Initial Performance of a Daily Disposable Contact Lens Featuring Molded Marks: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Initial Performance of a Daily Disposable Contact Lens Featuring Molded Marks (NCT02939170), a randomized na study. The primary outcome is Incidence of Ocular Discomfort Device-related Adverse Events (AE).

2. Clinical Question

3. Trial Design

The registry describes a randomized, single-masked, parallel-group device study. Participants were assigned to wear delefilcon A multifocal contact lenses either with molded marks on the back surface or without molded marks. The registry identifies the two interventions as devices and lists refractive error as the condition. It does not identify who was masked, so the masking description should not be taken to specify whether participants, investigators, outcome assessors, or another group were unaware of assignment.

The molded-mark lens and the comparator lens were both worn bilaterally for 9 hours. The primary endpoint was assessed at Day 1, Hour 9. This is a short, defined observation window; the posted primary result does not describe longer-term wear or outcomes beyond that time point. The registry lists enrollment of 87. For the primary endpoint, the arm records list 40.0 for each lens group, and the Safety Analysis Set is named as the endpoint population. The registry record does not explain how enrollment relates to these arm counts or describe participant flow between enrollment and endpoint assessment.

The study status is completed. The listed start date is 2016-11-14 and the listed primary completion date is 2016-12-02. The registry records ocular staining and limbal hyperemia as secondary outcomes, in addition to the primary outcome. Numerical secondary-outcome results are not reported in the registry record. The record does not report a protocol-level statistical plan, a sample-size justification, or details of the randomization procedure beyond the randomized allocation description.

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: Of the 87 enrolled, 7 subjects were exited as screen failures prior to randomization. This reporting group includes all randomized subjects (80).

Overall Study

Analysis population for the primary outcome, as defined in the registry: Safety Analysis Set

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.

Population: This analysis population includes all subjects/eyes exposed to any study lenses (Safety Analysis Set).

6. Primary Endpoint

The registry lists the primary outcome as Incidence of Ocular Discomfort Device-related Adverse Events (AE), measured over Day 1 at Hour 9.

The primary endpoint is titled Incidence of Ocular Discomfort Device-related Adverse Events and is recorded as a number of events. The registry defines an adverse event as an untoward medical occurrence, unintended disease or injury, or untoward clinical signs in subjects, users, or other persons, whether or not related to the investigational device. For this endpoint, an event had to be an ocular adverse event classified as related to the study device and deemed related to ocular discomfort.

The endpoint therefore concerns a selected category of reported adverse events, not all adverse events and not all ocular symptoms. Its specified assessment time is Day 1, Hour 9, after the described 9 hours of bilateral lens wear. The posted values are 0.0 events for the molded-mark lens and 1.0 event for the lens without molded marks. These are event counts, not percentages or rates; the registry does not report a rate calculation or an uncertainty interval.

As a general statistical point, an event count can describe how many qualifying occurrences were recorded, while a comparison of groups also needs careful attention to the number of people assessed and to the observation period. This endpoint is useful for describing the device-related ocular discomfort events observed during the stated assessment window. It does not, by itself, characterize discomfort outside that definition or establish how frequently such events might occur during longer use.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the design as randomized, single-masked, and parallel-group. Random allocation is intended, as a general design principle, to reduce systematic differences between assigned groups. A parallel-group design means the groups receive their assigned lens design rather than being described as a sequence of both designs. The registry does not report the randomization method, allocation concealment, masking procedures, or who was masked. Those details cannot be inferred from the design labels alone.

What does the event count represent?

The primary measure is a number of events, with the unit recorded as events. The result is not a mean or a continuous measurement. It counts occurrences meeting the registry’s definition: an ocular adverse event classified as related to the device and deemed related to ocular discomfort. The broad adverse-event definition includes untoward medical occurrences, unintended disease or injury, and untoward clinical signs in subjects, users, or other persons, regardless of whether they were related to the device. The primary endpoint applies the additional ocular, device-related, and discomfort-related criteria.

For a count endpoint, interpretation depends on the event definition, assessment period, and population at risk. General count-data methods can account for the possibility that variability is not well described by a simple Poisson model; over-dispersion is one such concern when counts vary more than that model expects. The registry does not report a model, dispersion estimate, or inferential analysis for this endpoint. No particular count model should therefore be attributed to the study.

How should the group comparison be read?

The posted count is 0.0 events for the molded-mark design and 1.0 event for the design without molded marks. These are observed values, not a model-based effect estimate. The registry does not report a risk ratio, rate ratio, risk difference, confidence interval, or test statistic. Calculating a new contrast from the counts would not supply the missing information about participant-level outcomes, analysis choices, or uncertainty, so the interpretation should remain descriptive.

As a general statistical explanation, a confidence interval expresses the uncertainty associated with an estimate under a specified method and assumptions. It helps readers judge which effect sizes remain compatible with the data and method. No confidence interval is reported for this endpoint, so the precision of a comparative effect cannot be assessed from the registry result. A p-value is also not reported; the event counts alone do not establish statistical significance or its absence.

What do the planning assumptions mean?

The registry includes assumptions for sample-size planning illustrations: a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the effect to detect defined as a stated fraction of the observed effect. These are assumptions for planning illustrations, not evidence of the trial’s actual design rationale or statistical plan. The registry record does not report the trial’s sample-size justification or show that these assumptions were used to plan this study.

Any sample-size values associated with those illustrations are planning quantities, not observed power. They describe hypothetical future planning under the stated assumptions, rather than the probability that the completed study detected an effect. The registry record does not report an observed-power analysis. It also does not report a protocol-defined target effect for this trial or a rationale for the endpoint group sizes.

What analyses are reported?

No analysis entries are reported for the posted outcomes. That absence means the registry record does not give a test, model, adjustment strategy, or analysis population details beyond naming the Safety Analysis Set for the primary endpoint. It does not establish which procedures may have been used outside the registry. Without a reported inferential analysis, the result should be described as the posted event counts rather than as an estimated treatment effect.

In general, statistical interpretation also considers whether the analysis matches the outcome scale and study design, how missing observations are handled, and whether prespecified comparisons were selected. Those choices can affect estimates and uncertainty. The registry record does not report enough detail to assess them for this trial. The arm values and endpoint definition remain directly interpretable as the posted descriptive result, but they do not substitute for a documented comparative analysis.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists ocular staining and limbal hyperemia as secondary outcomes alongside the primary ocular discomfort device-related adverse-event endpoint. It does not report numerical results for those secondary outcomes or describe the statistical analyses performed for them. The record identifies three outcome measures, but does not give a multiplicity strategy, such as a prespecified hierarchy or adjustment across outcomes. Without that information, the secondary outcomes cannot be used to support a statistical claim about the primary endpoint.

Missing-data handling is not reported in the registry record. The primary endpoint names the Safety Analysis Set, but the record does not define that set in detail, state how participants with unavailable assessments were treated, or provide a participant flow accounting. Enrollment is listed as 87 and the primary endpoint arm records list 40.0 in each group; the reason these figures differ is not reported in the registry record. The posted figures alone do not identify whether any difference reflects eligibility, assignment, analysis-set rules, missing observations, or another cause.

The registry does not report a statistical analysis plan, prespecified covariates, imputation methods, or sensitivity analyses. It also does not report whether any analyses were planned at interim stages. As a general matter, these details help readers understand which outcomes and comparisons were intended, and how incomplete data might affect interpretation. Their absence from the registry record limits evaluation of the analysis process; it does not establish that any particular procedure was or was not used elsewhere.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

The registry separately reports serious and other adverse-event summaries. In the pre-treatment group, 0 of 87 at-risk participants were recorded as affected for serious adverse events, and 0 were recorded as affected for other adverse events. For each lens arm, 0 of 40 at-risk participants were recorded as affected in each category. The deaths field is 0 for the pre-treatment group and both lens groups. No serious adverse-event terms are listed.

These safety summaries are distinct from the primary endpoint count. The primary endpoint includes ocular events classified as device-related and related to ocular discomfort; the serious and other adverse-event categories are reported separately. A zero affected count in these summaries means that the registry reports no affected participants in those categories for the stated groups. It does not mean that every possible adverse event was excluded, nor does it establish the absence of risk beyond the registry’s observation and reporting.

As a general statistical point, rare or unobserved events are difficult to characterize precisely from a limited observation period. The safety entries should therefore be read as reported counts, not as proof that serious or other events cannot occur. The record does not provide additional detail on follow-up beyond the stated primary assessment time or on the methods used to collect safety information.

12. What the Result Does, and Does Not, Mean

The posted primary result documents 0.0 qualifying ocular discomfort device-related adverse events for the molded-mark contact lens and 1.0 event for the lens without molded marks at Day 1, Hour 9. This is a description of the events recorded under the study’s definition in the stated endpoint population. It is not a reported estimate of the relative or absolute effect of the lens designs.

The result does not establish that the designs are equivalent. Equivalence requires a defined margin and an analysis showing adequate precision relative to that margin; neither is reported in the registry record. Nor does the result establish that molded marks reduce events or that the comparator increases them. The registry gives no inferential test or interval, and the small number of recorded events does not by itself determine the direction or certainty of an underlying effect.

The endpoint is specific to ocular adverse events classified as related to the device and deemed related to ocular discomfort. It should not be read as a count of all adverse events, all discomfort, or the secondary outcomes of ocular staining and limbal hyperemia. Those secondary outcomes are named in the registry, but numerical results are not reported in the registry record.

The timing also constrains what the result can address. The assessment occurred at Day 1, Hour 9, after bilateral wear for 9 hours. It does not describe longer-term wear, outcomes at other times, or results in populations not represented by the study. The record does not provide enough detail to assess how enrollment of 87 relates to the arm records of 40.0 each.

In practical statistical terms, the result is a sparse descriptive observation with no reported measure of uncertainty. It can inform a discussion of what was recorded during this assessment, but not a firm comparative conclusion about the designs or a prediction of future event frequency.

13. Why This Trial Matters Statistically

This trial illustrates why an observed count and a comparative statistical conclusion are not the same thing. The primary endpoint records 0.0 events in one lens arm and 1.0 event in the other, but the registry does not report an uncertainty interval or an inferential test. A numerical contrast can be easy to notice while remaining difficult to interpret precisely when the outcome is rare and the endpoint population and missing-data handling are not fully described.

It also highlights the importance of matching an endpoint to its definition and observation window. The primary outcome is not all ocular discomfort or all adverse events; it is an ocular adverse event judged related to both the device and ocular discomfort. Assessment at Day 1, Hour 9 characterizes a specific short-term window. Keeping those boundaries clear prevents a narrow event count from being generalized to broader safety or longer-term experience.

The registry identifies randomized allocation and a single-masked parallel-group design, which gives readers useful design context. At the same time, masking procedures, randomization details, and a statistical analysis plan are not reported in the registry record. These details matter because they help readers assess how outcomes were collected, how comparisons were selected, and how uncertainty was handled.

Finally, the record demonstrates the distinction between planning illustrations and a trial’s actual rationale. The stated illustration assumptions do not establish the study’s sample-size justification or observed power. Careful reading keeps the posted descriptive findings, the design information, and the unreported analytical details separate.

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 primary result is based on a single assessment at Day 1, Hour 9, following 9 hours of bilateral wear. It therefore gives no information about results at other assessment times or during longer-term use. The number of qualifying events was sparse: the posted counts were 0.0 and 1.0. No confidence interval or inferential comparison is reported, so the precision of any difference between lens designs is not available.

The registry lists enrollment of 87 but reports 40.0 in each primary-outcome arm. It does not explain how the enrollment figure relates to the Safety Analysis Set or arm-level endpoint records. Participant flow, reasons for exclusion, endpoint availability, and missing-data handling are not reported. The population represented by the posted result therefore cannot be fully evaluated from the registry record.

The record names a single-masked design but does not specify who was masked or how masking was maintained. It also does not report randomization procedures, a protocol-level statistical plan, a sample-size justification, a prespecified approach to multiple outcomes, or an inferential analysis. These gaps prevent assessment of the planned comparison and its analytical assumptions.

The endpoint is narrowly defined and should not be generalized to all ocular symptoms or all adverse events. Although ocular staining and limbal hyperemia are listed as secondary outcomes, their numerical results are not reported in the registry record. These limitations constrain interpretation of the posted primary count; they do not establish that unreported procedures or results were absent outside the registry.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Initial Performance of a Daily Disposable Contact Lens Featuring Molded Marks — NCT02939170.
• Registry record last updated 2018-07-02; status last verified 2017-12.
• Results first posted 2018-01-23.
• 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.

18. Record Summary

The completed study is a randomized, single-masked, parallel-group comparison of delefilcon A multifocal contact lenses with and without back-surface molded marks. Both lenses were worn bilaterally for 9 hours. The primary endpoint was the number of ocular discomfort device-related adverse events in the Safety Analysis Set at Day 1, Hour 9.

The posted primary values are 0.0 events for the molded-mark lens and 1.0 event for the lens without molded marks. The registry lists enrollment of 87 and arm records of 40.0 for each group. It does not report an inferential comparison, confidence interval, or numerical results for the secondary outcomes of ocular staining and limbal hyperemia. The relationship between enrollment and endpoint arm counts, as well as missing-data handling and the statistical analysis plan, is not reported in the registry record.