A Study to Evaluate the Safety and Effectiveness of a Contact Lens Cleaning and Disinfecting Solution: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study to Evaluate the Safety and Effectiveness of a Contact Lens Cleaning and Disinfecting Solution (NCT05565937), a randomized na study. The primary outcome is Overall Comfort Averaged Over All Follow-up Visits.

2. Clinical Question

3. Trial Design

This was a completed randomized, double-masked, parallel-group study of BL-3100-NBR03 multi-purpose solution and renu® Advanced Formula multi-purpose solution. The registry records the allocation as randomized and the model as parallel. The brief description specifies a two-arm, 1:1 allocation and bilateral lens wear. The record does not report which participants, investigators, or assessors were masked, or the operational procedures used to preserve masking.

The registry description planned a three-month study at approximately 22 investigative sites in the United States. It described approximately 340 participants and 680 eyes, daily wear of dispensed study lenses, and scheduled in-office lens replacement at the 1-Month and 2-Month Follow-Up Visits. Actual enrollment in the completed record was 295 participants. The record lists the start date as 2023-04-12, primary completion as 2024-02-28, and status as COMPLETED. The duration and site count in the brief description are planned characteristics; the record does not state how many sites ultimately participated or how closely conduct followed the planned schedule.

The listed condition was refractive ametropia, and the study phase was recorded as NA. The interventions were both identified as devices. The primary outcome was mean overall comfort averaged across follow-up visits through 3 months. The record lists four outcome measures but reports no secondary outcomes in the posted results. It does not report the original sample-size justification, the detailed randomization procedure, or the analysis populations.

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

Reasons for not completing this period:

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 Overall Comfort Averaged Over All Follow-up Visits, measured over Assessed at all follow-up visits through 3 months..

The primary endpoint measures participants’ reported overall comfort with each eye assessed on a scale from 0 to 100. A score of 100 denotes the most favorable response. The registry describes the outcome as the mean score averaged over all follow-up visits through 3 months, rather than a score at only one visit. An average across follow-up visits is intended to represent comfort across the stated follow-up period, though the registry record does not explain the exact averaging procedure or how missing visit scores were handled.

Comfort is a patient-reported experience, so it captures a subjective aspect of lens wear that may not be represented by a clinical examination or device measurement alone. The scale provides a numerical summary that can be compared between randomized groups. The posted group means were 91.7 for BL-3100-NBR03 and 90.7 for renu® Advanced Formula. These averages describe the observed scores in the groups; they do not show how individual responses were distributed or whether each participant’s comfort remained constant over time.

The record does not report a threshold for a difference that would be considered meaningful to participants, nor does it explain whether the outcome was selected as primary for a particular clinical or regulatory reason. Without that context, the comparison can be interpreted statistically, but its practical importance cannot be determined from the registry record alone.

7. Results Posted in the Registry

• Renu® Advanced Formula: mean 90.70 versus 91.70 on control; difference -1.00 (95% CI -3.38 to 1.38), standardized effect d = -0.10; z-test p = 0.409.

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous: each eye receives a numerical comfort score, and the endpoint is expressed as a mean. A comparison of means summarizes the difference between the groups in their average scores. For this study, the reported comparison is oriented as renu® Advanced Formula minus BL-3100-NBR03. A negative estimate therefore corresponds to a lower observed mean in the renu® Advanced Formula group.

What does a mean difference describe?

A mean is a measure of the center of a set of observations. The two reported group means, 90.7 and 91.7, give a concise account of the average scores, while the mean difference of -1.0 expresses their separation on the same comfort scale. This summary is useful for comparing average outcomes, but it can conceal variation among participants. Two groups can have similar means while individual scores vary widely, or their distributions can differ in ways not conveyed by the means alone.

The reported standard deviations, 10.83 and 9.99, describe the spread of scores around each group mean. A standard deviation is not the standard error of the mean and is not a confidence interval. It characterizes individual-level variability in the observed scores, whereas the uncertainty interval for the mean difference describes uncertainty about the estimated group contrast. The record does not give a distributional plot description or enough individual-level information to assess score shape, outliers, or skewness.

How should the comparison be read?

The unadjusted comparison uses the two group means and their observed variability to estimate a difference. It does not control for other participant characteristics. Random allocation is intended to make groups comparable on average, but the registry record does not report baseline characteristics or an adjusted analysis. The reported comparison therefore should not be described as adjusted for baseline differences or other covariates.

The posted record does not describe whether the statistical analysis treated both eyes from a participant as correlated observations, how the averaging across visits was implemented, or whether the analysis unit was the participant, eye, or a derived participant-level score. Those details matter because observations from two eyes or repeated visits from the same participant may be related. Treating related observations as independent can affect standard errors and confidence intervals. The record does not provide enough information to determine how that issue was handled.

What does the p-value tell the reader?

The unadjusted p-value is 0.409. In general, a p-value measures how compatible the observed data are with a specified null model, under the assumptions of the analysis. It is not the probability that the null hypothesis is true, and it does not measure the size or practical importance of a difference. A large p-value does not prove that the groups are the same; it indicates that the observed result is not unusual enough under the null model to provide strong evidence against it by that test.

The registry record does not report a statistical analysis plan, the significance threshold used for the trial’s original analysis, or any adjustment for multiple comparisons. The sample-size illustration has a stated two-sided significance level of 0.05, but that assumption is for the planning illustration and should not be presented as the trial’s original analysis plan. No sponsor analysis is reported among the posted analyses. The unadjusted comparison should therefore be interpreted according to the information available in the registry record, not as a complete account of all planned or conducted analyses.

Why can over-dispersion matter?

General statistical context: over-dispersion occurs when observed variability is greater than a model assumes. It can make uncertainty estimates too small if the model does not account for the extra variability. This study reports a continuous score and standard deviations, not a count outcome model, so over-dispersion is not a specific feature established by these results. More generally, uncertainty estimates depend on whether the analysis accounts appropriately for the structure and variability of the data. The record does not provide the model details needed to evaluate that issue.

What is unknown about the analysis?

The registry record does not report the original sample-size justification, the exact statistical model, the analysis population, the handling of missing scores, or any prespecified subgroup analyses. It also does not report interim analyses. These omissions limit assessment of whether the posted comparison follows the original plan and how robust it is to alternative analysis choices. They do not change the arithmetic meaning of the displayed group means and unadjusted mean difference, but they do constrain the strength of methodological conclusions that can be drawn from the registry record.

10. Confidence Intervals and Precision

The estimated mean difference is -1.0 points, with a confidence interval from -3.376 to 1.376. A confidence interval gives a range of values compatible with the data and the method used to calculate the interval. It expresses uncertainty in the estimated group difference; it is not a range containing most participants’ comfort scores, and it does not describe the full spread of individual responses.

This interval includes zero, the value corresponding to equal group means. Its lower end is compatible with a difference in one direction and its upper end with a difference in the opposite direction. Thus, the estimate is not precise enough to rule out either direction of a mean difference. The interval also does not, on its own, determine whether any value within it would matter to participants. The registry record does not report a clinically meaningful difference threshold or an equivalence margin.

The group standard deviations were 9.99 for BL-3100-NBR03 and 10.83 for renu® Advanced Formula. These describe score variability within groups, not uncertainty in the mean difference. The comparison is based on 143 participants in the BL-3100-NBR03 group and 152 in the renu® Advanced Formula group. Although larger samples can generally improve precision, the observed interval also depends on variability and the analysis method. The record does not provide details about missing observations, eye-level correlation, or repeated-measures handling that would allow a fuller assessment of the interval’s construction.

The interval should be read with the unadjusted estimate and p-value, rather than in isolation. It conveys that the data do not pinpoint a narrow range around a single group difference. It neither proves no difference nor establishes that the solutions are equivalent.

11. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size figures are planning illustrations, not the trial’s original design calculations. They use a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. Each row considers a stated fraction of the observed effect as the effect to detect. These figures are participants per arm, not total events.

For the planning scenario based on 100% of the observed effect, the illustration gives 1,709 participants per arm for 80% power and 2,287 participants per arm for 90% power. For planning for 75% of the observed effect, it gives 3,037 participants per arm for 80% power and 4,066 participants per arm for 90% power. For planning for 50% of the observed effect, it gives 6,833 participants per arm for 80% power and 9,147 participants per arm for 90% power. The sample-size curve presents the same general relationship visually; it is a planning display, not a report of enrollment or observed outcomes.

Power is the chance, under the assumptions used for planning and if the specified effect were real, of detecting that effect at the stated significance level. The 80% and 90% columns show the participant counts per arm associated with those planning targets. A smaller target effect is harder to distinguish from random variation, so the illustration requires more participants as the assumed effect becomes smaller. This is not observed power. The original trial’s sample-size assumptions and justification are not reported in the registry record, so these illustrations should not be interpreted as the study’s own planned enrollment target.

12. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -1.000; pooled standard deviation σ = 10.431.
2. n = 2 × (1.96 + 0.842)² × 10.431² / -1.000² = 1,708.1, rounded up to 1,709 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- -1                      # observed difference in means
sigma <- 10.4313517492895                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(5565937)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 1,709 (80% power), 2,287 (90% power)
 75% of observed effect: n per arm = 3,037 (80% power), 4,066 (90% power)
 50% of observed effect: n per arm = 6,833 (80% power), 9,147 (90% power)
power.t.test: 1709.1 
Simulated power at n = 1,709 per arm: 0.801 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

13. Multiplicity, Missing Data and Analysis Populations

The registry record lists four outcome measures, while the primary outcome is overall comfort averaged over all follow-up visits through 3 months. No secondary outcome results are posted. The record reports no analyses, and it does not describe the statistical analysis plan or the ordering of outcomes for formal testing. It is therefore not possible to determine from the registry record whether the primary comparison was part of a wider family of tests or whether multiplicity adjustments were planned or used.

Multiplicity arises when several statistical hypotheses are tested. In general, the more tests conducted, the greater the chance that at least one result may appear statistically notable by chance if no adjustment or prespecified testing strategy is used. This is a general consideration, not evidence that multiplicity affected this study. The unadjusted p-value of 0.409 should be identified as unadjusted rather than treated as an adjusted result.

The record also does not report missing-data counts for the comfort endpoint, reasons for missingness, or the method used to include participants with incomplete follow-up. It does not state whether an intention-to-treat, per-protocol, or another analysis population was used. Those details are important for understanding how the randomized groups were carried into the outcome analysis and whether participants with incomplete data could affect the comparison.

Repeated visits and bilateral measurements raise additional methodological questions. The endpoint is averaged over follow-up visits and assessed for each eye, but the record does not explain how within-participant dependence or missing eye and visit measurements were handled. It also does not report whether baseline values were used in the analysis. These are unknowns, not evidence that any particular method was or was not used. A full assessment of the analysis would require a protocol or analysis plan and more complete reporting than appears in the registry record.

14. Safety Results

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

Deaths

Other (non-serious) adverse events

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

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: appendicitis (0.7%).

The serious adverse event counts are reported separately from the comfort outcome. In the BL-3100-NBR03 group, 143 participants were at risk, with 0 serious adverse events and 0 deaths reported. In the renu® Advanced Formula group, 151 participants were at risk, with 1 serious adverse event and 0 deaths. The listed serious adverse event term is appendicitis, reported as 0.7%.

The safety denominators differ from the group counts for the primary outcome: the comfort summaries include 143 participants in the BL-3100-NBR03 group and 152 in the renu® Advanced Formula group, whereas the serious-event counts use 143 and 151 participants at risk. The registry record does not explain the denominator difference, so it should not be attributed to a particular reason.

These counts describe the reported serious events in the record. A count of zero means no such events were reported for that group in this record; it does not establish that the risk is zero. A single event provides limited information about how often an event might occur in a broader population. The record does not provide event timing, relatedness assessments, or further clinical details. The counts should not be interpreted as proving a causal relationship between a solution and an event.

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

The posted comfort results show similar observed group means: 91.7 for BL-3100-NBR03 and 90.7 for renu® Advanced Formula on a 0-to-100 scale, where 100 is the most favorable response. The estimated mean difference was -1.0 points in the direction of a lower average score for renu® Advanced Formula. The confidence interval extends from -3.376 to 1.376, and the unadjusted p-value is 0.409. Together, these statistics describe an estimate that is uncertain and compatible with differences in either direction.

They do not establish that the solutions are equivalent, because the registry record does not report an equivalence margin or a non-inferiority margin. A nonsignificant p-value is not proof that there is no difference. Nor do the data establish superiority for either solution. The record also does not identify a threshold for a comfort-score difference that participants would consider meaningful, so the practical importance of the estimated difference cannot be determined from these results alone.

The comfort outcome is an average across follow-up visits, and therefore does not describe every visit or every participant’s experience. Group means do not reveal the distribution of individual scores, the number of participants with particularly high or low scores, or the stability of comfort over time. The standard deviations indicate variation but do not answer those questions.

The study also reports serious adverse event counts: 0 in the BL-3100-NBR03 group and 1 in the renu® Advanced Formula group, with 0 deaths in either group. These are descriptive counts and should not be taken as proof of a causal effect or as a complete characterization of safety. Overall, the registry record supports a cautious statistical description of the posted outcomes, not a treatment recommendation or a definitive judgment about the relative performance of the solutions.

16. Why This Trial Matters Statistically

This study illustrates why the wording of an endpoint matters. Overall comfort is measured on a numerical scale, and averaging across follow-up visits turns repeated subjective assessments into a single group-level summary. That summary is easy to compare, but it does not preserve all the information about individual responses, changes over time, or the relationship between assessments from two eyes.

It also demonstrates the distinction between an estimate and the certainty around it. The group means differ by -1.0 points, but the confidence interval from -3.376 to 1.376 includes zero and leaves room for differences in either direction. A p-value of 0.409 does not prove equality. These concepts are important whenever a study reports a nonsignificant comparison: lack of strong evidence against no difference is not the same as evidence that a meaningful difference has been ruled out.

The planning illustration provides another statistical lesson. Sample-size requirements depend on the effect targeted for detection, along with the assumptions used in the calculation. Smaller target effects require more participants in the illustration. Those figures are distinct from the completed study’s enrollment of 295 participants and cannot be used as evidence of the trial’s original design rationale, which is not reported in the registry record.

Finally, the record makes clear why transparency about analysis choices is valuable. The endpoint involves both eyes and follow-up visits, yet the record does not explain how those measurements were combined or how missing data were handled. Such details help readers assess whether uncertainty estimates reflect the structure of the observations. The posted statistics can be interpreted in their stated terms, while the unreported methods limit broader conclusions.

17. 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 primary limitations for interpreting this particular record concern missing methodological detail. Although the comfort endpoint is described as an average over follow-up visits and assessed for each eye, the registry record does not explain the averaging procedure, analysis unit, or treatment of correlation between eyes and repeated visits. It also does not report how missing comfort scores were handled, how many observations were missing, or which analysis population was used.

The record does not give the original sample-size justification, the statistical analysis plan, a prespecified meaningful-difference threshold, or an equivalence or non-inferiority margin. As a result, the planning illustration cannot explain why the completed study enrolled 295 participants, and the interval cannot be judged against a stated threshold for practical importance. The record does not report whether analyses were adjusted for baseline measures or other participant characteristics.

The planned description refers to approximately 22 investigative sites and approximately 340 participants, while the completed record reports enrollment of 295 participants. The record does not state the final number of participating sites or explain the difference between the planned and completed enrollment descriptions. It also does not report adherence, protocol deviations, or participant flow by group.

For safety, the numbers at risk differ between the two groups and from the corresponding comfort-outcome counts. The record does not explain that difference or provide detailed event timing, relatedness, or clinical narratives. These gaps make the findings useful as a concise account of the posted results, but they limit independent assessment of the analysis and the full context of the observed outcomes.

18. Related Tutorials

19. Related Statistical Calculators

20. Sources

• ClinicalTrials.gov: A Study to Evaluate the Safety and Effectiveness of a Contact Lens Cleaning and Disinfecting Solution — NCT05565937.
• Registry record last updated 2025-05-20; status last verified 2025-05.
• Results first posted 2025-05-20.
• 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.

21. Record Summary

NCT05565937 is a completed randomized, double-masked, parallel-group study comparing BL-3100-NBR03 multi-purpose solution with renu® Advanced Formula multi-purpose solution. The listed condition is refractive ametropia, the phase is recorded as NA, and enrollment was 295 participants. The record lists 2023-04-12 as the start date and 2024-02-28 as the primary completion date.

The primary outcome was overall comfort averaged over all follow-up visits through 3 months, assessed for each eye on a scale from 0 to 100. The group means were 91.7 for BL-3100-NBR03 and 90.7 for renu® Advanced Formula. The unadjusted mean difference was -1.0, with a confidence interval from -3.376 to 1.376 and an unadjusted p-value of 0.409. The record reports 0 serious adverse events in the BL-3100-NBR03 group and 1 in the renu® Advanced Formula group, with 0 deaths in either group. No secondary outcome results are posted.