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 Evaluation of a Johnson & Johnson Vision Care Investigational Contact Lens Compared to a Marketed Monthly Replacement Contact Lens (NCT02515994), a randomized na study. The primary outcome is Slit Lamp Findings.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02515994 |
| Phase | NA |
| Condition | Refractive Error |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 224 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Johnson & Johnson Vision Care, Inc. |
| Results posted | Yes |
2. Clinical Question
The clinical question is whether slit-lamp findings graded as more severe were reported differently for subjects dispensed the investigational senofilcon C lens or the marketed comfilcon A lens during follow-up. The primary outcome counts eyes with a grade of 3 or higher. The registry also identifies symptoms and average wear time as secondary outcomes; numerical results for symptoms are not reported in the registry record.
Population
Subjects with refractive error who were dispensed a study lens. The primary-outcome description specifies this population as all subjects dispensed a study lens. Enrollment was 224.
Intervention
Senofilcon C, described as the investigational contact lens for daily-wear replacement.
Comparator
Comfilcon A, described as a marketed contact lens for daily-wear replacement.
Primary question
What number of eyes had slit-lamp findings graded 3 or higher through the up-to-3-month follow-up, and how does that count compare between the assigned lens groups?
The registry reports a value for each group, but it does not report an estimated between-group effect or an inferential analysis for this count outcome. Therefore, the posted figures describe the recorded counts; they do not establish whether the groups differ beyond what could be expected from sampling variation. The design is randomized and double-masked, which describes how assignment and masking were intended, but the registry record does not give enough detail to evaluate implementation or the analysis of the primary comparison.
3. Trial Design
This was a randomized, double-masked, controlled, parallel-group study with two arms. It is described as a multi-site, 3-month dispensing study. The investigational arm received senofilcon C and the comparator arm received comfilcon A; both were described as daily-wear replacement contact lenses. The study is marked completed. The registry records enrollment of 224, with a start date of 2015-07 and primary completion in 2015-11.
The primary outcome was assessed at follow-up visits at 1-, 2-, 4-, 8- and 12-week evaluations. The description says each subject eye was assessed using a biomicroscope and graded on the FDA grading scale. Grade 0 represents absence of findings; grades 1 to 4 represent progressively worse findings, described as trace, mild, moderate and severe. The grading data were then grouped into grade 3 or higher and grade 2 or lower, and the number of grade 3-or-higher findings by eye was reported.
The primary endpoint population is described as all subjects dispensed a study lens. The posted arm-level counts are 109 for senofilcon C and 112 for comfilcon A. The registry does not report how these counts relate to the enrolled population, nor does it provide further participant-flow details. It also does not report the randomization procedure, allocation concealment, masking procedures, or whether subjects could switch or stop lens use.
Average wear time is listed as a secondary outcome at 3 month follow-up, measured in hours per day. Symptoms are also listed among the secondary outcomes, but numerical results for symptoms are not reported in the registry record. A study-specific sample-size justification, protocol, and detailed statistical analysis 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: A total of 224 subjects were enrolled in this study. Of the enrolled subjects 3 did not meet the eligibility criteria and 221 were dispensed a study lens. Of the dispensed subjects 204 completed the study while 17 subjects were discontinued.
Overall Study
| Stage | Senofilcon C | Comfilcon A |
|---|---|---|
| STARTED | 109 | 112 |
| COMPLETED | 99 | 105 |
| NOT COMPLETED | 10 | 7 |
Reasons for not completing this period:
| Reason | Senofilcon C | Comfilcon A |
|---|---|---|
| Protocol Violation | 3 | 5 |
| No Longer Meets Eligibility Criteria | 2 | 1 |
| Adverse Event | 3 | 1 |
| Withdrawal by Subject | 2 | 0 |
Analysis population for the primary outcome, as defined in the registry: All subjects that were dispensed a study lens.
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 that were dispensed a study lens.
| Characteristic | Unit | Senofilcon C | Comfilcon A | Total |
|---|---|---|---|---|
| Participants analysed | 109 | 112 | 221 | |
| Age, Continuous | years | 30.4 (SD 7.26) | 30.9 (SD 7.33) | 30.7 (SD 7.24) |
| Sex: Female, Male: Female | Participants | 79 | 71 | 150 |
| Sex: Female, Male: Male | Participants | 30 | 41 | 71 |
| Region of Enrollment: United States | participants | 109 | 112 | 221 |
6. Primary Endpoint
The registry lists the primary outcome as Slit Lamp Findings, measured over Up to 3 Month Follow-up.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Eyes |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the number of eyes with slit-lamp findings graded 3 or higher through up to 3 Month Follow-up. Slit-lamp examination uses a biomicroscope to assess visible ocular findings. The registry describes a grading scale from 0 through 4, where grade 0 indicates absence of findings and increasing grades indicate more severe findings. The analysis description then separates grades 3 or higher from grades 2 or lower.
This endpoint focuses on findings in the more severe part of the grading scale, rather than treating every grade as a separate outcome. Such categorization can make a particular severity threshold easier to interpret, but it also discards distinctions within each category. For example, the reported category combines grade 3 and grade 4 findings, while the other category combines grades 0, 1 and 2. The record does not provide the full distribution across individual grades.
The measurement unit is eyes, and the outcome is a count. The study description says each subject eye was assessed at multiple follow-up evaluations, but does not explain whether the posted count represents unique eyes meeting the threshold at any visit, visit-level findings, or another summary across visits. This matters because repeated observations of the same eye are not necessarily independent observations. The precise construction of the reported count is not reported in the registry record.
The endpoint can describe the frequency of more severe findings under the study’s assessment approach. On its own, however, a count does not show the probability of a finding without a clearly specified denominator and analysis. The registry does not report a comparative estimate or uncertainty interval for this primary outcome.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted primary-outcome values are 3 for senofilcon C and 2 for comfilcon A. These are counts of eyes with findings graded 3 or higher, as described by the registry. The displayed arm sizes are 109 and 112, respectively, but the outcome unit is eyes and the record does not explain the relationship between the participant counts and the eye-level outcome counts. The values should therefore be read as reported counts, not as rates or percentages.
No comparative estimate, confidence interval, or p-value for the primary endpoint is reported in the registry record. A numerical difference between the displayed counts is not, by itself, an inferential result. Without a specified denominator and an analysis that accounts for the outcome’s structure, the degree of uncertainty around a group contrast cannot be assessed from these figures. The registry also does not report whether the primary count was summarized across visits, based on a participant-level rule, or analyzed using a count model.
The secondary average-wear-time analysis reports a mean difference of 0.02 hours per day for comfilcon A relative to senofilcon C, with p = 0.931. Its reported confidence interval spans zero, so the posted analysis is compatible with effects in either direction as well as little or no difference. This unadjusted secondary result does not establish equivalence or prove that the groups are identical. The estimate is also specific to the participants included in that secondary analysis, whose reported group sizes differ from the primary-outcome arm sizes.
The results should be distinguished by endpoint and analysis status. The primary outcome is reported as arm-level counts without a comparative statistical analysis. Average wear time has a reported unadjusted comparison. Symptoms are identified as a secondary outcome, but numerical results are not reported in the registry record. The registry does not report a multiplicity strategy for interpreting the secondary outcomes.
The posted findings do not support a conclusion that one lens is better or worse overall. They describe a small number of recorded higher-grade findings in each arm and a secondary wear-time comparison with substantial uncertainty around its estimated difference. The record does not provide enough information to assess the full severity distribution, the handling of repeated eye assessments, or the effect of missing observations. These limitations constrain how confidently the numerical results can be interpreted.
9. Statistical Methods Explained
The registry describes a count outcome for the primary endpoint, but does not report an inferential comparison for it. The following explains general statistical considerations for this type of data; it does not describe methods known to have been used in this study.
Why does the outcome type matter?
A count records how many events or findings occurred, rather than measuring a continuous quantity such as hours of wear. Counts are often nonnegative and may have a strongly skewed distribution, particularly when many observations are small and relatively few are large. Methods designed for normally distributed measurements may not describe such data well. A suitable analysis depends on how the count was constructed, its distribution, and the unit being analyzed.
General count-data methods include Poisson regression and, when variability exceeds the Poisson model’s assumptions, negative-binomial regression. Over-dispersion means that observed variability is greater than the model expects; ignoring it can make uncertainty estimates too narrow. These are general options, not methods reported for this trial. The registry record does not report a model, distributional assessment, or dispersion estimate for the primary outcome.
Why does the eye-level unit require care?
The primary outcome is measured in eyes, while the population description refers to subjects. If both eyes from a subject contribute, their results may be correlated because they belong to the same person. Treating correlated eye observations as if they were independent can understate uncertainty. General approaches can account for clustering, but the appropriate choice depends on the endpoint definition and analysis plan. The registry record does not report whether one or both eyes contributed per subject, how repeated measurements were combined, or whether within-subject correlation was addressed.
What would a comparative estimate add?
An arm-level count describes what was recorded in each group. A comparative estimate would quantify the contrast between groups using a defined scale, while an uncertainty interval would show the range of values reasonably compatible with the analysis. A p-value addresses how unusual the data would be under a specified null model; it does not measure the probability that the null hypothesis is true or the size of an effect. These general interpretations depend on a suitable model and analysis population.
For the primary endpoint, the registry reports counts but no comparative estimate or uncertainty interval. Accordingly, there is no posted primary p-value to interpret. A reader should not infer a test result from the arm counts alone. The registry’s reason for omitting an estimable two-arm comparison is that values were missing or not estimable for this count outcome.
How should the secondary comparison be read?
Average wear time is a continuous outcome reported as a mean and standard deviation for each arm. The secondary comparison gives a mean difference for comfilcon A relative to senofilcon C, along with an unadjusted p-value and confidence interval. In general, a confidence interval communicates both the estimated direction and the precision of an estimate. When an interval includes zero for a mean difference, the data are compatible with no difference as well as with some differences in either direction, at the interval’s stated confidence level. The confidence level is not reported in the registry record.
The reported p-value is unadjusted. That means the record does not indicate that it has been modified to account for the number of outcomes or comparisons considered. A p-value alone does not tell whether an effect is important, precise, or reproducible. The registry record does not report an adjustment for multiplicity or a prespecified hierarchy for interpreting secondary outcomes.
What do the planning illustrations mean?
The planning illustrations are based on the observed average-wear-time effect, not on the trial’s original design. Their stated assumptions are a two-sided significance level of 0.05, equal allocation, and a normal approximation. Rows describe planning for 100%, 75% and 50% of the observed effect, with participants per arm for 80% power and participants per arm for 90% power. These are hypothetical planning quantities. They are not observed power, do not explain the enrollment target, and do not establish that the trial was designed around the observed effect. The study’s own sample-size assumptions are not reported in the registry record.
In general, planning estimates based on a small observed effect can imply very large sample requirements. Such calculations can be unstable when the observed effect is imprecise, and they should not be treated as evidence about what the original investigators expected. The planning assumptions also do not resolve the primary endpoint’s unreported comparison or the uncertainties about its eye-level count construction.
10. Multiplicity, Missing Data and Analysis Populations
The registry record does not report a multiplicity plan, such as a hierarchy of outcomes or an adjustment for multiple comparisons. This is relevant because the study lists more than one secondary outcome, and the posted average-wear-time comparison is unadjusted. Without a prespecified approach, the reported secondary p-value should not be interpreted as if it necessarily controlled the overall chance of a false-positive result across all outcomes examined. The record does not state how many analyses were planned or whether any were selected for reporting.
Missing-data methods are not reported in the registry record. The primary outcome population is described as all subjects dispensed a study lens, but the record does not explain the handling of subjects or eyes without follow-up assessments, incomplete examinations, withdrawals, or other unavailable measurements. It also does not report whether any imputation or sensitivity analysis was used. These omissions make it difficult to judge whether the posted counts represent all eligible observations or a subset with available assessments.
The analysis population is not described beyond the primary endpoint’s population statement. The registry does not say whether analyses followed randomized assignment, included only participants who completed follow-up, or used another rule. The reported arm sizes for the primary endpoint and the secondary wear-time analysis are not the same, but the reasons for this difference are not reported in the registry record.
There is no posted comparative analysis for the primary count endpoint. The registry record says values were missing or not estimable for a two-arm comparison of this count outcome. This limits interpretation to the arm-level counts and prevents assessment of an estimated contrast or its precision. The record does not report whether this resulted from the data structure, missing observations, or another analytic issue.
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 |
|---|---|---|---|
| Senofilcon C | 0 | 109 | 0.0% |
| Comfilcon A | 0 | 112 | 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 |
|---|---|
| Senofilcon C | 5 of 109 |
| Comfilcon A | 5 of 112 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Senofilcon C | Comfilcon A |
|---|---|---|---|
| Non-Significant Ocular Event | Eye disorders | 5 of 109 | 5 of 112 |
The registry reports zero serious adverse events among 109 participants at risk in the senofilcon C group and zero among 112 participants at risk in the comfilcon A group. It also reports other adverse events affecting 5 participants in each group, with the same respective group counts at risk. These are the posted event figures; the registry record does not provide further detail about event definitions, severity categories, timing, or causal attribution.
Zero recorded serious adverse events in both groups means that no serious events are listed in these summaries. It does not establish that the underlying risk is zero, particularly because the study was limited in size and follow-up duration. Likewise, matching counts of other adverse events do not by themselves demonstrate that the groups have identical safety profiles. Interpretation would require additional details about event types, follow-up completeness, and uncertainty.
Deaths are not reported in the registry record. The adverse-event summaries should be read as descriptive information, not as a formal safety comparison or a basis for conclusions about treatment effects.
12. What the Result Does, and Does Not, Mean
The registry records a randomized comparison of an investigational contact lens and a marketed monthly replacement contact lens, with slit-lamp findings selected as the primary outcome. Its primary results are arm-level counts of eyes with grades of 3 or higher. Those counts give a descriptive view of the findings recorded under the study’s assessment approach, but the registry does not provide a comparative estimate or statistical test for this endpoint.
The posted results therefore do not establish that the lenses differ on the primary outcome, nor do they establish that they are the same. The absence of a reported comparison is not evidence of equivalence. An equivalence or non-inferiority conclusion would require a suitable design and prespecified criteria, which are not reported in the registry record.
The reported secondary wear-time comparison estimates a small mean difference and has an unadjusted p-value. This result does not answer the primary question, and an unadjusted secondary analysis has less confirmatory force when the multiplicity plan is unknown. Symptoms are named as a secondary outcome, but numerical results are not reported in the registry record. Thus, the posted evidence does not describe every outcome listed for the study.
The records of adverse events are also descriptive. They show the numbers recorded in each arm, but do not establish identical safety profiles or exclude uncommon events. The record does not provide enough detail to evaluate event types, attribution, or uncertainty.
Overall, the results support a limited description of the reported counts, average wear-time analysis, and adverse-event summaries. They do not support a broad claim about comparative effectiveness or safety. Important features of the endpoint construction, missing-data handling, analysis populations, and statistical methods are not reported in the registry record. Those gaps should remain part of any interpretation.
13. Why This Trial Matters Statistically
This trial illustrates why the type and unit of an endpoint matter. Its primary outcome is a count of eye-level findings, but the study population is described in terms of subjects and assessments were made repeatedly over follow-up. Those features raise questions about how observations were combined and whether dependence among eyes or visits was considered. Without that information, a count in each arm is not enough to reconstruct a valid comparative analysis.
It also demonstrates the distinction between describing groups and estimating a contrast. The registry gives primary arm values, but does not report an inferential comparison. A reader may observe that the displayed counts differ, but cannot determine from those values alone how precise that difference is or whether it is compatible with chance variation under a suitable model.
The average-wear-time outcome provides a contrast with a reported unadjusted analysis, yet it addresses a different question from the primary endpoint. Its presence does not resolve the missing primary comparison. The registry also names symptoms as a secondary outcome without reporting numerical results, illustrating why outcome labels alone are not a substitute for complete results.
Finally, planning calculations based on an observed effect should be kept separate from the original study design and from observed power. The registry’s planning assumptions describe hypothetical future-study calculations; the original sample-size justification is not reported in the registry record. Together, these points make the study a useful example of careful interpretation: identify the endpoint’s unit, distinguish descriptive counts from comparative estimates, and keep unadjusted secondary evidence in its proper context.
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.
A key trial-specific limitation is that the primary endpoint is described as an eye-level count after assessments at multiple follow-up visits, but the registry does not explain how the count was formed across eyes and visits. It is unclear whether the reported values represent unique eyes, repeated findings, or another summary. The full distribution across grades is also not reported; only the division at grade 3 or higher versus grade 2 or lower is described.
The primary results lack a comparative estimate and uncertainty measure. Although the arm-level values are posted, the registry gives no inferential analysis for the primary count outcome and states that values were missing or not estimable for a two-arm comparison. This prevents assessment of the size and precision of a primary group contrast.
The registry does not report detailed participant flow, reasons for differences between the primary and secondary analysis sizes, missing-data handling, or the analysis population beyond the primary population description. It also does not report the randomization procedure, masking implementation, protocol, or statistical analysis plan. Numerical results for symptoms are not reported in the registry record, and the multiplicity approach for secondary analyses is not reported.
Follow-up is described through 12-week evaluation within an up-to-3-month timeframe. This record therefore does not provide longer-term outcome information. The adverse-event summaries lack event-level detail, and deaths are not reported in the registry record. These limitations apply to interpreting the posted registry information; they do not establish what may have been collected or analyzed outside that record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Evaluation of a Johnson & Johnson Vision Care Investigational Contact Lens Compared to a Marketed Monthly Replacement Contact Lens — NCT02515994.
- Registry record last updated 2016-07-15; status last verified 2016-06.
- Results first posted 2016-06-14.
- 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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18. Record Summary
NCT02515994 is a completed randomized, double-masked, two-arm parallel study sponsored by Johnson & Johnson Vision Care, Inc. It compared investigational senofilcon C with marketed comfilcon A in a multi-site, 3-month dispensing study for refractive error. Enrollment was 224. The study started in 2015-07, with primary completion in 2015-11.
The primary endpoint was the number of eyes with slit-lamp findings graded 3 or higher through up to 3 Month Follow-up. The registry reports arm-level values but no comparative analysis for this count outcome. Average wear time is reported as a secondary outcome with an unadjusted comparison; numerical symptoms results are not reported in the registry record. Serious and other adverse-event counts are posted for each arm, while deaths are not reported in the registry record.
The registry does not report the primary analysis method, sample-size justification, multiplicity plan, or missing-data approach. These omissions limit conclusions about comparative effects and the precision of the primary findings.