This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Daily Disposable Comparison Study (NCT02094677), a randomized na study. The primary outcome is Lens Preference - Filcon II 3 and Etafilcon A or Filcon II 3 and Nelfilcon A.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02094677 |
| Phase | NA |
| Condition | Myopia |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 70 |
| Arms in the primary outcome | n/a |
| Lead sponsor | CooperVision, Inc. |
| Results posted | Yes |
2. Clinical Question
Population
Participants with myopia were enrolled. The registry record lists enrollment as 70. It does not report additional eligibility details or describe the characteristics of the participants included in each lens-pairing group.
Intervention
The study included the hydrogel lens filcon II 3. In each of the two pairings, participants were randomized to a test and control lens in a contralateral design. The record does not explain further how lens assignment or wearing periods were organized.
Comparator
The two stated pairings were filcon II 3 with etafilcon A and filcon II 3 with nelfilcon A. The record presents these as distinct groups. It does not report results that would establish a preference for either lens within either pairing.
Primary question
At the baseline visit, following insertion and settling for 10-15mins, how did participants report their preference between filcon II 3 and the paired lens? Responses could range from strongly preferring filcon II 3 to strongly preferring etafilcon A or nelfilcon A, with no preference as a middle option.
This is a question about participants’ stated preferences at a particular assessment, not a question about a clinical event or a long-term outcome. The registry record’s primary outcome title covers both lens pairings, while the arm descriptions identify them as separate groups. It does not report how preference responses were analyzed across the two groups or whether the same summary measure was intended for each. No category counts, effect estimate, uncertainty interval, or test result are reported in the registry record. Accordingly, the clinical question can be described from the recorded endpoint, but the posted information does not establish which lens was preferred or how consistent any preference was.
3. Trial Design
The registry record describes a completed study with randomized allocation, double masking, and a parallel model. It lists myopia as the condition and 70 as the enrollment. The study began in 2014-03, and primary completion is listed as 2014-04. The listed phase is NA. CooperVision, Inc. is identified as the sponsor.
Three device interventions are named: filcon II 3, etafilcon A, and nelfilcon A. The arm descriptions specify two lens pairings: filcon II 3 with etafilcon A, and filcon II 3 with nelfilcon A. For each pairing, participants were randomized to a test and control lens in a contralateral design. The record does not give more detail about which lens was assigned to which eye, the sequence of exposure, or whether participants used each lens for the same duration. It also does not explain how the contralateral assignment relates to the parallel-model classification.
The number of participants at risk for adverse events is listed separately for the two pairings: 40 for filcon II 3 and etafilcon A, and 30 for filcon II 3 and nelfilcon A. These figures describe the safety groups recorded for those outcomes; the registry record does not provide further accounting of participant flow or explain the relationship between these group counts and the enrollment figure.
The record lists 29 outcome measures, including the primary lens-preference outcome and secondary outcomes concerning comfort, dryness, and handling, including removal. It lists no analyses. Randomization and masking describe design features, but by themselves do not provide evidence about the size, precision, or direction of a result. Those depend on reported outcome data and the analysis, which are not available 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.
Overall Study
| Stage | Filcon II 3 and Etafilcon A | Filcon II 3 and Nelfilcon A |
|---|---|---|
| STARTED | 43 | 31 |
| COMPLETED | 40 | 30 |
| NOT COMPLETED | 3 | 1 |
Reasons for not completing this period:
| Reason | Filcon II 3 and Etafilcon A | Filcon II 3 and Nelfilcon A |
|---|---|---|
| Screening | 3 | 1 |
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.
| Characteristic | Unit | Filcon II 3 and Etafilcon A | Filcon II 3 and Nelfilcon A | Total |
|---|---|---|---|---|
| Participants analysed | 40 | 30 | 70 | |
| Age, Continuous | years | 28 (SD 9) | 33.1 (SD 12.4) | 30.2 (SD 10.8) |
| Sex: Female, Male: Female | Participants | 27 | 23 | 50 |
| Sex: Female, Male: Male | Participants | 13 | 7 | 20 |
| Region of Enrollment: Canada | participants | 40 | 30 | 70 |
6. Primary Endpoint
The registry lists the primary outcome as Lens Preference - Filcon II 3 and Etafilcon A or Filcon II 3 and Nelfilcon A, measured over Baseline visit.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary outcome is participants’ subjective preference between filcon II 3 and either etafilcon A or nelfilcon A. The assessment was scheduled at the baseline visit, following lens insertion and a settling period of 10-15mins, and was collected by questionnaire. The five response options were strongly prefer filcon II 3, slightly prefer filcon II 3, no preference, slightly prefer etafilcon A or nelfilcon A, and strongly prefer etafilcon A or nelfilcon A.
This endpoint captures a participant’s stated comparative impression at the specified assessment. It is different from an objective measurement of lens performance, and the registry description does not define a preference as evidence of a particular clinical benefit. The categories preserve distinctions in direction and strength of stated preference, as well as the possibility that a participant reports no preference.
As a general statistical point, a multi-category outcome can be summarized in different ways, and the choice affects what a result means. Category counts would describe the distribution of responses; a single contrast or score would require a clear definition of how categories are combined or compared. The registry record does not report such a scoring rule or category-level results. It therefore supports describing what the questionnaire asked, but not identifying a preferred lens from the posted results.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record gives the design and the endpoint definition, but it does not report primary outcome results. In particular, it does not provide the number of participants selecting each of the five preference categories in either lens pairing. It also does not report an effect estimate, confidence interval, or statistical test for preference. The recorded primary question is therefore identifiable, but its answer cannot be determined from the registry record.
The endpoint is categorical, with responses ranging from strong preference for one lens to strong preference for the other and including no preference. A result would need to make clear whether it describes the full distribution of categories, a chosen summary, or a particular comparison. These approaches answer different questions. For example, a distribution indicates how responses are spread across the available options, while a single contrast may combine or emphasize some options. No such analysis choice or result is reported in the registry record. The record also gives no basis for interpreting a change over time, since the stated primary assessment is at the baseline visit.
Randomized allocation and double masking are recorded design characteristics. In general, randomization is used to reduce systematic differences in assignment, and masking can limit some influences on participant or investigator assessment. Those design features do not substitute for outcome reporting: without the observed response counts and a defined analysis, the direction and precision of the preference result remain unknown. The registry record does not report details about how masking was implemented or maintained.
The study lists two comparison groups and separate adverse-event denominators of 40 and 30. These figures should not be treated as preference counts. The registry record does not connect the adverse-event denominators to the number of participants who completed the preference questionnaire, nor does it report outcome-specific denominators. It also does not explain whether any participants lacked a preference response or how such responses would have been handled.
The record lists 29 outcome measures, but no analyses. A count of registered outcomes is not a count of statistically tested comparisons, and no multiplicity procedure can be identified from the record. The listed secondary outcomes concern comfort, dryness, and handling, but their result values are not reported. Consequently, there is no basis for comparing primary and secondary findings or judging whether a pattern was consistent across outcomes.
Any sample-size illustrations associated with an observed effect should be read as planning exercises rather than as observed trial findings or evidence of power. General planning calculations can depend on assumptions about the target effect and allocation. No primary effect estimate is reported for this trial in the registry record, and no conclusion about the precision of its preference comparison can be drawn from a planning illustration alone.
9. Statistical Methods Explained
What does a five-category preference measure represent?
The primary outcome records a choice among five ordered response labels. The labels distinguish direction of preference, strength of preference, and no preference. In general, ordered categories carry more information than a simple preferred/not-preferred label, but the categories are not automatically equally spaced numerical values. Treating them as a score would require an explicit scoring rule, and treating them as a binary endpoint would require an explicit rule for combining categories. The registry record does not report either rule.
A descriptive presentation could retain all response categories, while an inferential analysis could compare distributions or define a focused contrast. These are general options, not a description of an analysis reported for this study. The record does not state which option was used. Its note that the primary outcome has several categories and was not reduced to one comparison is consistent with the absence of a single reported estimate, but it does not specify a replacement analysis.
How should randomization and the contralateral design be understood?
Randomization means that assignment is intended to be determined by chance rather than by participant or investigator choice. As a general principle, this can help avoid systematic assignment differences. The arm descriptions say participants were randomized to a test and control lens for each group in a contralateral design. A contralateral design generally involves comparisons involving the two eyes of a participant, but the registry record does not explain the implementation details for these lens assignments. It also separately classifies the study model as parallel. The record does not explain this combination, so the design labels should be reported as recorded rather than resolved by assumption.
Paired observations from two eyes can be statistically related because they come from one participant. As a general matter, an analysis that treats paired measurements as independent may misstate uncertainty. The registry record does not report the statistical method used to account for any within-participant dependence, and it lists no analyses. It is therefore not possible to assess from the record whether the analysis, if conducted, reflected the design’s pairing.
What do estimates and confidence intervals ordinarily tell readers?
In general, an effect estimate describes the size and direction of a comparison according to a defined measure. A confidence interval conveys uncertainty around that estimate under the assumptions of the analysis. A narrow interval indicates greater statistical precision than a wide interval, while an interval spanning values that would support different interpretations can leave the result uncertain. These concepts require an estimate and an interval to interpret. Neither is reported for the primary preference outcome in the registry record, so no precision assessment is possible.
A p-value, when reported, relates the observed data to a specified statistical model and a null hypothesis. It does not by itself describe the magnitude or importance of an effect. The registry record does not report a primary p-value or analysis model. No conclusion about statistical significance should be inferred from the design description or enrollment number.
What do the planning assumptions mean?
The stated planning assumptions describe an illustration rather than the trial’s own design justification: a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The illustrated effect to detect is a stated fraction of the observed effect. For time-to-event planning, the method is described as giving a total number of events using Schoenfeld; other planning outputs are described as participants per arm.
These are general planning conventions, not observed results. A planning calculation depends on its assumptions and the effect used as the target. The registry record does not report a protocol sample-size justification or identify these assumptions as the original design plan. It also does not report the observed primary effect needed to interpret a planning illustration for this endpoint. Such illustrations are not observed power and do not establish that the study could or could not detect a particular preference difference.
Because the registered primary outcome has several response categories and is not reduced to one comparison, a simple two-arm illustration may not directly represent the analysis of the full preference distribution. The record does not give a statistical model or a rule mapping the categories to a single effect. Any interpretation of a sample-size figure would need to take account of that missing definition rather than assume a particular binary, ordinal, or continuous analysis.
Why do outcome counts and analysis counts matter?
The registry record lists 29 outcome measures and no analyses. In general, having several outcomes raises questions about which outcomes were primary, which comparisons were planned, and how interpretation accounts for multiple opportunities to identify a result. A multiplicity adjustment is not always appropriate in every setting, but the analysis plan should make the intended comparisons clear. No multiplicity strategy is reported in the registry record, and no outcome-specific results are available to assess.
Similarly, the analysis population matters: results can differ depending on who was included and how missing measurements were handled. The record does not report analysis populations, participant flow for the preference outcome, missing-data methods, or an analysis plan. These omissions limit evaluation of the statistical methods beyond the information encoded in the endpoint and design descriptions.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists 29 outcome measures, including the primary preference measure and secondary measures concerning lens comfort, dryness, and handling. It lists no analyses. The record does not report a multiplicity strategy, such as a hierarchy of tests or an adjustment for multiple comparisons. Without an analysis plan and outcome results, it is not possible to determine which comparisons were tested or how any multiplicity was addressed. This matters because interpreting many results as if they were a single prespecified test can overstate the strength of evidence; that is a general statistical concern, not a finding about this trial.
Information about missing outcome data is not reported in the registry record. The record does not state how many participants completed the preference questionnaire, whether any responses were missing, or how missing responses were handled. It also does not report imputation methods or sensitivity analyses. A missing-data approach can affect both the estimated response distribution and its uncertainty, so those details would be needed to assess the analysis.
The analysis populations are not reported in the registry record. Although enrollment is listed as 70, the record does not state which participants were included in the primary analysis or provide participant flow for that outcome. The adverse-event denominators do not establish the preference analysis population. The record also does not report a protocol statistical plan, interim analyses, or a justification for the sample size. These items should be regarded as unknown rather than inferred from the completed status or the recorded design.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Filcon II 3 and Etafilcon A | 0 | 40 | 0.0% |
| Filcon II 3 and Nelfilcon A | 0 | 30 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Filcon II 3 and Etafilcon A | 0 of 40 |
| Filcon II 3 and Nelfilcon A | 0 of 30 |
For the filcon II 3 and etafilcon A group, the registry record lists 40 participants at risk for serious adverse events and 0 affected. It also lists 40 at risk for other adverse events and 0 affected. For the filcon II 3 and nelfilcon A group, it lists 30 at risk for serious adverse events and 0 affected, and 30 at risk for other adverse events and 0 affected. These figures describe what the record reports for the recorded groups; they are not estimates of lens preference.
The death fields are not reported in the registry record. The record does not give further details about the duration or completeness of adverse-event monitoring, event definitions, or how events were collected. A reported count of zero affected participants means no events in that category are recorded in these registry fields; it does not establish that every possible safety outcome was assessed or that risk is absent. The denominators also do not explain participant flow or establish how many participants contributed to the primary preference outcome. Safety interpretation should remain limited to the counts and groups recorded.
12. What the Result Does, and Does Not, Mean
The record establishes that the study was designed to compare subjective preference for filcon II 3 against etafilcon A or nelfilcon A, with the primary questionnaire scheduled at the baseline visit after insertion and settling. It also establishes that the study was recorded as randomized, double-masked, and parallel, with contralateral test and control lens assignments described within each pairing. These details define the setting and intended question.
The posted registry information does not establish which lens participants preferred. It does not report the numbers choosing each response, a summary of the response distribution, an effect estimate, a confidence interval, or a test result. The completed status and enrollment figure do not fill this gap. Without endpoint results, neither the direction nor the precision of the primary comparison can be evaluated.
The endpoint concerns participants’ subjective assessment at the stated visit. It does not by itself measure long-term use, persistence of preference, or an objective clinical outcome. The registry record does not report such conclusions, and the preference question should not be extended to claims beyond its stated measure and timing.
The record also lists comfort, dryness, and handling outcomes, but no results for those measures. The adverse-event fields record zero affected participants in the listed groups for both serious and other events, with denominators of 40 and 30 respectively. Those entries should be read as registry counts, not as proof that there was no risk or as a substitute for complete safety follow-up information.
In short, the available record describes the study question and selected design and safety details, but not the primary response data or inferential analysis needed to quantify the preference comparison. Any conclusion about the comparative preference result would go beyond what the registry record reports.
13. Why This Trial Matters Statistically
This study illustrates an important distinction between registering an outcome and reporting its result. The primary endpoint is described in enough detail to identify the question: participants selected among five preference categories after trying a lens pairing at the baseline visit. Yet the category counts and analysis are absent. A well-defined question is necessary for interpretation, but it cannot show the observed answer without outcome data.
The multi-category endpoint also highlights how statistical interpretation depends on the analysis target. Keeping the response categories separate, comparing a selected subset, or assigning a score would yield different summaries. As a general statistical principle, the method should match the intended question and be specified clearly enough for readers to understand what an estimate represents. The registry record does not report that method, and its note indicates that the endpoint was not reduced to one comparison.
The design description raises a further general issue: paired measurements within participants may require analysis that reflects their dependence. The record describes a contralateral design alongside a parallel model, without giving details that resolve how the design was implemented or analyzed. This makes clear why design labels alone are not sufficient for evaluating statistical methods; operational details and the analysis population also matter.
Finally, the record lists many outcome measures but no analyses. This limits assessment of multiplicity, missing data, and the relationship between planned and reported analyses. These are not reasons to presume a favorable or unfavorable result. They identify the information needed to judge the reliability and precision of a finding. The trial is statistically informative as an example of a clearly stated preference construct whose posted result and analysis details are not available.
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 primary preference results. There are no counts for the five response categories, no outcome-specific denominators, and no estimate or uncertainty interval. Thus, the comparison’s direction, magnitude, and precision cannot be described.
The record gives only a brief account of the design. It identifies randomization, double masking, a parallel model, and contralateral test and control lenses, but does not explain how these elements were implemented together. Details about lens assignment, exposure, assessment procedures beyond the stated settling period, and maintenance of masking are not reported in the registry record.
Participant flow and analysis populations are also not reported. Enrollment is listed as 70, while the two adverse-event groups have denominators of 40 and 30. The record does not explain the relationship between these figures or establish which participants contributed to each efficacy outcome. Missing-response counts and methods for handling missing data are not reported.
The record lists 29 outcome measures and no analyses. It does not report a multiplicity strategy, a statistical model, or a protocol analysis plan. Nor does it report a sample-size justification for the trial. Although planning assumptions are described for illustrations, the record does not provide the primary effect estimate needed to interpret such planning in relation to this multi-category endpoint. These limitations restrict statistical appraisal; they do not establish that any particular result is biased or that the study lacked value.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Daily Disposable Comparison Study — NCT02094677.
- Registry record last updated 2020-07-28; status last verified 2020-07.
- Results first posted 2016-03-11.
- 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.
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Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
The registry record describes a completed randomized, double-masked study in participants with myopia, with enrollment of 70. It lists a parallel model and two contralateral lens pairings: filcon II 3 with etafilcon A, and filcon II 3 with nelfilcon A. The primary outcome was a five-category subjective preference assessed at the baseline visit after insertion and settling for 10-15mins. Comfort, dryness, and handling were among the listed secondary outcomes.
The record lists 29 outcome measures and no analyses. Primary preference category counts and inferential results are not reported in the registry record. For adverse events, the two groups have 40 and 30 participants at risk, respectively, and zero affected participants recorded for both serious and other events. Death information and further safety-monitoring details are not reported. These details describe the registered study, but they do not determine the comparative preference result.