This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Ophthalmologic Safety Study of Pramipexole Immediate Release (IR) Versus Ropinirole in Early Parkinson's Disease (PD) Patients (NCT00144300), a randomized phase 4 study. The primary outcome is Expert Panel Overall Assessment Following 2 Years on Drug.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00144300 |
| Phase | Phase 4 |
| Condition | Parkinson Disease |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 246 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Boehringer Ingelheim |
| Results posted | Yes |
2. Clinical Question
Population
Participants with early Parkinson’s disease. The trial enrolled 246 participants, and the primary endpoint population was described as the full analysis set with last observation carry forward.
Intervention
Pramipexole immediate release, identified in the intervention and arm descriptions as Mirapex tablets taken three times daily according to the manufacturer’s guidelines.
Comparator
Ropinirole, identified as Requip tablets taken three times daily according to the manufacturer’s guidelines.
Primary question
Did the expert panel’s overall assessment identify retinal deterioration after up to 2 years on drug, and was there a difference between the two treatment groups?
The trial was designed to compare ophthalmologic safety rather than to present a single clinical measure of Parkinson’s disease progression as its primary question. Comprehensive ophthalmologic assessments were reviewed by an expert panel, which assessed retinal deterioration. The primary endpoint is named as an overall assessment following 2 years on drug, with the endpoint timeframe listed as up to 2 years.
The registry record identifies the study as randomized and parallel-group, but its masking entry is “none.” The official title describes blinded assessment, so the title and registry masking entry do not give a complete account of who knew treatment assignment and at what stages. The specific procedures used to preserve blinding for the expert panel are not reported in the registry record.
The question is whether the posted assessments support a comparison between pramipexole and ropinirole. The registry record does not include the primary outcome categories, group results, an effect estimate, or a confidence interval. It therefore does not allow a numerical estimate of the difference in retinal deterioration from the information reported in the record.
3. Trial Design
This was a Phase 4 randomized, parallel-group trial with 246 enrolled participants. It compared pramipexole immediate release with ropinirole in early Parkinson’s disease. Both treatment arms are described as tablets taken three times daily according to the manufacturer’s guidelines. The study is marked completed in the registry record.
The official title describes a 2-year, open-label trial with blinded assessment. The registry’s masking entry is “none.” These entries indicate that the trial was not recorded as masked in the registry, while its title describes an intention to blind the assessment. The people who were blinded, the procedures used, and whether blinding was maintained are not reported in the registry record. This distinction matters because knowledge of treatment assignment can affect participant reporting and clinical care, while blinded assessment is intended to limit influence on outcome evaluation.
The primary endpoint was an expert panel’s overall assessment following 2 years on drug. The panel reviewed components of comprehensive ophthalmology assessments to evaluate retinal deterioration. The primary population is described as the full analysis set using last observation carry forward. The registry record does not give the numbers included in this endpoint analysis or explain how participants entered or left that set.
The record lists 21 outcome measures and one analysis. Secondary outcomes include an expert panel assessment following 1 year, Hoehn and Yahr Scale assessments at baseline, 1 year, and 2 years, and Unified Parkinson’s Disease Rating Scale Part II measures at baseline, 1 year, and 2 years. Although several outcomes and time points are named, the specific statistical models, testing hierarchy, and adjustment procedures are not reported in the registry record. The enrollment number is not, by itself, evidence about the number of participants with evaluable primary outcome data.
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
| Stage | Pramipexole | Ropinirole |
|---|---|---|
| STARTED | 121 | 125 |
| COMPLETED | 92 | 97 |
| NOT COMPLETED | 29 | 28 |
Reasons for not completing this period:
| Reason | Pramipexole | Ropinirole |
|---|---|---|
| Adverse Event | 18 | 16 |
| Protocol Violation | 1 | 3 |
| Lost to Follow-up | 3 | 0 |
| Withdrawal by Subject | 6 | 6 |
| Other reason (not specified) | 1 | 3 |
Analysis population for the primary outcome, as defined in the registry: FAS LOCF - full analysis set with last observation carry forward
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.
| Characteristic | Unit | Pramipexole | Ropinirole | Total |
|---|---|---|---|---|
| Participants analysed | 121 | 125 | 246 | |
| Age, Continuous | years | 57.5 (SD 9.3) | 59.1 (SD 8.7) | 58.3 (SD 9.0) |
| Age, Customized: < 50 years | Participants | 23 | 17 | 40 |
| Age, Customized: 50 to < 65 years | Participants | 71 | 74 | 145 |
| Age, Customized: 65 to < 75 years | Participants | 21 | 30 | 51 |
| Age, Customized: >= 75 years | Participants | 6 | 4 | 10 |
| Sex: Female, Male: Female | Participants | 42 | 47 | 89 |
| Sex: Female, Male: Male | Participants | 79 | 78 | 157 |
| Race/Ethnicity, Customized: Asian | Participants | 1 | 1 | 2 |
| Race/Ethnicity, Customized: Black | Participants | 7 | 3 | 10 |
| Race/Ethnicity, Customized: White | Participants | 113 | 121 | 234 |
| Height | centimeters | 171.3 (SD 9.2) | 171.6 (SD 12.4) | 171.5 (SD 10.9) |
| Weight | kilograms | 81.32 (SD 17.64) | 82.80 (SD 18.39) | 82.07 (SD 18.00) |
| Duration of Parkinson's disease diagnosis | years | 0.97 (SD 1.15) | 1.29 (SD 1.70) | 1.13 (SD 1.46) |
| Hoehn and Yahr stage: Stage 0 | Participants | 0 | 0 | 0 |
| Hoehn and Yahr stage: Stage 1 | Participants | 28 | 23 | 51 |
| Hoehn and Yahr stage: Stage 1.5 | Participants | 11 | 19 | 30 |
| Hoehn and Yahr stage: Stage 2 | Participants | 71 | 71 | 142 |
| Hoehn and Yahr stage: Stage 2.5 | Participants | 8 | 5 | 13 |
| Hoehn and Yahr stage: Stage 3 | Participants | 3 | 7 | 10 |
| Hoehn and Yahr stage: Stage 4 | Participants | 0 | 0 | 0 |
| Hoehn and Yahr stage: Stage 5 | Participants | 0 | 0 | 0 |
| Alcohol history: Does not drink | Participants | 46 | 49 | 95 |
| Alcohol history: Has an average consumption | Participants | 75 | 76 | 151 |
| Alcohol history: Fulfills criteria for Abuse/Dependence | Participants | 0 | 0 | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Expert Panel Overall Assessment Following 2 Years on Drug, measured over up to 2 years.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is named “Expert Panel Overall Assessment Following 2 Years on Drug.” It measures an expert panel’s assessment of retinal deterioration based on review of components of comprehensive ophthalmology assessments. The unit is participants, and the outcome is described as a number of participants. Its timeframe is up to 2 years. The stated analysis population is the full analysis set with last observation carry forward.
An expert assessment can bring multiple examination components together into an overall judgment, which may be useful when the safety question concerns changes across a broad ophthalmologic evaluation rather than a single measurement. In general, a structured review can make clinical evidence easier to interpret across participants. Its meaning depends, however, on how the assessment categories are defined, how disagreements are handled, and whether assessors are unaware of treatment assignment. Those details are not reported in the registry record.
The primary endpoint is relevant to the stated trial objective because the study sought to determine whether retinal deterioration differed between treatment groups. But the record does not report the assessment categories, the number of participants in each category, or a group comparison. It is therefore not possible to describe the observed frequency of retinal deterioration, its precision, or the direction and size of any difference between the groups. The endpoint name and its measurement description establish what was intended to be assessed, not what the assessment found.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies an ophthalmologic safety question and the assessment intended to address it, but it does not report the primary outcome results. In particular, no participant counts by primary assessment category, treatment-group effect estimate, confidence interval, or p-value are reported. Without these quantities, the posted record does not show how often retinal deterioration was assessed in either group or how precisely the groups can be compared.
The primary outcome is recorded as an expert panel overall assessment, and the endpoint is described as a number of participants. The record also indicates that the primary outcome has several categories or time points and is not reduced to one comparison. A single binary contrast should not be inferred from that description. Combining or choosing categories without an explicit analysis definition would change the question being answered. The categories, their ordering if any, and the way the panel’s assessment was turned into a statistical comparison are not reported in the registry record.
A confidence interval, when reported, describes the range of effect values compatible with the data and the specified statistical procedure. Its width conveys precision: wider intervals indicate greater uncertainty about the effect estimate. A p-value, when reported, describes how compatible the data are with a specified null hypothesis under the model; it does not state the probability that the null hypothesis is true or measure clinical importance. Neither type of inferential result is reported for the primary endpoint in this record. No numerical conclusion about the size, direction, or precision of a treatment-group difference can therefore be drawn from the registry information.
The full analysis set with last observation carry forward is named as the endpoint population and approach. The record does not provide the number of participants analyzed, missing-data counts, or sensitivity analyses. Consequently, the robustness of the primary assessment to missing observations cannot be evaluated from the record. Last observation carry forward uses an earlier available observation in place of a later missing value; as a general statistical matter, this approach can misrepresent change when the outcome would have changed after the last observation. The record does not give enough detail to determine how consequential this issue was in this trial.
The serious adverse event counts are reported separately from the primary retinal endpoint. They provide descriptive safety information, but do not replace the ophthalmologic comparison or establish why an event occurred. Counts of participants with serious or other adverse events cannot be interpreted as randomized treatment effects without a suitable comparative analysis, relevant definitions, and uncertainty estimates. The record does not report a formal comparison of these adverse-event counts.
Overall, the registry record establishes the randomized comparison, the intended assessment, and some adverse-event counts. It does not include the results needed to quantify the primary treatment contrast. The appropriate statistical reading is therefore that the primary comparison is not reported in the registry record, rather than that the treatments had equal outcomes or that either group had more retinal deterioration.
9. Statistical Methods Explained
The study is described as randomized and parallel-group. Randomization is a method for assigning participants to treatment groups by chance. In general, if implemented as intended, it helps balance both measured and unmeasured baseline characteristics across groups on average. It does not guarantee identical groups in a particular trial, and it does not remove the need to describe participant flow, missing outcomes, or analysis choices. The registry record does not report the randomization sequence method, allocation concealment procedures, or stratification factors.
What does a parallel-group design mean?
In a parallel-group design, participants are assigned to one treatment group and followed in that group, rather than switching between trial treatments as part of a crossover design. The two arms were pramipexole immediate release and ropinirole. The record describes both as three-times-daily tablet regimens according to manufacturer’s guidelines. It does not report actual adherence, treatment interruptions, dose changes, or switching between treatments. Those details can matter when interpreting outcomes because assignment and treatment received are not always identical.
What is the role of masking?
The official title describes blinded assessment, whereas the registry masking entry is “none.” In general, blinding an outcome assessor is intended to limit the possibility that knowledge of treatment assignment influences measurement or judgment. This is particularly relevant to an expert panel’s overall assessment. The record does not identify who was blinded, explain how treatment information was concealed from assessors, or describe procedures for maintaining blinding. The title alone cannot establish the operational details or success of blinding.
How should the primary endpoint be understood?
The primary endpoint is an expert panel’s overall assessment of retinal deterioration following 2 years on drug, based on a review of comprehensive ophthalmology assessment components. The unit is participants, and the population is described as the full analysis set with last observation carry forward. The endpoint has several categories or time points and is not reduced to one comparison in the registry record. For an interpretable statistical analysis, the categories, the definition of deterioration, the handling of indeterminate assessments, and the prespecified group contrast would need to be clear. These details are not reported in the registry record.
For a simple binary outcome, a group comparison might be expressed as a difference in event proportions or another effect measure. That general description does not imply that a binary analysis was used in this trial. The record’s indication of several categories or time points means that reducing the endpoint to one binary outcome without further information would require an unsupported choice. The record does not report a model, an effect estimate, a confidence interval, or a test for the primary endpoint.
What does a confidence interval contribute?
In general, a confidence interval communicates uncertainty around an estimated effect under the assumptions of the analysis. A relatively narrow interval indicates greater precision than a wide interval, while an interval spanning effects in different directions may leave the direction uncertain. The interval’s interpretation depends on the effect measure, model, and method used to calculate it. No primary-endpoint confidence interval is reported in the registry record, so the precision of the primary comparison cannot be assessed from these details.
In general, a p-value is calculated under a specified statistical model and null hypothesis. It is not the probability that a treatment has no effect, and it does not measure the magnitude or practical importance of an effect. The registry record does not report a primary-endpoint p-value or identify the test used. A p-value cannot be reconstructed without the relevant outcome counts or other analysis data and the correct analysis specification.
What does last observation carry forward do?
Last observation carry forward (LOCF) fills a missing later measurement by carrying forward the participant’s last available observation. It is a missing-data approach, not a statistical test. As a general matter, LOCF treats the carried value as if it represented the participant at the later assessment, even though the outcome may have changed. This can introduce bias if the assumption is unsuitable, and it does not reflect the uncertainty associated with an unobserved value. Whether LOCF was appropriate for this endpoint depends on the assessment schedule, missingness patterns, and outcome behavior; these details are not reported in the registry record.
The stated primary population is a full analysis set with LOCF, but the record does not define the set, specify which randomized participants were excluded, or report the number analyzed in each arm. The phrase full analysis set should not be assumed to mean that every randomized participant contributed a primary endpoint result. The number and reasons for missing assessments, withdrawals, or exclusions are not reported in the registry record.
How should sample-size illustrations be read?
Any sample-size illustration based on an observed effect is a planning exercise, not an observed trial result and not observed power. The stated illustration 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 a stated fraction of the observed effect. These assumptions describe how such an illustration is framed, not the trial’s original design justification. The trial’s own sample-size justification and the results of any such calculation are not reported in the registry record.
In general, power is the probability that a prespecified statistical procedure will reject a null hypothesis when a particular alternative is true. It depends on the assumed effect, variability or event frequency, sample size, significance level, and analysis method. Calculating a planning sample size from an effect observed in the same trial does not show that the trial had that probability of detecting the effect before it was conducted. Here, the record does not provide a single primary comparison or the observed primary effect needed to interpret such a calculation for the stated endpoint.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists 21 outcome measures, including multiple assessment times and several secondary outcomes. Testing multiple outcomes or time points can increase the chance of obtaining at least one apparently unusual result by chance if each is examined separately. Statistical approaches can address this issue by prespecifying a primary outcome and testing hierarchy, adjusting significance thresholds, or distinguishing confirmatory from exploratory analyses. Which approach was used, whether any multiplicity adjustment was planned, and how outcomes were prioritized are not reported in the registry record.
The record lists one analysis, but that count alone does not establish that only one hypothesis test was performed or that multiplicity was handled. The primary outcome itself is described as having several categories or time points and is not reduced to one comparison. Its categories and intended contrast are not reported, so the statistical question cannot be reconstructed from the endpoint title alone.
The primary analysis population is described as the full analysis set with last observation carry forward. The record does not report how many participants were included, how many observations were missing, reasons for missingness, or how missing assessments were distributed between groups. It also does not report sensitivity analyses using other missing-data assumptions. In general, missing-data methods can affect estimates if participants with incomplete follow-up differ from those with complete observations or if the outcome changes after the last recorded assessment.
Other analysis-population definitions, protocol deviations, exclusion rules, and the handling of participants who stopped or changed treatment are not reported in the registry record. These gaps limit assessment of whether the analysis population preserved the benefits of randomization and how dependent the result would be on analytic choices. Because the primary results themselves are not reported, the impact of multiplicity or missing data on a treatment-effect estimate cannot be evaluated.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Pramipexole | 22 | 121 | 18.2% |
| Ropinirole | 21 | 125 | 16.8% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Pramipexole | 97 of 121 |
| Ropinirole | 101 of 125 |
Most frequent serious adverse event terms
| Event term | Organ system | Pramipexole | Ropinirole |
|---|---|---|---|
| Basal cell carcinoma | Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 5 of 121 | 2 of 125 |
| Osteoarthritis | Musculoskeletal and connective tissue disorders | 2 of 121 | 2 of 125 |
| Atrial fibrillation | Cardiac disorders | 2 of 121 | 1 of 125 |
| Road traffic accident | Injury, poisoning and procedural complications | 1 of 121 | 2 of 125 |
| Cardiac failure congestive | Cardiac disorders | 2 of 121 | 0 of 125 |
| Coronary artery occlusion | Cardiac disorders | 0 of 121 | 2 of 125 |
| Chest discomfort | General disorders | 0 of 121 | 2 of 125 |
| Appendicitis | Infections and infestations | 2 of 121 | 0 of 125 |
| Femur fracture | Injury, poisoning and procedural complications | 2 of 121 | 0 of 125 |
| Lower limb fracture | Injury, poisoning and procedural complications | 2 of 121 | 0 of 125 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Pramipexole | Ropinirole |
|---|---|---|---|
| Somnolence | Nervous system disorders | 53 of 121 | 71 of 125 |
| Nausea | Gastrointestinal disorders | 31 of 121 | 59 of 125 |
| Dizziness | Nervous system disorders | 27 of 121 | 35 of 125 |
| Fatigue | General disorders | 27 of 121 | 25 of 125 |
| Insomnia | Psychiatric disorders | 19 of 121 | 27 of 125 |
| Constipation | Gastrointestinal disorders | 18 of 121 | 26 of 125 |
| Headache | Nervous system disorders | 15 of 121 | 27 of 125 |
| Oedema peripheral | General disorders | 22 of 121 | 18 of 125 |
| Nasopharyngitis | Infections and infestations | 17 of 121 | 16 of 125 |
| Sudden onset of sleep | Nervous system disorders | 11 of 121 | 16 of 125 |
Serious events with the highest arm-level rate: basal cell carcinoma (4.1%), atrial fibrillation (1.7%), cardiac failure congestive (1.7%), appendicitis (1.7%), femur fracture (1.7%).
The adverse-event record lists serious adverse events for each treatment group. In the pramipexole group, 22 of 121 participants at risk were affected by serious adverse events; in the ropinirole group, 21 of 125 participants at risk were affected. Other adverse events were recorded for 97 of 121 participants at risk in the pramipexole group and 101 of 125 in the ropinirole group. These are descriptive counts, not adjusted treatment comparisons.
The record lists basal cell carcinoma at 4.1% among the top serious adverse-event terms. Atrial fibrillation, congestive cardiac failure, appendicitis, femur fracture, and lower limb fracture are each listed at 1.7%. The record does not provide event-specific participant counts alongside these percentages or explain the denominator and coding conventions for the term list. The listed terms should therefore be read as registry-reported adverse-event entries, not as proof that treatment caused them.
Serious adverse-event counts and other adverse-event counts are distinct from the primary ophthalmologic endpoint. The registry record does not report a formal statistical comparison, confidence intervals, event timing, exposure-adjusted rates, or detailed event definitions for these summaries. Deaths are not reported in the registry record. The counts alone cannot establish whether any difference is clinically meaningful or attributable to treatment.
12. What the Result Does, and Does Not, Mean
This trial addresses a specific safety question: whether an expert panel’s overall review of ophthalmologic assessments identified retinal deterioration over up to 2 years in participants assigned to pramipexole immediate release or ropinirole. The registry record identifies the treatments, randomized parallel-group structure, intended endpoint, and the full analysis set with last observation carry forward. It also records some adverse-event counts.
However, the record does not report the primary outcome results. It gives no treatment-group counts for the panel assessment, no effect estimate, and no uncertainty interval. The endpoint is described as involving several categories or time points and is not reduced to one comparison. Without those details, the posted information cannot establish how many participants were assessed as having retinal deterioration or quantify a difference between the groups.
This absence of a reported comparison does not mean that the treatments had the same outcome, nor does it show that one group had more retinal deterioration. It means that the registry record, as represented in the available information, does not provide the results needed to answer that comparison quantitatively. No conclusion about the size or precision of a treatment difference should be drawn from the enrollment number or adverse-event summaries.
The serious adverse-event counts describe participants affected in each group, but they are not substitutes for the primary endpoint. They do not establish causation and are not accompanied by a reported comparative analysis or uncertainty estimates. Similarly, the listed adverse-event terms do not provide an overall judgment about ophthalmologic safety.
In general, a trial result is best interpreted by considering the prespecified outcome definition, analysis population, treatment-group estimates, uncertainty, and missing-data handling together. For this study, some of those design elements are named, but key outcome and analysis details are not reported in the registry record. The data described support a careful account of what was planned and what safety counts were posted, not a claim that either treatment did or did not affect retinal outcomes.
13. Why This Trial Matters Statistically
This trial illustrates why a clear endpoint definition and accessible results matter in a randomized comparison. The registry record identifies retinal deterioration as the safety concern and describes an expert panel review of comprehensive ophthalmology assessments. Yet the primary endpoint is an overall assessment with several categories or time points, and the record does not reduce it to a single comparison or report the group results. Naming an outcome is not enough to determine its observed frequency or the precision of a treatment contrast.
The study also highlights the distinction between randomization and masking. Random assignment can support a fair comparison by reducing systematic baseline differences on average. Blinded outcome assessment can help limit the influence of treatment knowledge on measurement. The official title describes blinded assessment, while the registry masking entry is “none”; the practical arrangements are not reported. That discrepancy in description makes it important to distinguish the intended assessment approach from the documented masking information.
Missing-data handling is another important statistical feature. The endpoint population is described as a full analysis set using last observation carry forward, but the participant counts and missingness details are absent. LOCF may simplify an analysis, but its assumptions can matter when an outcome changes over time. Without missingness information or sensitivity analyses, readers cannot judge the stability of a result under alternative assumptions.
Finally, the record lists numerous outcomes and time points but does not report the testing hierarchy or multiplicity strategy. Those choices affect how multiple findings should be interpreted. Taken together, the study provides a useful example of why statistical interpretation depends not only on design labels but also on outcome definitions, analysis details, and complete reporting of estimates and uncertainty.
14. 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 interpreting this trial is that the primary endpoint results are not reported in the registry record. No group-specific participant counts for the expert panel assessment, effect estimate, confidence interval, or p-value are available. Since the endpoint has several categories or time points and is not reduced to one comparison, the outcome cannot be reconstructed as a simple treatment contrast from the record.
The endpoint description does not explain the assessment categories, the operational definition of retinal deterioration, or how panel judgments were combined. The official title refers to blinded assessment, but the registry masking entry is “none”; who was blinded and what safeguards were used are not reported. These omissions make it difficult to assess measurement consistency and the potential for assessment bias.
The primary analysis population is described as the full analysis set with last observation carry forward, but the record does not provide the number analyzed by group, participant flow, missing-assessment counts, reasons for missingness, or sensitivity analyses. It also does not report how treatment discontinuation, adherence, dose changes, or other departures from assigned treatment were handled. The trial’s own sample-size justification, statistical analysis plan, and multiplicity procedures are not reported in the registry record.
Safety information is also limited. Serious and other adverse-event counts are available, along with a list of serious-event terms, but event definitions, timing, detailed denominators, exposure-adjusted comparisons, and uncertainty estimates are not reported. Deaths are not reported in the registry record. These limitations constrain interpretation of both the primary ophthalmologic question and the broader safety summaries; they do not establish that an effect was absent.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Ophthalmologic Safety Study of Pramipexole Immediate Release (IR) Versus Ropinirole in Early Parkinson's Disease (PD) Patients — NCT00144300.
- Registry record last updated 2014-03-14; status last verified 2014-02.
- Results first posted 2011-11-04.
- 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.
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18. Record Summary
The registry record describes a completed Phase 4 randomized, parallel-group study of pramipexole immediate release versus ropinirole in early Parkinson’s disease, with 246 participants enrolled. Both regimens are described as tablets taken three times daily according to the manufacturer’s guidelines. The primary endpoint was an expert panel’s overall assessment of retinal deterioration following up to 2 years on drug, based on comprehensive ophthalmologic assessments. The primary population is described as the full analysis set with last observation carry forward.
The record lists 21 outcome measures and one analysis. It also reports serious and other adverse-event counts for both groups and several serious-event terms. The primary endpoint results, a treatment-effect estimate, confidence interval, and p-value are not reported in the registry record. The record does not report the primary assessment categories or a single comparison, and it does not provide detailed missing-data, multiplicity, or blinding procedures. Consequently, the design and intended question can be described, but the primary treatment difference cannot be quantified from the reported information.