Evaluating Two Multifocal Daily Disposable Contact Lenses: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluating Two Multifocal Daily Disposable Contact Lenses (NCT05579886), a non-randomized na study. The primary outcome is Comfort Just After Lens Insertion.

2. Clinical Question

The objective was to adapt existing multifocal lens wearers to the Control Lens and then evaluate switching them to the Test Lens, with a review after 2 weeks. The study therefore addresses the experience of changing lens designs in a particular wearer group. It does not test the two lenses in independently assigned groups, and the order of lens exposure was not randomized.

The registry record identifies the study as a crossover and lists allocation as nonrandomized and masking as none. Those design features matter when interpreting a perceived-comfort outcome: participants experienced both lenses, in the same sequence, and knew which lens they were wearing. Comfort ratings can reflect the lens experience, but can also be influenced by the order and context in which ratings are collected. The record does not report numerical primary outcome results, so the stated research question cannot be answered from the posted results.

3. Trial Design

The registry record describes a completed device study, NCT05579886, sponsored by CooperVision, Inc. Its title is Evaluating Two Multifocal Daily Disposable Contact Lenses. The official title specifies refitting lens wearers already adapted to Clariti 1Day Multifocal 2-Add Design with MyDay Multifocal. Presbyopia is the listed condition. The study phase is recorded as not applicable.

The design is identified as a nonrandomized crossover with no masking. All participants wore the Control Lens for 2 weeks in Period 1, followed by the Test Lens for 2 weeks in Period 2. The study summary says existing multifocal soft lens wearers were adapted to the Control Lens for at least 2 weeks, then switched to the Test Lens and reviewed after 2 weeks. The record does not describe a randomized order or a separate concurrent control group.

The listed study start date is 2022-10-10, and the primary completion date is 2023-02-07. Overall study status is completed. The registry lists enrollment as 60. That is the enrollment figure, not a report of how many participants contributed to the primary endpoint: the number analyzed and the handling of any unavailable ratings are not reported in the registry record.

The fixed sequence means lens type and period are linked: the Control Lens was always worn first and the Test Lens second. A difference in ratings, if reported, could therefore reflect lens experience, period or order effects, or a combination. The record does not give a statistical analysis plan or explain whether any adjustment for period, sequence, or within-participant correlation was planned. It also does not report a sample-size justification. These omissions limit how much can be inferred about the intended analysis and its precision.

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: Control Lens, 2 Weeks

Period 2: Test Lens, 2 Weeks

Analysis population for the primary outcome, as defined in the registry: All participants wore Control Lens and Test Lens in sequential order.

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.

6. Primary Endpoint

The registry lists the primary outcome as Comfort Just After Lens Insertion, measured over 2 weeks.

The primary endpoint is Comfort Just After Lens Insertion. It is a subjective rating on a scale from 0-10, in 0.5 steps. The anchors are 0 for Painful and 10 for Can’t feel the lenses. The registry record describes the outcome as a mean with standard deviation and gives a timeframe of 2 weeks.

Comfort is relevant to this study because its objective concerns adapting wearers to one multifocal lens and switching them to another. A rating allows participants to describe their immediate subjective experience rather than relying only on a clinical measurement. The scale’s direction is important for interpretation: a higher score corresponds to greater reported comfort, while a lower score corresponds to less comfort.

The record says all participants wore the Control Lens and Test Lens in sequential order, but does not clarify the exact timing of each comfort assessment beyond the stated 2-week timeframe and endpoint title. It does not report the observed mean, standard deviation, number of ratings available, or a statistical comparison. Consequently, the endpoint definition is available, but its observed result and precision are not reported in the registry record.

A mean describes the central level of ratings, while a standard deviation describes how spread out individual ratings are around that mean. These are different summaries: the mean alone does not show whether participants’ experiences were similar or varied widely. Without the actual values, neither the average comfort rating nor variation in ratings can be evaluated.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The record identifies a continuous primary outcome summarized as a mean and standard deviation. It does not report an analysis or numerical outcome results. The concepts below explain how such data are commonly interpreted; they do not describe methods confirmed as having been used in this study.

What does a mean communicate?

For a continuous score, the mean is the arithmetic average of the recorded values. It provides a compact description of the group’s central rating. Here, the score is a subjective comfort rating, with higher values on the stated scale representing greater comfort. A mean does not show the full distribution: two sets of ratings can have the same mean but differ in how much participants’ ratings vary or in whether ratings cluster at particular values.

What does a standard deviation add?

A standard deviation describes the spread of individual observations around the mean. A smaller spread indicates that ratings are more concentrated around the average; a larger spread indicates greater variability. It is not the same as a standard error or a confidence interval. The standard deviation describes variation among observations, whereas a standard error reflects the uncertainty in an estimated quantity under a statistical model. Neither measure is reported for the primary endpoint in the registry record.

How would a crossover comparison be analyzed?

In general, a crossover design measures participants under more than one condition. Since the same participant contributes experience under both conditions, the two observations may be correlated. An analysis that treats all observations as independent can fail to represent that relationship. Common approaches for paired or repeated measurements use the within-participant structure, or use a model that represents it explicitly. The registry record does not say which approach, if any, was used.

Period also matters. In this study, the Control Lens was worn in Period 1 and the Test Lens in Period 2 for the specified 2-week periods. Because lens and period are linked, a difference between period ratings would not by itself separate a lens effect from changes associated with time or order. A randomized sequence can help distinguish these influences in some crossover designs; this study is listed as nonrandomized and the record describes the same sequence for all participants. The record does not report an adjustment for period effects or other design features.

What would an estimate and confidence interval mean?

In general, an estimated difference summarizes the contrast between conditions under a specified analysis. A confidence interval expresses the uncertainty associated with that estimate under the assumptions of the method. A narrow interval indicates greater precision than a broad interval, but the interval does not remove possible bias from design features or missing observations. No primary estimate or confidence interval is reported in the registry record, so neither the direction nor precision of a contrast can be assessed.

How should a significance test be read?

A significance test evaluates data against a specified statistical model and null hypothesis. Its result does not measure the size or practical importance of an effect, and it does not repair limitations in allocation, masking, or outcome availability. The registry record reports no primary analysis and no test result. It also does not report a prespecified analysis plan, so the intended hypothesis test and decision criteria are not reported in the registry record.

What do the planning assumptions mean?

The record describes a planning illustration based on the 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. Such illustrations concern hypothetical future planning under their assumptions; they are not observed trial outcomes and should not be described as observed power. The record does not report the numerical planning outputs or a sample-size justification used to design this study. It also describes different reporting units for time-to-event outcomes and other outcomes, but the primary endpoint is a continuous measure rather than a time-to-event measure.

Why does over-dispersion matter in general?

Over-dispersion occurs when the variability in data is greater than a model assumes. If it is ignored, uncertainty estimates can be too optimistic. This concept is most relevant to particular outcome types and models; it is not evidence of a problem in this continuous comfort endpoint. The registry record does not report a model or a dispersion assessment.

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("Control Lens (2ADD)", "Test Lens (3ADD)")
n   <- c(60, 60)
m   <- c(9.1, 9.2)
sp  <- c(1.4, 1.1)
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  Control Lens (2ADD)  60  9.100  1.400  8.738  9.462
CARM  Test Lens (3ADD)  60  9.200  1.100  8.916  9.484

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists one outcome measure, the primary comfort endpoint, and no analyses. It does not report whether additional endpoints were prespecified elsewhere, whether multiple time points or comparisons were evaluated, or whether any multiplicity adjustment was planned. The number of listed outcome measures alone cannot establish how many statistical tests were conducted. No multiplicity procedure is reported in the registry record.

Multiplicity matters in general when researchers make several statistical comparisons: the chance of at least one false-positive finding can increase as the number of tests grows. Methods to address this depend on the questions and analysis plan. Since no primary analysis results or statistical plan are reported, the role of multiplicity in this study cannot be assessed. It would be inappropriate to infer that an adjustment was either necessary or unnecessary from the registry entry alone.

The record does not report missing primary outcome data, participant-level analysis counts, reasons for missing measurements, or an approach to missingness. These details matter because an analysis based only on available ratings can be affected if the availability of a rating is related to comfort or other participant characteristics. In general, statistical methods for missing data rely on assumptions, and their appropriateness depends on why data are missing. No missing-data method or assumption is reported in the registry record.

Likewise, the record does not state which analysis population was used, such as whether the primary analysis included all enrolled participants or only those with available measurements. The enrollment figure of 60 should not be taken as the number analyzed. The absence of an analysis report leaves both the handling of missing data and the population contributing to the primary result unreported in the registry record.

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 0% reporting threshold.

Most frequent non-serious adverse event terms

The registry record reports serious adverse events for each lens group, with 60 at risk and 0 affected in the Control Lens group, and 60 at risk and 0 affected in the Test Lens group. It lists deaths as 0 in both groups. These are the posted counts; they should be read as descriptive registry entries, not as proof that no safety concern is possible.

For other adverse events, the record lists 60 at risk and 1 affected in the Control Lens group, compared with 60 at risk and 0 affected in the Test Lens group. The type or clinical description of the other event is not reported in the registry record. The record does not provide an assessment of severity beyond the separate serious-event classification, nor does it describe the event’s timing, duration, or relationship to lens use.

These counts do not establish that one lens is safer than the other. The study is nonrandomized, unmasked, and uses a fixed lens sequence; the registry record does not report a comparative safety analysis. Small descriptive counts also do not characterize the full range of possible events. The figures should therefore be interpreted narrowly as the adverse-event counts recorded for the listed groups, with event details and broader safety conclusions not reported in the registry record.

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

The record establishes that a study was conducted to evaluate a switch from a Control Lens to a Test Lens among existing multifocal soft lens wearers with presbyopia. It specifies the lens sequence, the 2-week wearing periods, and a subjective comfort score collected in relation to lens insertion. These details define the question and help readers understand what the study was intended to examine.

However, the primary outcome results are not reported in the registry record. There are no posted comfort means, standard deviations, comparisons, confidence intervals, or test results. As a result, the record does not show the average comfort reported for either lens, the size or direction of any difference, or how precisely such a difference was estimated. It also does not establish whether any observed contrast would be attributable to lens design rather than order or period.

The posted safety entries describe no serious adverse events and no deaths in either group, alongside one other adverse event in the Control Lens group and none in the Test Lens group. The detail needed to characterize that event is not reported. These counts are not a complete comparative assessment of safety and cannot fill the gap in the primary outcome reporting.

In general, a registry record is most informative when its stated outcomes are accompanied by analysis methods, participant counts for each analysis, numerical estimates, and uncertainty measures. Here, the outcome definition and study structure are present, but the results and analysis are not. The appropriate interpretation is therefore limited: the registry describes what was studied and the recorded adverse-event counts, but it does not support a quantitative conclusion about comfort or a reliable estimate of the difference between the lens periods.

14. Why This Trial Matters Statistically

This study is statistically instructive because the same participants experienced both lens conditions, but the sequence was fixed. Crossover studies can make within-participant comparisons useful by accounting for each participant’s ratings under both conditions. That advantage depends on collecting and analyzing the repeated measurements appropriately. The registry record does not report how that was done.

The fixed sequence also shows why a within-participant design does not automatically isolate a treatment contrast. The Control Lens was worn first and the Test Lens second, so lens and period are linked. Any observed change could reflect the lens, time, familiarity, or other period-related influences. Those are possible interpretive issues, not claims that any particular influence occurred.

The endpoint is subjective, with an explicit scale direction and anchors. Such clarity helps readers understand what the score represents, while the lack of masking is relevant to how a subjective rating may be interpreted. Statistical significance alone, if it had been reported, would not resolve these design considerations; the estimate, its uncertainty, and the analysis assumptions would also matter.

Finally, the record illustrates the difference between a registered study description and a report of results. It gives a defined primary question and basic safety counts, but no numerical primary outcome analysis. Without those results, the central comparison cannot be evaluated statistically. This distinction matters for clinical researchers reading registry entries: study completion and a well-defined endpoint do not by themselves provide evidence about the magnitude or precision of an outcome.

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 of the registry record is that it does not report the primary comfort results or any analysis. Without observed scores and a comparison estimate, the direction, size, and precision of the primary outcome are unknown. The listed endpoint definition does not answer whether comfort ratings differed between the lens periods.

The study is recorded as nonrandomized, unmasked, and crossover. All participants wore the Control Lens first and the Test Lens second. This fixed order makes period and lens condition inseparable in a simple before-and-after comparison. Participants also knew which lens they were wearing, which is relevant because comfort is self-reported. The record does not describe procedures intended to address order, expectation, or period effects.

The entry does not report the analysis method, participant counts contributing to the primary endpoint, missing-data handling, or analysis population. It also does not report a statistical analysis plan, a sample-size justification, or a multiplicity approach. These gaps prevent readers from checking how the result was derived, what assumptions were used, or how incomplete ratings were treated.

Safety information is limited to event counts. The description of the one other adverse event in the Control Lens group is not reported in the registry record, and no comparative safety analysis is given. The study’s listed enrollment should not be interpreted as the number of participants analyzed for comfort or safety. These limitations concern what the registry entry reports; they do not establish what may or may not have appeared in other study documents.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Evaluating Two Multifocal Daily Disposable Contact Lenses — NCT05579886.
• Registry record last updated 2024-02-20; status last verified 2024-01.
• Results first posted 2024-02-20.
• 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

NCT05579886 is a completed, nonrandomized, unmasked crossover device study sponsored by CooperVision, Inc., with presbyopia listed as the condition. The record lists enrollment as 60 and gives study dates from 2022-10-10 to primary completion on 2023-02-07.

All participants wore the Control Lens (2ADD) for 2 weeks in Period 1 and the Test Lens (3ADD) for 2 weeks in Period 2. The primary endpoint was comfort just after lens insertion, rated on a 0-10 scale in 0.5 steps, with higher values indicating greater comfort. The registry record does not report the primary outcome values, an analysis, or the number analyzed.

The safety entries list 0 serious adverse events and 0 deaths in each group. One other adverse event is listed for the Control Lens group and none for the Test Lens group; details of the event are not reported in the registry record. No primary statistical result is available to quantify or assess the precision of the comfort comparison.