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 Performance of Somofilcon A Over One Week in Wearers Adapted to Omafilcon A (NCT03226353), a na na study. The primary outcome is Lens Fit - Post-blink Lens Movement.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03226353 |
| Phase | NA |
| Condition | Myopia |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 77 |
| Arms in the primary outcome | n/a |
| Lead sponsor | CooperVision, Inc. |
| Results posted | Yes |
2. Clinical Question
Population
People with myopia who were habitual or adapted wearers of omafilcon A contact lenses. The record says 71 participants completed all protocol visits, while also describing exclusions from particular analyses.
Intervention
Refitting into somofilcon A 1-day soft contact lenses for a week of daily wear.
Comparator
The registry identifies a single-group study, with allocation listed as NA and no masking. It does not describe a randomized, like-for-like control comparison. Omafilcon A appears in the record as a lens intervention and in the primary-measure timeframe, but the record does not establish a randomized comparator design.
Primary question
Whether wearers adapted to omafilcon A could be refitted into somofilcon A and assessed for lens fit over one week. The named primary measure is post-blink lens movement, assessed at dispense and at one week. Numerical results for this measure are not reported in the registry record.
The study objective also refers to investigator responses to refit questions and lens fit. Its stated primary outcome variables include investigator responses to refit questions and lens fit, while the named primary endpoint describes post-blink lens movement. The record does not provide the investigator-response results or numerical lens-movement results. Consequently, the clinical question can be described from the objective and endpoint definition, but the posted results do not allow an estimate of the observed fit or a statistical assessment of change over the week.
3. Trial Design
This was a completed, single-group study of somofilcon A in habitual or adapted omafilcon A wearers. The registry lists allocation as NA and masking as none. It reports enrollment of 77 and says that 71 participants completed all protocol visits. The record identifies the condition as myopia and lists CooperVision, Inc. as sponsor. The study started on 2017-07-06 and has a primary completion date of 2017-09-27.
The arm description says habitual and refitted omafilcon A wearers were refit into somofilcon A for a week. The intervention list names both somofilcon A and omafilcon A devices, but the single-group designation means the record should not be read as describing a randomized, parallel comparison. The registry's own note also cautions that the arms are not a like-for-like control comparison. The record does not report a randomization procedure or a masked assessment process.
The primary measure is listed for dispense and one week. The outcome description says that 71 participants completed all protocol visits, that two were completely excluded from all analyses because of protocol deviations and an adverse event, and that two habitual omafilcon A wearers did not need new lenses and were not included in the omafilcon A dispense analysis. These statements describe exclusions for specified analyses; they do not establish a single analysis population applicable to every endpoint.
The registry lists ten outcome measures and zero analyses. Numerical estimates for the primary lens-fit measure are not reported in the registry record. The protocol, eligibility details beyond the stated population, sample-size justification, and 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.
Overall Study
| Stage | Overall Participants |
|---|---|
| STARTED | 77 |
| Habitual Wearers of Proclear 1 Day | 2 |
| Other Habitual Lens Types | 75 |
| COMPLETED | 71 |
| NOT COMPLETED | 6 |
Reasons for not completing this period:
| Reason | Overall Participants |
|---|---|
| Withdrawal by Subject | 1 |
| Screen Failure | 5 |
Analysis population for the primary outcome, as defined in the registry: Though 71 participants completed all protocol visits, two are completely excluded from all analyses. One participant was excluded because of three protocol deviations and other Participant was excluded because of an adverse event (non-significant ocular from Omafilcon A).
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: Two participants were habitual wearers of omafilcon A; the remaining participants were habitual wearers of other lens types. 71 subjects completed the study and 69 were included in analysis. One participant was excluded from all analysis due to protocol deviation and one participant was excluded from all analysis due to an adverse event.
| Characteristic | Unit | Overall Participants |
|---|---|---|
| Participants analysed | 71 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 71 |
| Age, Categorical: >=65 years | Participants | 0 |
| Age, Continuous | years | 25.3 (SD 7.6) |
| Sex: Female, Male: Female | Participants | 52 |
| Sex: Female, Male: Male | Participants | 19 |
| Race and Ethnicity Not Collected | Participants | — |
| Region of Enrollment: Canada | participants | 71 |
6. Primary Endpoint
The registry lists the primary outcome as Lens Fit - Post-blink Lens Movement, measured over Dispense and 1 Week.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | units on a scale |
| Endpoint classification | Continuous Endpoint |
The named primary endpoint is post-blink lens movement, measured at dispense and one week. It is a lens-fit rating on a scale from 0 to 4 in one-step increments. The description identifies 0 as insufficient, unacceptable movement and 4 as excessive, unacceptable movement. It does not describe the interpretation of every intervening scale point, so the scale should not be given a more detailed clinical meaning than the record states.
The registry specifies the endpoint as a mean, with standard deviation as its measure of dispersion. In general, lens movement is assessed as one feature of lens fit; measuring it at the stated visits can describe ratings at the start of wear and after the one-week period. The score is bounded and takes discrete steps, so a mean can give a concise group-level description but does not show the full distribution of ratings or how many participants had ratings at either unacceptable extreme.
The endpoint definition explains what was intended to be measured, not what was observed. The numerical mean, standard deviation, and other result details for this measure are not reported in the registry record. Therefore, the endpoint cannot be used to quantify the observed fit or the precision of an estimate from the record alone.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes the purpose, setting, and endpoint of a one-week refitting study, but it does not provide numerical primary-outcome results. No mean post-blink movement rating, standard deviation, confidence interval, or p-value for the primary endpoint is reported in the registry record. The main statistical conclusion is therefore about the limits of interpretation: the stated outcome can be identified, but its observed value and uncertainty cannot be assessed from the posted results.
The endpoint was scheduled for dispense and one week. Those time points could, in principle, describe lens-fit ratings at dispensing and after a week of wear. However, without the corresponding estimates or participant-level data, the direction and magnitude of any change are unknown. It would not be appropriate to infer that fit improved, worsened, or remained stable. Nor can the record establish how variable the ratings were among participants.
The enrollment figure is 77, and the registry says 71 participants completed all protocol visits. It separately notes exclusions from analyses, including two participants excluded from all analyses because of protocol deviations and an adverse event, and two habitual omafilcon A wearers not included in the omafilcon A dispense analysis because they did not need new lenses. These descriptions do not provide complete endpoint-specific denominators or explain how missing observations were handled. They should not be combined into a newly calculated count or treated as proof that every outcome used the same participants.
The single-group design also constrains interpretation. The registry lists no masking and allocation as NA, and cautions that its arms are not a like-for-like control comparison. The study description therefore does not support interpreting any possible difference between lens entries as a randomized treatment effect. The record does not report adjusted or unadjusted effect estimates, and it does not report an analysis plan that would clarify how comparisons across visits or lens entries were handled.
The posted safety figures list zero serious adverse events, zero other adverse events, and zero deaths in each of the two lens entries, with 71 at risk in each entry. These are registry-record counts, not evidence that adverse-event reporting was complete beyond the listed categories or that risks are absent. The record also says that an adverse event was a reason for excluding two participants from all analyses; it does not provide further details about that event. The safety counts and the analysis-exclusion statement should be read as distinct pieces of registry information.
Any sample-size illustrations associated with the posted material are planning calculations based on an observed effect, not the trial's original design or observed power. The registry record does not report numerical primary-outcome results from which to evaluate such an effect. Such planning calculations cannot replace the missing endpoint estimate, uncertainty interval, or prespecified analysis information.
9. Statistical Methods Explained
The primary measure is continuous in the registry's outcome classification and is summarized as a mean with standard deviation. In general, a mean describes the average score in a group, while the standard deviation describes how spread out the individual scores are around that average. A mean alone cannot show whether most observations cluster near the center or whether ratings are distributed across the scale. A standard deviation is descriptive; it is not the same as a confidence interval and does not by itself express how precisely the group mean has been estimated.
The endpoint is rated from 0 to 4 in one-step increments, with the lowest and highest scores described as unacceptable movement. Although the registry classifies the measure as continuous, its stated scale has a bounded range and discrete steps. In general, summarizing such ratings with a mean can be convenient, especially for describing a group, but it can obscure the shape of the score distribution. A full distribution or counts at each rating could add context. Those data are not reported in the registry record.
A confidence interval, in general, presents a range of values compatible with an estimate under the statistical method used. It conveys uncertainty in the estimate, not the range containing most individual participant scores. The registry record does not report a confidence interval for the primary endpoint. It also does not report the numerical mean and standard deviation needed to describe the primary outcome quantitatively. As a result, neither the point estimate nor its precision can be evaluated from the posted results.
A p-value, in general, describes how unusual data at least as extreme as those observed would be under a specified null model. It does not measure the size or importance of an effect, and it does not establish that a treatment does or does not work. No primary-endpoint p-value or inferential comparison is reported in the registry record. The statistical analysis plan, including any intended tests or models, is also not reported in the registry record. It would therefore be speculative to attribute a particular test, model, or significance threshold to the trial's analysis.
The measure is listed at dispense and one week. In general, repeated observations from the same participants are correlated, so a method for comparing visits may need to account for that dependence. A comparison of separate groups would instead have different assumptions. The single-group design and the timepoints do not, by themselves, specify which analysis was carried out. The registry record does not report the analysis method, the endpoint-specific number of observations, or whether any visit comparison was performed.
The registry lists a sample-size planning approach using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It states that the effect to detect is a stated fraction of the observed effect. These are assumptions for a planning illustration, not evidence that the original trial was designed using those assumptions. The record does not report the trial's sample-size justification. A planning calculation based on an observed effect is not observed power, and the record's missing numerical primary-outcome results prevent evaluation of the observed effect from the registry alone.
The planning description distinguishes between participants per arm for non-time-to-event illustrations and total events for time-to-event illustrations. This distinction is general: a sample-size quantity must be read in the units used by its design, rather than treated as a count of people in every setting. The registry's illustration assumes equal allocation between two arms, but the trial itself is designated single-group and its registry note says the arms are not a like-for-like control comparison. The planning assumptions should not be mistaken for the trial's actual allocation or design.
Over-dispersion is a general issue when variation exceeds what a statistical model assumes. For count outcomes, a model that assumes too little variation can yield uncertainty estimates that are too narrow. The primary endpoint is a bounded rating rather than a count, and the registry does not report a model or a distributional assessment. It is therefore not possible to say whether over-dispersion was assessed or whether it affected any analysis. More generally, the suitability of a statistical method depends on the data structure and assumptions, which are not documented in the registry record.
Multiplicity arises when several outcomes or comparisons are examined. In general, the more statistical tests conducted, the greater the chance of finding at least one apparently notable result by chance if no adjustment or other prespecified strategy is used. The registry lists ten outcome measures but zero analyses. It does not report whether any multiplicity strategy was planned or applied. No inference about adjustment, outcome hierarchy beyond the named primary measure, or selective reporting can be made from those counts alone.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists ten outcome measures and zero analyses. The named primary endpoint is post-blink lens movement, but the record also describes investigator responses to refit questions and lens fit as primary outcome variables. It does not provide numerical results for the named endpoint or the investigator responses. It also does not report a complete analysis plan that would explain which outcomes were tested, how they were prioritized, or how results across outcomes were handled.
When several outcomes or comparisons are considered, multiplicity can increase the chance of a false-positive finding. General approaches include defining a primary outcome in advance, controlling error across tests, or treating secondary analyses as exploratory. The registry record does not state whether such an approach was used. With no reported analysis results, it is not possible to assess how multiplicity affected interpretation.
The record says 71 participants completed all protocol visits. It separately reports that two participants were excluded from all analyses because of protocol deviations and an adverse event, and that two habitual omafilcon A wearers were not included in the omafilcon A dispense analysis because they did not need new lenses. It does not fully specify the participant set used for each endpoint or visit. The record does not report how missing observations were identified, whether any values were imputed, or what sensitivity analyses were conducted.
In general, missing-data methods matter because results can depend on why observations are unavailable and on the assumptions used to address them. The registry's participant-flow statements are not enough to determine those assumptions or reconstruct endpoint-specific analysis populations. These analysis-population and missing-data details are not reported in the registry record.
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 |
|---|---|---|---|
| Somofilcon A | 0 | 71 | 0.0% |
| Omafilcon A | 0 | 71 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Somofilcon A | 0 of 71 |
| Omafilcon A | 0 of 71 |
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 |
|---|---|
| Somofilcon A | 0 of 71 |
| Omafilcon A | 0 of 71 |
The adverse-event figures list 71 at risk for each of the Somofilcon A and Omafilcon A entries. For each entry, the registry reports zero serious adverse events, zero other adverse events, and zero deaths. These are the posted counts for the listed groups; they do not establish that the probability of an event is zero or that no events could occur outside the reporting captured in the record.
The study description separately states that two participants were excluded from all analyses because of protocol deviations and an adverse event. The registry does not give further details about that event, and the record does not explain how this exclusion relates to the adverse-event counts. The exclusion statement and the group-level safety counts should therefore not be treated as interchangeable summaries.
The safety information does not include event descriptions, timing, severity beyond the serious-event category, or an explanation of how adverse events were collected. Those details are not reported in the registry record. The counts can be described as recorded, but they do not support a broader conclusion about safety or a comparison between lenses.
12. What the Result Does, and Does Not, Mean
The registry record establishes that the study examined refitting habitual or adapted omafilcon A wearers into somofilcon A for a week, and that post-blink lens movement was the named primary endpoint at dispense and one week. It also describes the rating scale and the number of participants who completed all protocol visits. These details clarify the study question and the intended measurement.
The record does not report the numerical primary endpoint results. As a result, it cannot establish the average post-blink movement rating, its variability, the size or direction of any change over the week, or the precision of an estimate. It also cannot establish whether any observed difference was statistically distinguishable from chance or whether it was meaningful in a clinical context. No such conclusion should be inferred from the endpoint definition or the study objective.
The design matters as well. This is identified as a single-group study, with allocation listed as NA and masking as none. The registry cautions that the arms are not a like-for-like control comparison. Thus, the record does not support a randomized comparative-effect interpretation. The objective describes the intended refitting question, but an objective is not itself evidence of an observed outcome.
The safety figures report no serious adverse events, other adverse events, or deaths in the listed groups, with 71 at risk in each. These counts are limited to what the registry reports and do not demonstrate absence of risk. The separate statement that an adverse event led to exclusion from all analyses adds context but does not supply enough detail to reconcile event reporting or evaluate its implications.
Overall, the registry supports a description of the design and intended endpoint, but not a quantitative judgment about lens fit after one week. The missing numerical results and analysis details prevent a complete statistical interpretation.
13. Why This Trial Matters Statistically
This study illustrates why a clearly named endpoint is not enough for statistical interpretation. The registry defines post-blink lens movement, its scale, its summary measure, and its assessment timepoints. Those details tell readers what was intended to be measured. Without the observed mean, standard deviation, or other outcome results, however, the central empirical question remains unanswered by the registry record.
It also highlights the importance of matching interpretation to design. A single-group refitting study can describe outcomes among participants in that setting, but it is not equivalent to a randomized comparison. The registry's warning that its arms are not a like-for-like control comparison is especially important when interpreting entries that name both lens types. A reader should not infer a comparative treatment effect merely because two lens names appear in the record.
Participant accounting is another statistical issue. The record reports completed visits and gives specific reasons for exclusions from analyses, including a distinct exclusion for the omafilcon A dispense analysis. Because the endpoint-specific denominators and missing-data handling are not reported, readers cannot tell exactly which observations contributed to each estimate. Clear analysis-population reporting is necessary to connect participant flow with outcome summaries.
Finally, the record lists multiple outcome measures but no analyses. This makes it impossible to assess the role of multiplicity or the relation between intended outcomes and reported findings. The case demonstrates the difference between an outcome definition, a study objective, and an analyzable result: each serves a different purpose, and only the last can quantify what the observed data show.
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 statistical interpretation is that numerical results for the named primary endpoint are not reported in the registry record. Without the mean and standard deviation, readers cannot assess the level or variability of post-blink movement ratings. No confidence interval or p-value is reported for the endpoint, and the analysis method is not reported.
The registry identifies a single-group design, no masking, and allocation as NA. It cautions that the arms are not a like-for-like control comparison. The record therefore does not provide a randomized, masked comparison from which to estimate a controlled difference between lens types. It also does not state whether any comparison was intended to be descriptive or inferential.
The participant descriptions leave some analysis details unresolved. The registry reports that 71 participants completed all protocol visits, two were excluded from all analyses because of protocol deviations and an adverse event, and two habitual omafilcon A wearers were excluded from the omafilcon A dispense analysis because they did not need new lenses. Endpoint-specific denominators, the handling of missing observations, and sensitivity analyses are not reported in the registry record.
The scale description specifies the endpoints and step size but does not describe all intermediate categories. The registry does not provide the distribution of ratings, which could help readers understand how a mean represents a bounded, discrete measure. The record also does not report the planned multiplicity strategy, sample-size justification, or statistical analysis plan. These limitations prevent reconstruction of the intended analysis and a full appraisal of its assumptions.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Performance of Somofilcon A Over One Week in Wearers Adapted to Omafilcon A — NCT03226353.
- Registry record last updated 2019-09-12; status last verified 2019-08.
- Results first posted 2019-02-04.
- 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
The registry describes a completed, single-group study of refitting habitual or adapted omafilcon A wearers into somofilcon A 1-day soft contact lenses for a week. The named primary endpoint is post-blink lens movement, rated on a 0-to-4 scale at dispense and one week and summarized as a mean with standard deviation. The record reports enrollment of 77 and says 71 participants completed all protocol visits.
The study lists ten outcome measures and zero analyses. Numerical results for the primary endpoint, endpoint-specific analysis details, and the statistical analysis plan are not reported in the registry record. Safety entries list zero serious adverse events, zero other adverse events, and zero deaths for each lens entry, with 71 at risk in each. The registry cautions that the arms are not a like-for-like control comparison.