Clinical Characterization of Symptomatic Populations: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Clinical Characterization of Symptomatic Populations (NCT03319212), a na na study. The primary outcome is Meibomian Gland Imaging.

2. Clinical Question

The study concerns people with symptoms as well as people without symptoms, in a clinical characterization investigation involving contact lens wear. The registry identifies ametropia as the condition and describes the enrolled group as current spherical soft contact lens wearers aged 18-55. Participants were assigned to a single study lens type, worn bilaterally for approximately 4 weeks, followed by 1 week without contact lenses.

This is a question about measurements in a single study group over scheduled visits, not a randomized comparison of lens types or treatments. The registry lists six secondary outcome topics concerning conjunctival findings, corneal staining, and tear-film characteristics. It does not report a numerical result for the primary outcome or describe how any change was estimated. Consequently, the clinical question can be characterized from the planned measurements and study population, but the posted record does not answer it with an effect estimate.

3. Trial Design

The investigation is registered as completed and is described as an unmasked, non-randomized, single-arm, stratified, dispensing investigation. Allocation is listed as NA, masking as NONE, and the model as SINGLE GROUP. The phase is recorded as NA. Enrollment is 105. The registry records the start date as 2017-09-29 and the primary completion date as 2018-08-15.

The intervention is senofilcon A contact lenses. The arm description says that current spherical soft contact lens wearers aged 18-55 were assigned to a single study lens type, worn bilaterally for approximately 4 weeks, followed by a week without contact lens wear. The brief summary refers to symptomatic and asymptomatic populations. It does not provide further details about how those populations were defined or stratified, or how assignment to the lens type was conducted.

The registry labels the arm Active Comparator, but its overall design is a single group and the record does not describe a separate control arm. The label should not be interpreted as evidence of a randomized or concurrent control comparison. The study can support a description of measurements collected during and after the specified lens-wear period, subject to the absence of posted outcome analyses. It cannot, from this design description alone, isolate an effect relative to an alternative lens or to a control group.

The primary outcome is meibomian gland imaging at the 4-Week Follow-up, with assessment described at baseline, during lens wear, and at the 5-Week Follow-up on bare eyes. The primary outcome population is defined as subjects who successfully completed all visits and did not substantially deviate from the protocol, according to a trial cohort review committee decision before database hardlock. Further details of the protocol, the stratification procedure, and the statistical plan are not reported in the registry record.

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: Subjects were stratified into two subject groups: symptomatic (baseline CLDEQ-8 score of 15 or greater) and asymptomatic (baseline CLDEQ-8 score of 7 or lower).

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: All subjects who have successfully completed all visits and did not substantially deviate from the protocol as determined by the trial cohort review committee prior to database hardlock.

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 Meibomian Gland Imaging, measured over 4-Week Follow-up.

The primary outcome is meibomian gland imaging, expressed as area of loss and recorded in eyes. The registry describes assessment in each subject eye at baseline, at the 4-Week Follow-up during lens wear, and at the 5-Week Follow-up on subjects' bare eyes. The specified primary time frame is the 4-Week Follow-up.

The grading scale has five degrees: Degree 0 is approximately 0%; Degree 1 is ≤ 25%; Degree 2 is 26% - 50%; Degree 3 is 51% - 75%; and Degree 4 is ≥ 75%. These grades describe categories of area loss rather than a continuous measurement reported with a unit such as a length or volume. The registry does not state a specific summary measure, such as a mean grade, a proportion in each grade, or a change from baseline.

In general, a structured grading scale can make image assessments easier to categorize consistently and can describe the extent of a feature in clinically interpretable bands. That rationale is general; the registry does not report validation details, reader training, image-reading procedures, or how reliability was assessed for this scale. The endpoint is relevant to the stated objective of clinical characterization because it records an ocular feature across scheduled assessments. However, without posted results or an analysis method, the grades cannot be used to quantify the extent or precision of any change in this study.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical interpretation begins with identifying what was measured, in whom, and at which visit. In this investigation, the primary measure is an ordinal imaging grade for area of meibomian gland loss, recorded in eyes. The record specifies baseline, a 4-Week Follow-up during lens wear, and a 5-Week Follow-up on bare eyes. The primary time frame is the 4-Week Follow-up. It does not specify the primary contrast or summary statistic, so an analysis cannot be reconstructed from the outcome description alone.

What does an ordinal grade mean?

An ordinal scale groups observations into ordered categories. A higher degree in this scale corresponds to a larger stated range of area loss, but the distance between adjacent degrees is not necessarily equal. In general, that means a difference of one degree should not automatically be interpreted as the same amount of change throughout the scale. Analyses may describe category counts, use rank-based approaches, or use models designed for ordered outcomes, depending on the question and assumptions. The registry does not state which approach was used, or whether any approach was used.

The category definitions should also be read literally. Degree 1 is listed as ≤ 25%, Degree 2 as 26% - 50%, Degree 3 as 51% - 75%, and Degree 4 as ≥ 75%, while Degree 0 is approximately 0%. The record's wording makes the 75% boundary appear in both Degree 3 and Degree 4. It does not explain how an observation at that boundary was classified. That is a reporting ambiguity, not a basis for selecting a category or altering the scale.

Why do the unit and visit structure matter?

The endpoint is recorded in eyes, while the study population consists of subjects. Measurements from two eyes of the same subject, if both contribute, are generally not independent: they share characteristics of the same person and study experience. Repeated observations from the same eye at multiple visits can also be correlated. In general, an analysis that treats correlated measurements as independent can understate uncertainty. Methods for paired or repeated measurements can account for such dependence, but the registry record does not report whether the analysis used such methods or how the eye-level data were handled.

The schedule distinguishes assessment during lens wear from assessment on bare eyes. In general, visit timing and lens-wear status are part of the definition of the measured condition, so results at different visits are not automatically interchangeable. A comparison across visits would need to specify whether it concerns change from baseline, a follow-up value, or another contrast. The registry provides the visit descriptions but does not state the planned comparison, how baseline values were handled, or whether the 5-Week Follow-up was part of the primary analysis.

What can a confidence interval tell a reader?

In general, a confidence interval expresses the uncertainty around an estimated quantity under the assumptions of the analysis. A narrower interval indicates greater statistical precision, while a wider interval indicates less precision. It does not eliminate concerns about bias, the appropriateness of the model, or the study design. No confidence interval for the primary outcome is reported in the registry record, and no point estimate is provided from which precision could be assessed. The absence of an interval should not be interpreted as evidence that there was no change; it means the posted record does not quantify the outcome.

A p-value, in general, describes how compatible data are with a specified null model under the assumptions of a particular test. It is not the probability that a hypothesis is true and does not describe the size or practical importance of an effect. No primary outcome p-value or test is reported. Since there is no posted primary estimate or test result, a significance claim would not be supported by the registry record.

How should planning calculations be read?

Planning illustrations are not observed trial results. The stated illustration assumptions use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. For outcomes other than time-to-event outcomes, the stated convention is participants per arm; for time-to-event outcomes, it is the total number of events under a Schoenfeld approach. These are generic planning assumptions, not a description of the actual single-group design, which has allocation listed as NA and no separate control arm described.

In general, sample-size planning asks how much information a proposed design may need for a specified effect and analysis assumptions. It does not show that a study actually achieved a particular power, and it does not replace a confidence interval or observed estimate. The registry record does not report the trial's own sample-size justification. It also does not report a planned effect size, a sample-size target by group, or a statistical model for the primary endpoint. Any planning illustration based on a two-arm allocation therefore should not be mistaken for the design or analysis conducted in this single-group investigation.

Finally, the record identifies 11 outcome measures but reports 0 analyses. An outcome listing documents what was intended to be measured; it is not evidence that results were analyzed or reported. Statistical interpretation requires the observed outcome data, a defined analysis population, a specified estimand or contrast, and an account of uncertainty. Those elements are not available for the primary endpoint in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 11 outcome measures. The six secondary outcome topics are conjunctival redness, conjunctival staining, corneal staining, tear film lipid layer thickness, tear film stability, and tear film lipid pattern. Meibomian gland imaging is the named primary outcome. The registry record does not report a multiplicity strategy, a hierarchy among secondary outcomes, or which outcomes were intended to support confirmatory conclusions.

In general, when several outcomes or comparisons are tested, the chance of at least one apparently unusual result can increase if each is interpreted separately without accounting for the family of analyses. Methods such as a prespecified hierarchy or an adjustment to testing can address aspects of this issue, but the appropriate method depends on the study question and analysis plan. No such method is reported. The number of analyses reported is 0, so there are no posted outcome tests to interpret for multiplicity.

Missing-data handling is not reported in the registry record. The primary outcome population is described as subjects who completed all visits and did not substantially deviate from protocol, as determined by the trial cohort review committee before database hardlock. The number of people meeting that definition, the number excluded, the reasons for missing visits or measurements, and any imputation or sensitivity analysis are not reported.

In general, restricting an analysis to participants with complete follow-up can affect interpretation if the availability of data is related to outcomes or participant characteristics. This is a general concern, not evidence that such a pattern occurred in this study. The registry does not identify an intention-to-treat population, a per-protocol population beyond the completion and deviation description, or any other analysis set. It also does not report how eye-level observations were included when a participant had incomplete measurements.

11. 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 safety summary lists the Senofilcon A group with 81 participants at risk for serious adverse events and 81 at risk for other adverse events. It reports 0 affected in the serious category, 0 affected in the other category, and 0 deaths. These are counts in the posted safety record, not rates or comparative estimates.

The at-risk count is not the same as the enrollment figure of 105. The registry does not explain why these counts differ or specify whether the safety group includes all enrolled participants. The figures should therefore be read as recorded for the safety summary rather than used to infer the disposition of the full enrolled population.

A zero count means that no affected participants are listed in that category in this registry summary. It does not establish that an event was impossible or that the intervention has no safety risks. General interpretation of safety counts depends on how events were defined, collected, attributed, and followed; those details are not reported in the registry record. The summary also does not provide event descriptions, timing, duration, or severity details beyond the serious versus other grouping. It should be read as limited descriptive information, not as a complete safety assessment or a comparison with another group.

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

The registry record can establish that a completed, unmasked, non-randomized, single-group investigation was conducted with senofilcon A contact lenses and that meibomian gland imaging was designated as the primary outcome. It describes an assessment schedule during lens wear and after lens discontinuation, an ordinal area-of-loss grading scale, and several secondary outcome topics. The safety listing records zero affected participants in the serious and other adverse-event categories and zero deaths among the listed at-risk group.

Those details do not quantify the primary outcome. No imaging grade distribution, change estimate, confidence interval, p-value, or analysis method is reported. Thus, the posted results do not show how the measured outcome varied, how large any variation was, or how precisely it was estimated. The absence of reported outcome results is not evidence of no change, nor does it establish a favorable or unfavorable finding.

The design also limits what could be inferred even if measurements across visits were available. A single-group, non-randomized study has no separate concurrent control group described in the registry. A difference between visits could be described, but it could not by itself distinguish an effect of lens wear from other influences that change over time. The study is also unmasked, so the record does not establish that assessment was protected from knowledge of lens exposure.

The study population and the primary analysis population are not identical descriptions: the enrollment figure is 105, while the primary outcome definition requires completion of all visits and no substantial protocol deviation. The number included in the outcome analysis is not reported. The registry therefore supports a clear account of the planned measurement and the available safety counts, but it does not support a numerical claim about primary outcome effects, their precision, or a causal comparison.

13. Why This Trial Matters Statistically

This trial is statistically informative as an example of why design labels, outcome definitions, and result reporting must be read together. The arm is labeled Active Comparator, yet the overall model is listed as SINGLE GROUP, allocation is NA, and no separate control group is described. A reader who relies on the arm label alone could mistakenly treat the study as a comparative trial. The design description is the more direct guide to the kind of inference the record can support.

The primary endpoint also illustrates the distinction between collecting measurements and reporting an analyzable result. The registry identifies an eye-level ordinal grade, a time frame, and assessments at three visits, but does not give the outcome distribution, a selected contrast, or a method for accounting for repeated eye-level observations. Without those details and an estimate with uncertainty, a measurement plan cannot be converted into a quantitative conclusion.

Enrollment and analysis populations are another important distinction. The record lists enrollment of 105 but defines the primary outcome population by visit completion and protocol adherence. It does not state how many subjects met that definition. Clear reporting of participant flow and analysis sets helps readers understand which observations contribute to an estimate and how missing measurements may affect its interpretation.

Finally, a registry may contain useful information even when it has no posted analysis results. In this case, the design, endpoint scale, timing, secondary outcomes, and safety counts are described, while the primary outcome analyses are not. That contrast shows why a completed status is not itself evidence that results are available or that a treatment effect has been estimated. Statistical conclusions require reported results and an account of their uncertainty and limitations.

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 principal limitation of interpretation is the absence of posted primary outcome analyses. The registry lists meibomian gland imaging and its grading scale but provides no numerical outcome results, estimate, confidence interval, or test. The number of analyses reported is 0. Consequently, the magnitude and precision of any observed pattern cannot be assessed from the registry record.

The single-group, non-randomized design does not provide a separate control comparison. The study is also unmasked. These design features limit causal interpretation and leave open the possibility that changes over visits could reflect factors other than lens wear. The registry does not report procedures intended to reduce assessment bias or adjust for potential differences among participants.

The population description is incomplete for detailed interpretation. The brief summary refers to symptomatic and asymptomatic populations, while the arm description specifies current spherical soft contact lens wearers aged 18-55. Definitions of symptom status and details of stratification are not reported. The primary outcome population excludes subjects who did not complete all visits or substantially deviated from protocol, but the number meeting the definition and the reasons for exclusions are not reported.

The endpoint is categorized by an ordinal scale, and its stated Degree 3 and Degree 4 ranges both include the 75% boundary. The record does not explain how that boundary was handled. It also does not report the image assessment procedures, reader reliability, statistical handling of repeated visits, or how measurements in eyes were incorporated into analysis. These omissions make it difficult to assess measurement consistency and the appropriateness of any potential analysis.

Further details about missing-data methods, multiplicity, the statistical plan, and the trial's sample-size justification are not reported in the registry record. The safety counts are descriptive and do not include detailed event narratives or a control group for comparison. These limitations apply to interpretation of the registered information; they do not establish what may have been available outside the registry.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Clinical Characterization of Symptomatic Populations — NCT03319212.
• Registry record last updated 2019-10-15; status last verified 2019-10.
• Results first posted 2019-10-15.
• 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.

18. Record Summary

The registry identifies a completed, unmasked, non-randomized, single-group dispensing investigation of senofilcon A contact lenses in symptomatic and asymptomatic populations. Enrollment is 105. The study lens was to be worn bilaterally for approximately 4 weeks, followed by 1 week without contact lens wear. The primary outcome is meibomian gland imaging, assessed in eyes and graded by area of loss at baseline, the 4-Week Follow-up, and the 5-Week Follow-up. The primary outcome population is defined by visit completion and absence of substantial protocol deviation.

The record lists 11 outcome measures and reports 0 analyses. It provides no numerical primary outcome result or statistical uncertainty. Its safety summary lists 81 at risk for serious events and 81 at risk for other events, with 0 affected in either category and 0 deaths. A separate control group, detailed missing-data methods, multiplicity procedures, and the statistical analysis plan are not reported in the registry record.