Evaluation of a Multi-Purpose Solution: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluation of a Multi-Purpose Solution (NCT00710879), a non-randomized na study. The primary outcome is Antimicrobial Efficacy.

2. Clinical Question

The registry describes evaluation of the solution rather than a randomized comparison of solutions. It names solution-related adverse events and lens changes, and solution utility, as secondary outcomes. However, outcome values and analysis results are not reported in the registry record. The record therefore identifies what investigators intended to assess, but does not establish the observed distribution of efficacy categories or the relationship between the solution and any clinical outcome.

3. Trial Design

This was a completed, non-randomized, parallel-design study of a multi-purpose solution. Masking is listed as none, and the allocation is listed as non-randomized. Enrollment is recorded as 180. The intervention is Bausch & Lomb Multi-Purpose Solution, described as administered to adapted FDA group I and FDA group IV soft contact lens wearers. The study summary characterizes use as daily wear among currently adapted soft contact lens wearers.

The record lists the study start as 2008-07 and primary completion as 2009-02. Phase is listed as NA. The sponsor is Bausch & Lomb Incorporated, and the status is completed. These details describe the registry design and timing; they do not establish how participants were recruited, how allocation to lens groups occurred, or whether all enrolled participants completed follow-up. Those details are not reported in the registry record.

The primary measure is antimicrobial efficacy, reported as a number of eyes. The endpoint timeframe lists 2 weeks and 3 months, with group-specific culture visits: FDA group I subjects were cultured at the 3-Month Visit, while FDA group IV subjects were cultured at the 2-week Follow-up visit. The safety record separately identifies groups using Optima 38 lenses and Acuvue 2 lenses. The record does not establish that these lens groups were assigned concurrently or under otherwise comparable conditions.

Because allocation was not randomized and masking was absent, differences between groups, if reported, could reflect factors other than the solution or lens type. The registry record does not describe a randomized control, a blinding procedure, or a detailed statistical plan. It also does not report how the endpoint categories were compared, or whether the study was designed to estimate a causal treatment effect.

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: This study focused on participants of Japanese descent (at least one grandparent born in Japan) for a minimum of 20% of total enrollment. 180 participants were enrolled, 3 participants were ineligible at screening, 177 participants were eligible at the start of the study.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: All eligible, dispensed eyes with cultures taken within window. Group I subjects were cultured at the 3-Month Visit. Group IV subjects were cultured at the 2-week Follow-up visit.

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.

6. Primary Endpoint

The registry lists the primary outcome as Antimicrobial Efficacy, measured over 2 weeks, 3 months.

The primary endpoint is titled Antimicrobial Efficacy and uses eyes as its unit. It classifies culture findings into Excellent, Good, Skeptical, and No Efficacy categories. The descriptions combine clinical suspicion or certainty of bacterial infection with whether ocular pathogens were detected and the amount of bacteria of normal flora. The registry lists H. aegyptius, H. influenzae, Moraxella spp., P. aeruginosa, S. pneumoniae, S. aureus, and N. gonorrhoeae as pathogens relevant to the classification.

In general, a culture-based endpoint can provide a structured way to summarize microbiological findings alongside clinical assessment. A categorical outcome can distinguish different patterns of culture results rather than reducing them to a single continuous measurement. Its interpretation depends on the category definitions, culture collection, and timing. The record gives category descriptions, but its normal-flora threshold notation is not clear enough to restate unambiguously in prose.

The endpoint population is described as eligible, dispensed eyes with cultures taken within the window. FDA group I subjects were cultured at the 3-Month Visit, while FDA group IV subjects were cultured at the 2-week Follow-up visit. Thus the listed endpoint timepoints differ by lens group. The registry reports no category counts or other endpoint results, so the observed antimicrobial efficacy distribution is not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical interpretation begins by identifying the outcome, its unit, the population being measured, and the comparison that the design can support. In this study, the primary measure is a number of eyes assigned to antimicrobial efficacy categories. The record identifies an eligible, dispensed-eye population with cultures within a specified window, but it does not report the category counts or an analysis of them.

What does a categorical endpoint convey?

A categorical endpoint assigns observations to defined groups rather than measuring a single continuous quantity. Here, the categories are based on suspected or definite infection, pathogen detection, and bacteria of normal flora. The category labels provide an interpretation framework, but the observed count in each category is needed to describe the study findings. A category name alone is not an outcome result.

For a categorical outcome, an analysis might describe counts or proportions in each category, or compare category distributions between groups. Those are general possibilities, not methods reported for this study. The registry lists no analyses, so it does not establish which method, if any, was used. The specific category thresholds should also be interpreted cautiously because the normal-flora threshold notation in the record is unclear.

Why does the unit matter?

The primary endpoint uses eyes as the unit, while enrollment is reported as 180. These quantities describe different things: enrollment refers to the study, while the endpoint population is stated in eyes. If both eyes from a participant contributed data, outcomes from those eyes might be statistically related. In general, treating correlated observations as independent can make uncertainty appear too small. The registry does not report how many eyes contributed, whether both eyes could be included for an individual, or whether any analysis accounted for within-person correlation.

What does the non-randomized design imply?

Random assignment is a general way to reduce systematic differences between comparison groups. This record states that allocation was non-randomized and masking was none. The lens-specific groups therefore cannot be treated as randomized arms that differ only by the intervention. Participant characteristics, lens choice, clinical circumstances, and other factors could differ across groups. The registry record does not report an adjustment strategy, so it is not possible to assess whether measured differences were considered in an analysis. Even a statistical adjustment would rely on assumptions and could not necessarily address unmeasured differences.

The registry also cautions that the arms are not a like-for-like control comparison. Therefore, a numerical contrast between groups, if one were available, would not automatically be a causal estimate of the solution's effect. Interpretation would require an explicit estimand, a clear description of group formation, and suitable analysis details; these are not reported in the registry record.

How should timing be understood?

The endpoint timeframe lists 2 weeks and 3 months, but cultures were scheduled differently by lens group: group I at the 3-Month Visit and group IV at the 2-week Follow-up visit. General comparisons of outcomes require attention to when measurements were obtained, because the opportunity for an outcome to occur and be detected can depend on follow-up duration. The record does not describe a common culture timepoint across groups or an analysis accounting for the different schedules.

What do planning calculations mean?

In general, a sample-size calculation estimates how much information a future study might need under stated assumptions. The planning illustration described in the registry uses a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. For non-time-to-event outcomes, its stated convention is participants per arm; time-to-event calculations use a total event count. These are planning assumptions, not evidence about the trial's observed precision.

The calculation is explicitly an illustration based on the observed effect, not the trial's own design. Such an illustration is conditional on the effect chosen and the other assumptions. It is not observed power, and it does not show that the original study was adequately sized. Since the registry record does not report the endpoint results or a trial-specific sample-size justification, the illustration cannot fill those gaps.

What uncertainty can be assessed?

A confidence interval is a general statistical device for expressing uncertainty around an estimate. Its width depends on the amount and variability of information and on the analysis method. No confidence interval, standard error, p-value, or effect estimate for the primary endpoint is reported in the registry record. Therefore, precision and compatibility with different possible effects cannot be assessed from the registry results.

For count outcomes, general methods may need to account for over-dispersion, where observed variation exceeds what a simple model assumes. Whether that issue is relevant depends on the actual data and model. No count-model specification, dispersion estimate, or model-based analysis is reported in the registry record. It would not be appropriate to infer that a particular model was used from the fact that the primary measure is a count.

10. Multiplicity, Missing Data and Analysis Populations

The record names one primary outcome, Antimicrobial Efficacy, and two secondary outcomes: Solution Related AE's and Lens Changes, and Solution Utlility. It lists 3 outcome measures and zero analyses. The registry record does not report a multiplicity strategy, such as how interpretation would account for examining more than one outcome or category.

Multiplicity matters in general when several outcomes, groups, timepoints, or comparisons are assessed. Looking across many tests can increase the chance of finding an apparently notable result by chance. The record does not say whether categories were analyzed separately, whether any outcomes were prioritized beyond the primary designation, or whether any adjustment was planned. No p-values or analysis results are reported, so the impact of multiplicity cannot be evaluated.

The primary population is described as all eligible, dispensed eyes with cultures taken within the window. The registry does not report a broader analysis-population definition, such as how participants without a culture or with an out-of-window culture would be handled. It also does not describe missing-data methods, exclusions, or sensitivity analyses. These details are not reported in the registry record.

In general, missing outcomes can affect both the apparent distribution and the precision of an estimate. The effect depends on why data are missing and how missingness relates to outcomes and participant characteristics. Without counts of missing cultures, reasons for missingness, and an analysis plan, it is not possible to determine how complete the primary endpoint data were or whether missingness could have influenced the findings. The different culture schedules for FDA group I and group IV add a further reason to distinguish the defined population and timepoint for each group.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

The registry lists two safety groups: Multi-purpose Solution and Optima 38 Lenses, with 120 at risk, and Multi-Purpose Solution and Acuvue 2 Lenses, with 240 at risk. It records zero serious adverse events in each group. It also records zero other adverse events in each group. These are counts within the safety record, not estimates from a comparative statistical analysis.

The record does not report deaths; the death fields are not populated with a count. No serious adverse-event terms are listed. A count of zero in the registry means no events are recorded for that category in the listed group; it does not establish that an event could not occur, that every event was detected, or that follow-up was complete. The registry record does not describe the event-collection procedures or provide further follow-up detail.

The two group entries should not be treated as a randomized safety comparison. Allocation is non-randomized, masking is none, and the record cautions that the arms are not a like-for-like control comparison. The figures therefore do not isolate the effect of the solution from differences between lens groups or other characteristics. No inferential safety analysis is reported in the registry record.

12. What the Result Does, and Does Not, Mean

The record establishes that a completed, non-randomized study evaluated Bausch & Lomb Multi-Purpose Solution among adapted soft contact lens wearers. It specifies antimicrobial efficacy as the primary endpoint, identifies culture-based categories, and describes secondary outcomes relating to solution-associated adverse events and lens changes, and solution utility. The safety entries record zero serious and zero other adverse events in each listed lens group.

Those details do not establish what the study found for its primary endpoint. Category counts, endpoint estimates, uncertainty intervals, and statistical comparisons are not reported in the registry record. The endpoint title is not evidence that the solution met a particular category or that a clinical benefit occurred. Likewise, zero recorded adverse events in the listed categories is not proof of no risk.

The design cannot support a simple causal contrast between lens-specific groups. Allocation was non-randomized, masking was absent, and group I and group IV cultures were taken at different scheduled visits. Any between-group difference could reflect these design features or other differences, rather than the solution alone. The registry does not report an analysis addressing these issues.

General statistical interpretation distinguishes the existence of a measurement plan from evidence about its results. A defined endpoint tells readers what investigators intended to measure; counts and estimates are needed to assess what was observed, and uncertainty measures are needed to assess precision. Since those results are absent, the appropriate conclusion is limited to the design and registry-reported safety counts. Neither a positive nor a negative efficacy conclusion can be drawn from the outcome information in the registry record.

13. Why This Trial Matters Statistically

This study illustrates why a registry description and a result are not the same kind of evidence. The record defines a microbiological endpoint with clinically interpreted categories, but does not report how many eyes fell into those categories. Without the observed counts, readers cannot judge the endpoint distribution or its precision. A detailed endpoint definition is useful for understanding what was intended to be measured, but it cannot replace the results.

It also highlights the importance of the analysis unit. Enrollment is expressed for the study, while the primary endpoint is counted in eyes. In general, eye-level observations from the same participant may be correlated. Clear reporting of the number of evaluable eyes and the handling of within-participant dependence would help readers understand the analysis. Those details are not reported in the registry record.

The design features matter as much as the endpoint. Non-random allocation and absent masking limit the interpretation of comparisons, and the registry warns that the arms are not like-for-like controls. The different culture visits for FDA group I and group IV further complicate direct comparisons. These are not minor reporting details: they shape which statistical questions the data can answer.

Finally, the listed safety counts demonstrate the need to distinguish recorded events from assurances about safety. Zero recorded events in a group is a descriptive finding for the registry entry; it does not quantify the chance of future events or resolve whether all events were captured. Together, these features make the record a useful example of how design, measurement, analysis, and transparent results reporting must align for a clinical study to support a clear statistical interpretation.

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 record provides limited detail about how participants entered each lens group. It states that allocation was non-randomized but does not describe the allocation process, baseline characteristics, or reasons a participant used a particular lens. Consequently, comparability between groups cannot be assessed from the registry description.

The primary endpoint has a measurement and timing limitation. Cultures were obtained at the 3-Month Visit for FDA group I and at the 2-week Follow-up visit for FDA group IV. These different schedules mean that group-specific endpoint results would not represent measurements at the same follow-up time. The record does not describe a common-timepoint analysis. In addition, the endpoint's normal-flora threshold notation is unclear as written.

The endpoint is measured in eyes, but the registry does not report the number of evaluable eyes, how eyes were linked to participants, or whether an analysis addressed possible correlation between eyes from the same person. It also does not report culture completion, missing culture counts, exclusions, or reasons for missing data. Therefore, the completeness and statistical handling of the endpoint population cannot be assessed.

Masking is listed as none, and the record does not detail assessment procedures that might limit subjective influence on infection suspicion or outcome classification. The registry lists secondary outcomes but does not report their results or analyses. It also does not report a statistical analysis plan, multiplicity handling, or a trial-specific sample-size justification. These limitations are specific to the information recorded and should not be taken as proof that unreported procedures were not conducted.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Evaluation of a Multi-Purpose Solution — NCT00710879.
• Registry record last updated 2011-12-13; status last verified 2011-12.
• Results first posted 2011-02-08.
• 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.

18. Record Summary

NCT00710879 is a completed, non-randomized, parallel-design evaluation of Bausch & Lomb Multi-Purpose Solution in adapted soft contact lens wearers using daily-wear lenses. Enrollment is recorded as 180. Masking is listed as none, and phase is listed as NA. The study start is 2008-07, with primary completion in 2009-02.

The primary outcome is antimicrobial efficacy, measured as a number of eyes and classified using culture findings and infection assessments. FDA group I subjects were cultured at the 3-Month Visit; FDA group IV subjects were cultured at the 2-week Follow-up visit. Secondary outcomes concern solution-related adverse events and lens changes, and solution utility.

The safety record lists zero serious and zero other adverse events in the Optima 38 and Acuvue 2 lens groups. Deaths are not reported in the registry record. The primary endpoint results, statistical analyses, missing-data procedures, and multiplicity approach are not reported in the registry record. Because the design is non-randomized and the lens groups are not like-for-like controls, the record does not support a direct causal comparison between them.