A Study of Patients With Primary Open Angle Glaucoma or Ocular Hypertension Switched to Lumigan® UD Monotherapy for Medical Reasons: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study of Patients With Primary Open Angle Glaucoma or Ocular Hypertension Switched to Lumigan® UD Monotherapy for Medical Reasons (NCT01853085), a registered phase not stated study. The primary outcome is Intraocular Pressure (IOP) in the Study Eye at Baseline.

2. Clinical Question

The clinical question is consequently descriptive: what is the baseline intraocular pressure among the eligible patients for whom outcome data are recorded, and how are treatment and tolerability described in routine physician-directed care? The listed secondary outcomes include physician and patient assessments, treatment continuation or discontinuation, and patient compliance compared with previous treatment. These measures could describe experience during treatment, but the registry record does not provide their observed results. Because treatment decisions lie with the physician and allocation is not stated, the record does not support treating the study as a randomized efficacy comparison.

3. Trial Design

The registry describes a study of patients with primary open angle glaucoma or ocular hypertension who switched to Lumigan® UD monotherapy for medical reasons. The brief description says the switch follows physician standard clinical practice and that treatment decisions lie with the physician. The record lists one treatment group, with bimatoprost ophthalmic solution administered according to standard practice for up to 12 weeks. It does not report a randomized allocation or a comparable control group.

The listed status is completed. The registry records a start date of 2013-04-01 and a primary completion date of 2014-03-01. Enrollment is listed as 1830. These are registry descriptors; they do not establish how many patients contributed data to each particular outcome. For the primary outcome, the stated analysis population is all patients with data for that measure, but the corresponding count is not reported in the registry record.

The primary outcome is baseline mean intraocular pressure in the study eye. Secondary outcomes concern physician assessment of pressure-lowering effect, patient and physician tolerability assessments, continuation or discontinuation before 12 weeks, and physician assessment of compliance compared with previous treatment. The registry lists eight outcome measures, but the outcome results are not reported in the information summarized by this record. It reports no analyses.

This design description should not be read as evidence of an assigned intervention or a prespecified comparison. In a physician-directed setting, treatment choice and continuation may reflect clinical decisions and patient circumstances. Without a comparable control group and reported outcome estimates, the record is primarily informative about the study question and recorded measures, rather than a quantified treatment contrast.

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

Analysis population for the primary outcome, as defined in the registry: All patients with data for this outcome measure

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 Intraocular Pressure (IOP) in the Study Eye at Baseline, measured over Baseline.

The primary endpoint is intraocular pressure (IOP) in the study eye at baseline. IOP is a measurement of the fluid pressure inside the eye. The registry specifies a mean as the summary measure and standard deviation as the measure of dispersion, with millimeters of mercury as the unit. The outcome population is described as all patients with data for this measure.

Baseline IOP can characterize the starting pressure of the study eye among patients whose measurements are recorded. A mean gives a central summary of the measurements, while the standard deviation describes how spread out those measurements are around the mean. These are different kinds of information: the mean describes the group’s average, and the standard deviation describes variation among individual measurements. Neither, by itself, gives the precision of the estimated mean; that would require an uncertainty measure such as a confidence interval.

This endpoint is measured at baseline, so it does not quantify a change after switching treatment. A treatment-effect question would generally require a defined follow-up measurement and an analysis comparing change or follow-up values across an appropriate contrast. The registry record does not report a baseline mean, standard deviation, confidence interval, or treatment-effect estimate. The listed endpoint therefore identifies what was intended to be described, but the reported record does not allow the magnitude or precision of the baseline measurements to be assessed.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies a continuous primary outcome and specifies that it is summarized using a mean and standard deviation. It does not report the numerical results or an inferential analysis. The concepts below explain how such statistics are generally interpreted; they do not assert that any particular analysis was performed for this study.

What does a mean describe?

In general, the arithmetic mean is a measure of the center of a set of measurements. For IOP, it would represent the average pressure among the patients included in the outcome analysis. A mean is easier to interpret when paired with information about the distribution and spread of the measurements. It can be influenced by unusually high or low values, so it does not describe every patient’s measurement or the shape of the distribution.

The registry specifies standard deviation as the dispersion measure. In general, standard deviation describes how far individual observations tend to lie from the mean. A larger standard deviation indicates more spread in the measurements; a smaller one indicates that measurements are more concentrated around the mean. It is not the standard error and it is not a confidence interval. The standard deviation describes variation among observations, whereas a standard error describes uncertainty in an estimated quantity.

What would a confidence interval add?

In general, a confidence interval presents a range of values compatible with the data and the assumptions of the statistical procedure. Its width communicates precision: a narrower interval indicates greater precision than a wider interval, under the same analytic framework. A confidence interval around a baseline mean would address uncertainty in that mean. An interval for a treatment contrast would address uncertainty in the contrast. Those are different estimands and should not be interchanged.

No confidence interval is reported for the primary outcome in this registry record. Nor is a comparison estimate reported. Consequently, readers cannot evaluate the precision of the mean or the uncertainty around any treatment contrast from the registry information.

Why does the comparison structure matter?

In general, a controlled comparison asks how outcomes differ between groups under defined conditions. Random allocation, when used, is intended to make groups comparable on average with respect to measured and unmeasured factors at the time of assignment. This record does not state a randomized allocation and characterizes its arms as not a like-for-like control comparison. The physician-directed switch is part of the study description, not evidence of random assignment.

When treatment is selected for medical reasons in routine practice, factors that influence the decision may also relate to the outcome. This is a general source of confounding. Statistical adjustment can sometimes address measured differences, but it cannot automatically remove unmeasured differences, and no adjusted analysis is reported in the registry record. A before-and-after change, if one were reported, would also need cautious interpretation because time trends, co-interventions, measurement variation, and patient selection can contribute to observed change. The registry does not report a change estimate for the primary endpoint.

How should planning illustrations be understood?

Sample-size calculations answer a planning question: under specified assumptions, how much information might be needed to detect a chosen effect with a specified probability and significance threshold. The planning framework described for this study uses a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It defines the effect to detect as a stated fraction of the observed effect. These assumptions describe planning illustrations, not the trial’s own design or observed power.

The record does not report the trial’s sample-size justification or a design based on those assumptions. A sample-size illustration does not establish that a study had a particular probability of detecting an effect after the data were collected. “Observed power” is not a substitute for the estimate and its confidence interval: after a study, the observed estimate and its uncertainty are more informative about what the data show. The sample-size illustrations should therefore be treated as hypothetical planning information, not as a finding about the study’s success or failure.

Why can over-dispersion matter?

In general, over-dispersion occurs when the observed variability in a count outcome is greater than expected under a model’s assumptions. If ignored, it can make standard errors too small and confidence intervals too narrow, leading to overconfident inference. Modeling choices for count outcomes should reflect the outcome distribution and the study design. This is a general principle, not a claim about the analyses in this record: the registry reports no analyses and does not report a model for the secondary count outcomes.

For the continuous baseline endpoint, the registry’s mean and standard deviation provide a descriptive framework, but the actual values are absent. For the listed ratings and treatment continuation outcomes, interpreting results would require the observed category counts or estimates, appropriate denominators, and clear definitions of the analysis population. Those results are not reported in the registry record. The statistical methods cannot be reconstructed from outcome titles alone.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Patients With POAG or OHT")
n   <- c(1672)
m   <- c(21.15)
sp  <- c(3.43)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Patients With POAG or OHT  1672  21.150  3.430  20.985  21.315

11. Multiplicity, Missing Data and Analysis Populations

The registry lists eight outcome measures, including baseline IOP and secondary measures of physician assessment, tolerability, treatment continuation or discontinuation, and compliance compared with previous treatment. It reports no analyses. The statistical analysis plan, including any prespecified hierarchy or adjustment for multiple outcomes, is not reported in the registry record.

In general, testing many outcomes creates more opportunities for apparently notable findings to arise by chance. A multiplicity strategy may define a primary outcome, adjust significance thresholds, or specify an ordered testing procedure. Such strategies affect how inferential results should be interpreted. The outcome list alone does not establish which outcomes were tested, whether they were tested, or whether any adjustment was used. No multiplicity-adjusted or unadjusted results are reported.

Missing-data handling is also not reported in the registry record. The primary population is described as patients with data for that outcome, but the number with measurements and the reasons measurements may be missing are not stated. The record does not explain whether missing values were excluded, imputed, or addressed using another method. These choices can affect the population represented and the interpretation of estimates.

Analysis populations for the secondary outcomes are not reported in the registry record. Their denominators, time-specific populations, and handling of discontinuation are also not described in the information available. In general, a clear analysis population and missing-data approach help readers determine who contributed to each estimate and how much the conclusions may depend on unobserved data. Without these details and the outcome results, neither the extent nor the impact of missing data can be assessed.

12. 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.

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: cataract operation (0.1%), death (0.1%).

The registry lists two serious adverse events among 1830 patients at risk in the group labeled “Patients With POAG or OHT.” It lists zero other adverse events among 1830 at risk. These are the posted counts and denominators; no additional rate is calculated. The record’s top serious terms are “Cataract Operation” and “Death,” each listed as 0.1%.

The term list and the group-level counts are different registry entries. A dedicated death count is not reported in the registry record, even though “Death” appears among the top serious terms. The record does not provide enough information to reconcile those entries, identify whether terms overlap, or establish how the term percentages were derived. The displayed 0.1% values should therefore be retained as reported rather than recalculated from the group counts.

These figures do not establish that the study treatment caused an event. The registry information does not provide event narratives, timing, relatedness assessments, or a comparison group’s safety results. A count of reported events is a descriptive safety record; it is not, by itself, an estimate of excess risk or a causal assessment.

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

This record establishes that a physician-directed study was conducted among patients with primary open angle glaucoma or ocular hypertension who switched to Lumigan® UD monotherapy for medical reasons. It identifies baseline IOP in the study eye as the primary outcome and names secondary measures concerning physician and patient assessments, treatment continuation, discontinuation, and compliance. It also records serious and other adverse-event counts for the listed group.

It does not establish how IOP changed after the switch. The primary endpoint is measured at baseline, and the record does not report its mean or standard deviation. It also does not report numerical results for the secondary outcomes, an analysis estimate, a confidence interval, or a p-value. As a result, the posted registry information does not quantify a treatment effect or its precision.

The record also does not establish a causal comparison. Allocation is not stated, and the record specifically notes that the arms are not a like-for-like control comparison. Treatment decisions were made by physicians according to standard practice, with switches for medical reasons. In general, those features mean that differences between patients or their clinical circumstances may affect observed outcomes. Without an appropriate comparison and a reported analysis, an outcome cannot be attributed to treatment from this record alone.

The completion status and enrollment entry describe the registry record, not the amount of outcome information available for each analysis. The primary outcome population is patients with data for that measure, but its size is not reported in the registry record. Likewise, missing-data methods and analysis populations for secondary outcomes are not reported. The listed safety counts and terms are descriptive and do not establish causation.

The appropriate conclusion is limited but clear: the record documents a clinical-practice treatment setting, planned measures, and selected safety entries, while leaving the numerical outcome results and comparative statistical evidence unreported. It cannot support a claim that treatment did or did not produce a particular clinical effect.

14. Why This Trial Matters Statistically

This study is statistically informative because its clinical setting differs from a randomized comparison. The record describes switches made for medical reasons under physician standard practice, with treatment decisions left to physicians. That context is important when deciding what kinds of conclusions an analysis could support. In general, routine-practice data may describe treatment use and patient or physician assessments, while causal interpretation requires careful attention to how treatment selection and outcome measurement occurred.

The endpoint definition also matters. Baseline IOP is a continuous measurement summarized by a mean and standard deviation. That format can describe a group’s starting measurements, but it is not a follow-up contrast. A baseline value cannot, on its own, answer whether an outcome changed after treatment. Keeping the measurement timepoint distinct from the clinical question prevents a descriptive starting value from being mistaken for a response estimate.

The record lists secondary assessments that capture more than a single pressure measurement, including tolerability, continuation, discontinuation, and compliance compared with previous treatment. Their inclusion reflects different kinds of questions, but each requires its own clear outcome definition, analysis population, and results for interpretation. The registry does not report those outcome results or analyses.

The record’s limits are also a useful reminder that registration details and statistical evidence are not interchangeable. An enrollment entry, completed status, outcome list, and safety count can characterize a study without supplying the estimates needed to judge statistical precision or treatment contrasts. Here, those distinctions are especially important because the primary measure is at baseline and the record does not describe a comparable control group.

15. 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 most direct limitation is that numerical primary and secondary outcome results are not reported in the registry record. The primary outcome is defined as baseline mean IOP with standard deviation, but neither value is reported. The record reports no analyses, so it does not provide an inferential estimate, confidence interval, or p-value to assess precision.

The comparison structure limits causal interpretation. Allocation is not stated, and the record says the arms are not a like-for-like control comparison. Treatment changes were made for medical reasons according to physician standard practice. The record does not describe an analysis that addresses potential differences associated with physician treatment decisions, nor does it report a controlled treatment contrast.

The primary outcome is a baseline measure rather than a reported change or follow-up contrast. Although treatment is described for up to 12 weeks, outcome values at follow-up are not reported in the registry information. The number of patients contributing primary outcome data, reasons for missing measurements, and handling of missing data are not reported in the registry record.

The analysis plan, multiplicity approach, and analysis populations for secondary outcomes are not reported in the registry record. The safety entries also have limited detail: the dedicated death count is not reported, despite Death appearing among the listed serious terms. Event timing, relatedness, and narratives are not reported. These limitations restrict interpretation of both efficacy-related outcomes and safety information.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: A Study of Patients With Primary Open Angle Glaucoma or Ocular Hypertension Switched to Lumigan® UD Monotherapy for Medical Reasons — NCT01853085.
• Registry record last updated 2019-04-19; status last verified 2019-04.
• Results first posted 2015-05-28.
• 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.

19. Record Summary

The registry record concerns patients with primary open angle glaucoma or ocular hypertension switched to Lumigan® UD monotherapy for medical reasons, with treatment following physician standard practice. The listed status is completed; the record gives a start date of 2013-04-01, a primary completion date of 2014-03-01, and enrollment of 1830.

The primary outcome is baseline mean IOP in the study eye, measured in millimeters of mercury and described using standard deviation. Secondary outcomes include physician and patient assessments, continuation or discontinuation, and compliance compared with previous treatment. The registry lists eight outcome measures and reports no analyses. Numerical outcome results and missing-data methods are not reported in the registry record.

The safety record lists two serious adverse events and zero other adverse events among 1830 at risk. “Cataract Operation” and “Death” are each listed as 0.1% among the top serious terms; a dedicated death count is not reported in the registry record. The record does not report a like-for-like control comparison or a numerical treatment-effect estimate.