deviations. The study is described as a single-visit evaluation, with acuity assessed 5 min after insertion; results for other durations or settings are not reported. These limitations restrict interpretation to the study framework described and prevent conclusions about unreported populations, conditions, or outcomes.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Evaluation of Visual Performance of Two Types of Cosmetic Contact Lenses — NCT04534764.
- Registry record last updated 2021-09-01; status last verified 2021-08.
- Results first posted 2021-09-01.
- 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
NCT04534764 is a completed randomized, single-masked, crossover study titled Evaluation of Visual Performance of Two Types of Cosmetic Contact Lenses. The record lists an enrollment of 35 and describes a single-visit, brand-masked, non-dispensing, 2×2 bilateral crossover. Participants were randomized to Test/Control or Control/Test sequences and wore both lens types with a 5-minute washout period.
The primary endpoint was distance monocular visual acuity in logMAR, assessed 5 min after lens insertion under two lighting and contrast conditions. The record defines the endpoint and its scale but does not report numerical visual-acuity results or the statistical comparison. It reports 0 serious adverse events, 0 other adverse events, and 0 deaths for both listed groups. The study start is recorded as 2020-07-31, with primary completion on 2020-08-12.