DAILIES® AquaComfort Plus® Multifocal (MF) - Comparative Assessment of Visual Performance: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for DAILIES® AquaComfort Plus® Multifocal (MF) - Comparative Assessment of Visual Performance (NCT02403180), a randomized na study. The primary outcome is Mean Stereoacuity at Near After 5+/-1 Days of Contact Lens Wear.

2. Clinical Question

3. Trial Design

This was a completed randomized, double-masked, crossover study sponsored by Alcon Research. The registry record gives an enrollment of 70 and lists presbyopia as the condition. The stated purpose was to evaluate the visual performance of DACP MF and PROCLEAR 1D MF daily disposable contact lenses in an established presbyopic population. The study was not assigned a drug phase; the registry lists its phase as NA.

The crossover structure means that participants were assigned to a product sequence rather than simply to one product for the whole study. One sequence wore DACP MF in Period 1 and PROCLEAR 1D MF in Period 2. The other sequence wore PROCLEAR 1D MF first, followed by DACP MF. Both products were worn in both eyes, for 5 ±1 days in a daily wear, daily disposable modality in each period. Randomization and double masking are stated in the registry record, but the methods used to generate the sequence allocation and maintain masking are not reported.

The primary outcome was mean stereoacuity at near after 5+/-1 days of contact lens wear, with the timeframe described as Day 5 for each product. The posted results give a mean and standard deviation for each product. The analysis population is described as intention-to-treat participants with non-missing observations, while the product-specific outcome denominators are 69 for PROCLEAR 1 Day MF and 68 for DACP MF. The registry record does not report how the crossover data were analyzed, whether period or sequence effects were considered, or how missing observations were handled.

One secondary outcome is listed: mean area of focus under the mean defocus curve after 5 +/- 1 days of contact lens wear. The registry record does not report a result for that secondary outcome in the registry record for this analysis.

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 reporting group includes all enrolled participants (70).

Pre-Treatment Period

Reasons for not completing this period:

Period 1 (5 Days)

Period 2 (5 Days)

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Intention to treat participants with non-missing observations

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: Intention to treat, defined as the set of all randomized participants.

6. Primary Endpoint

The registry lists the primary outcome as Mean Stereoacuity at Near After 5+/-1 Days of Contact Lens Wear, measured over Day 5, each product.

The primary endpoint is mean stereoacuity at near after 5+/-1 days of contact lens wear for each product. Stereoacuity is described in the registry record as the ability to detect differences in distance, or depth perception. It was measured at a distance of 40 cm using the Howard-Dolman system, and the recorded unit is arcsec. A lower stereoacuity value indicates better depth perception.

Using a defined visual task and distance gives the outcome a specific, measurable interpretation: it records performance on near depth perception after each product period. Reporting the mean describes the average observed value within the non-missing observations for each product. The standard deviation describes the spread of individual values around that mean; it is not the uncertainty interval for the mean difference.

The registry record reports a mean of 30.7 for DACP MF and 40.6 for PROCLEAR 1 Day MF. Since lower values indicate better depth perception, the DACP MF group mean is numerically lower. The endpoint is one component of visual performance, not a complete measure of vision or of contact-lens experience. The registry record does not report a threshold for a meaningful change in stereoacuity or explain how the result relates to other visual outcomes.

7. Results Posted in the Registry

• DACP MF: mean 30.70 versus 40.60 on control; difference -9.90 (95% CI -13.34 to -6.46), standardized effect d = -0.96; z-test p = <0.001.

8. Statistical Interpretation

9. Statistical Methods Explained

What does a mean describe?

A mean is the arithmetic average of the observed values in a group. In this study, the reported means describe near stereoacuity after the stated wear period for each product. The DACP MF mean is 30.7 arcsec, and the PROCLEAR 1 Day MF mean is 40.6 arcsec. Since lower values indicate better depth perception, the direction of the observed difference can be interpreted using the endpoint's stated scale. A group mean does not show how every participant performed, and it can conceal variation across individual measurements.

The standard deviation is a measure of how spread out the observations are around their group mean. The registry reports standard deviations of 8.67 for DACP MF and 11.67 for PROCLEAR 1 Day MF. These values describe variability among observations; they are not confidence intervals and do not directly state how precisely the difference between product means has been estimated.

How should the reported difference be read?

The registry comparison reports the mean difference as DACP MF relative to PROCLEAR 1 Day MF. Its estimate is -9.9 arcsec. A negative value means the first product's reported mean is lower than the comparator's mean under this stated direction of subtraction. The outcome description says lower values indicate better depth perception, so the direction is meaningful for the measured endpoint. The difference remains a summary of the posted data and does not by itself identify the statistical model used to compare products.

The registry also reports a confidence interval from -13.34 to -6.461 and an unadjusted p-value of <0.001. A confidence interval conveys uncertainty about an estimated quantity under a particular statistical method. A p-value describes how compatible the data are with a specified null hypothesis under the assumptions of a test. Neither quantity establishes clinical importance, and the p-value is not the probability that the null hypothesis is true. The confidence level, test, and model are not reported in the registry record.

Why does the crossover design matter?

In a crossover design, participants receive products in a sequence, so outcomes can be observed after each product period for a participant. Comparing measurements within the same participant can account for stable differences between participants, but valid interpretation also depends on features such as period effects, sequence effects, and possible carryover from one period to another. These are general considerations for crossover studies, not claims about what happened in this study.

The registry gives both product sequences and states that each product was worn for 5 ±1 days in its period. It does not report whether there was a washout, whether the analysis used paired observations, how period or sequence was handled, or whether carryover was assessed. The posted group means and comparison can be described, but the analysis cannot be characterized as paired or adjusted based on the registry information available.

What does the analysis population mean?

The primary population is described as intention-to-treat participants with non-missing observations. Intention-to-treat generally refers to analyzing participants according to their randomized assignment, while the non-missing-observation qualification indicates that a value had to be available for the outcome being summarized. In a crossover study, missingness may affect one product-period measurement, both measurements, or other parts of the record. The registry does not explain the pattern or reason for missing observations, nor the handling of incomplete pairs. The product-specific denominators are 68 and 69; they should be read as reported denominators for the outcome, not as a description of all enrollment or completion details.

What is not reported about the statistical plan?

The registry record does not report the method used for the primary comparison, the confidence level, assumptions for an analysis model, or a prespecified statistical plan. It also does not report how multiplicity was handled across outcomes or any interim analyses. These details matter because they define how uncertainty is quantified and how confirmatory claims are interpreted. Their absence does not invalidate the posted descriptive values, but it limits assessment of the analysis choices and the strength of inferential conclusions.

General statistical interpretation distinguishes the observed estimate from its uncertainty and from its practical meaning. The estimate describes the observed contrast; the interval communicates precision under its method; and a clinical interpretation requires context about meaningful differences and other outcomes. The registry provides the estimate, interval, and p-value, but does not report a threshold for a meaningful stereoacuity difference or enough detail to reconstruct the crossover analysis.

10. Confidence Intervals and Precision

The registry comparison reports a mean difference of -9.9 arcsec for DACP MF relative to PROCLEAR 1 Day MF, with a confidence interval from -13.34 to -6.461. The interval gives a range of values compatible with the observed data under the calculation method. It is more informative about precision than the point estimate alone: it indicates that the estimated difference is not exact and quantifies uncertainty around it according to that method.

The interval's endpoints are both below zero. In the stated direction of comparison, that is consistent with a lower mean stereoacuity value for DACP MF. The outcome description says that lower values indicate better depth perception, but the registry does not report a threshold for a clinically meaningful difference. The interval therefore addresses uncertainty in the estimated mean contrast, not whether that contrast is important in practice.

The confidence level and construction method are not reported in the registry record. Nor does the record specify whether the comparison accounts for the within-participant nature of the crossover, period, or sequence. Those details affect how the interval should be understood. The product means are based on 68 observations for DACP MF and 69 for PROCLEAR 1 Day MF; the record describes the outcome population as intention-to-treat participants with non-missing observations. It does not explain missing values or report an interval for each product mean. The interval should thus be interpreted as the posted comparison, without assuming an unreported model or confidence level.

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 planning figures are participants per arm, not total events. They are illustrations based on the observed effect and are not the trial's original design assumptions. The calculation assumptions listed in the registry information are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. Each planning row uses the stated fraction of the observed effect as the effect to detect.

The 80% power column gives the illustrative participants per arm under those assumptions for a design with an 80% chance of detecting the specified effect if that effect were the true one. The 90% power column gives the corresponding illustrative number for a 90% chance. For planning at 100% of the observed effect, the figures are 17 participants per arm for 80% power and 23 participants per arm for 90% power. Planning for 75% of the observed effect gives 31 and 41 participants per arm, respectively; planning for 50% gives 68 and 91.

Smaller effects require more participants to detect under otherwise unchanged assumptions, which is why the planning figures rise as the target fraction of the observed effect becomes smaller. These are not observed power calculations and do not indicate the probability that the study's result is true. The registry record does not report the original sample-size justification or the assumptions used to plan the trial itself.

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 = -9.900; pooled standard deviation σ = 10.291.
2. n = 2 × (1.96 + 0.842)² × 10.291² / -9.900² = 17.0, rounded up to 17 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 <- -9.9                      # observed difference in means
sigma <- 10.2910106403599                     # 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(2403180)
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 = 17 (80% power), 23 (90% power)
 75% of observed effect: n per arm = 31 (80% power), 41 (90% power)
 50% of observed effect: n per arm = 68 (80% power), 91 (90% power)
power.t.test: 18 
Simulated power at n = 17 per arm: 0.780 (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 primary outcome is mean stereoacuity at near. One secondary outcome is listed: mean area of focus under the mean defocus curve after 5 +/- 1 days of contact lens wear. The registry record does not report a multiplicity strategy for interpreting results across outcomes or any adjustment to the primary p-value. The primary comparison's p-value is identified as unadjusted. Without a reported plan for multiple outcomes, readers cannot determine how the study intended to control the chance of false-positive findings across a set of tests.

The analysis population is described as intention-to-treat participants with non-missing observations. The outcome denominators are 69 for PROCLEAR 1 Day MF and 68 for DACP MF. Enrollment is reported as 70, but those outcome denominators do not explain who contributed observations to each product result or why any observations are absent. The registry record does not describe a missing-data method, imputation, or sensitivity analysis. In a crossover study, incomplete data may affect the availability of a within-participant comparison; the record does not explain whether the posted comparison required paired observations.

The registry lists zero analyses in its analysis listing, while it also contains posted primary outcome results. It does not report a detailed statistical analysis plan, interim analyses, or how analyses were selected for reporting. These omissions limit evaluation of multiplicity and missing-data decisions. They do not change the arithmetic meaning of the posted means, but they leave uncertainty about the inferential procedures behind the reported comparison and p-value.

14. 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 serious adverse event figures report zero affected participants for both product rows. For Proclear 1 Day MF, 69 were listed as at risk and zero as affected; for DACP MF, 69 were listed as at risk and zero as affected. These are the registry's reported counts for the exposure groups. Because this was a crossover study, the product rows represent exposure periods and should not be added to infer a total number of distinct participants.

The other adverse event counts are also reported as zero affected among 69 at risk for each product. The registry record does not list serious adverse event terms. Death counts are not reported in the registry record. The figures describe reported events within the recorded at-risk groups; they do not establish that an event could not occur, and the record does not provide further information about event definitions, collection procedures, or follow-up beyond the stated product-wear periods.

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

The posted data show mean near stereoacuity values of 30.7 arcsec after DACP MF and 40.6 arcsec after PROCLEAR 1 Day MF. The registry reports a mean difference of -9.9 arcsec for DACP MF relative to PROCLEAR 1 Day MF, with a confidence interval from -13.34 to -6.461 and an unadjusted p-value of <0.001. Since the outcome description states that lower values indicate better depth perception, the observed mean is lower for DACP MF on this measure.

This finding concerns one defined outcome, measured at 40 cm with the Howard-Dolman system after 5+/-1 days of wear of each product. It does not describe every aspect of visual performance, and it does not establish whether the size of the difference is meaningful to participants. The registry record does not report a threshold for meaningful change. Nor does it provide enough statistical detail to determine how the comparison handled the paired measurements, periods, or sequences in this crossover design.

The posted numbers do not establish effects outside the studied population and wear conditions. They do not provide information on longer-term use, other populations, or outcomes not reported in the record. The registry lists one secondary visual outcome, but a result for it is not reported in the registry record for this analysis. Zero adverse events are reported in the listed at-risk groups, but the safety record is limited to those counts and does not show that risk is absent. The result should be read as a comparison of the posted outcome summaries, with the listed uncertainty and the stated reporting limits.

16. Why This Trial Matters Statistically

This study illustrates why the design and endpoint both matter when interpreting a clinical comparison. The randomized, double-masked crossover design exposes participants to both products in different sequences, while the endpoint measures near stereoacuity after each product period. That structure can support a within-participant comparison, but interpretation depends on whether the analysis accounts for the repeated measurements and relevant period or sequence effects. Those analysis details are not reported in the registry record.

The primary outcome is a continuous measure with an interpretable direction: lower arcsec values indicate better depth perception. The posted means and mean difference give a concise account of the observed contrast, while the confidence interval conveys uncertainty around that contrast. The unadjusted p-value adds information about compatibility with a null hypothesis under a statistical test, but does not replace the effect estimate or establish practical importance. The registry does not state a threshold for meaningful change.

The record also shows why denominators and analysis populations should be read carefully. It describes an intention-to-treat population with non-missing observations and reports different product-specific denominators, but does not explain missingness or the handling of incomplete crossover data. Safety counts are reported by product exposure, which should not be interpreted as a count of unique participants across the crossover periods. These distinctions help keep descriptive results, uncertainty, and the design's limits separate.

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.

Several details needed to assess this crossover comparison are not reported in the registry record. It does not describe a washout between product periods, the method used to generate randomized sequences, or how masking was maintained. It also does not report the statistical model, whether the primary comparison used paired observations, or whether period, sequence, or possible carryover effects were considered. These omissions limit evaluation of how the design was reflected in the analysis.

The record describes the primary population as intention-to-treat participants with non-missing observations and reports product-specific denominators of 69 and 68. It does not give reasons for missing observations, explain whether incomplete product-period data were included, or report sensitivity analyses. The confidence level and method for calculating the confidence interval are also not reported.

The primary outcome is a specific near stereoacuity measure after 5+/-1 days of wear, rather than a broad assessment of all visual performance. The record does not report a meaningful-change threshold or further participant characteristics beyond an established presbyopic population. One secondary outcome is listed, but its result is not reported in the registry record for this analysis. The registry also does not report the trial's original sample-size assumptions, a detailed multiplicity plan, or longer-term results. These limits narrow what can be concluded from the posted comparison.

18. Related Tutorials

19. Related Statistical Calculators

20. Sources

• ClinicalTrials.gov: DAILIES® AquaComfort Plus® Multifocal (MF) - Comparative Assessment of Visual Performance — NCT02403180.
• Registry record last updated 2016-08-18; status last verified 2016-07.
• Results first posted 2016-08-18.
• 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

NCT02403180 is a completed, randomized, double-masked crossover study sponsored by Alcon Research. It compared DACP MF and PROCLEAR 1 Day MF multifocal daily disposable contact lenses in an established presbyopic population. Each product was worn bilaterally for 5 ±1 days in its period, with two product sequences.

The primary endpoint was mean near stereoacuity after 5+/-1 days of wear, measured at 40 cm in arcsec; lower values indicate better depth perception. The posted means were 30.7 for DACP MF and 40.6 for PROCLEAR 1 Day MF. The reported mean difference was -9.9, with a confidence interval from -13.34 to -6.461 and an unadjusted p-value of <0.001. The outcome population is described as intention-to-treat participants with non-missing observations.

The registry lists one secondary outcome and reports zero affected participants for serious and other adverse events in the product-specific at-risk groups. Details of the crossover analysis, missing-data handling, and the trial's original sample-size plan are not reported in the registry record.