Evaluation of Marketed Soft Contact Lenses: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluation of Marketed Soft Contact Lenses (NCT05201807), a na na study. The primary outcome is Overall Quality of Vision Score.

2. Clinical Question

3. Trial Design

The registry describes Evaluation of Marketed Soft Contact Lenses as a completed, single-group study of Dailies Total 1 (DT1), also identified as delefilcon A. The recorded enrollment is 80. The study began on 2022-01-14, and primary completion was recorded as 2022-02-24. Its phase and allocation are listed as NA. The model is single group, and masking is listed as NONE.

The brief summary describes a bilateral, 2-week dispensing, non-randomized, controlled, single-masked, single-arm study intended to evaluate overall vision and comfort. These descriptions are not fully aligned: the registry lists masking as NONE, while the summary says single-masked; it also calls the study controlled while identifying a single arm and no separate comparator. The record does not explain these differences. Consequently, the study should be read as a single-group evaluation, not as a randomized comparison or a like-for-like control comparison.

The arm description says eligible subjects who were habitual soft contact lens wearers received the TEST Lens for the duration of the study. The primary outcome’s population is described as all subjects who completed all study visits without a major protocol deviation. The record does not report how many participants met that endpoint-population definition, how many completed follow-up, or how missing observations were handled.

The registry lists two outcome measures but no analyses. It does not report a numerical primary endpoint estimate, a comparison with another lens, or an inferential test. The design therefore supports describing the recorded experience in the studied group, but the registry entry does not supply the endpoint data needed to judge its observed level or uncertainty.

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 subjects that completed all study visits without a major protocol deviation.

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 a study lens.

6. Primary Endpoint

The registry lists the primary outcome as Overall Quality of Vision Score, measured over 2-Week Follow-up.

The primary endpoint is the Overall Quality of Vision Score at 2-Week Follow-up. It uses the vision component of the Contact Lens User Experience™ (CLUE) questionnaire, a validated patient-reported outcomes questionnaire developed to assess soft contact lens experience. Its attributes include comfort, vision, handling, and packaging. The registry describes its intended population as contact-lens wearers in the US, ages 18-65.

The endpoint is a continuous score. CLUE scores are derived using Item Response Theory and are described as following a normal distribution, with a population average score of 60 and SD 20. Scores range from 0-120, and higher scores indicate a more favorable or positive response. The study reports that the average CLUE vision score for each lens type was to be reported; the named lens type is DT1.

A patient-reported vision score is useful for describing how participants experience vision while wearing a lens, rather than relying only on a technical or clinical measurement. A continuous endpoint can convey both the average reported experience and variation among participants when its estimate and standard deviation are reported. However, the registry record does not report either value for this endpoint. It therefore does not establish the observed score, its precision, or how the group’s experience compares with another lens or a benchmark.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Several statistical ideas help interpret a continuous patient-reported endpoint, even though the registry record does not report the numerical endpoint estimate or an analysis. The general explanations below clarify what such statistics would mean; they do not imply that those analyses were reported for this study.

What does a mean describe?

For a continuous measure, the mean describes the average score among the participants included in the analysis. In this study, the intended measure is the CLUE vision score at 2-Week Follow-up. A mean alone does not show whether participants’ scores were tightly grouped or widely spread. It also does not describe every individual’s response. The registry record identifies the mean as the parameter of interest but does not report its observed value.

Why does the standard deviation matter?

The standard deviation describes variation in individual scores around their mean. In general, a larger standard deviation indicates more spread in the observed scores; a smaller one indicates less spread. It is not the same as the standard error, which describes uncertainty in an estimated mean. The registry identifies standard deviation as the measure of dispersion for the primary endpoint, but its value is not reported in the registry record. Without that value, the amount of observed variability cannot be assessed.

What would a confidence interval add?

In general, a confidence interval gives a range of values compatible with the data and the assumptions of the statistical method. For an estimated mean, it communicates uncertainty about the population mean, rather than the spread of individual participant scores. A narrow interval indicates greater precision under the method’s assumptions; a wide interval indicates less precision. The registry record does not report a confidence interval for the primary endpoint. It therefore does not permit an assessment of the estimate’s precision using an interval.

How should the scale reference be used?

The record describes CLUE scores as ranging from 0-120, with higher scores indicating a more favorable or positive response. It also reports a population average score of 60 and SD 20 as characteristics of the derived scores. These reference characteristics can help a reader understand the scale, but they are not a substitute for the DT1 study estimate. General interpretation requires keeping scale properties separate from results measured in this particular study.

What does a single-group design allow?

In general, a single-group study can describe outcomes among participants receiving the study intervention. It cannot, by itself, separate the intervention’s effect from other explanations for the observed experience, because it lacks a concurrent comparison group. The registry identifies this study as single group and lists only the TEST Lens arm. Although the brief summary uses the word “controlled,” it does not identify a separate control arm. The record does not report a randomized or adjusted comparison.

What is the status of the planning illustration?

The record describes a planning illustration based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. It also specifies that non-time-to-event planning quantities are expressed as participants per arm. These are planning assumptions, not evidence that the study was designed with two arms: the registry identifies the trial as single group. The record does not report the numerical illustration or the observed endpoint estimate on which it is based. Any such planning quantity is not observed power and should not be read as an analysis of this trial’s outcome.

More generally, planning calculations depend on the assumed effect, variability, allocation, and statistical model. A planning illustration explores what a hypothetical design might require under its assumptions; it does not show that a completed study had adequate power, nor does it replace a reported confidence interval or test. Here, the listed two-arm assumptions do not match the listed single-group structure. Without a reported observed mean and standard deviation, the basis and interpretation of the effect-based illustration cannot be checked against the endpoint results.

Finally, the registry’s description of the endpoint population matters for any statistical estimate. The specified population includes subjects completing all study visits without a major protocol deviation. In general, estimates from a restricted completion population may differ from estimates using everyone enrolled, especially if completion is related to outcome. The record does not report the size of that population, reasons for non-completion, or sensitivity analyses. Those omissions limit assessment of the analysis population as well as the outcome itself.

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("DT1 (Delefilcon A)")
n   <- c(78)
m   <- c(56.9)
sp  <- c(25.18)
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  DT1 (Delefilcon A)  78  56.900  25.180  51.223  62.577

11. Multiplicity, Missing Data and Analysis Populations

The registry lists two outcome measures, but it does not report their full statistical analysis plan, the role of each measure in testing, or whether any formal hypothesis tests were conducted. A multiplicity strategy is not reported in the registry record. In general, when several outcomes or comparisons are tested, the chance of at least one false-positive finding can increase unless the analysis accounts for multiple testing. That general concern cannot be quantified for this study from the available record, and it should not be taken to mean that a particular adjustment was or was not used.

The primary endpoint population is described as subjects who completed all study visits without a major protocol deviation. The registry does not report the number in that population, how many enrolled participants completed follow-up, or whether the endpoint was analyzed for anyone outside that definition. It also does not report how missing questionnaire items or missing visits were handled, whether data were imputed, or whether sensitivity analyses were performed. Missing-data methods can affect a continuous endpoint estimate, so the absence of this information limits evaluation of potential bias.

The record does not report a statistical analysis plan, prespecified estimand, or an analysis population beyond the endpoint’s completion-based description. The listed enrollment of 80 should not be interpreted as the number contributing to the primary endpoint. Without a reported denominator and missing-data approach, the completeness and representativeness of the analyzed observations cannot be assessed. These uncertainties are separate from the scale’s reference properties and remain even if an endpoint estimate is available elsewhere.

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 reports one adverse-event group, DT1 (Delefilcon A), with 80 at risk for serious adverse events and 0 affected. It also reports 80 at risk for other adverse events and 0 affected, with 0 deaths. These figures describe the registry’s recorded counts for the listed group; they do not supply event-rate estimates beyond those counts, and no such rates are calculated.

The serious-adverse-event figures should be read as counts of participants reported as affected, alongside the number recorded as at risk. They are not a measure of the primary vision endpoint, and they do not describe the magnitude or precision of a CLUE score. The registry lists no top serious-event terms. The record does not state the adverse-event observation period or provide further detail on event collection and classification.

A recorded count of 0 affected does not establish that an event is impossible or that no event could occur in another setting. It means that the registry reports no affected participants in the listed category for this group. The enrollment and adverse-event at-risk figures do not establish the primary endpoint population size, which is not reported in the registry record.

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

The record identifies a completed evaluation of a marketed soft contact lens and specifies a patient-reported vision outcome after 2-Week Follow-up. It describes the scale, its direction, and the population intended for the primary endpoint. Those details clarify what the study set out to measure: the average reported quality-of-vision score among subjects completing study visits without a major protocol deviation.

However, the registry does not report the observed mean or standard deviation for that endpoint. It also does not report a confidence interval or inferential test. Consequently, the posted results do not establish the group’s observed score, how variable participant scores were, or how precisely an average was estimated. The scale’s general reference mean and SD describe the measure, not the study’s DT1 outcome.

The single-group design has an important interpretive boundary. With no separate comparator listed, the record cannot establish how DT1 compares with another lens or with a control condition. A score observed after lens use would be descriptive of the study group; by itself, it would not identify an effect attributable to the lens. The summary’s wording about a controlled study does not resolve this issue because a control arm is not identified in the registry entry.

The recorded enrollment is 80, but the endpoint population is restricted by completion of all study visits without a major protocol deviation. The number meeting that criterion and the handling of missing observations are not reported in the registry record. Thus, the enrollment figure should not be used as the endpoint denominator.

These limitations do not negate the study’s descriptive aim. They define what can and cannot be inferred from the posted record: it documents the measure and design, but does not furnish the primary outcome estimate needed to assess the observed vision score or its precision.

14. Why This Trial Matters Statistically

This study illustrates why a clear endpoint definition is only one part of interpreting a clinical evaluation. The registry names a patient-reported vision measure, specifies its scoring direction and range, and identifies the follow-up time. That helps readers understand what a numerical estimate would represent. Yet without the mean and standard deviation, the central descriptive result is not available in the registry record.

It also demonstrates the distinction between scale references and study findings. The record gives a population average score of 60 and SD 20 for the derived CLUE scores. Those details explain the measure’s context, but they cannot stand in for an observed score among participants using DT1. Separating a measure’s reference characteristics from trial estimates is essential to avoid reading background information as an outcome.

The design descriptions further show why registry fields need to be read together. A single-group model and one listed arm do not identify a comparator, even though the brief summary calls the study controlled. Similarly, the masking field says NONE while the summary says single-masked. The record does not reconcile these descriptions, so a reader should avoid assuming a masked or comparative design beyond what is explicitly specified.

Finally, the planning assumptions refer to a hypothetical two-arm allocation, whereas the listed study is single group. Planning calculations can illustrate design requirements, but they do not replace observed outcome estimates or convert a single-group study into a comparison. This case highlights the importance of reporting analysis populations, missing-data handling, and endpoint estimates alongside design descriptions. Without those elements, the record supports a careful account of what was measured, but not a precise assessment of the study’s primary 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.

Several limitations are specific to interpreting this record. First, the primary endpoint estimate and its standard deviation are not reported in the registry record. The absence of those values prevents evaluation of the observed average and response variability. No confidence interval or inferential analysis is reported, so statistical precision and evidence from a formal test cannot be assessed.

Second, the registry identifies a single-group model and lists only the TEST Lens arm. A separate comparator is not reported. The brief summary describes the study as controlled, while also calling it single-arm; the registry does not explain the wording. The record likewise lists masking as NONE, whereas the brief summary says single-masked. These discrepancies leave aspects of the design description unresolved.

Third, enrollment is recorded as 80, while the primary endpoint population is defined by completing all study visits without a major protocol deviation. The number meeting that definition is not reported. The record also does not describe missing-data handling, questionnaire completion, reasons for non-completion, or sensitivity analyses. This makes it difficult to assess how representative the endpoint population may be.

Finally, the planning assumptions describe equal allocation between two arms, despite the listed single-group design, and the numerical planning illustration is not reported in the registry record. The record does not provide the statistical analysis plan or explain how any planning exercise relates to the enrolled study. These limitations constrain interpretation of the posted information and should not be filled in by assumptions about the protocol.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Evaluation of Marketed Soft Contact Lenses — NCT05201807.
• Registry record last updated 2023-03-15; status last verified 2023-02.
• Results first posted 2023-03-15.
• 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

Evaluation of Marketed Soft Contact Lenses is listed as a completed, single-group study of Dailies Total 1 (DT1), a delefilcon A device. Recorded enrollment is 80. The registry identifies the primary endpoint as the average Overall Quality of Vision Score from the CLUE questionnaire at 2-Week Follow-up. Higher scores are described as more favorable, on a scale ranging from 0-120.

The primary endpoint population is defined as subjects completing all study visits without a major protocol deviation. The registry record does not report the endpoint mean, standard deviation, confidence interval, or inferential analysis, nor does it report the size of that endpoint population or missing-data methods. No separate comparator arm is listed. Serious adverse events are recorded as 0 affected among 80 at risk; other adverse events are also 0 affected among 80 at risk, and deaths are 0. The study summary and registry fields differ on masking and control descriptions, with no explanation of the discrepancy.