One-Day Dispensing Clinical Evaluation of SofLens Daily Disposable Lenses Compared to a Marketed 1 Day Contact Lens: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for One-Day Dispensing Clinical Evaluation of SofLens Daily Disposable Lenses Compared to a Marketed 1 Day Contact Lens (NCT00902850), a randomized na study. The primary outcome is Clinical Performance.

2. Clinical Question

3. Trial Design

The registry describes a randomized, double-masked, parallel-group study of two contact lens products. The named study was a one-day dispensing clinical evaluation, and its stated objective was to compare clinical performance of SofLens Daily Disposable lenses with a marketed 1 Day Contact Lens. The official title identifies the comparator as 1-Day Acuvue TruEye Lenses. The condition listed is myopia.

The registry reports enrollment of 28 and a completed status. It records a study start of 2008-10 and primary completion in 2008-11. These dates describe the registry record; they do not provide further detail about the conduct of the one-day assessments. The record does not state how participants were allocated between the arms, whether every enrolled participant received a lens, or whether anyone discontinued or was excluded from an analysis.

Randomization is intended to assign participants by chance, which can reduce systematic differences between comparison groups. It does not guarantee that groups will be alike in every characteristic, particularly in a study with limited enrollment. Double masking indicates that the study is recorded as double-masked, but the registry record does not specify who was masked, how masking was maintained, or whether masking was assessed. A parallel design means the arms are compared as groups rather than being described as a sequence of crossover periods; the record does not provide a more detailed protocol description.

The registry lists one primary outcome measure, clinical performance, and gives a participant-rated comfort score across multiple assessment times and sensory components. It lists no analyses. The definition of randomization procedures, the protocol's statistical plan, its analysis populations, and any sample-size justification are not reported in the registry record. Enrollment alone should not be treated as evidence that the study had adequate precision to detect a particular difference.

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.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: All eligible participants

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 Clinical Performance, measured over Insertion, 4 hours & End of Day.

The primary endpoint is described as comfort of lens wear, recorded as a number on a 0-100 scale and graded by participants. The assessment was made at insertion, 4 hours after insertion, and at the end of the day, for which the registry gives a wear-time of 8-16 hours. The score included lens edge awareness, scratchiness or grittiness, foreign body sensation, and general lens awareness. The stated population for the outcome is all eligible participants.

Participant ratings can capture experiences that are not fully represented by a physical examination or device measurement. A scale also provides a structured way to record subjective experiences and compare them across groups or assessment times. These are general features of patient-reported measures, not evidence about how the scale performed in this study.

The registry does not state the direction of the scale, such as whether a higher score represents greater comfort or greater awareness of discomfort. It also does not describe the scale's validation, how the component sensations were combined, or a threshold for a meaningful difference. The individual component ratings and the recorded group values are not reported in the registry record. Consequently, the outcome definition explains what participants were asked to rate, but it does not show the observed comfort level or establish which product had higher or lower ratings.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods are useful only when the outcome, comparison, analysis population, and assumptions are sufficiently specified. In this study, the registry identifies a participant-rated comfort outcome and three assessment occasions, but it does not report an analysis plan or results. The concepts below are general explanations of how such data might be analyzed; they are not descriptions of methods used in this study unless expressly stated in the registry record.

What does a group comparison estimate?

A comparative analysis would summarize comfort ratings for the two lens groups and estimate a contrast between them. The chosen contrast might concern scores at one assessment time or a pattern across the assessment times. The registry does not report which contrast was prespecified or analyzed. It also does not provide scores, distributions, or an estimated contrast. Therefore, no effect estimate can be interpreted for this study from the registry record.

For a scale outcome, an analyst may examine the distribution of scores and choose a summary and model suited to the data. A mean describes a distribution's arithmetic center, while a median describes its middle value after ordering. A model can account for design features and relevant covariates, but its specification must be stated and justified. The record does not say whether scores were summarized by means, medians, or another measure, or whether any covariate adjustment was planned.

Why do repeated assessments matter?

Ratings from the same participant at insertion, 4 hours, and the end of the day are not necessarily independent observations. In general, measurements from one person can be related because they share characteristics and experiences. Treating all ratings as if they came from unrelated people can understate or otherwise mischaracterize uncertainty. A repeated-measures method can represent within-participant association, while separate analyses at each time can answer time-specific questions. Which approach is appropriate depends on the scientific question, data structure, and analysis plan. The registry does not report whether repeated-measures modeling or separate time-specific analyses were used.

The outcome also encompasses lens edge awareness, scratchiness or grittiness, foreign body sensation, and general lens awareness. Those features could be treated as parts of an overall rating or as distinct items, depending on how the instrument was designed and scored. The registry does not state whether the ratings were combined, whether each item was analyzed separately, or how missing item responses were handled. These details matter because different definitions of the outcome can lead to different interpretations.

What does a confidence interval add?

In general, a confidence interval communicates uncertainty around an estimated effect. A narrow interval indicates greater precision under the model's assumptions; a wide interval indicates less precision. The interval's endpoints are not a guarantee that the true effect lies within them, and interval interpretation depends on how the analysis was conducted. No confidence interval or effect estimate is reported in the registry record, so precision cannot be evaluated for the comfort comparison.

A p-value is also not reported. Generally, a p-value describes the compatibility of the observed data with a specified null hypothesis and model assumptions. It does not measure the probability that the null hypothesis is true, and it does not provide the size of an effect. A small p-value would not by itself establish practical importance; a larger p-value would not demonstrate equivalence. This distinction is especially important when results and uncertainty estimates are absent.

How should planning illustrations be read?

General sample-size planning asks how many participants may be needed to detect a chosen effect at a chosen significance level and power under specified assumptions. The registry's planning description says its illustration is computed from the observed effect, uses a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. It also states that the effect to detect is a stated fraction of the observed effect. Such illustrations are planning exercises rather than observed results or proof that the trial had a particular power.

The registry does not report the study's own sample-size justification or design assumptions. The planning description does not establish that these assumptions governed the actual trial, and no numerical planning estimates are included in the registry record described for this study. In general, planning estimates depend on the assumed effect and variability, the intended analysis, and the required precision or power. When the observed effect is used as a planning anchor, the illustration should not be confused with a prospective design rationale.

What does over-dispersion mean in general?

Over-dispersion is a general concern for count outcomes when variability exceeds what a chosen model assumes. It can make standard errors too small if the model does not account for the extra variation. The primary outcome in this study is described as a participant-graded number on a 0-100 scale, not as a count of events. The registry does not report an outcome model, a dispersion assessment, or a statistical analysis. No claim about over-dispersion or a method to address it can therefore be made for this trial.

Overall, the registry record leaves the central inferential steps undocumented: the analysis population, the definition of the primary contrast, the treatment of repeated ratings and outcome components, the handling of missing observations, and the method for estimating uncertainty. General statistical principles clarify why those details matter, but they cannot substitute for the absent study-specific results and methods.

10. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when several hypotheses or contrasts are examined, because repeated testing can increase the chance of at least one apparently notable result even when no underlying difference exists. General approaches include prespecifying a primary contrast, adjusting for multiple comparisons, or clearly labeling analyses as exploratory. The registry describes comfort at insertion, 4 hours, and the end of the day, and includes several sensory components in the score. Its note says the outcome has several categories or time points and was not reduced to one comparison. The registry does not report a multiplicity strategy, a hierarchy of comparisons, or which time or component would be primary for testing.

Missing-data handling is also not reported. The record does not state whether every participant provided ratings at every assessment, how incomplete questionnaires were treated, or whether any imputation or sensitivity analysis was used. Missingness can matter if participants with recorded scores differ systematically from those without scores. General methods range from analyses of available observations to model-based approaches, but the suitability of any method depends on why data are missing and on assumptions that should be stated. No such study-specific information appears in the registry record.

The registry identifies all eligible participants as the outcome population, but it does not define an analysis population or specify how participants were included after randomization. It does not state whether the analysis followed randomized assignment, was restricted to participants who wore lenses, or used another rule. The number of analyses is listed as 0, and no participant flow or comfort analysis is reported. Consequently, the handling of exclusions, adherence, and missing ratings cannot be assessed. These gaps limit interpretation independently of the absence of effect estimates.

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 0% reporting threshold.

The registry reports serious adverse event counts for both lens groups. For SofLens Daily Disposable, 0 of 28 participants at risk are listed as affected by a serious adverse event. For the Marketed 1 Day Contact Lens, 0 of 28 participants at risk are listed as affected. The record also lists 0 of 28 at risk as affected for other adverse events in each group. These are the recorded counts, not estimates of comparative risk with uncertainty.

A zero count means that no affected participants are listed in the registry's safety fields for the stated groups. It does not prove that an event is impossible or that the underlying event rate is zero. The precision of a rate estimate depends on the amount and duration of observation as well as the event counts. Although the study is described as a one-day evaluation, the record does not give detailed safety surveillance procedures, event definitions, or a separate duration of safety follow-up.

The death fields are null, and the registry does not provide a death count. A null entry should not be interpreted as a reported zero. The serious-event terms list is empty, so no specific serious adverse event terms are included. These safety entries should be read as registry reporting, not as a complete account of all possible harms or as a basis for comparing safety between products.

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

The registry record identifies a completed randomized, double-masked, parallel study of SofLens Daily Disposable lenses and a marketed 1 Day Contact Lens. It states that 28 participants were enrolled and that the study concerned clinical performance in myopia. Its primary outcome was participant-rated comfort across insertion, 4 hours after insertion, and the end of the day, with end of day described as 8-16 hours of wear-time. This information clarifies the question and measurement, but does not provide the outcome values needed to answer the comparison.

The record does not report group scores, a difference between groups, confidence intervals, p-values, or analyses. As a result, it is not possible to determine from the posted results whether ratings differed, how large any difference was, or how precisely it was estimated. It would be incorrect to treat the lack of a reported analysis as a finding of no difference. It would also be unsupported to claim that one lens produced greater comfort or less awareness of discomfort.

The scale's direction is not reported, and the record does not explain how the listed sensations were combined or whether each was assessed separately. Even if a score comparison were available, understanding its meaning would require knowing what higher and lower values represent, how the measurement was constructed, and whether a difference was important to participants. The registry does not state a threshold for meaningful change.

The adverse-event fields list no affected participants for the listed categories in either group, while the death fields are null. Those entries are limited safety reports and do not establish that no adverse event could occur or that the products have identical safety. The record also omits detailed follow-up and analysis information needed to assess the completeness of safety reporting.

In general, a trial's interpretation depends on its design, the quality and completeness of outcome measurements, and the uncertainty around its estimates. The registry supports description of the study design, intended comfort assessments, and recorded safety counts. It does not support a quantitative judgment about comparative comfort, a claim of equivalence, or a broader conclusion beyond the one-day evaluation described.

13. Why This Trial Matters Statistically

This trial illustrates an important distinction between a clearly stated research question and an interpretable statistical result. The registry names the two lens groups, describes a participant-rated comfort outcome, and specifies assessment times. Yet it does not report the group measurements or an analysis. A defined endpoint is necessary for an evaluation, but it cannot show the direction or size of a comparison without results.

The study also highlights why outcomes measured repeatedly within participants need an explicit analysis strategy. Ratings at insertion, 4 hours, and the end of the day may address different aspects of the wear experience, and observations from the same participant may be related. The registry's note that the outcome was not reduced to one comparison makes the missing analysis definition particularly relevant. Without a prespecified contrast or reported estimates for the assessment times, readers cannot identify which comparison was intended to carry the main inference.

Precision matters as much as the direction of an estimate. An estimate without an uncertainty interval may be difficult to distinguish from random variation, and a statistical test alone would not communicate practical importance. Here, neither an estimate nor an interval is reported. The enrollment figure cannot replace those quantities or demonstrate adequate precision.

Finally, the record distinguishes a planning illustration from the trial's own design rationale. General sample-size calculations depend on assumptions and are not observed evidence. The registry's description of an illustration does not document the study's actual sample-size justification or statistical plan. Taken together, the record is useful for understanding what the study set out to measure, while also showing why outcome reporting and transparent analysis methods are essential for 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 main limitation for interpretation is that the registry record does not report the primary comfort scores or any comparative analysis. Without these results, the study's effect size and precision cannot be assessed. The record also does not give a scale direction, a meaningful-difference threshold, or details about how the sensory components were combined. Those omissions prevent a direct interpretation of what a score difference would mean.

The primary outcome involves multiple assessment times and several sensory components, but the record does not explain how they were handled analytically. It does not identify a primary time-specific contrast, describe a repeated-measures method, or report any adjustment for multiple comparisons. The registry explicitly notes that the outcome was not reduced to one comparison. This leaves the intended inferential target unclear.

Enrollment was 28, but the record does not provide participant flow, the number with available comfort ratings at each time, or the analysis population. It does not describe missing data, exclusions, adherence, or deviations from assigned treatment. These details are important for judging whether the reported outcome, if available, would represent the randomized groups.

The description of double masking does not specify who was masked or how masking was maintained. The randomization method and allocation procedures are not reported. The registry also does not report the trial's own sample-size rationale, protocol, or statistical analysis plan. These omissions limit assessment of bias, precision, and whether the final analysis matched the intended one.

The evaluation is described as one-day, and the findings therefore cannot be treated as evidence about longer-term wear. Safety reporting is limited to the listed adverse-event counts; the death fields are null, and detailed definitions and follow-up procedures are not reported. These limitations concern what can be concluded from the registry record, rather than proof that an unreported procedure or event did or did not occur.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: One-Day Dispensing Clinical Evaluation of SofLens Daily Disposable Lenses Compared to a Marketed 1 Day Contact Lens — NCT00902850.
• Registry record last updated 2015-03-02; status last verified 2015-02.
• Results first posted 2015-03-02.
• 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 describes NCT00902850, a completed, randomized, double-masked, parallel study sponsored by Bausch & Lomb Incorporated. It enrolled 28 participants and compared SofLens Daily Disposable lenses with a Marketed 1 Day Contact Lens, identified in the official title as 1-Day Acuvue TruEye Lenses. Myopia is the listed condition.

The primary outcome was participant-rated comfort on a 0-100 scale, assessed at insertion, 4 hours, and the end of the day, defined as 8-16 hours of wear-time. The measure included lens edge awareness, scratchiness or grittiness, foreign body sensation, and general lens awareness.

The registry lists no analyses and does not report comfort results or a between-group estimate. It records 0 of 28 affected for serious adverse events and 0 of 28 affected for other adverse events in each group; the death fields are null. The analysis plan, missing-data handling, and sample-size justification are not reported in the registry record.