Evaluation of Rotation With a Multifocal Toric Contact Lens: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluation of Rotation With a Multifocal Toric Contact Lens (NCT05433571), a randomized na study. The primary outcome is Proportion of Eyes With Absolute Rotation ≤ 10 Degrees.

2. Clinical Question

3. Trial Design

NCT05433571, titled “Evaluation of Rotation With a Multifocal Toric Contact Lens,” is a completed, randomized, single-masked crossover study. The registry describes it as bilateral, single-visit and non-dispensing, with a 2x2 crossover design. Enrollment was 102. The study started on 2022-06-28, and primary completion was 2022-07-22. The listed phase is NA.

Each subject was randomized to receive two study lens types, worn one at a time bilaterally over two wear periods. The registry describes eight possible study lens types and sequences, organized by myopia or hyperopia, astigmatism orientation, and whether low or high DC came first. This sequence structure is relevant to interpretation: the study was not described as assigning each person to wear only one lens throughout. However, the posted results do not provide the sequence-specific numbers or a model that accounts for sequence, period, or paired measurements.

The two lenses with posted primary results were Senofilcon A multifocal toric lenses with a UV/HEV filter, one with low DC and one with high DC. For each, the registry reports an estimate of the proportion of eyes meeting the rotation threshold. It does not report a direct comparison between the lenses. Details such as the masking procedure, washout arrangements, and the exact analysis model for the crossover design are not reported in the registry record. The record identifies Johnson & Johnson Vision Care, Inc. as sponsor.

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: A total of 102 subjects were enrolled in this study. Of those enrolled, all subjects were dispensed both lenses and completed the study. No subjects were discontinued.

Period 1

Period 2

Analysis population for the primary outcome, as defined in the registry: All randomized subjects regardless of actual treatment and subsequent withdrawal from study or deviation from 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.

Population: All subjects dispensed at least one study lens.

6. Primary Endpoint

The registry lists the primary outcome as Proportion of Eyes With Absolute Rotation ≤ 10 Degrees, measured over 15-minutes post lens insertion.

The primary endpoint was the proportion of eyes with absolute rotation at most 10 degrees at 15-minutes post lens insertion. Rotation was assessed using a slit lamp at 1-, 3-, 7-, 15- and 25-minutes after insertion. The endpoint converted the measured rotation into a binary outcome: an eye met the criterion if its absolute rotation was at most 10 degrees; a rotation greater than 10 degrees did not meet it.

A proportion gives the share of observations meeting a prespecified criterion. Here, the criterion turns a continuous measurement—rotation in degrees—into a yes-or-no result. This can make the result easier to interpret in relation to a stated threshold, but it also discards information about how far an observation was from that threshold. Eyes just on either side of the cutoff are classified differently even if their measured rotations are close.

The primary time point was 15-minutes, even though other post-insertion assessments were made. The registry does not report the rationale for selecting this time point or how the eye-level observations were handled when measurements were unavailable. The posted proportions therefore address the threshold at the specified time, not rotation across all assessment times or the distribution of rotation values.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What do the posted estimates represent?

The registry reports a proportion for each lens and a bootstrap mean population estimate for each. A proportion is the share of observed outcomes classified as meeting the endpoint. In this study, an eye counted as meeting the endpoint when absolute rotation was at most 10 degrees at 15-minutes post lens insertion. The posted values are 0.917 for the low-DC lens and 0.887 for the high-DC lens. The corresponding bootstrap estimates are 0.917 and 0.887.

Bootstrapping is a general statistical approach that estimates uncertainty by repeatedly resampling data and recalculating a statistic. The registry identifies bootstrapping as the method for the reported mean population estimates. The details of the resampling procedure—including the resampling unit and whether the bilateral and crossover structure was preserved—are not reported in the registry record. Those details matter because resampling eyes independently may not represent the dependence between eyes or measurements from the same subject.

How should the confidence intervals be read?

The registry reports 95% confidence intervals for each lens estimate: 0.878 to 0.955 for the low-DC lens and 0.845 to 0.930 for the high-DC lens. In general, a confidence interval communicates the precision of an estimate under the method and assumptions used. A narrower interval indicates greater precision than a wider interval on the same scale, but an interval does not account for limitations that are not represented in the analysis, such as an unsuitable model or unaddressed dependence.

These intervals are attached to the individual lens estimates. They do not directly quantify uncertainty in the contrast between lenses. Comparing whether two separate confidence intervals overlap is not a substitute for estimating the contrast and its uncertainty. A crossover study can use within-subject information, but the registry does not report a paired contrast or its confidence interval.

Why does the crossover structure matter?

In a crossover design, each subject receives more than one condition in sequence. This can allow comparisons within the same subject, which may account for stable differences between subjects. It also requires attention to period and sequence effects and to the relationship between repeated measurements. The registry describes two wear periods and randomized sequences, but does not report the analysis model or whether period, sequence, or within-subject correlation was incorporated.

The study was also bilateral, and the primary endpoint is defined at the eye level. Measurements from two eyes of the same subject may be correlated. In general, treating related observations as independent can make uncertainty estimates inaccurate. The record does not explain the statistical unit used for the bootstrap or how bilateral measurements contributed to the estimates. This prevents a full assessment of whether the reported confidence intervals reflect the design.

What is missing from the comparison?

The posted analyses give a separate estimate for each lens but no p value or direct estimate of the low-DC versus high-DC contrast. The registry also does not report a statistical model, an adjustment strategy, or a prespecified test of superiority between these lenses. The analysis labels identify superiority, but the reported entries are single-group estimates, not a two-group superiority result. Without a contrast and its uncertainty, the evidence cannot quantify the comparative effect.

The registry record does not report a sample-size justification, interim analyses, or the full statistical analysis plan. Such details should not be inferred from the enrollment or the presence of confidence intervals. A planning illustration based on an observed effect is a hypothetical design calculation, not observed power and not evidence about the trial's original planning assumptions. General statistical planning calculations depend on their stated assumptions and do not replace a reported comparison.

The primary endpoint was selected from assessments made at 1-, 3-, 7-, 15- and 25-minutes, with 15-minutes identified as primary. The record does not report how testing across assessment times was managed or whether any multiplicity adjustment was planned. Since no secondary outcomes are posted, the results available for interpretation are limited to the primary outcome estimates for the two lens conditions.

10. Analyses Reported by the Sponsor

The registry reports the sponsor’s analyses as bootstrap mean population estimates for each lens, with 95% confidence intervals. The low-DC estimate is 0.917, with an interval from 0.878 to 0.955; the high-DC estimate is 0.887, with an interval from 0.845 to 0.930. No p value is listed for either estimate.

These reported analyses are single-lens estimates, not a direct comparison of the two lenses. The registry does not give a sponsor-reported contrast, confidence interval for a contrast, or p value testing the difference. The record also does not provide enough detail to reconstruct a crossover-aware analysis from the posted summary results. Accordingly, a separate unadjusted recalculation cannot be used to fill in the missing paired comparison. The registry marks no discrepancy between its posted values and the reported analyses, but that does not supply the absent comparative result.

The bootstrap estimates are the sponsor’s reported statistical results. Their interpretation depends on the analysis details, including the resampling unit and handling of bilateral and repeated measurements, which are not reported in the registry record. The estimates should be read as describing each lens condition separately.

11. Multiplicity, Missing Data and Analysis Populations

The primary outcome was the proportion of eyes meeting the rotation threshold at 15-minutes. Rotation was also assessed at 1-, 3-, 7- and 25-minutes, but these are not listed as primary outcomes. The record does not report whether analyses at other assessment times were planned, whether they were formally tested, or how multiplicity across times was addressed. No secondary outcomes are posted.

The registry reports two analyses, one for each lens, and provides a separate estimate and confidence interval for each. It does not report a p value or direct contrast between the lenses. A multiplicity strategy for comparative testing is therefore not described in the available results. The registry record does not report the full statistical analysis plan, any interim analyses, or a sample-size justification, so those procedures cannot be inferred.

The stated analysis population includes all randomized subjects regardless of actual treatment, subsequent withdrawal, or protocol deviation. This describes the intended population, but does not explain how missing endpoint measurements were handled or whether every randomized subject contributed an evaluable eye-level outcome. The record does not report imputation, a missing-data sensitivity analysis, or numbers of missing observations for the primary endpoint.

Because the endpoint is defined for eyes and the study was bilateral and crossover, the analysis also needs to account for the relationship between observations from the same subject if that dependence affects the uncertainty. Whether this was done is not reported in the registry record. These omissions limit assessment of the analysis population, the potential impact of missing data, and the precision of the estimates.

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 lists 0 serious adverse events and 0 other adverse events for the low-DC lens, with 102 at risk in each category. For the high-DC lens, it likewise lists 0 serious adverse events and 0 other adverse events, with 102 at risk in each category. Deaths are listed as 0 for both lens groups.

These entries describe the adverse-event counts recorded in the registry. They do not show that no events of any kind occurred outside the categories or reporting period represented in the record. The registry does not provide serious-event terms, and no top serious-event terms are listed. The record also does not provide additional detail about event collection or how exposure during the crossover periods was assigned to these safety groupings.

Zero reported events should be interpreted as zero recorded in these entries, not as proof that the risk of an event is absent. Safety conclusions require context about observation, reporting, and follow-up, and those details are not reported in the registry record.

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

The results describe how often the primary rotation criterion was met for each lens at 15-minutes post insertion. The low-DC lens estimate was 0.917 with a 95% confidence interval from 0.878 to 0.955, while the high-DC lens estimate was 0.887 with a 95% confidence interval from 0.845 to 0.930. The posted raw proportions were 0.917 and 0.887, respectively. These are estimates for separate lens conditions.

The data do not establish a statistically supported difference between the lenses because the registry does not report a direct comparison or its uncertainty. The separate confidence intervals cannot substitute for a paired or otherwise design-appropriate contrast. The record also does not explain whether the eye-level and crossover structure was incorporated into the bootstrap estimates.

The outcome measures a threshold classification, not the full distribution of rotation. It does not indicate how far rotation values were from the 10-degree cutoff, nor does it summarize the assessments made at other times. It also does not answer questions about other outcomes, since no secondary outcomes are posted.

These estimates should not be generalized beyond the population, conditions, and endpoint described in the registry without additional evidence. The results alone do not establish broader clinical performance or make a treatment recommendation. They provide estimates of a specific eye-level measure at a specific post-insertion time, with stated statistical uncertainty and important details about the comparison and analysis left unreported.

14. Why This Trial Matters Statistically

This study illustrates a common distinction between estimating each condition separately and comparing conditions directly. Separate proportions can describe the observed endpoint for each lens, but a comparative question requires an estimate of the contrast and its uncertainty. The registry reports individual bootstrap estimates and confidence intervals, yet no direct comparison. That distinction is especially important when the study is randomized and crossover: the design can support within-subject comparisons, but the posted summaries do not show whether or how that information was used.

The endpoint also demonstrates the trade-off involved in dichotomizing a measurement. A threshold makes a result easy to classify, but it hides the amount and distribution of rotation within each category. The estimate answers a focused question about meeting the cutoff at 15-minutes; it does not describe rotation at other times or the distance of individual observations from the threshold.

Finally, bilateral outcomes require clarity about the unit of analysis and dependence among measurements. The study reports an eye-level endpoint in a bilateral crossover design, while the registry does not explain the resampling unit or model. Reporting those details alongside a direct contrast would make the uncertainty and comparative interpretation more transparent.

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 the primary results is the absence of a direct comparison between the low-DC and high-DC lenses. The registry supplies separate estimates and confidence intervals, but no contrast, contrast interval, or p value. The results therefore do not quantify the uncertainty in the difference between the lens conditions.

The analysis details are limited. Although the study is bilateral and crossover, the registry does not report whether the analysis accounted for paired eyes, repeated wear periods, sequence, or within-subject correlation. It identifies bootstrapping but does not state the resampling unit or enough procedural detail to evaluate the confidence intervals fully. The posted arm size is 102 for each lens, but the record does not clarify the denominator used for each eye-level proportion.

The registry does not report how missing endpoint measurements were handled, despite defining the analysis population to include all randomized subjects regardless of withdrawal or protocol deviation. It also does not provide a sample-size justification, interim analysis information, or the full statistical analysis plan. Procedures for multiplicity across assessment times are not reported.

The endpoint is a binary threshold at 15-minutes. It does not capture the distribution of rotation or summarize the measurements at 1-, 3-, 7- and 25-minutes. Safety entries report no adverse events or deaths in the listed categories, but event-collection details are not reported. These limitations restrict interpretation to the posted estimates and the specific endpoint defined in the registry.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Evaluation of Rotation With a Multifocal Toric Contact Lens — NCT05433571.
• Registry record last updated 2023-07-27; status last verified 2023-06.
• Results first posted 2023-07-27.
• 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

NCT05433571 is a completed, randomized, single-masked crossover study of multifocal toric contact lenses. The registry describes a bilateral, single-visit, non-dispensing 2x2 design in which each subject was assigned two lens types for two wear periods. The primary endpoint was the proportion of eyes with absolute rotation at most 10 degrees at 15-minutes post insertion.

The posted proportions were 0.917 for the low-DC lens and 0.887 for the high-DC lens. Bootstrap mean population estimates were 0.917 and 0.887, with 95% confidence intervals of 0.878 to 0.955 and 0.845 to 0.930, respectively. No direct comparison between lenses is reported. The registry lists 0 serious adverse events, 0 other adverse events, and 0 deaths in each lens group.