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 Comparative Performance of a Bausch & Lomb Multipurpose Solution and Alcon OptiFree Replenish Multipurpose Solution (NCT00636194), a randomized na study. The primary outcome is Subjective Assessment of Comfort and Cleanliness.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00636194 |
| Phase | NA |
| Condition | Adverse Effect of Contact Lens Solution |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 361 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Bausch & Lomb Incorporated |
| Results posted | Yes |
2. Clinical Question
Population
The primary endpoint is described for all eyes. The official title specifies silicone hydrogel contact lenses worn on a daily wear basis. Further details about participant characteristics and eligibility are not reported in the registry record.
Intervention
Bausch & Lomb Multipurpose Solution, identified in the arm description as Bausch & Lomb Multipurpose Contact Lens Solution.
Comparator
Alcon OptiFree Replenish Multipurpose Solution, identified in the arm description as Alcon OptiFree Replenish Multipurpose Contact Lens Solution.
Primary question
How did participants' subjective assessments of comfort and cleanliness compare between the solutions after 7 days? The registry record describes a 0-100 scale for each eye, with 100 the most favorable rating and 0 the least favorable rating, but does not report the comparative result.
The trial record frames the question as a product-performance comparison, rather than a comparison of a solution with no solution. It lists symptoms and complaints, and graded slit lamp findings above Grade 2, as secondary outcomes. Those outcomes could provide other kinds of information about product performance, but their results are not reported in the registry record.
The registry record identifies 361 participants enrolled. It does not give enough information to characterize the enrolled participants, explain how each person contributed eyes to the endpoint, or describe which participants completed the assessment. Those details matter when interpreting an eye-level subjective measure, and should not be inferred from the stated endpoint population alone.
3. Trial Design
The registry record describes a randomized, double-masked, parallel-group trial. Participants were assigned to Bausch & Lomb Multipurpose Solution or Alcon OptiFree Replenish Multipurpose Solution. In a parallel design, participants are allocated to one treatment group rather than switching between the compared interventions. Randomization is intended to make the groups comparable on average; masking is intended to limit the influence of treatment knowledge on care or assessment. The record does not describe how randomization or masking was implemented.
The enrollment is listed as 361. The recorded start is 2008-02, and the primary completion is 2008-03; trial status is completed. These dates and the enrollment count describe the registry record, but do not establish how many participants contributed data to the primary endpoint. The registry record does not report participant flow, numbers assessed at the endpoint, withdrawals, or reasons for missing assessments.
The interventions are classified as devices in the registry. The primary endpoint is a subjective assessment of comfort and cleanliness, described for all eyes, on a scale from 0 to 100 for each eye. The stated timeframe is 7 days. The registry also lists symptoms and complaints and graded slit lamp findings above Grade 2 as secondary outcomes.
The record does not report the allocation ratio, the sequence-generation method, concealment procedures, the specific masking procedures, or details of the assessment schedule beyond the primary endpoint timeframe. It also does not describe the sample-size justification used for the trial's design. No statistical analysis records are listed. As a result, the design can be described from the registry, but its implementation and the approach used to analyze the collected outcomes cannot be fully assessed from this 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: Fourteen Investigators enrolled 361 subjects in the study. Of these subjects, 347 successfully completed the study, 3 discontinued and 11 were ineligible at baseline, but were dispensed study materials
Overall Study
| Stage | B&L Multipurpose Solution | Alcon Multipurpose Solution |
|---|---|---|
| STARTED | 175 | 175 |
| COMPLETED | 172 | 175 |
| NOT COMPLETED | 3 | 0 |
Reasons for not completing this period:
| Reason | B&L Multipurpose Solution | Alcon Multipurpose Solution |
|---|---|---|
| Study related symptoms and complaints | 1 | 0 |
| Protocol Violation | 2 | 0 |
Analysis population for the primary outcome, as defined in the registry: All eyes
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 | B&L Multipurpose Solution | Alcon Multipurpose Solution | Total |
|---|---|---|---|---|
| Participants analysed | 175 | 175 | 350 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 175 | 175 | 350 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Female | Participants | 125 | 121 | 246 |
| Sex: Female, Male: Male | Participants | 50 | 54 | 104 |
| Race/Ethnicity, Customized: Asian | participants | 175 | 175 | 350 |
6. Primary Endpoint
The registry lists the primary outcome as Subjective Assessment of Comfort and Cleanliness, measured over 7 days.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | Scores on a scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is titled “Subjective Assessment of Comfort and Cleanliness.” It is a mean score on a scale for each eye, with a stated timeframe of 7 days. The scale ranges from 0 to 100: a rating of 100 is the most favorable, and 0 the least favorable. The registry identifies the endpoint population as all eyes.
This endpoint is used to capture participants' subjective impressions of two features relevant to the recorded product-performance question. A scale gives a way to express degrees of favorability rather than only recording a binary response. Because the result is described as a mean, interpretation would ordinarily depend on the score distribution, the difference between treatment groups, and the uncertainty around that difference.
General statistical context: a mean summarizes the average score, but it does not describe how much individual ratings vary or whether a small number of ratings strongly influence the average. A standard deviation describes spread among observations; the registry identifies standard deviation as the measure of dispersion. For an eye-level outcome, observations from the same participant may be related. An analysis should account for that structure if both eyes contribute, but the registry record does not report how the analysis handled it.
The endpoint definition is available, but no group means, standard deviations, treatment contrast, or confidence interval are reported in the registry record. The data therefore do not establish the direction, size, or precision of a difference in comfort and cleanliness ratings.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record supplies the design and endpoint definition, but not numerical primary-outcome results. It does not report the mean comfort and cleanliness scores for either group, a between-group estimate, or a confidence interval. Without those quantities, the direction and size of any observed difference cannot be described, and its precision cannot be assessed.
The record lists 361 participants enrolled, but enrollment is not the same as the number analyzed. The primary endpoint is defined for all eyes; the registry record does not state how many eyes or participants contributed usable endpoint data. It also does not explain how observations from two eyes of one participant were handled. These omissions limit interpretation of both the endpoint and any comparison between groups.
The registry lists zero analysis records. It also indicates that the primary outcome has several categories or time points and is not reduced to one comparison in the recorded analysis information. Accordingly, there is no sponsor analysis result in this registry record to interpret. This should not be replaced with an assumed effect or an estimate reconstructed without the underlying summary statistics.
General statistical context: a confidence interval expresses a range of values compatible with an estimate under the analysis assumptions. Its width helps readers judge precision; it does not by itself indicate whether an effect is important. A p-value, if reported, would address compatibility with a specified statistical null model, not the probability that one solution is better or worse. Neither a confidence interval nor a p-value for the primary comparison is reported in the registry record.
The same caution applies to the secondary outcomes. Symptoms and complaints and graded slit lamp findings above Grade 2 are listed, but outcome values and comparative analyses are not reported. Their presence in the registry does not show that a difference was observed, nor does the absence of posted results establish that no difference occurred.
Adverse-event entries report zero serious events affecting participants at risk in each listed group. These entries are a narrow summary of the recorded serious-event counts. They do not replace the primary endpoint results, nor do they describe the comfort and cleanliness scores. The record also lists zero other affected participants in each group, but does not provide event details or broader safety analyses. Interpretation should remain limited to the counts recorded, rather than extending them into claims about the comparative performance of the solutions.
9. Statistical Methods Explained
The registry describes a continuous primary endpoint: a mean score for subjective comfort and cleanliness. It identifies standard deviation as the dispersion measure and gives a scale from 0 to 100 for each eye. However, no numerical summary of the endpoint is reported in the registry record, and no analysis record is listed. The methods below explain how such data are generally interpreted; they do not describe an analysis that the registry confirms was performed.
What does a mean represent?
In general, the mean is the arithmetic average of recorded scores. It provides a concise description of the center of the observations, while the standard deviation describes how dispersed scores are around that center. A group mean alone does not show the distribution of ratings or whether observations cluster near one end of the scale. The registry identifies both the mean and standard deviation as relevant summary measures, but reports neither group's values.
How would a group comparison be read?
In general, a comparison of group means estimates how far apart the average scores are. A confidence interval around that contrast describes uncertainty in the estimate under the assumptions of the analysis. An interval that is narrow indicates greater precision than a wide interval, while the interval's location indicates which values remain compatible with the data and method. No contrast or confidence interval for the primary endpoint is reported in the registry record, so neither magnitude nor precision can be evaluated.
A p-value is another possible summary of a comparison. In general, it measures how unusual results at least as inconsistent with a specified null model would be if that model and the analysis assumptions held. It is not the probability that the null hypothesis is true, and it does not quantify the size or practical importance of a difference. The record does not report a primary-outcome p-value or a statistical analysis for that comparison.
Why does the eye-level endpoint need attention?
The primary population is described as all eyes, which means the unit of measurement is an eye. If both eyes from one participant are included, their ratings may be correlated because they come from the same person. General statistical context: treating correlated eye measurements as if every eye were fully independent can make uncertainty estimates too small. Appropriate methods can account for within-participant clustering or define a participant-level summary. The registry record does not say whether both eyes contributed for each participant or how any correlation was handled.
The record's stated dispersion measure is standard deviation, but that alone does not identify the statistical model used for a comparison. A standard deviation describes variation among observations; a standard error or confidence interval describes uncertainty in an estimated quantity. These are different concepts. No standard error, confidence interval, model specification, or adjustment method is reported for the primary endpoint.
What does the planning illustration mean?
The registry record does not report the trial's own sample-size justification. Any planning illustration associated with the posted material is described as a planning calculation based on the observed effect, not as the basis for the trial's original design. Its stated assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation; the effect to detect is expressed as a fraction of the observed effect. Such illustrations are hypothetical planning aids, not observed power and not evidence that an effect was present.
In general, planning calculations depend on assumptions about the effect to detect, variability, allocation, and the chosen error rate. Changing those assumptions changes the required sample size. A calculation based on an observed effect also inherits uncertainty from that estimate. The registry record does not report a trial-specific design rationale or a sample-size target supported by such a rationale. The enrollment figure should therefore not be presented as proof that the study had adequate power for its primary endpoint.
What can be concluded from missing analysis details?
The registry lists zero analysis records, and the primary endpoint is not reduced to a single comparison in the recorded analysis information. The analysis population, handling of missing values, treatment of multiple outcomes or comparisons, and any prespecified model are not reported in the registry record. Without these details and the outcome estimates, readers cannot check whether the reported approach followed a prespecified plan or independently reproduce the primary comparison. This is a limit of what the registry record documents; it does not establish what analyses may have been performed elsewhere.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists more than one outcome: the primary subjective assessment of comfort and cleanliness, along with symptoms and complaints and graded slit lamp findings above Grade 2 as secondary outcomes. The record does not report a multiplicity plan explaining how the interpretation of several outcomes or comparisons was handled. It also indicates that the primary outcome has several categories or time points and is not reduced to one comparison in the recorded analysis information. The precise comparisons intended for each category or time point are not reported in the registry record.
General statistical context: when many outcomes or comparisons are examined, the chance of finding an apparently notable result by chance can increase. Prespecified testing strategies or adjustment methods can address this issue, but the registry does not identify any such strategy. The number of outcomes listed alone does not reveal how many statistical tests were actually conducted.
The record does not describe missing-data handling, the number of missing endpoint values, or how participants with incomplete assessments were treated. The primary endpoint population is described as all eyes, but the analysis population is not reported in the registry record. It is therefore not possible to determine whether all randomized participants were included, whether only participants with observed endpoint data were analyzed, or whether any imputation method was used.
The registry lists zero analysis records. That absence means the record does not provide a statistical plan or results from which multiplicity and missing-data decisions can be evaluated. It should not be taken as proof that no analyses were performed. The distinction is between information documented in the registry record and methods that may or may not have been used outside it.
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 |
|---|---|---|---|
| B&L Multipurpose Solution | 0 | 175 | 0.0% |
| Alcon Multipurpose Solution | 0 | 175 | 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 |
|---|---|
| B&L Multipurpose Solution | 0 of 175 |
| Alcon Multipurpose Solution | 0 of 175 |
The adverse-event entries list 175 participants at risk in each group. In the B&L Multipurpose Solution group, zero serious events and zero other affected participants are recorded. In the Alcon Multipurpose Solution group, zero serious events and zero other affected participants are also recorded. The death counts are not reported in the registry record.
These figures describe the entries in the registry record; they do not provide event narratives, timing, severity detail beyond the serious-event classification, or a statistical comparison. The record also does not explain the relationship between these at-risk counts and the enrollment figure, or provide a participant-flow account. The counts should therefore be read as recorded group summaries, not as a complete description of every safety outcome.
General statistical context: observing zero events in a group does not demonstrate that the underlying event risk is zero. Rare events may not occur in a study even when a risk exists, and the ability to characterize uncommon events depends on the amount and duration of observation. Follow-up duration for the adverse-event summaries is not reported in the registry record. The listed counts alone do not establish equivalence between the solutions or support a broader safety conclusion.
12. What the Result Does, and Does Not, Mean
The record establishes that a randomized, double-masked, parallel-group comparison was registered, with an enrollment of 361 and a primary endpoint defined as a subjective comfort and cleanliness score for each eye after 7 days. It also identifies the two solutions, the direction of the scale, and secondary outcomes concerning symptoms, complaints, and slit lamp findings. These details clarify what the trial set out to compare.
The record does not report the primary endpoint values or a comparative estimate. It therefore does not show whether the average scores differed, how large any difference was, or how precise an estimate might have been. Nor does it report results for the listed secondary outcomes. A description of the question and design is not a substitute for an outcome result.
General statistical context: the estimate of an effect and its uncertainty are both important. A point estimate without an interval can conceal substantial uncertainty, while a statistically notable result alone would not establish practical importance. In this case, neither an effect estimate nor its uncertainty is reported in the registry record, so readers cannot make those assessments from this record.
The adverse-event entries show zero serious events and zero other affected participants recorded for each listed group. They do not establish that no adverse events of any kind occurred, that the groups have identical risks, or that uncommon risks have been ruled out. The death figures are not reported in the registry record.
Accordingly, the defensible interpretation is limited: the registry documents a comparison and selected endpoint definitions, but does not provide the comparative outcome results needed to judge the observed difference. It cannot establish superiority, equivalence, or absence of an effect. It also cannot establish that no analysis was conducted outside the registry; it shows that no analysis records are listed in this record.
13. Why This Trial Matters Statistically
This trial raises statistical issues that are common in clinical research using subjective, continuous endpoints. A mean score can summarize responses, but readers need group-level values and a treatment contrast to understand what the data show. Measures of uncertainty are needed to judge the precision of that contrast. The registry record defines the scale and its direction, but does not report the estimates needed for those interpretations.
The eye-level endpoint also makes the observational unit important. When more than one eye per participant contributes, the measurements may be related. Analysis choices that respect this structure matter for the validity of uncertainty estimates. The registry identifies all eyes as the endpoint population but does not describe the unit of analysis or the statistical handling of within-participant correlation.
The record lists multiple outcomes and indicates that the primary outcome has several categories or time points without reducing it to a single comparison in the analysis information. That makes prespecification and multiplicity particularly relevant questions. The registry record does not document an analysis plan, adjustment approach, or treatment of missing assessments, so those questions remain unresolved.
Finally, the record distinguishes a completed trial from a posted statistical result: it records status as completed, yet lists zero analysis records. This illustrates why design and enrollment information alone cannot answer the research question. For interpretation, readers need transparent outcome reporting, clear analysis populations, and estimates with measures of uncertainty. Without those details, conclusions must stay within the bounds of what the registry actually records.
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 central limitation is that the registry record does not report numerical results for the primary endpoint. Group means, standard deviations, a comparative estimate, and its uncertainty are not reported. The record also lists zero analysis records, so no sponsor analysis of the primary comparison is available in this registry record to interpret.
The endpoint is described for all eyes, but the record does not report how many eyes contributed data, whether both eyes were included for each participant, or how observations within a participant were handled. The enrolled count does not establish the analyzed population. Participant flow, endpoint completion, withdrawals, and reasons for missing data are not reported in the registry record.
Important design and analysis details are also absent: randomization procedures, allocation ratio, masking implementation, the analysis model, handling of missing data, multiplicity methods, and the prespecified analysis population are not reported in the registry record. The registry does not report the trial's own sample-size justification. These gaps prevent a detailed assessment of the planned and executed analysis.
The secondary outcomes are listed without reported results. Adverse-event entries include group counts, but the registry does not provide event descriptions, follow-up duration for safety reporting, or death counts. Finally, the record's indication that the primary outcome has several categories or time points is not accompanied by a single comparative result. These limitations restrict conclusions to the recorded design and counts; they do not establish what analyses or results may exist outside the registry.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Comparative Performance of a Bausch & Lomb Multipurpose Solution and Alcon OptiFree Replenish Multipurpose Solution — NCT00636194.
- Registry record last updated 2011-12-13; status last verified 2011-12.
- Results first posted 2011-02-15.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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 describes a completed, randomized, double-masked, parallel-group trial comparing Bausch & Lomb Multipurpose Solution with Alcon OptiFree Replenish Multipurpose Solution. Enrollment is listed as 361, with a start recorded as 2008-02 and primary completion as 2008-03.
The primary endpoint is a mean subjective assessment of comfort and cleanliness for all eyes, using a 0-100 scale in which 100 is most favorable and 0 is least favorable. The timeframe is 7 days. Symptoms and complaints, and graded slit lamp findings above Grade 2, are listed as secondary outcomes.
No primary-outcome estimates or analysis records are reported in the registry record. The adverse-event entries list zero serious events and zero other affected participants in each group, with 175 participants at risk per group; death counts are not reported in the registry record.