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 Somofilcon A 1-Day Multifocal Study - Real World Subjective Acceptance Study (NCT03519919), a na na study. The primary outcome is Vision Clarity During the Day - Distance Vision.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03519919 |
| Phase | NA |
| Condition | Presbyopia |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 51 |
| Arms in the primary outcome | n/a |
| Lead sponsor | CooperVision, Inc. |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned habitual wearers of multifocal contact lenses with presbyopia. The registry lists enrollment of 51 participants. It does not report further eligibility details or describe the characteristics of the participants who contributed data to the primary endpoint.
Intervention
Participants were refit to a somofilcon A multifocal lens intended for daily disposable wear. The study objective was to evaluate its performance over a period of up to 3 weeks. The registry does not provide further details about fitting procedures or how lens use was monitored.
Comparator
No concurrent comparator is described. The registry classifies the study as single-group, with allocation listed as not applicable and no masking. It therefore does not describe a randomized, like-for-like comparison against another lens or a control group.
Primary question
The primary endpoint is vision clarity during the day for distance vision, recorded at baseline as a percentage of participants. It is based on subjective expectation responses completed at the office. The registry record does not report the percentage, the underlying response counts, or a definition of which response or responses count toward that percentage. Consequently, the record does not establish how participants’ expectations compared with their later experience.
3. Trial Design
The registry describes a completed, single-group device study of somofilcon A multifocal lenses. Habitual multifocal contact lens wearers were refit to the study lens and asked to provide a subjective assessment. The stated objective was to evaluate lens performance during daily disposable wear over a period of up to 3 weeks. The registry lists presbyopia as the condition and enrollment of 51 participants.
Allocation is listed as not applicable, and the study is not masked. With no concurrent comparator described, the design can characterize observations in the study group but cannot by itself separate a lens-related change from other influences, such as expectation, adaptation, or differences over time. A comparison with habitual lenses is not described as a randomized or controlled comparison in the registry record.
The registry lists the start date as 2017-08-21, the primary completion date as 2018-09-22, and the status as completed. These dates describe the trial record and do not supply results for the primary endpoint. The primary outcome timeframe is baseline, while the study objective refers to wear over up to 3 weeks. The relationship between baseline measurement and later assessments is not explained further in the registry record.
The record lists 32 outcome measures and 0 analyses. Secondary outcome titles include lens centration, visual acuity, post-blink lens movement, and corneal staining. Their individual results, assessment details, and analysis populations are not reported in the registry record. The record also does not report further information about recruitment, adherence, protocol deviations, or the analysis plan.
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 | Somofilcon A Multifocal Lens |
|---|---|
| STARTED | 51 |
| COMPLETED | 48 |
| NOT COMPLETED | 3 |
Reasons for not completing this period:
| Reason | Somofilcon A Multifocal Lens |
|---|---|
| Withdrawal by Subject | 1 |
| Lack of Efficacy | 1 |
| Screen Failure | 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.
Population: Fifty-one participants were enrolled in the study. Habitual wearers of multifocal soft contact lenses were refit with clariti 1day multifocal. 48 participants completed the study.
| Characteristic | Unit | Overall Study |
|---|---|---|
| Participants analysed | 51 | |
| Age, Continuous | years | 55.6 (SD 7.3) |
| Sex: Female, Male: Female | Participants | 41 |
| Sex: Female, Male: Male | Participants | 10 |
| Race and Ethnicity Not Collected | Participants | — |
6. Primary Endpoint
The registry lists the primary outcome as Vision Clarity During the Day - Distance Vision, measured over Baseline.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | percentage of participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is titled vision clarity during the day for distance vision. It is recorded at baseline as a percentage of participants and concerns subjective expectations, not an objective measurement of visual acuity. The description says that responses were collected at the office and assigned scores: fell short of expectations = 1, met my expectations = 2, and exceeded my expectations = 3.
Subjective ratings can capture whether a wearer feels that vision meets personal expectations, an aspect of lens experience that an instrument-based measure may not fully represent. However, the registry record does not state how the three response categories were converted into the reported percentage, which category or categories qualify for inclusion, or how missing responses were handled. It also does not report the percentage or response counts. The title’s reference to vision clarity should therefore not be read as a reported finding about visual performance.
The listed timeframe is baseline. That timing matters: a baseline assessment of expectations is not, on its own, a measure of change during lens wear or a comparison with a later assessment. Although the study objective mentions wear for up to 3 weeks, the registry record does not provide a result connecting this baseline endpoint to later experience. The endpoint may describe what participants expected at the start, but the posted information does not show whether those expectations were met after refitting.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The primary endpoint is identified, but its observed result is not reported in the registry record. There is no percentage, response distribution, participant-level count, uncertainty interval, or test result for baseline distance-vision expectations in the information available for this analysis. The record therefore does not support a quantitative statement about how participants rated their expectations.
The endpoint description offers three ordered response options, from falling short of expectations to exceeding them. Those labels indicate the direction of the scale, but they do not reveal how responses were distributed. Nor does the record explain the threshold used to define the percentage of participants in the endpoint. Without that operational definition and the observed values, the percentage cannot be interpreted as the proportion who met expectations, exceeded them, or had a favorable response.
The study is single-group and unmasked, with no concurrent comparator described. Even if a before-and-after result were available, a single-group change would not isolate the effect of the lens from other explanations. Expectation, familiarity with multifocal lenses, adaptation, and changes in measurement conditions could influence subjective assessments. These are general considerations for interpreting unmasked, uncontrolled studies; the registry record does not say that any one of them affected this study.
The registry lists 51 participants enrolled, while the serious adverse event record gives 48 participants at risk. These figures refer to different record entries and should not be treated as interchangeable denominators. The primary endpoint denominator and the number of participants with an endpoint response are not reported in the registry record.
The registry also lists 32 outcome measures and 0 analyses. This means the record does not furnish analysis results that would allow readers to assess the primary endpoint or the secondary outcomes. No confidence interval or p-value for the primary endpoint is reported. Without an estimate and a measure of its precision, neither the size nor the uncertainty of the endpoint can be evaluated statistically.
Overall, the registry record describes the study question and endpoint but does not provide the endpoint findings. This is a limitation of the posted information, not evidence that a result was favorable, unfavorable, or unchanged. Any interpretation should remain at the level of the design and the stated measurement rather than infer a clinical effect from the endpoint title or study objective.
9. Statistical Methods Explained
Statistical methods help distinguish what a study measured from what its results can establish. In this record, the study is identified as single-group, the primary outcome is a baseline subjective response, and no analysis results are listed. The explanations below describe general statistical principles and how they relate to the information recorded for this trial.
What does a percentage endpoint represent?
In general, a percentage summarizes how many observations meet a specified condition relative to an eligible denominator. Interpreting it requires knowing both the event definition and the number of participants whose data were included. For this endpoint, the registry labels the measure as a percentage of participants and gives three response categories, but does not state which category or categories define the event. It also does not report the numerator, denominator, or resulting percentage. The event definition and the data are therefore insufficiently described to interpret a proportion.
The response categories are ordered: falling short, meeting, and exceeding expectations. An ordinal scale preserves that order, but the gap between adjacent categories need not represent an equal amount of perceived change. Treating the scores as though they were equally spaced would require an analysis rationale that is not reported in the registry record. The title’s percentage framing also differs from a complete presentation of the ordinal distribution: a single percentage can conceal how responses are spread across categories.
What would uncertainty add?
In general, a confidence interval describes the range of values reasonably compatible with an estimate under a specified statistical model and sampling assumptions. It communicates precision, not the probability that a particular treatment effect is true. A narrow interval generally indicates more precise estimation than a wide one, while an interval spanning a broad range leaves more uncertainty about the magnitude of the underlying proportion or effect.
No estimate or confidence interval for the primary endpoint is reported in the registry record. Precision therefore cannot be assessed. A p-value is also not reported; even when available, a p-value would address compatibility with a specified null model, not by itself establish the importance or practical meaning of a result. Neither an interval nor a p-value can substitute for a clear endpoint definition and transparent denominator.
Why does the study design matter?
In general, a single-group study can describe responses among participants who receive the study intervention. It does not supply a contemporaneous control group to represent what might have happened under another lens or under no refitting. Randomization, when used, can help balance measured and unmeasured prognostic factors between groups; this trial is not described as randomized and has no comparator group in the registry record. That design limits causal comparisons.
Masking can reduce some influences on reporting and assessment. The registry lists masking as none. For a subjective endpoint, knowledge of the lens or study purpose could potentially shape responses; this is a general concern, not evidence that responses in this study were biased. The record does not report methods intended to address such influences.
How should planning assumptions be read?
General sample-size planning uses assumptions about the target effect, variability, significance level, power, allocation, and analysis method. The planning description associated with this record specifies 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. It says time-to-event calculations use total events and other calculations use participants per arm.
Those assumptions describe a planning illustration, not the design actually recorded for this single-group study. In particular, an equal-allocation, two-arm illustration is not a description of the trial’s single-group structure. Planning calculations are not observed power, and they do not demonstrate that an endpoint result is precise or that a treatment effect exists. The registry record does not report the observed effect used for such planning, any resulting sample-size values, or the study’s own sample-size justification. These details should not be inferred from the illustration’s assumptions.
Why can percentages require careful modeling?
General methods for binary outcomes often rely on assumptions about independent observations and the distribution of responses. If observations are more variable than a model expects, standard errors may be too small and intervals may be too narrow; this is commonly described as over-dispersion. Whether that issue is relevant depends on the actual outcome definition, data structure, and analysis. The registry record does not provide participant-level results or an analysis plan, so it is not possible to assess over-dispersion or identify the model used.
For an ordinal response, analyses may retain the ordering of categories rather than collapse them into a binary percentage. Each approach answers a different question and depends on explicit assumptions. The registry description does not state which statistical approach was used or whether any category collapsing occurred. In general, transparent reporting should identify the target quantity, analysis population, handling of incomplete observations, model, and uncertainty measure. Those details are not reported for the primary endpoint in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 32 outcome measures and 0 analyses. Multiple outcomes can create multiplicity: when many statistical questions are tested, the chance of at least one apparently notable result can increase. General approaches include defining a primary endpoint in advance, controlling an error rate across selected tests, or presenting results as exploratory. Which approach was used for this study is not reported in the registry record. No multiplicity adjustment or testing hierarchy is described.
The record identifies one primary endpoint, but does not report a result or an analysis population for it. It also does not describe how missing endpoint responses were handled, whether observations were excluded, or whether any imputation method was used. In general, missing-data handling can affect a percentage when participants with unavailable responses differ from those with recorded responses. The amount and pattern of missing primary endpoint data are not reported in the registry record, so their potential influence cannot be evaluated.
The enrollment entry lists 51 participants, and the serious adverse event entry lists 48 at risk. The registry does not explain the relationship between these figures or identify the primary endpoint denominator. They should not be substituted for one another. The record also does not report whether all enrolled participants contributed to each outcome, how withdrawals or protocol deviations were handled, or whether an intention-to-treat or other analysis population was defined.
These omissions do not show that missing data or multiplicity altered the results. They mean the posted record does not contain enough detail to assess those issues. A complete statistical interpretation would require outcome-specific denominators, response counts, analysis methods, and information about missing observations.
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 Multifocal Lens | 0 | 48 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Somofilcon A Multifocal Lens | 0 of 48 |
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 Multifocal Lens | 0 of 48 |
The registry reports 0 serious adverse events among 48 participants at risk in the somofilcon A multifocal lens group. It also records 0 deaths. These are the posted counts for the safety entry; they are not estimates of the probability of an event over a specified period and do not establish that risk was absent.
The entry does not provide a detailed account of safety surveillance, the duration each participant was observed, or how serious events were defined and collected. It also does not list serious adverse event terms. The record gives a separate count of 0 for other adverse events among 48 participants at risk, but the available information does not provide further event descriptions.
Safety counts need their denominator and observation context. The safety denominator of 48 should not be confused with the enrollment entry of 51 or treated as the primary endpoint denominator. The registry record does not explain the difference. A zero count means no event was recorded in that entry; by itself, it cannot rule out events that were unobserved, unreported, or too uncommon to appear during the recorded observation.
12. What the Result Does, and Does Not, Mean
The record establishes that a single-group study evaluated a somofilcon A multifocal lens and included a baseline subjective expectation endpoint for distance vision. It describes three response categories and gives the study objective of assessing performance during daily disposable wear over up to 3 weeks. These details clarify the question and the type of measurement, but they are not outcome findings.
The primary endpoint value is not reported in the registry record. There is no basis in the posted information to say what percentage of participants fell short of, met, or exceeded expectations, or whether expectations changed after refitting. The record also does not provide a controlled comparison that could estimate how outcomes differed from another lens or a no-refit condition.
In general, a subjective assessment can be relevant to wearer experience, while also being sensitive to expectations and awareness of the intervention. The study’s unmasked, single-group design does not remove those interpretive concerns. This does not establish that the assessment was biased; it identifies limits on what the design can distinguish.
The record’s safety entry reports 0 serious adverse events among 48 participants at risk and 0 deaths. These counts describe the recorded entry and should not be treated as proof that no risk exists. The registry does not provide enough detail about observation or ascertainment to interpret the counts beyond what was recorded.
The distinction is between a study objective and evidence answering that objective. A completed status and a described endpoint do not substitute for an endpoint estimate, response distribution, or uncertainty measure. Because these are not reported, the posted data do not establish the magnitude, precision, or direction of a primary endpoint finding. Nor do they support a causal claim about the lens compared with an alternative. The appropriate conclusion is limited: the registry describes the study design and intended measurement, but does not report the primary result needed to judge what the assessment found.
13. Why This Trial Matters Statistically
This study illustrates why an endpoint title and a study objective should be separated from the evidence needed to interpret a result. The record names subjective distance-vision expectations and gives the response categories, but does not report the percentage or define exactly how the categories produce that percentage. Without that information, readers cannot assess either the observed response pattern or the meaning of the endpoint value.
It also demonstrates the importance of matching a statistical comparison to the design. A single-group, unmasked study can document observations after refitting, but it has no concurrent comparator in the registry record. That distinction matters when interpreting change or attributing an observed experience to an intervention. The absence of a comparator is a design limitation, not a finding about the lens.
Denominators are equally important. Enrollment is listed as 51, while the safety record lists 48 participants at risk. The primary endpoint denominator is not reported. Readers should not assume those entries refer to the same analysis population. Reporting outcome-specific denominators would make it possible to understand how much information supports each measure.
Finally, the record lists 32 outcome measures and 0 analyses. Multiple outcomes make clear reporting of the primary question and the analysis plan especially useful. Without posted analysis results, precision estimates, or missing-data details, statistical conclusions remain limited. The example underscores a general lesson for clinical research: a transparent record needs not only a design and endpoint, but also a defined estimand, interpretable outcome counts, analysis methods, and uncertainty information.
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 interpreting this trial is that the registry record does not report the primary endpoint result. The response definition is also incomplete: it gives the three expectation categories but does not state how they were used to calculate a percentage of participants. The endpoint denominator, response distribution, and uncertainty are not reported.
The design is single-group and unmasked, with no comparator described. This limits interpretation of causal effects and leaves subjective responses open to general influences such as expectation or awareness. The registry does not describe procedures that might mitigate these concerns. The primary endpoint is listed at baseline, while the objective refers to wear over up to 3 weeks; further details about later assessments and how they relate to the baseline endpoint are not reported.
Although the registry lists 32 outcome measures, it lists 0 analyses. Outcome-specific results and analysis methods are not reported in the registry record. There is no description of multiplicity control, the primary endpoint analysis population, handling of missing data, or a sample-size justification for the actual single-group design.
The enrollment entry and safety at-risk count differ, and the registry does not explain their relationship. The safety record reports zero serious events, but observation duration and ascertainment details are not reported. These limitations concern the interpretability and completeness of the posted record; they do not establish what the unreported results would have shown.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Somofilcon A 1-Day Multifocal Study - Real World Subjective Acceptance Study — NCT03519919.
- Registry record last updated 2019-12-19; status last verified 2019-12.
- Results first posted 2019-12-10.
- 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.
Continue through the Clinical Biostats statistical pathway
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, single-group, unmasked device study of somofilcon A multifocal lenses in habitual multifocal contact lens wearers with presbyopia. Enrollment is listed as 51. The stated objective was to evaluate performance during daily disposable wear over up to 3 weeks.
The primary endpoint is baseline subjective expectation for daytime distance vision, expressed as a percentage of participants. Three response categories are described, but the percentage and its event definition are not reported. The registry lists 32 outcome measures and 0 analyses. The serious adverse event entry records 0 events among 48 participants at risk and 0 deaths.
Without primary outcome results, denominators, or analysis details, the registry record does not permit assessment of the endpoint estimate or its precision.