Multi-Center 2-Week Clinical Evaluation of Three Silicone Hydrogel Contact Lenses: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Multi-Center 2-Week Clinical Evaluation of Three Silicone Hydrogel Contact Lenses (NCT01244516), a randomized na study. The primary outcome is Overall Subjective Comfort.

2. Clinical Question

The question is about reported patient experience at the end of a short wearing period, not about a long-term outcome. The CLUE questionnaire is described as a validated patient-reported outcomes questionnaire addressing comfort, vision, handling, and packaging in soft, disposable contact lenses. The primary outcome focuses on comfort; overall subjective lens handling is listed as a secondary outcome. The record does not report an explicit primary hypothesis or the decision rule used to determine whether one lens’s result would be considered importantly different from another.

3. Trial Design

This was a randomized, single-masked, parallel-group study listed as completed. It enrolled 540 participants and compared three silicone hydrogel contact lenses over a 2 week period. The registry lists myopia as the condition and Johnson & Johnson Vision Care, Inc. as the sponsor. The study phase is recorded as NA. The start date is 2010-09-01 and the primary completion date is 2010-11-01.

Participants were assigned to wear one lens throughout the course of the study: galyfilcon A with a base curve of 8.30, lotrafilcon B, or comfilcon A. The primary comparisons use galyfilcon A as the reference group. The record identifies the design as randomized and parallel, meaning the assigned groups are compared rather than each participant switching through all three lenses. It identifies masking as single, but does not report who was masked or how masking was implemented.

The primary endpoint analysis includes subjects who completed the study (n=501). The posted primary group estimates include 163 participants for galyfilcon A, 170 for lotrafilcon B, and 168 for comfilcon A. These are the analysis counts for the outcome, not a description of all randomized participants. The record does not detail participant flow, reasons for non-completion, or how missing endpoint measurements were handled.

The primary outcome was overall subjective comfort after 2 weeks of contact lens wear. Overall subjective lens handling is the listed secondary outcome. The registry lists three outcome measures and four analyses, but does not report a full protocol or a complete statistical analysis plan. Details such as the planned allocation ratio, recruitment procedures, intended sample-size justification, masking procedures, and rules for handling multiple outcomes are not reported in the registry 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: There were 20 subjects who did not meet the inclusion or did meet the exclusion criteria. There were 10 screen failures and 10 who wore spectacles to baseline visit invoking the exclusion criteria.

Period 1 (Baseline to 1-week Visit)

Reasons for not completing this period:

Period 2 (1-week to 2-week Visit)

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Analysis is on those subjects who completed the study (n=501).

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: Population consists of those subjects who were enrolled and randomly assigned to a treatment arm AND who completed the study per protocol.

6. Primary Endpoint

The registry lists the primary outcome as Overall Subjective Comfort, measured over after 2 weeks of contact lens wear.

Overall subjective comfort was assessed after 2 weeks of contact lens wear using a CLUE score. CLUE is described as a validated patient-reported outcomes questionnaire for patient experience with soft, disposable contact lenses. Its attributes include comfort, vision, handling, and packaging. The primary measure focuses on comfort rather than combining all of those attributes into a single reported endpoint.

The record states that CLUE scores follow a normal distribution with a population average score of 60 (SD 20), and that higher scores indicate a more favorable or positive response. The posted group results are least-squares means, with standard errors as the reported measure of spread. A mean gives a group-level summary of the continuous scores; it does not show how every participant responded or how widely individual experiences varied.

Patient-reported outcomes are used to describe experiences that are not fully represented by an external clinical measurement. A questionnaire can apply the same questions and scoring approach across groups, supporting a structured comparison of participants’ reported comfort. The registry record does not report the CLUE questionnaire’s item-level results, a threshold for a clinically important difference, or a rationale for selecting this outcome as primary. Without such a threshold, the numerical group contrasts alone do not establish how important a difference would be to participants.

7. Results Posted in the Registry

• Lotrafilcon B: mean 51.30 versus 51.70 on control; difference -0.40 (95% CI -6.08 to 5.28), standardized effect d = -0.02; z-test p = 0.890.
• Comfilcon A: mean 51.30 versus 51.70 on control; difference -0.40 (95% CI -6.08 to 5.28), standardized effect d = -0.02; z-test p = 0.890.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Overall Subjective Lens Handling

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard errors.
• Result:
  • Comfilcon A: mean 59.80 versus 64.30 on control; difference -4.50 (95% CI -8.93 to -0.07), standardized effect d = -0.22; z-test p = 0.047.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for Comfilcon A than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Overall subjective lens handling is the sole secondary outcome named in the registry record. It is a CLUE score assessed after 2 weeks of contact lens wear, and the posted comparison is between galyfilcon A and comfilcon A. The endpoint concerns handling rather than the primary comfort attribute, so it adds information about a different part of the participant-reported experience. It does not provide a direct replication of the primary comfort comparison.

The secondary result should be considered alongside, rather than in place of, the primary result. A finding for handling does not automatically imply a corresponding difference in comfort, because they are distinct outcomes. Nor does it establish an overall ranking across lenses on all dimensions of experience. The registry lists three outcome measures and four analyses, but does not report a complete outcome hierarchy, a prespecified testing sequence, or an adjustment for making multiple comparisons.

Unadjusted secondary results carry less weight because testing multiple outcomes or contrasts creates more opportunities for a result to appear noteworthy by chance. A multiplicity adjustment or a prespecified hierarchy can help control the interpretation of repeated testing, but the registry does not report whether either was used. The available secondary result is therefore best treated as a nominal, exploratory observation rather than definitive evidence on handling. The record also does not report a clinically important difference threshold for this score, limiting interpretation of its practical importance.

The broader pattern is that the primary comfort comparisons do not show a clear separation in the posted analyses, while the secondary endpoint addresses another aspect of lens use. Taken together, these outcomes describe separate dimensions and should not be collapsed into a single claim about overall performance. The registry’s limited reporting on multiplicity and the analysis plan means the secondary finding warrants cautious interpretation, regardless of its numerical result.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Overall Subjective Lens Handling

9. Statistical Interpretation

10. Statistical Methods Explained

The primary endpoint is continuous: each participant’s questionnaire response is represented by a numerical CLUE score, and group results are summarized by means. A mean is useful for comparing the average score across randomized groups, while the standard error describes the uncertainty in the estimated group mean. The standard error is not the spread of individual participants’ scores. The registry reports least-squares means and standard errors for the primary outcome, but does not detail the model terms used to obtain those adjusted means.

What does a mean difference represent?

A mean difference expresses the contrast between two group averages in the score’s own units. Its sign depends on which group is subtracted from which. In the recalculated comparisons, the estimate is defined as the non-reference group minus galyfilcon A, so a negative estimate indicates that the non-reference group’s estimated score is lower. The sponsor’s reported contrasts are oriented as galyfilcon A compared with the other lens, resulting in positive estimates. Interpretation should therefore consider both the estimate and the stated comparison direction, rather than treating the sign alone as a disagreement.

The simple recalculations are unadjusted comparisons derived from posted summary statistics. They use approximate standard deviations reconstructed from the reported standard errors and analysis counts; those estimates are explicitly approximate. This approach does not reproduce the sponsor’s mixed models analysis, which may account for model structure not represented in group-level summaries. The sponsor analysis is the trial’s reported inferential analysis. Since the posted recalculations do not show a discrepancy requiring a different conclusion, they are best treated as a supplementary, unadjusted view rather than as a replacement for that analysis.

How should a p-value be read?

A p-value describes how compatible the observed data are with a specified null model, under the assumptions of the test. It is not the probability that the null hypothesis is true, and it does not measure the size or practical importance of a difference. The recalculated primary p-values are unadjusted and equal 0.89. The sponsor’s primary analyses do not have p-values posted. The registry record does not report a full account of the sponsor’s testing procedure or the null hypotheses used in the mixed models analyses.

For a secondary comparison, the posted unadjusted p-value is 0.047. Because the record lists multiple outcome measures and analyses, this value should not be read as if it were automatically adjusted for all opportunities to detect a difference. Without a reported multiplicity plan, the nominal result is exploratory in interpretation. A p-value alone also cannot establish whether a score difference is meaningful to participants.

Why does over-dispersion matter?

Over-dispersion occurs when the observed variability is greater than a statistical model expects. It can make standard errors too small if the model does not accommodate that extra variability, creating confidence intervals that are too narrow and tests that are too optimistic. General statistical practice is to examine whether a model’s assumptions fit the outcome and to use methods that reflect the data’s variability. The primary outcome is a continuous score; the registry describes the score distribution as normal, but does not report diagnostics for model fit, tests for over-dispersion, or a model adjustment specifically addressing it. Over-dispersion is therefore a general consideration, not a reported finding in this trial.

For continuous outcomes, uncertainty in a mean difference depends in part on the variability of scores and the amount of information available in each group. The group standard errors and analysis counts contribute to the approximate recalculations, but those summaries do not retain all participant-level information. In particular, they cannot reconstruct covariate adjustment, correlations, or other model details unless those details are reported. The registry identifies the sponsor’s primary method as mixed models analysis, but does not give enough information to reproduce that model in full.

What is the role of the confidence interval?

A confidence interval gives a range of effect estimates compatible with the data and the method used to calculate it. Narrower intervals indicate greater precision, while wider intervals indicate more uncertainty. An interval that includes zero does not establish that the groups are identical; it indicates that the data and method do not rule out zero as a possible difference at that interval’s confidence level. The sponsor reports 97.4% intervals for the primary comparisons, and the recalculations report intervals without a stated confidence level in the posted summary. The record does not report a prespecified equivalence or non-inferiority margin, so an interval spanning zero cannot be used alone to declare equivalence or non-inferiority.

The planning illustrations use a normal approximation and equal allocation between two arms, with a two-sided significance level of 0.05. They consider effects defined as fractions of the observed effect and report the number of participants per arm for target power levels. These figures describe hypothetical planning under those assumptions, not the trial’s original design rationale. The record does not report the trial’s original sample-size assumptions or justification. They also do not represent observed power, which is not a useful substitute for interpreting the estimates and their uncertainty after a study has been conducted.

11. Confidence Intervals and Precision

The primary group estimates have standard errors of 2.1 for galyfilcon A and 2.0 for each of the other two lenses. These standard errors describe the uncertainty around the estimated group means, not the variation among individual participants. The posted recalculated mean-difference intervals run from -6.084 to 5.284 for each comparison. Because the intervals cover values on both sides of zero, the estimates are compatible with a range of possible directions and magnitudes of difference under the recalculation method.

The sponsor’s mixed models intervals are reported at 97.4% confidence. For galyfilcon A compared with lotrafilcon B, the reported mean difference is 0.39, with an interval from -5.91 to 6.70. For galyfilcon A compared with comfilcon A, the estimate is 0.42, with an interval from -5.96 to 6.79. These intervals also include zero. Their width indicates that the data do not pin down the comparative comfort effect very precisely. Neither the sponsor intervals nor the recalculated intervals establish that the groups have identical comfort scores.

Confidence intervals are useful because they convey both the estimated direction and the range of uncertainty, rather than reducing the interpretation to a binary test result. Precision depends on the observed variability, the analysis counts, and the estimation method. The record gives group counts and standard errors, but does not report participant-level scores or the complete model details required to independently reproduce the sponsor intervals.

Statistical precision is not the same as clinical importance. The CLUE score description gives a population average score of 60 (SD 20), but the registry record does not state what score difference would matter to participants or what margin would support an equivalence conclusion. Consequently, the intervals can be described as spanning a range of possible differences, but their practical importance cannot be determined from the registry results alone.

12. 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, not the sample-size calculation used to design this trial. Their 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 set to the stated fraction of the observed effect. The registry record does not report the trial’s original design assumptions or sample-size justification.

The 80% power column gives the number of participants per arm that the planning method estimates would be needed to have an 80% chance of detecting the specified effect under the stated assumptions, if that effect and those assumptions applied. The 90% power column gives the corresponding per-arm planning number for a higher target chance of detection. These are design targets, not guarantees that a future study will produce a particular result.

Rows describing a smaller fraction of the observed effect require larger planned groups. That is a general feature of power calculations: a smaller target difference is harder to distinguish from random variation, so more information is usually needed. The planning values do not establish that the trial had inadequate or adequate power for its own objectives, because the original target effect and design assumptions are not reported. These numbers are not observed power. Interpretation of the completed trial should focus on the estimated effects and their uncertainty rather than using a post-study power calculation to explain the findings.

13. 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 = -0.400; pooled standard deviation σ = 26.439.
2. n = 2 × (1.96 + 0.842)² × 26.439² / -0.400² = 68,580.0, rounded up to 68,581 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 <- -0.400000000000006                      # observed difference in means
sigma <- 26.4386915500017                     # 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(1244516)
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 = 68,581 (80% power), 91,810 (90% power)
 75% of observed effect: n per arm = 121,921 (80% power), 163,217 (90% power)
 50% of observed effect: n per arm = 274,321 (80% power), 367,237 (90% power)
power.t.test: 68581 
Simulated power at n = 68,581 per arm: 0.802 (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.

14. Analyses Reported by the Sponsor

The sponsor reports mixed models analyses for both primary comparisons. The reported mean differences are 0.39 for galyfilcon A compared with lotrafilcon B and 0.42 for galyfilcon A compared with comfilcon A. Each reported interval is at 97.4% confidence and includes zero. The sponsor does not report p-values for these analyses in the registry record.

The simple recalculations use the posted group summaries and orient the contrast as the other lens minus galyfilcon A. They yield estimates of -0.4 for both comparisons, with unadjusted p-values of 0.89. The opposite signs reflect the opposite comparison direction, and the estimated magnitudes are similar. The recalculations are unadjusted and do not reproduce the sponsor’s mixed models procedure, so the sponsor’s own analysis is the primary reported analysis for interpreting the trial.

The registry labels the sponsor analyses as non-inferiority or equivalence analyses, but does not report the margin, decision rule, or a conclusion against that margin. The estimates and intervals alone therefore do not establish non-inferiority or equivalence. The sponsor results are consistent with uncertainty about the comparative comfort effects; they should not be translated into a claim that the lenses perform identically.

15. Multiplicity, Missing Data and Analysis Populations

The registry lists three outcome measures and four analyses, identifies overall subjective lens handling as a secondary outcome, and reports two sponsor analyses for the primary endpoint. It does not report a full statistical analysis plan, the order in which outcomes were tested, or whether any multiplicity correction was applied. Without that information, the unadjusted secondary result should be interpreted cautiously because multiple analyses can increase the chance of a nominally notable finding.

The primary outcome analysis is described as including subjects who completed the study (n=501). The registry does not report the analysis population definition beyond that description, whether participants were analyzed according to randomized assignment, or how missing questionnaire measurements were handled. It also does not report imputation procedures, sensitivity analyses for missing data, or the reasons participants did not complete the study. The enrolled total is 540, but no participant-flow account is reported to explain the difference between enrollment and the primary analysis population.

The record reports least-squares means and standard errors for the primary group results and identifies the sponsor’s comparative method as mixed models analysis. It does not provide model covariates, assumptions, diagnostic checks, or enough detail to reproduce the full analysis. The simple recalculations are based on summary statistics and are unadjusted; they cannot answer whether a different missing-data approach or model specification would change the sponsor result.

The primary comparisons are labeled as non-inferiority or equivalence analyses, but the registry does not report the margin or decision rule. Those details are essential for evaluating such claims. The original sample-size justification and any interim analyses are also not reported in the registry record. These omissions limit evaluation of whether the analysis followed a prespecified plan and how robust the conclusions are to alternative assumptions.

16. 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 reports serious adverse event counts of 0 among 170 participants at risk in the galyfilcon A group, 0 among 177 at risk in the lotrafilcon B group, and 0 among 173 at risk in the comfilcon A group. It reports other adverse-event counts of 0 in each group, using the same respective at-risk counts. These are the posted affected-participant counts for the registry’s reporting categories; they should not be read as proof that no symptoms or events of any kind occurred outside the definitions or reporting collected for this record.

Death counts are not reported in the registry record. The record also lists no serious adverse event terms. It does not provide detailed event definitions, event-level descriptions, timing, severity beyond the serious/other categories, or information about how events were collected. The at-risk safety counts differ from the primary endpoint analysis counts, which is why the safety denominators should not be substituted for the endpoint group sizes.

These figures describe the adverse-event information posted for the study over its reported course. They do not support a broader conclusion about safety beyond the study’s limited 2 week period, participants, and reporting. No medical advice or treatment recommendation follows from these counts.

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

The results describe a randomized comparison of three lenses on participant-reported outcomes after 2 weeks of wear. For the primary comfort measure, the reported group means are close and the comparative estimates are accompanied by intervals that span zero. This means the posted analyses do not clearly distinguish the groups on the primary score, while still allowing a range of possible differences. It does not show that the lenses are identical, nor does it establish equivalence or non-inferiority.

The primary endpoint is a questionnaire score, not a direct measure of every aspect of lens performance. The questionnaire is described as covering comfort, vision, handling, and packaging, but the primary outcome reported is overall subjective comfort. The secondary outcome concerns handling. The evidence is therefore specific to the named CLUE dimensions and the stated assessment time. It does not answer what happens over longer use or on outcomes not reported in the registry.

The record does not state a threshold for a clinically meaningful score difference. Statistical uncertainty can be described from the estimates and intervals, but practical importance cannot be judged confidently without knowing what size of difference would matter to participants. Likewise, the sponsor analyses are labeled as non-inferiority or equivalence analyses, but the margin and decision rule needed to interpret those labels are absent from the registry record.

The secondary outcome should be interpreted separately and cautiously because the analysis plan for multiple outcomes is not reported. A result on handling cannot be used as a substitute for the primary comfort evidence or as a comprehensive measure of overall lens experience. Safety counts are also limited to the registry’s reported categories and study period.

In short, the registry presents estimates of short-term patient-reported experience and adverse-event counts. Its results can inform statistical description of those measured outcomes, but they do not establish a clinically important advantage, prove equivalence, or support generalization beyond the studied conditions and reporting.

18. Why This Trial Matters Statistically

This trial illustrates why a numerical difference and a conclusion about equivalence are not the same thing. The primary group estimates are close, but a comparison requires uncertainty intervals and a prespecified standard for deciding what degree of difference would count as important or acceptable. The sponsor’s analyses are labeled as non-inferiority or equivalence, yet the registry record does not include the margin or decision rule. Without those elements, readers can describe the estimates and intervals but cannot verify a formal equivalence conclusion.

The record also shows why comparison direction matters. The sponsor reports galyfilcon A relative to each other lens, while the simple recalculations use the other lens relative to galyfilcon A. Opposite signs can therefore represent the same underlying contrast. Reading the group ordering alongside the estimate avoids mistaking a change in direction for a change in result.

Another statistical issue is the distinction between a primary result and a secondary result. Comfort and handling are separate patient-reported attributes, and the record does not explain how multiple analyses were planned or adjusted. A nominal secondary signal should not automatically outweigh the primary comparisons. Transparent reporting of outcome hierarchies, multiplicity procedures, and missing-data methods helps readers understand how much confidence to place in each finding.

Finally, the planning illustrations are not a retrospective verdict on whether the trial was adequately designed. They use explicit assumptions and the observed effect, whereas the trial’s original target effect and sample-size rationale are not reported. The case therefore highlights the value of publishing the original design assumptions, model details, analysis population rules, and clinically meaningful thresholds alongside results.

19. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The main limitation for statistical interpretation is incomplete reporting of the design and analysis details. The registry does not report the original sample-size justification, intended target effect, allocation ratio, or the full statistical analysis plan. Masking is described as single, but the masked parties and procedures are not specified. These gaps prevent a full assessment of how the reported analyses relate to the planned design.

The primary analysis is described as using participants who completed the study, but the record does not provide a participant-flow explanation, reasons for non-completion, or missing-data methods. The primary group analysis counts are posted, as are distinct at-risk counts for safety, but the registry does not explain all differences between those populations. The full eligibility criteria and participant characteristics are also not reported in the information available.

The sponsor reports mixed models analyses, but does not provide model covariates, assumptions, diagnostic information, or p-values. The reported non-inferiority or equivalence label is not accompanied by a margin or decision rule. The unadjusted recalculations are based on summary statistics and use approximate standard deviations; they cannot replace the sponsor’s model or establish the same inference.

Interpretation of clinical importance is limited because the record does not report a meaningful-difference threshold for the CLUE score. Multiple outcome measures and analyses are listed, but multiplicity handling and outcome hierarchy are not reported. The study assesses outcomes after 2 weeks, so the record does not address longer-term experience. Finally, the safety reporting is limited to counts in serious and other categories, with death counts not reported in the registry record and no detailed event descriptions.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Multi-Center 2-Week Clinical Evaluation of Three Silicone Hydrogel Contact Lenses — NCT01244516.
• Registry record last updated 2018-06-19; status last verified 2018-04.
• Results first posted 2012-01-24.
• 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.

23. Record Summary

NCT01244516 is a completed, randomized, single-masked, parallel-group study comparing galyfilcon A, lotrafilcon B, and comfilcon A over a 2 week period. It enrolled 540 participants and lists myopia as the condition. The primary outcome was overall subjective comfort measured by CLUE score after 2 weeks of contact lens wear; overall subjective lens handling is the named secondary outcome.

The primary analysis includes subjects who completed the study (n=501). The sponsor reports mixed models comparisons with 97.4% confidence intervals that include zero. Unadjusted recalculations based on posted summary statistics also show estimates near zero, but do not reproduce the sponsor model. The record does not report the margin needed to interpret the analyses labeled non-inferiority or equivalence.

Serious and other adverse-event affected counts are posted as 0 in each group; death counts are not reported in the registry record. Missing-data procedures, multiplicity handling, the original sample-size justification, and several analysis details are also not reported. Results should therefore be understood as short-term registry findings on the specified patient-reported outcomes and reported safety categories.