Patients With Geographic Atrophy and Their Patient Journey in the United States (US): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Patients With Geographic Atrophy and Their Patient Journey in the United States (US) (NCT05891275), a registered phase not stated study. The primary outcome is Change in Visual Acuity (VA) in Participant's Study Eye.

2. Clinical Question

The broader study aim is to describe patients with geographic atrophy and their subsequent disease course, including progression to neovascular age-related macular degeneration and receipt of Anti-VEGF, or geographic atrophy in the fellow eye. Listed secondary outcomes also cover visits, injections, ocular comorbidities, and selected medical procedures. These aims are descriptive; the record does not set out a treatment-effect question.

3. Trial Design

This is a database-based study of patients with geographic atrophy in the United States, not a randomized treatment comparison. The registry record lists Boehringer Ingelheim as the sponsor and records an enrollment of 68563. The study dates are 2023-05-31 to 2023-12-01, while the described database registration window for eligible patients is January 2015 through April 2023. The record does not explain how the study dates relate to the database observation window.

Eligibility for the described patient group required a geographic atrophy diagnosis in at least one eye, age of at least 50 years, information on laterality, and registration in the Vestrum health database within the stated window. The primary outcome population had additional requirements: geographic atrophy at the index date, at least one year of follow-up, and visual-acuity readings at index and at a later follow-up year. A participant therefore could contribute to one yearly comparison but not another. The registry record explicitly notes that the populations differed by year.

The index date is the date of geographic atrophy diagnosis used as the reference point for follow-up. The study eye is defined as the first eye with disease; the fellow eye is the participant’s second eye. The primary outcome is assessed from the index date up to 5 years. The registry record does not report whether follow-up was scheduled at fixed intervals, how diagnoses or readings were validated, or how long each participant was observed.

The listed outcomes include visual acuity, retinal-disease-related measures, and health-care resource use. However, the record reports 0 analyses and does not provide numerical outcome estimates. It also does not report a protocol-level statistical analysis plan, sample-size justification, interim analyses, or an assigned comparator. Accordingly, the design supports a descriptive account of the database population and recorded outcomes; it does not establish a causal contrast between treatments.

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: Only subjects that met all inclusion and none of the exclusion criteria were included. Subjects from the Vestrum database aged 50+ with information on laterality, and a GA diagnosis between January 1, 2015, to April 30, 2023, were analyzed. While both eyes participated in the study, one eye per participant was analyzed for outcome measures.

Overall Study

Analysis population for the primary outcome, as defined in the registry: Participants with GA at the index date and at least one year of follow-up data, with a VA reading at index, and at least one more VA reading at a subsequent follow-up year. The populations were different for each year since patients should have certain follow-up information to contribute to each cohort, and some participants had data in more than one year. Only those participants with VA readings at appropriate timepoints, with appropriate follow up, were analyzed.

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: Patients diagnosed with geographic atrophy (GA) in at least one eye, at least 50 years old, with information on laterality and registered in the Vestrum health database between January 2015 and April 2023.

6. Primary Endpoint

The registry lists the primary outcome as Change in Visual Acuity (VA) in Participant's Study Eye, measured over From index date of GA diagnosis up to 5 years.

The primary endpoint is change in visual acuity in the participant’s study eye, expressed as letters read. The study eye is the first eye with geographic atrophy, and the fellow eye is the participant’s second eye. Change is defined by comparing the mean visual-acuity reading at the index diagnosis with the mean reading at another timepoint. The record specifies yearly assessment among participants who have valid readings at both timepoints, from the index date up to 5 years. The reported summary measure is a mean with a 95% confidence interval.

Visual acuity provides a standardized way to express the ability to resolve visual detail, while the letters-read unit makes the measure interpretable as a reading-based score. Comparing readings over time describes the trajectory in the study eye after diagnosis. It does not, by itself, identify why any change occurred or isolate the effect of a particular treatment.

For each yearly comparison, the population must have the required follow-up and readings at both the index and later timepoint. Thus, an estimate at one year and an estimate at another year need not describe exactly the same set of participants. This matters when interpreting change over time: apparent differences between yearly estimates could reflect both changes within participants and differences in who remained eligible for each comparison. The registry record does not report the numerical endpoint estimates, confidence limits, or detailed measurement procedures.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a continuous measure summarized as a mean. The registry record states that visual acuity is measured in letters read and that change is determined by comparing the mean at index diagnosis with a mean at a later yearly timepoint. It also specifies a 95% confidence interval as the dispersion measure. No estimate or interval is reported, and the record does not give further details about the statistical procedure used to produce them.

What does a mean change describe?

General statistical explanation: a mean combines participant-level measurements into an average for the analyzed group. For a change outcome, the interpretation depends on which observations are compared and on how the change is defined. In this study description, the comparison is between the mean visual-acuity reading at index diagnosis and the mean at a later timepoint. The record does not state a sign convention, so a positive or negative direction should not be assigned to an unreported estimate.

The endpoint is based on readings at two timepoints. Participants need valid readings at both the index and subsequent year to contribute to that yearly comparison. This paired eligibility makes the observed group different from the entire diagnosed population: people without the required follow-up or readings are not included in that particular estimate. The record does not say whether the reported mean change was calculated from participant-level changes or by subtracting one group mean from another; it describes the difference between mean readings but gives no further computational detail.

How should a confidence interval be read?

General statistical explanation: a confidence interval expresses uncertainty around an estimate under the assumptions of the statistical method. It is not a prediction interval for individual readings and does not capture every source of uncertainty, such as systematic measurement differences or selection into follow-up. A 95% confidence interval is the specified interval level for the primary outcome. Its actual limits are not reported in the registry record, so neither the precision nor the range of values compatible with the analysis can be assessed.

Confidence intervals are most informative when read alongside the estimate, the outcome definition, and the population that contributed data. Here, the population can vary by year because the follow-up and paired-reading requirements vary. Even if estimates for several years were available, a change in their values could reflect differences in cohort composition as well as changes in visual acuity over time. The record does not report methods to account for this changing eligibility.

What does the observational design allow?

General statistical explanation: a database cohort can describe patterns in recorded diagnoses, measurements, and health-care use. Without random assignment or a suitable comparison strategy, the observations do not by themselves distinguish a causal effect from differences in patient characteristics, care, or recording. The registry record does not describe a randomized allocation, and its own study-design note says the comparison is not randomized and the arms are not a like-for-like control comparison. No treatment-effect claim is supported by the primary endpoint definition alone.

The listed sample-size assumptions are for planning illustrations rather than the study’s own design. They specify a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. For time-to-event illustrations, the stated quantity is total events using the Schoenfeld approach; other illustrations concern participants per arm. These assumptions do not establish that the study had two randomized arms, and the registry record does not report a sample-size justification for the database study. No numerical illustration results are available in the record.

Why can over-dispersion matter?

General statistical explanation: over-dispersion occurs when observed variability is greater than a statistical model expects. If a model assumes less variability than is present, standard errors can be too small and intervals or significance assessments can be misleading. This is a general issue for count outcomes, such as visits or injections, when counts vary substantially across people. The registry record lists visit and Anti-VEGF injection outcomes but does not report the model used, whether over-dispersion was assessed, or whether any adjustment was made. No particular over-dispersion problem can therefore be asserted for this study.

More broadly, the record does not report the statistical methods for secondary outcomes, covariate adjustment, handling of repeated measurements, missing-data procedures, multiplicity control, or sensitivity analyses. These omissions limit assessment of how estimates would have been generated and how robust they might be. Because no numerical analyses are reported, interpretation is restricted to the defined outcomes, eligibility descriptions, and general implications of the stated design.

10. Multiplicity, Missing Data and Analysis Populations

The study lists 12 outcome measures and 0 analyses. The primary outcome is yearly change in visual acuity; secondary outcomes include retinal-disease-related measures, ocular comorbidities, and selected procedures. The registry record does not report a multiplicity strategy, such as adjustment of statistical testing or designation of a limited set of confirmatory comparisons. Without the analysis results and testing plan, the chance of false-positive findings across multiple outcomes cannot be evaluated. No claim about statistical significance is possible from the record.

The primary outcome population requires at least one year of follow-up and valid visual-acuity readings both at index and at a later yearly timepoint. The record states that populations differ by year because participants must have the relevant follow-up information to contribute. This defines a potentially changing analysis population over time. The numbers eligible at each year, reasons for unavailable readings, and characteristics of participants with and without follow-up are not reported in the registry record.

The record does not report a missing-data method, imputation strategy, sensitivity analysis, or rules for incomplete measurements. It also does not explain whether missingness was treated as unrelated to participants’ health or outcomes. General statistical context: if the availability of follow-up readings is related to a participant’s condition or care, estimates among those with readings may differ from estimates for the full diagnosed population. That possibility cannot be assessed without information on missingness and the analysis population.

The record also does not describe how the database handled duplicate records, measurement consistency, or data validation. These are additional sources of uncertainty for database-based measurements, but their presence or impact cannot be determined from the registry record.

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

The study asks a descriptive question about visual-acuity change in the first eye diagnosed with geographic atrophy, alongside broader questions about disease progression and health-care use. The record defines the primary outcome and its eligible population, but it does not report numerical findings. It therefore does not establish the size or direction of change in letters read, the precision of any estimate, or the frequency of the listed secondary outcomes.

Even if yearly estimates were available, they would describe observations among participants who met each year’s follow-up and reading requirements. Since the registry record says the populations differed by year, those estimates would not necessarily represent repeated measurements in an unchanged group. They would also remain observational findings rather than evidence that a particular treatment caused a change.

The study’s stated focus on progression to neovascular age-related macular degeneration, Anti-VEGF use, and geographic atrophy in the fellow eye indicates what the investigators intended to characterize. The listed secondary measures also address visits, injections, comorbidities, and procedures. However, listed outcomes are not findings. The record does not provide counts, rates, or estimates for those outcomes.

The enrollment recorded is 68563, but the primary outcome has additional requirements that determine who can contribute to any yearly analysis. Enrollment should not be confused with the number of participants included in each visual-acuity estimate. Those yearly analysis counts are not reported in the registry record.

In practical statistical terms, the record supports understanding of the study question, outcome definitions, and the limits on interpretation. It does not support conclusions about treatment benefit, absence of risk, or the experience of every person with geographic atrophy. The listed zeros for adverse events and deaths describe the registry entries, not necessarily complete ascertainment of all events in the database population. No medical advice or treatment decision can be drawn from this record alone.

12. Why This Trial Matters Statistically

This study is statistically notable for framing a longitudinal question in a real-world database population rather than a randomized treatment comparison. The primary measure is a repeated visual-acuity outcome, with change assessed against the index diagnosis and summarized yearly. Such questions require careful attention to who has measurements at each timepoint, because follow-up availability determines which observations contribute.

The registry record explicitly says the yearly populations differ. That feature matters because a sequence of annual summaries may not describe a single fixed cohort. An apparent pattern across years could reflect changing participants as well as changes in their measurements. Clear reporting of analysis counts, missingness, and consistency of measurement would help readers distinguish these possibilities, but those details are not reported in the registry record.

The study also illustrates the difference between a broad enrollment figure and an endpoint-specific analysis population. The record lists enrollment of 68563, while the primary outcome requires follow-up and readings at both index and a later year. Without yearly analysis counts, it is not possible to know how much of the enrolled group informs each estimate.

Finally, the record lists many outcomes but reports 0 analyses. This means the registry description sets out a substantial range of intended characterization questions without posting estimates that can be assessed for magnitude or precision. The sample-size assumptions describe planning illustrations, not the design of a randomized comparison or the observed adequacy of this database cohort. Statistically, the key contribution in the record is the specification of the outcome and population; its empirical findings remain unreported.

13. 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 central limitation is that the registry record does not report numerical results for the primary or secondary outcomes. There are no posted mean visual-acuity changes, confidence limits, or participant counts by follow-up year. The record reports 0 analyses, so readers cannot assess the magnitude, precision, or statistical uncertainty of the intended findings.

The primary analysis population is defined by follow-up and valid readings at both index and a later year. The record notes that populations differ across years, but does not quantify the changing eligibility or describe who is missing from each comparison. Without those details, selection into the annual analysis populations cannot be evaluated. The handling of missing readings is not reported in the registry record.

The database-based design and absence of a like-for-like control comparison limit causal interpretation. The record does not report methods for adjustment, validation of diagnoses, standardization of visual-acuity measurements, or assessment of differences in care and recording. It is not possible to determine whether or how such factors were addressed.

The record identifies broad progression and health-care-use aims but does not provide operational definitions or analytic details for all outcomes. It also does not report multiplicity handling, sensitivity analyses, interim analyses, or a sample-size justification for the study itself. The planning assumptions listed for sample-size illustrations are not a substitute for these details. Finally, the adverse-event entries show zero reported events in the listed categories, but event ascertainment and reporting procedures are not described; completeness cannot be assessed.

14. Related Tutorials

15. Related Statistical Calculators

16. Sources

• ClinicalTrials.gov: Patients With Geographic Atrophy and Their Patient Journey in the United States (US) — NCT05891275.
• Registry record last updated 2025-05-01; status last verified 2025-04.
• Results first posted 2025-05-01.
• 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.

17. Record Summary

The registry record describes a completed United States study sponsored by Boehringer Ingelheim, with enrollment of 68563. Its study dates are 2023-05-31 to 2023-12-01, and the eligible database registration window is January 2015 through April 2023. The study concerns patients at least 50 years old with geographic atrophy in at least one eye and information on laterality.

The primary outcome is yearly change in mean visual acuity, measured in letters read, in the first affected eye. It is assessed from the index diagnosis up to 5 years among participants with the required follow-up and readings at both timepoints. The record lists a 95% confidence interval but reports no numerical outcome estimate or limits. It lists 12 outcome measures and 0 analyses.

The broader aims include progression to neovascular age-related macular degeneration, Anti-VEGF use, fellow-eye geographic atrophy, visits, comorbidities, and selected procedures. The registry record does not report numerical results for these outcomes or detailed methods for missing data, multiplicity, or analysis. The study is not described as a randomized comparison.