Clinical Performance of a Silicone Hydrogel Lens With Use of FID 114675A: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Clinical Performance of a Silicone Hydrogel Lens With Use of FID 114675A (NCT01240135), a randomized na study. The primary outcome is Lens Fit.

2. Clinical Question

The question is about the clinical performance of the lens in the setting of two care solutions, rather than a comparison of different lens types. The registry’s brief summary says the study’s purpose was to evaluate a silicone hydrogel contact lens when used with an investigational multi-purpose disinfecting solution. The active comparator supplies context for interpreting the results: the observed outcomes are reported for each solution, but a result in one arm is not by itself evidence of a difference between solutions.

The crossover design means the registry assigned participants to treatment sequences rather than only describing two unrelated groups. One sequence used FID 114675A and then renu fresh; the other used renu fresh and then FID 114675A. Each treatment period is described as 14 days, separated by a minimum 1-day washout. The primary outcome is specifically tied to Day 14 of lens wear. The registry record does not report whether the posted primary comparison accounts for the paired nature of the crossover or for treatment sequence and period.

3. Trial Design

This was a randomized, triple-masked, crossover study. The registry lists 89 participants enrolled and the status as completed. Its listed conditions are contact lens fit and myopia. The study compared the clinical performance of a silicone hydrogel contact lens while participants used FID 114675A or renu fresh for lens care.

The treatment descriptions specify two sequences. In one, participants used FID 114675A for 14 days, had a minimum 1-day washout, and then used renu fresh for an additional 14 days. In the other, they used renu fresh first, followed by the same minimum washout and a subsequent 14-day period using FID 114675A. The record identifies this as a crossover model. It does not report further details about how the treatment sequences were generated, the masking procedures, or whether participants, investigators, or other study personnel remained masked during each period.

The posted primary outcome is assessed at Day 14 of lens wear, and the secondary outcome is also assessed at Day 14. The primary population definition includes randomized participants with at least one post-baseline assessment after dispensing, according to randomized treatment. The primary outcome denominators are 87 and 88; the registry does not explain the differences between those denominators and the enrollment total. The adverse-event groups each list 89 participants at risk.

The registry record gives the study start as 2010-10 and primary completion as 2011-02. It lists Alcon Research as sponsor. The phase is listed as NA, and the interventions are classified as devices. The arm labels use FID 114576A, while the intervention and treatment-sequence descriptions identify FID 114675A. This inconsistent labeling should be kept in mind when reading the arm names; the record does not explain it.

Although a crossover structure is described, the registry does not report a statistical model, a treatment-period analysis, a carryover assessment, or an analysis accounting for within-participant correlation. It also does not report a sample-size justification. Those omissions limit how fully the posted comparisons can be connected to the design.

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 One, 14 Days of Wear

Period Two, 14 Days of Wear

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Intent to treat: All randomized subjects with at least one post-baseline assessment after dispensing, according to randomized treatment.

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 Lens Fit, measured over Day 14 of lens wear.

The primary endpoint is the percentage of participants with an acceptable contact lens fit at Day 14 of lens wear. Investigators assessed fit using three components: static movement, push-up movement, and centration. Static and push-up movement each used a five-point scale, ranging from reduced movement unacceptable through optimal movement to excessive movement unacceptable. Centration used a three-point scale: optimal, acceptable decentration, or unacceptable decentration.

A participant counted as acceptable on all measurements only when each component was rated optimal or acceptable. Thus, the endpoint combines the three component assessments into a single acceptability classification. A participant with an unacceptable rating on any of those measures would not meet the registry’s stated all-measures criterion. The result is reported as a percentage, making it a summary of the proportion meeting that composite criterion rather than a mean score on the underlying scales.

As a general statistical point, a composite acceptability endpoint can offer a direct summary of whether multiple prespecified dimensions meet a stated standard. It is also less detailed than reporting each component separately: equal overall percentages do not establish that the distributions of movement and centration ratings were identical. The registry does not post component-level results for these fit measures or a confidence interval for the primary percentages. The record also does not report a statistical test or an estimated treatment contrast for this endpoint. Accordingly, the posted values describe the observed classifications, but they do not quantify uncertainty around a difference between solutions.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies a randomized, triple-masked crossover design. Randomization assigns treatment sequence by chance, while a crossover design means that participants receive the two treatments in sequence. In this study, the described sequences switch between FID 114675A and renu fresh after a minimum 1-day washout, with each period lasting 14 days. The registry does not explain its randomization method or masking procedures. It also does not report whether the posted comparisons preserve the within-participant structure of the crossover.

What do the primary percentages say?

The primary result is a proportion: the number of participants meeting the acceptable-fit criterion relative to the participants included in that arm’s reported result. The registry gives 100.0% for each arm, with 87 and 88 participants, respectively. Because the outcome is categorical, a comparison would generally need to express uncertainty around the proportions or their contrast. The registry does not report such an interval or test. Equal observed proportions do not show that the true proportions are exactly equal, and they do not establish equivalence.

How should the secondary mean difference be read?

The secondary outcome is a change from baseline measured on a scale, summarized by a mean and standard deviation. The posted arm means are 0.6 and 1.4. The comparison is defined as Renu Fresh relative to FID 114576A, yielding a mean difference of 0.8. The posted 95% confidence interval runs from 0.041 to 1.559, and the unadjusted p-value is 0.039.

As a general explanation, a mean difference expresses the distance between two group means in the outcome’s units. A confidence interval gives a range of estimates compatible with the data and the specified statistical method. A narrower interval indicates greater precision than a wider interval, while an interval’s location relative to zero is relevant to whether the contrast is compatible with no difference under that method. These statements are general; the registry does not provide enough detail to verify whether the method used for this crossover outcome accounts for pairing, period, or sequence.

A p-value is a measure of how unusual the observed data, or more extreme data, would be under a specified null model and its assumptions. It is not the probability that the null hypothesis is true, and it does not measure clinical importance. The posted p-value is described as unadjusted. The registry does not report the full statistical model, test specification, or whether this comparison was planned as confirmatory.

Why does the crossover structure matter?

As a general statistical principle, measurements from the same participant may be correlated. A crossover analysis can use that within-participant information, and its uncertainty can differ from an analysis that treats treatment groups as independent. Treatment period and sequence may also matter, and a washout is intended to separate periods, although the record does not state the assumptions or checks used for this purpose. The posted registry comparison lists arm-level sample sizes and summary statistics but does not report the analytical handling of these design features. It is therefore not possible to determine from the registry record whether the reported comparison is a crossover-specific estimate.

What is the role of the planning illustration?

The sample-size illustration is based on the observed secondary effect, not on a reported trial design justification. It uses a two-sided significance level of 0.05, equal allocation, and a normal approximation. For planning for 100% of the observed effect, the illustration gives 161 participants per arm for 80% power and 216 participants per arm for 90% power. For planning for 75% of the observed effect, it gives 287 participants per arm for 80% power and 383 participants per arm for 90% power. For planning for 50% of the observed effect, it gives 644 participants per arm for 80% power and 862 participants per arm for 90% power.

These figures are planning illustrations, not observed power and not evidence that the completed trial had a particular power. They depend on the observed effect and stated assumptions. The registry record does not report the trial’s own sample-size assumptions or justification. The illustration also describes equal allocation, while the primary outcome denominators are 87 and 88; it should not be read as a retrospective assessment of the study’s success.

What remains unspecified?

The registry does not report an analysis plan for the primary outcome, an adjustment strategy for secondary outcomes, a missing-data method, or an explanation of the result denominators. It lists one secondary outcome and no reported analyses. These gaps matter because an outcome’s estimate and uncertainty depend on the analysis population, model, assumptions, and handling of multiple comparisons. The posted numerical results can be described as reported, but fuller assessment of their statistical properties requires information not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists two outcome measures and posts one secondary endpoint in addition to the primary endpoint. It does not report a multiplicity plan, such as a hierarchy of hypotheses or an adjustment for testing more than one outcome. The secondary comparison is identified as unadjusted. Without a reported plan, the evidential weight of that p-value is difficult to assess in relation to the full set of outcomes that may have been considered. As a general statistical principle, unadjusted testing across multiple outcomes can increase the chance of a nominally notable result arising by chance.

The registry’s primary population is described as intent to treat: all randomized subjects with at least one post-baseline assessment after dispensing, according to randomized treatment. The primary results list 87 participants in one arm and 88 in the other, while enrollment is 89. The adverse-event summaries list 89 participants at risk in each group. The record does not explain the differences in denominators, identify the participants without primary outcome data, or describe how missing observations were handled.

It is therefore not possible to determine whether missingness was related to treatment, outcome, period, or other factors. The registry does not report an imputation method, a sensitivity analysis, or a detailed flow of participants through each crossover period. The primary population definition specifies a minimum post-baseline assessment but does not fully describe how participants with incomplete period data contributed to each outcome.

The registry also does not report whether the secondary endpoint analysis used the same population definition as the primary endpoint. Nor does it provide a statistical analysis plan, an analysis model, or details of any prespecified handling of incomplete data. These are important limitations for interpreting precision and potential bias, especially in a crossover trial where availability of data from both periods may affect the analysis. The posted results remain useful descriptions, but the registry record does not support a complete assessment of multiplicity or missing-data consequences.

11. Safety Results

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

Other (non-serious) adverse events

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

The registry reports zero serious adverse events and zero other adverse events for each solution group. Each group lists 89 participants at risk for both categories. These are the counts posted for the registry’s adverse-event summaries; they do not provide detail about event definitions, collection procedures, or individual events. Deaths are not reported in the registry record.

As a general statistical point, a count of zero observed events is not proof that the underlying risk is zero. It means that no events in the specified category were recorded in the listed group during the reporting period. The registry does not state the adverse-event observation period or provide confidence intervals for event rates. The posted safety figures should therefore be read as event counts within the registry’s reporting, not as a precise estimate of risk or as evidence that the two solutions have identical safety profiles.

The crossover design and the adverse-event group summaries also require care: the registry lists 89 at risk in each group, but it does not explain the counting convention or participant exposure across treatment periods. These summaries alone do not establish how exposure time was considered. They describe the recorded serious and other adverse-event counts and should not be extended beyond those categories and reporting details.

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

The primary result describes the proportion of analyzed participants who met the registry’s composite acceptable-fit definition at Day 14. The posted percentage is 100.0% in each arm. This is a clear descriptive account of the participants included in those summaries, but it does not by itself establish that the treatments are equivalent, that their true outcomes are identical, or that all dimensions of lens performance are the same.

The secondary result describes change in conjunctival staining and gives an unadjusted comparison with a confidence interval and p-value. It is a distinct outcome, and its interpretation depends on the comparison’s statistical assumptions and on whether it was one of multiple outcomes considered. The registry does not report a clinically important threshold for the staining scale, a multiplicity plan, or a crossover-specific analysis. The estimate should therefore not be translated into a claim about clinical importance or overall treatment performance.

The record does establish that the study was randomized, triple-masked, and designed as a crossover, with two treatment sequences and a washout period described. Those features are relevant to the design, but the statistical details needed to evaluate their implementation and analysis are not reported. The registry does not describe the statistical model, treatment-period handling, carryover assessment, missing-data methods, or sample-size justification.

In general, a clinical trial result is strongest when the outcome definition, analysis population, statistical model, uncertainty, and decision criteria are all clearly specified. Here, the primary endpoint has no reported inferential comparison, while the secondary comparison is unadjusted and lacks a reported analysis plan. The results support a description of the posted outcomes and their precision where an interval is given; they do not justify a broader claim about comparative effectiveness, equivalence, or overall safety.

The findings also apply to the registered context: a marketed silicone hydrogel contact lens used with two named care solutions, assessed at Day 14. The registry does not provide enough information to extend the results to other lenses, solutions, populations, durations, or settings. The most defensible interpretation is bounded by the specific outcomes and timepoints that the record reports.

13. Why This Trial Matters Statistically

This trial illustrates why design and analysis need to be read together. A crossover design exposes participants to both treatments in sequence, so outcomes from the same person may be related. A comparison based only on treatment-arm summaries may not communicate how that within-participant structure was used. The registry identifies the crossover design and describes the sequences, but does not report the model or whether the analysis accounts for paired measurements, treatment period, or sequence.

It also illustrates the difference between a descriptive primary result and an inferential comparison. Both arms have the same posted acceptable-fit percentage, but no primary contrast or confidence interval is reported. Equal observed values are not a formal equivalence analysis. The record lacks the margin and analysis needed to determine whether clinically meaningful differences were ruled out.

The secondary result highlights the importance of distinguishing an unadjusted comparison from a complete analysis plan. Its confidence interval and p-value convey uncertainty under the method used, but the record does not report multiplicity handling or the role of the endpoint in confirmatory testing. The absence of a reported plan makes it harder to judge how much emphasis the result should receive.

Finally, the sample-size illustration is not the trial’s design justification. It is calculated from the observed effect under stated assumptions and gives planning examples, not observed power. Keeping those categories separate prevents a retrospective planning calculation from being mistaken for evidence that the trial was adequately sized or that its findings are conclusive. Together, these features make the record a useful example of how transparent reporting of methods, populations, and uncertainty shapes statistical interpretation.

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 registry record leaves several trial-specific details unresolved. Although it describes a randomized, triple-masked crossover study, it does not report the randomization method, the details of masking, or the statistical model used for either outcome. It does not say whether the analyses account for paired observations, period, sequence, or possible carryover. The minimum 1-day washout is described, but no assessment of washout adequacy or carryover is reported.

The primary outcome is reported as a percentage in each arm, but the registry provides no confidence interval, test, or estimated contrast. The equal values are therefore descriptive and cannot establish equivalence. The registry also does not post separate results for static movement, push-up movement, or centration, so the combined acceptability outcome cannot show which component contributed to the classifications.

The primary denominators differ from the enrollment total, and the registry does not explain why or describe missing outcome data. It does not provide a detailed participant flow across both treatment periods or report a missing-data method. The adverse-event groups list 89 participants at risk, but the record does not explain how exposure across crossover periods is counted.

The secondary result is unadjusted, and no multiplicity plan, clinical importance threshold, or reported analysis is given. The registry does not report the trial’s sample-size justification or any interim analyses. Finally, the arm title uses FID 114576A while the intervention and sequence descriptions use FID 114675A. The record does not clarify this label difference, so the exact naming should be read cautiously.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Clinical Performance of a Silicone Hydrogel Lens With Use of FID 114675A — NCT01240135.
• Registry record last updated 2012-07-12; status last verified 2012-06.
• Results first posted 2012-07-12.
• 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

NCT01240135 is a completed randomized, triple-masked crossover study sponsored by Alcon Research. It enrolled 89 participants and evaluated a marketed silicone hydrogel contact lens used with FID 114675A or renu fresh. The registry describes two 14-day treatment periods separated by a minimum 1-day washout.

The primary endpoint was acceptable lens fit at Day 14. The posted values are 100.0% in each arm, with 87 and 88 participants in the reported summaries. No inferential comparison for this endpoint is reported. One secondary outcome, mean change from baseline in circumlimbal conjunctival staining sum score, has a posted unadjusted comparison. The registry does not report a multiplicity strategy, a detailed analysis model, or a missing-data method.

Serious and other adverse-event counts are reported as zero in both groups, with 89 participants at risk in each. Deaths are not reported in the registry record. The arm label and intervention description use different identifiers for the investigational solution, and the record does not explain that inconsistency.