Clinical Evaluation of a Manufacturing Process for a Frequent Replacement Silicone Hydrogel Multifocal Contact Lens: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Clinical Evaluation of a Manufacturing Process for a Frequent Replacement Silicone Hydrogel Multifocal Contact Lens (NCT05765227), a non-randomized na study. The primary outcome is Binocular Visual Acuity (VA) With Study Lenses at 4 Meters (logMAR).

2. Clinical Question

The trial’s stated purpose was to evaluate the clinical performance of a manufacturing process on a frequent replacement multifocal contact lens. The posted endpoint is a continuous measurement of visual acuity rather than a categorical judgment of success. The description explains that lower logMAR values indicate better visual acuity, while a value of 0 corresponds to 20/20 Snellen visual acuity.

This question should be read as a comparison of measurements gathered in a crossover setting, not as a randomized treatment comparison. The record identifies two possible lens sequences: lehfilcon A followed by lotrafilcon B, or lotrafilcon B followed by lehfilcon A. It does not describe random assignment to sequence. The registry record does not report the observed visual acuity means or their standard deviations, so the size and precision of any difference cannot be assessed from the posted results.

3. Trial Design

This completed clinical evaluation is listed as non-randomized, single-masked, and crossover. Enrollment is listed as 18. The condition is refractive ametropia, and Alcon Research is identified as sponsor. The registry dates are 2023-03-08 for study start and 2023-03-30 for primary completion. The record lists the phase as not applicable.

The crossover structure means that the arm descriptions specify a sequence of lens use: one sequence starts with lehfilcon A multifocal lenses and proceeds to lotrafilcon B multifocal lenses, while the other starts with lotrafilcon B and proceeds to lehfilcon A. Each study lens type was to be worn bilaterally for approximately 2 days. CLEAR CARE is named in the arm descriptions for nightly cleaning and disinfection. The record does not state which people were masked, or provide further details about masking procedures.

Allocation is explicitly non-randomized. The registry record therefore does not support treating the sequences as exchangeable groups created by random assignment. Differences in the sequence groups could reflect factors other than lens type, and the record does not give enough information to determine whether or how such factors were addressed.

The primary endpoint was binocular visual acuity with study lenses at 4 meters, assessed on Day 2 during the corresponding crossover period. The record says the measurement used a letter chart and was expressed in logMAR. It states that no hypothesis testing was prespecified for this endpoint. Although the study status is completed, the record does not report numerical results for the primary endpoint or an analysis comparing lens types. Detailed protocol information, including any washout arrangements or sequence allocation procedures, is 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: Of the 18 enrolled, 1 participant was exited prior to study start as a screen failure. This reporting group includes all participants exposed to any study lenses evaluated in this study (17).

First Wear Period (Approx. 2 Days)

Second Wear Period (Approx. 2 Days)

Analysis population for the primary outcome, as defined in the registry: This analysis population includes all subjects/eyes exposed to any study lenses evaluated in this 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 subjects/eyes exposed to any study lenses evaluated in this study.

6. Primary Endpoint

The registry lists the primary outcome as Binocular Visual Acuity (VA) With Study Lenses at 4 Meters (logMAR), measured over Day 2, each study lens type worn during the corresponding crossover period.

The primary endpoint is binocular visual acuity with study lenses at 4 meters, measured in logMAR on Day 2 of each corresponding crossover period. Binocular assessment means that vision is measured with both eyes together. The registry description says that assessment used a letter chart.

LogMAR is a continuous scale for visual acuity. According to the registry record, a value of 0 equates to 20/20 Snellen visual acuity, and lower logMAR values indicate better visual acuity. A continuous outcome can preserve differences across a range of measured performance rather than reducing results to categories such as meeting or not meeting a threshold. The record does not describe a threshold for a clinically important difference.

The endpoint is relevant to the stated purpose because it measures visual acuity while each study lens type is worn. Measuring at the same stated distance and time point in the crossover periods gives the endpoint a defined context. However, the registry record does not provide the observed means, standard deviations, or a lens-to-lens estimate. It also states that hypothesis testing was not prespecified. Consequently, the available record describes what was intended to be measured, but does not establish the observed visual acuity under either lens type or the precision of a comparison.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record gives enough information to describe the outcome scale and broad study structure, but not enough to reconstruct a statistical analysis. It states that the primary outcome is a mean of a continuous measure, with standard deviation as the dispersion measure. It also states that no hypothesis testing was prespecified for this endpoint. Numerical means, standard deviations, and comparison estimates are not reported in the registry record.

What does a mean describe?

A mean is a measure of the central value of observations. For a continuous outcome such as logMAR visual acuity, it can summarize the average measured value for a defined group or condition. A mean alone does not show how much individual observations vary. The standard deviation describes spread around the mean, but it is not the same as the uncertainty in the mean or the uncertainty in a comparison. The registry record names the mean and standard deviation as the endpoint summary, but does not provide their values.

How should logMAR direction be read?

The endpoint description supplies the scale interpretation: 0 equates to 20/20 Snellen visual acuity, and lower logMAR values indicate better visual acuity. Thus, if numerical values were available, direction would need to be interpreted according to the scale rather than assuming that a larger number represents a better result. No endpoint values are reported, so the direction of the observed results cannot be evaluated.

What does a crossover design contribute?

In general, a crossover design measures participants under more than one condition, so comparisons may be made within the same participant. Within-person comparisons can account for stable differences between people, but they also require attention to period, sequence, and carryover effects. A period effect is a change associated with when a measurement occurs; a sequence effect is a difference associated with the order of conditions; and carryover refers to an influence of an earlier condition on a later one. These are general design concepts, not reported findings from this trial.

The registry record describes two predetermined lens sequences and says that each lens type was worn bilaterally for approximately 2 days. It does not say that sequence assignment was randomized, and allocation is listed as non-randomized. It does not report a washout period, a method for accounting for period or sequence, or whether an analysis used within-participant comparisons. Those details cannot be inferred from the crossover label alone.

What does non-randomized allocation mean for interpretation?

In general, random allocation can help balance measured and unmeasured participant characteristics across assigned groups. With non-randomized allocation, baseline or sequence differences may remain. In a crossover study, participants may contribute measurements under both conditions, but sequence and time-related differences can still matter. The registry record does not describe how these issues were handled, so the relative contribution of lens type and other influences cannot be assessed from the posted results.

What can be said about hypothesis tests?

The record explicitly states that hypothesis testing was not prespecified for the primary endpoint. It also lists no analyses. A p-value, when reported, is a measure of how compatible data are with a specified statistical model and null hypothesis; it is not a measure of clinical importance. A confidence interval is generally useful for communicating uncertainty around an estimate. Neither a p-value nor a confidence interval for the primary endpoint is reported in the registry record. Without an estimate and its uncertainty, the data cannot be characterized as demonstrating a difference or absence of a difference.

How should planning illustrations be understood?

In general, a sample-size planning illustration asks how much information might be needed to detect an assumed effect under stated statistical assumptions. The record describes an illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is described as a stated fraction of the observed effect. Such an illustration is not an observed trial result and is not observed power. It cannot replace the trial’s outcome estimates or establish that the study was adequately powered. Numerical planning results and the observed effect are not reported in the registry record.

Why can over-dispersion matter?

In general, over-dispersion means that observed variability is greater than assumed by a statistical model. If a model underestimates variability, its uncertainty estimates may be too narrow and its inferential results may be misleading. This issue is especially relevant to outcomes whose variability is modeled, but no over-dispersion assessment is described for this continuous visual acuity endpoint. No particular model or variance adjustment is reported in the registry record.

Overall, the statistical methods that can be confirmed are limited to the endpoint scale and summary type, the crossover description, and the statement that hypothesis testing was not prespecified. The analysis model, handling of sequence and period, uncertainty estimates, and detailed implementation are not reported in the registry record.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("LID#224381", "AOHG MF")
n   <- c(17, 17)
m   <- c(-0.08, -0.06)
sp  <- c(0.06, 0.06)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  LID#224381  17  -0.080  0.060  -0.111  -0.049
CARM  AOHG MF  17  -0.060  0.060  -0.091  -0.029

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists binocular visual acuity as the primary endpoint and states that no hypothesis testing was prespecified for it. It does not report a family of confirmatory tests, a hierarchy of endpoints, or a multiplicity adjustment. The approach to multiplicity is therefore not reported in the registry record. Without a reported testing plan, there is no basis to interpret unreported p-values as confirmatory evidence.

The record describes the visual acuity analysis population as all subjects or eyes exposed to any study lenses evaluated in the study. It does not provide endpoint-specific numbers analyzed or explain how observations with missing measurements were handled. The reasons for any missing measurements, if there were any, are not reported in the registry record. It is also not reported whether all exposed participants contributed data for both lens types, or whether an analysis used only complete crossover observations.

In general, missing-data methods matter because estimates can be affected when observations are unavailable, particularly if missingness is related to outcome or treatment experience. Different assumptions about missingness can lead to different analyses. The registry record does not describe an imputation method, a missing-data assumption, or a sensitivity analysis, so none should be presumed.

The registry lists no analyses. This does not establish that no analysis was performed outside the registry; it means that analysis details and results are not reported in the registry record. The enrollment figure should not be substituted for an endpoint analysis count, because the record does not report how many observations contributed to the visual acuity summaries.

12. 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 safety groups report serious adverse event counts and other adverse event counts, along with counts at risk and deaths. For pretreatment, the serious adverse event count is 0 among 17 at risk, the other adverse event count is 0 among 17 at risk, and deaths are 0. For LID#224381 Ocular, the serious adverse event count is 0 among 34 at risk, the other adverse event count is 0 among 34 at risk, and deaths are 0. For LID#224381 Nonocular, the corresponding counts are 0 among 17 at risk, 0 among 17 at risk, and 0 deaths.

For AOHG MF Ocular, the serious adverse event count is 0 among 34 at risk, the other adverse event count is 0 among 34 at risk, and deaths are 0. For AOHG MF Nonocular, the corresponding counts are 0 among 17 at risk, 0 among 17 at risk, and 0 deaths. No serious adverse event terms are listed.

These are the counts as categorized in the registry record. The ocular and nonocular labels and differing at-risk counts should be retained when reading them; they should not be treated as interchangeable denominators or added together. The record does not explain the denominator construction or provide event-level detail. Zero recorded events in these groups does not establish that an event is impossible or that the lens types are free from risk.

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

The registry record establishes that this was a completed, non-randomized crossover evaluation of lehfilcon A and lotrafilcon B multifocal contact lenses. It describes bilateral wear for approximately 2 days per lens type and identifies binocular visual acuity at 4 meters on Day 2 as the primary endpoint. It also defines how to read the logMAR scale. These details clarify the intended measurement and comparison context.

The record does not report the visual acuity means, standard deviations, or an estimate comparing the lens types. It states that hypothesis testing was not prespecified and lists no analyses. Accordingly, the posted results do not show whether the observed measurements differed, how large any difference was, or how precise an estimate might be. They do not establish equivalence, non-inferiority, or superiority.

The non-randomized allocation and predetermined sequences also limit what can be inferred about a lens-specific effect. The record does not report whether the analysis accounted for sequence, period, or within-participant correlation. These omissions prevent readers from assessing how the crossover structure was incorporated into an estimate.

The safety record lists zero serious adverse events and zero other adverse events in each reported category, with zero deaths. These recorded counts are useful descriptions of what the registry reports, but they do not by themselves rule out uncommon events or establish comparative safety. The record does not give further event-level details.

In general, an outcome description, a numerical estimate, and an inferential conclusion are different things. The registry supplies the first, but does not report the endpoint results needed for the latter. The appropriate reading is therefore descriptive: the trial intended to measure visual acuity under each lens condition and recorded the stated safety counts, while the quantitative visual acuity findings and their uncertainty are not reported in the registry record.

14. Why This Trial Matters Statistically

This trial is statistically notable because it pairs a continuous outcome with a crossover structure. Visual acuity measured in logMAR has an interpretable direction, and the registry states that lower values indicate better visual acuity. A crossover can permit measurements under more than one condition for a participant, which in general can be useful when stable differences between people are substantial. At the same time, the order and timing of conditions can become important features of the analysis.

The record makes the non-randomized allocation explicit and describes predetermined lens sequences. This highlights a central distinction: a crossover label alone does not guarantee randomized sequence assignment or remove the need to assess period and sequence effects. Those design and analysis details are not reported in the registry record.

The record also illustrates why endpoint definitions should be separated from endpoint findings. It identifies the measurement, scale, time point, and summary type, while the numerical outcome summaries and inferential analyses are absent. Readers can understand what was intended to be measured without being able to judge the estimated performance or precision.

Finally, the stated absence of prespecified hypothesis testing matters for interpretation. A design may generate descriptive measurements even when a confirmatory statistical comparison is not planned. Without a reported estimate and uncertainty, a completed study cannot be read as evidence for or against a difference. The registered safety counts likewise provide a descriptive record, rather than a comprehensive basis for comparing risks.

15. 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 important limitation for interpreting this trial is that the registry record does not report the primary visual acuity values or standard deviations. It therefore does not permit assessment of the observed results, their variability, or the precision of a comparison. No inferential analysis is listed, and the record states that hypothesis testing was not prespecified.

The allocation is non-randomized, and the two arm descriptions specify different predetermined lens sequences. The registry record does not explain how sequence was assigned or whether sequence-related differences were addressed. It also does not report a washout procedure or an analysis of period, sequence, or carryover effects. These are relevant uncertainties in a crossover evaluation.

The endpoint population is described broadly as all subjects or eyes exposed to study lenses. Endpoint-specific analysis counts, completeness of observations, and missing-data handling are not reported in the registry record. The record does not say whether all exposed participants contributed measurements under both lens types.

Masking is listed as single, but the identity of the masked party and the practical masking procedures are not reported. The registry describes bilateral lens wear and the measurement time point, but does not provide further details needed to assess measurement implementation. The meaning and construction of safety denominators are also not explained. These limits restrict interpretation to the design descriptions and the recorded counts, rather than supporting a quantitative judgment about visual acuity or comparative safety.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Clinical Evaluation of a Manufacturing Process for a Frequent Replacement Silicone Hydrogel Multifocal Contact Lens — NCT05765227.
• Registry record last updated 2024-04-16; status last verified 2024-03.
• Results first posted 2024-04-16.
• 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.

19. Record Summary

NCT05765227 is a completed, non-randomized, single-masked crossover study sponsored by Alcon Research. The condition is refractive ametropia, and enrollment is listed as 18. The registry dates are 2023-03-08 for study start and 2023-03-30 for primary completion.

The study evaluated lehfilcon A and lotrafilcon B multifocal contact lenses in predetermined sequences. Each lens type was worn bilaterally for approximately 2 days, with nightly cleaning and disinfection using the named hydrogen peroxide-based system. The primary endpoint was binocular visual acuity at 4 meters in logMAR on Day 2 of each lens period.

The record states that lower logMAR values indicate better visual acuity and that hypothesis testing was not prespecified. It does not report the endpoint values, standard deviations, or analysis results. Safety groups report zero serious adverse events, zero other adverse events, and zero deaths in each listed category.