Clinical Evaluation of a Daily Wear Frequent Replacement Silicone Hydrogel Lens: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Clinical Evaluation of a Daily Wear Frequent Replacement Silicone Hydrogel Lens (NCT03920280), a randomized na study. The primary outcome is Distance Visual Acuity (VA) With Study Lenses - Completed Eyes.

2. Clinical Question

3. Trial Design

The registry record describes a randomized, double-masked, parallel-group clinical study. It lists the study as completed, with enrollment of 120 and phase recorded as not applicable. The sponsor is Alcon Research. The record lists refractive errors as the condition under study. It does not report details of the randomization sequence, allocation concealment, masking procedures, or the allocation ratio, so those design features cannot be described more specifically.

The two arm descriptions specify daily wear of the assigned lens in both eyes, with lenses removed nightly and cleaned using CLEAR CARE. Each arm description gives a schedule of at least 8 hours per day and 5 days per week over a 3-month exposure period. The comparator lens is Comfilcon A, referred to as Biofinity in the arm description. The record lists LID015385 contact lenses, Comfilcon A contact lenses, and CLEAR CARE among the interventions.

The primary outcome is distance visual acuity with study lenses. Assessments were scheduled at Day 1 dispense, Week 1 follow-up, Week 2 follow-up, Month 1 follow-up, Month 2 follow-up, and Month 3 follow-up or exit. The description specifies that each follow-up assessment was performed at least 4 hours after lens insertion. Visual acuity was assessed for each eye individually with a letter chart at a distance of 6 meters. The outcome population is described as enrolled and dispensed subjects and eyes that completed the study.

The record does not report a planned statistical comparison, a sample-size justification, an interim analysis plan, or details about handling correlation between eyes or repeated visits. It explicitly states that no formal hypothesis testing was planned for the visual-acuity outcome. These omissions limit how fully the design and analysis can be reconstructed from 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: Of the 120 subjects enrolled, 1 was exited from the study prior to randomization as a screen failure. This reporting group includes all enrolled and dispensed subjects (119).

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: This analysis population includes all enrolled and dispensed subjects/eyes that completed the study.

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 enrolled and dispensed subjects.

6. Primary Endpoint

The registry lists the primary outcome as Distance Visual Acuity (VA) With Study Lenses - Completed Eyes, measured over Day 1 Dispense; Week 1 Follow-up; Week 2 Follow-up; Month 1 Follow-up; Month 2 Follow-up; Month 3 Follow-up/Exit (at least 4 hours after lens insertion at each follow-up assessment visit).

The primary endpoint is distance visual acuity measured with study lenses in place, for completed eyes. The record describes testing each eye individually using a letter chart at a distance of 6 meters. Visual acuity was initially collected in Snellen notation and converted to logarithm minimum angle of resolution, or logMAR. The endpoint is reported as a mean with standard deviation, and the stated unit is logMAR.

The record explains the scale’s interpretation: a logMAR value of 0 equates to 20/20 Snellen visual acuity, and lower logMAR values indicate better visual acuity. Thus, the direction of the scale matters when reading any reported means. A mean describes the group’s average measured acuity; the standard deviation describes variability among measured values. Neither statistic alone shows how uncertain a comparison between the lenses may be.

Distance visual acuity is used in this study as a measure of visual performance while wearing the study lenses. Assessments were scheduled from dispensing through follow-up and exit, with the record specifying at least 4 hours after lens insertion at each follow-up assessment visit. The listed endpoint does not itself summarize other aspects of safety or lens performance. Numerical results for the endpoint, including means and standard deviations by lens and assessment time, are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the outcome scale represent?

The primary outcome is a continuous measure summarized as a mean and standard deviation. It is expressed in logMAR, a transformed scale for visual acuity. The registry record states that 0 logMAR corresponds to 20/20 Snellen visual acuity and that lower logMAR values indicate better acuity. When interpreting a reported mean, the scale direction should be kept in mind: a lower value represents better acuity according to the registry’s description. The standard deviation conveys how spread out individual eye measurements are around the group mean; it is not the uncertainty in the estimated group mean or in a comparison between groups.

The record says that acuity was assessed for each eye individually. Measurements from two eyes belonging to the same person may be related rather than statistically independent. Repeated assessments of an eye may also be related over time. General statistical context: when data have such dependencies, an analysis may need to account for them to avoid treating correlated observations as if they were independent. The registry record does not report whether or how any analysis accounted for correlation between eyes or visits. No numerical outcome results are reported, so no such modeling approach can be inferred from the endpoint description.

What does randomization contribute?

General statistical context: random assignment is intended to create groups that are comparable, on average, with respect to measured and unmeasured characteristics at the start of a study. Double masking can reduce the influence of expectations on care, assessment, or reporting when the masking is effective. These are general reasons randomization and masking are used; they do not guarantee that groups are identical or that bias is absent. The record identifies the study as randomized and double-masked, but does not describe the allocation procedure, how masking was maintained, or whether masking was assessed.

The parallel design indicates that participants were assigned to study groups rather than the record describing a crossover sequence. The arm descriptions specify the assigned lens and its wearing schedule. The record does not report the randomization ratio or provide details that would establish whether participants, investigators, outcome assessors, or other personnel were masked. Those particulars are not reported in the registry record.

How should multiple assessment times be understood?

Visual acuity was scheduled for Day 1 dispense, Week 1, Week 2, Month 1, Month 2, and Month 3 follow-up or exit. These are repeated assessments, not independent replications of a trial. General statistical context: a single time-point contrast asks how the groups compare at that particular visit; a repeated-measures analysis may instead estimate an average pattern or change over time, depending on its specification. Such an analysis must address correlations among observations from the same eye or participant and make clear which time points contribute to the estimate.

The registry record supplies the schedule but does not report a statistical model for combining visits, a designated summary time point for comparison, or a method for handling visits that were not completed. It also states that no formal hypothesis testing was planned for this outcome. Therefore, the schedule alone should not be interpreted as evidence that a longitudinal treatment comparison was prespecified or carried out.

What would a confidence interval add?

General statistical context: a confidence interval expresses uncertainty around an estimate under the assumptions of the method used. A narrow interval indicates greater precision than a wide interval, but the interval still depends on the analysis model and the quality and completeness of the data. A confidence interval for a difference would help distinguish the estimated magnitude from its uncertainty. The registry record does not report an interval or a difference estimate for visual acuity. It is therefore not possible to assess the precision of a lens comparison from the listed endpoint description.

A p-value, when used, addresses compatibility between data and a specified null hypothesis under a statistical model; it does not directly measure clinical importance or the probability that a hypothesis is true. Here, the registry explicitly says no formal hypothesis testing was planned. No p-value for the primary visual-acuity outcome is reported in the registry record. The absence of a planned formal test should not be converted into a claim that the lenses were equivalent, or that any difference was absent.

How should the planning assumptions be read?

The record describes a planning illustration based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. For non-time-to-event settings, the described planning quantities are participants per arm for 80% power or for 90% power; time-to-event settings are described in terms of total events. This study’s listed primary endpoint is continuous, not time-to-event.

General statistical context: sample-size calculations estimate the amount of information a hypothetical study would need under stated assumptions. They are planning illustrations, not observed power and not evidence about the results of the completed trial. Their interpretation depends on the assumed effect, variability, allocation, significance level, and analysis method. The registry record does not report a formal sample-size justification for this trial. The numerical planning outputs and the observed effect needed to evaluate the illustration are not reported in the registry record.

The statistical analysis plan, including any planned adjustment, handling of outliers, missing-data approach, or treatment of multiple outcome assessments, is not reported in the registry record. Because no formal hypothesis test was planned for the primary endpoint, a formal inferential conclusion should not be attributed to the study on the basis of the registry description alone.

10. Multiplicity, Missing Data and Analysis Populations

The primary outcome has several scheduled assessment times: Day 1 dispense, Week 1 follow-up, Week 2 follow-up, Month 1 follow-up, Month 2 follow-up, and Month 3 follow-up or exit. Each assessment provides an opportunity to describe acuity at that visit. If multiple time points or other outcomes are tested, the chance of a false-positive finding can increase unless the analysis plan addresses multiplicity. General statistical context: methods for controlling multiplicity may include selecting a primary time point in advance, adjusting significance thresholds, or using a prespecified hierarchical testing procedure. The registry record does not report a multiplicity strategy, and it states that no formal hypothesis testing was planned for visual acuity.

The record lists two outcome measures and zero analyses. Those entries do not supply numerical visual-acuity findings or explain how outcome measures were related in an analysis. The registry record does not report a statistical analysis plan specifying which outcomes or visits would support formal comparisons.

The stated outcome population consists of enrolled and dispensed subjects and eyes that completed the study. The record does not provide counts of missing visual-acuity observations, visit-specific denominators, reasons for missingness, or a method for addressing missing data. It therefore does not establish whether missingness was limited or whether missing observations could have influenced the descriptive results.

The described completed-eye population should not be assumed to be identical to an all-randomized analysis population. The registry record does not report whether participants were analyzed according to their randomized assignment, whether eyes were excluded, or how discontinuations were handled. It also does not report how the statistical dependence between two eyes from one participant was addressed. These missing details restrict assessment of the analysis population and the robustness of any comparison.

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.

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: ulcerative keratitis (1.2%).

The registry record reports serious and other affected counts in separate pretreatment and treatment-category groups. In the Biofinity ocular group, 1 serious affected case is reported among 82 at risk, while the listed count for other affected cases is 0. The serious-event term listed is ulcerative keratitis, at 1.2%. In the Biofinity nonocular/systemic group, the LID015385 ocular group, and the LID015385 nonocular/systemic group, serious and other affected counts are reported as 0. The pretreatment group also has zero serious and other affected counts. No deaths are reported.

These are registry counts, not comparative effect estimates. The groups have different numbers at risk, and the record does not provide a formal statistical comparison or uncertainty interval for these event counts. The percentage attached to ulcerative keratitis is reported as 1.2%; it should not be treated as a measure of comparative risk without a defined comparison and analysis. The registry record does not provide further details about event timing, severity beyond the serious classification, or causal attribution in the registry record.

General statistical context: rare events are difficult to compare precisely because a small number of observations can yield substantial uncertainty. A zero count in a listed group means no affected cases were reported there; it does not establish that the underlying event risk is zero. Safety counts should therefore be read alongside the study population, follow-up, event definitions, and reporting completeness, details that are not fully reported in the registry record.

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

The registry record documents a randomized, double-masked, parallel study of an investigational contact lens and a commercially available Comfilcon A lens. It identifies distance visual acuity with study lenses as the primary outcome and describes how it was measured, its scale, its scheduled assessment times, and the completed-eye population. It also reports adverse-event counts by treatment category. These details clarify the study question and the structure of the recorded outcomes.

The record does not report numerical primary visual-acuity results, such as group means, standard deviations, or a between-lens estimate. It does not provide a confidence interval or formal test result, and it states that no formal hypothesis testing was planned. As a result, the registry record does not establish the direction, magnitude, or precision of any visual-acuity difference. It also cannot support a conclusion that the lenses were equivalent or that there was no difference.

The safety entries report one serious affected case in the Biofinity ocular group, with ulcerative keratitis listed at 1.2%, and zero serious affected cases in the other listed groups. These counts describe what the registry record reports; they do not demonstrate causation or provide a precise comparative safety estimate. The absence of reported serious cases in a group is not proof that no risk exists.

General statistical context: evidence from a trial is interpreted in light of its design, outcome definitions, analysis population, completeness of follow-up, and uncertainty in estimates. Several of those details are not reported in the registry record. The reported enrollment of 120 is not a substitute for the number of completed observations contributing to each outcome and visit. The primary outcome population is described in terms of completed subjects and eyes, but visit-specific observation counts are not reported.

The registry information therefore supports a description of the study’s design and planned measurement approach, alongside the reported safety counts. It does not, by itself, provide enough outcome data to quantify visual-acuity performance or make a statistically supported comparison between the lenses.

13. Why This Trial Matters Statistically

This trial raises a useful statistical issue: the primary outcome was measured for each eye individually, at multiple scheduled visits, in a parallel-group study. Such data can have more than one source of dependence. Two eyes from the same person may be related, and measurements from the same eye over time may also be related. General statistical context: analyses that ignore relevant dependence can misstate uncertainty, so the unit of analysis and handling of correlated measurements are important parts of interpretation. The registry record does not report how those features were handled.

The scale itself also matters. The registry record defines logMAR as a continuous measure, states that 0 corresponds to 20/20 Snellen acuity, and explains that lower values indicate better acuity. This allows the direction of any reported mean to be interpreted, but means and standard deviations are not reported in the registry record. Without an estimate and its uncertainty, readers cannot judge the magnitude or precision of a comparison.

The assessment schedule creates another statistical consideration: a result at a particular visit is not necessarily the same question as a result averaged across visits or modeled over time. The record lists multiple assessment times but does not report a summary approach or multiplicity plan. It also states that no formal hypothesis testing was planned for the primary outcome. These details matter because they limit claims that can be made about differences across groups or time.

The safety record illustrates the difference between counts and comparative inference. It reports one serious affected case in the Biofinity ocular category and none in the other listed groups, but gives no comparative uncertainty estimate. Sparse event counts can be informative descriptively while remaining imprecise for assessing differences. The registry record does not provide the event-level detail or formal analysis needed to interpret the counts as a comparative effect.

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 most direct limitation for interpretation is that the registry record does not report numerical results for the primary visual-acuity outcome. Group means, standard deviations, time-specific values, and a between-lens estimate are not reported. The record also states that no formal hypothesis testing was planned, so it does not provide a formal inferential comparison for this endpoint.

The record describes a completed-eye analysis population but does not report the number of subjects or eyes contributing data at each visit, the amount or pattern of missing data, reasons for missingness, or the method used to handle incomplete observations. Enrollment of 120 does not establish how many observations were available for each endpoint assessment. The record also does not report whether the analysis followed randomized assignment or how exclusions and discontinuations were treated.

Although visual acuity was collected for each eye individually and at several scheduled visits, the registry record does not describe whether analyses accounted for correlation between eyes or repeated measures. It does not report a primary visit for inference, a method for combining visits, or a strategy for multiplicity. These omissions prevent a detailed appraisal of the statistical handling of the outcome schedule.

The record identifies the study as randomized and double-masked, but does not describe the sequence generation, allocation concealment, masking procedures, or success of masking. It does not report a statistical analysis plan, a sample-size justification, or an interim analysis plan. These details are not reported in the registry record and should not be inferred from the design labels.

The adverse-event entries provide counts and one serious-event term, but the registry record does not give a comparative statistical analysis or uncertainty estimates. Details about timing and causal attribution are not reported in the registry record for this interpretation. As a result, the safety entries are best read as descriptive registry data rather than precise estimates of comparative risk.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Clinical Evaluation of a Daily Wear Frequent Replacement Silicone Hydrogel Lens — NCT03920280.
• Registry record last updated 2022-07-28; status last verified 2022-07.
• Results first posted 2022-02-01.
• 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.

18. Record Summary

The registry record identifies NCT03920280 as a completed, randomized, double-masked, parallel study sponsored by Alcon Research. Enrollment was 120, and phase was listed as not applicable. The study evaluated LID015385 contact lenses against Comfilcon A contact lenses, identified as Biofinity, with both arms using nightly CLEAR CARE cleaning.

The primary outcome was distance visual acuity with study lenses, measured in logMAR for completed eyes at scheduled visits from Day 1 dispense through Month 3 follow-up or exit. The record explains that lower logMAR values indicate better acuity and states that no formal hypothesis testing was planned. Numerical visual-acuity results are not reported in the registry record.

The adverse-event record lists one serious affected case in the Biofinity ocular group, with ulcerative keratitis reported at 1.2%. No deaths are listed. The record does not report a formal comparative analysis of these events or several details needed to evaluate missing data and outcome analysis.