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 Safety and Effect of Mirapex(Pramipexole) Tablet Among Korean RLS (NCT01170091), a registered phase not stated study. The primary outcome is Number of Reported Adverse Events.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01170091 |
| Phase | Phase not stated |
| Condition | Restless Legs Syndrome |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 651 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Boehringer Ingelheim |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns patients with restless legs syndrome (RLS) in a Korean postmarketing surveillance setting. The registry lists an enrollment of 651. The primary outcome population is described as patients with RLS who took at least one dose of Mirapex, in the Safety Analysis Set. Whether every enrolled participant entered that set is not reported in the registry record.
Intervention
The intervention was Mirapex (pramipexole) tablets. The record describes the study as open-label. The arm description does not give a dosing schedule. The primary outcome timeframe is up to 4 weeks, with another 4 weeks of follow-up if dose titration occurs; details of how dosing or titration was carried out are not reported in the registry record.
Comparator
No comparator arm is described. The record does not state an allocation method, and it is not a randomized comparison. Consequently, the registry record does not support a like-for-like comparison between treatment groups or an estimate of a comparative treatment effect.
Primary question
The primary outcome is the number of reported adverse-event cases during the stated follow-up. The registry also lists change in the International Restless Legs Syndrome Rating Scale (IRLS) after 4 weeks, Patient-Global Impressions (PGI-I), and Clinical Global Impressions-Global Improvement (CGI-I) as secondary outcomes. Numerical results and analyses for these outcomes are not reported in the registry record. The record therefore describes what was intended to be assessed, but does not provide enough outcome information to quantify symptom change or interpret a treatment effect.
3. Trial Design
The registry describes an open-label, postmarketing surveillance study of Mirapex (pramipexole) tablets among Korean patients with restless legs syndrome. It lists Boehringer Ingelheim as the sponsor, a start date of 2007-12, a primary completion date of 2011-02, and a status of COMPLETED. The enrollment listed is 651. These registry entries describe the study record; they do not establish how many participants contributed data to each outcome.
Only one intervention arm, Pramipexole, is described. The arm description itself is blank. The allocation method is not stated, and the study is not a randomized comparison. No control group is described, so the design does not offer a contemporaneous, like-for-like comparison for separating treatment effects from other influences. Open-label indicates that the study was not described as blinded; further details about who knew treatment status are not reported in the registry record.
The primary outcome is the number of reported adverse-event cases, with a timeframe of up to 4 weeks. The description says that if dose titration occurs, another 4 weeks should be followed up. The secondary outcomes listed are IRLS change after 4 weeks, PGI-I, and CGI-I. The registry identifies four outcome measures overall, corresponding to the primary outcome and the three listed secondary outcomes.
The record marks the study as completed, but completion status is not itself evidence that each outcome was analyzed or that all planned data are posted. The number of analyses is listed as 0. Details about the protocol, recruitment procedures, participant flow, dosing, outcome-assessment schedules beyond the listed timeframes, and analysis methods 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.
Overall Study
| Stage | Mirapex |
|---|---|
| STARTED | 651 |
| COMPLETED | 627 |
| NOT COMPLETED | 24 |
Reasons for not completing this period:
| Reason | Mirapex |
|---|---|
| Missing efficacy evaluation | 3 |
| Treatment duration is less than 4 weeks | 21 |
Analysis population for the primary outcome, as defined in the registry: Patients with RLS who took at least one dose of Mirapex - Safety Analysis Set
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: Safety Analysis Set
| Characteristic | Unit | Patients With Restless Legs Syndrome (RLS) |
|---|---|---|
| Participants analysed | 651 | |
| Age, Continuous | Years | 60.9 (SD 13.2) |
| Sex/Gender, Customized: Female | Participants | 369 |
| Sex/Gender, Customized: Male | Participants | 276 |
| Sex/Gender, Customized: Not reported | Participants | 6 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Reported Adverse Events, measured over Up to 4 weeks.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | cases |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the number of reported adverse-event cases, measured in cases, among patients with RLS who took at least one dose of Mirapex in the Safety Analysis Set. Its stated timeframe is up to 4 weeks; if dose titration occurs, the outcome description calls for another 4 weeks of follow-up. The endpoint is intended to describe adverse events reported during that period, rather than to compare treatment with a control.
As a general statistical point, a count endpoint records how many events or cases were observed, rather than averaging a continuous measurement such as a symptom score. Such counts can describe the burden recorded during follow-up, but interpretation depends on clear definitions of what counts as an event, how events are collected, and which participants contribute observation time. Those operational details are not reported in the registry record.
The registry names this endpoint but does not include a numerical primary outcome result in the record information available. The separate safety summary lists affected counts for serious and other adverse events, but those fields do not establish the total number of reported adverse-event cases. The primary endpoint’s value and any analysis of it are not reported in the registry record. This distinction matters: a named endpoint, a category-specific safety count, and an analyzed primary result are not interchangeable.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes the broad setting and outcome plan: an open-label, postmarketing surveillance study of pramipexole among Korean patients with RLS, with a listed enrollment of 651 and a primary safety outcome. It does not post numerical results for the primary endpoint or the secondary symptom and global-impression outcomes. The number of analyses is listed as 0. Accordingly, the record does not support a quantitative account of reported adverse-event cases, IRLS change, PGI-I, or CGI-I.
The safety summary lists 651 at risk and 0 affected for serious adverse events, and 651 at risk and 0 affected for other adverse events. These are the categories and counts recorded in that summary. They should not be read as a full estimate of the primary endpoint: the endpoint is the number of reported adverse-event cases, while the summary reports affected counts in specified safety categories. The relationship between these summary fields and the primary endpoint is not explained in the registry record. Deaths are listed as null, and no top serious adverse-event terms are listed. A null entry is not a numerical count of zero; the death count is not reported in the registry record.
There is no control group described, and allocation is not stated. The study is not a randomized comparison. The posted record therefore cannot provide a treatment-versus-control contrast, and the safety figures do not establish whether outcomes differ from what would have occurred without the intervention. This is a limitation of the design and the record, not a reason to infer an unreported result.
As a general statistical point, an observed count describes what was recorded in the study under its data-collection procedures. It does not, on its own, characterize the precision of an underlying event rate or establish that events were absent in a broader population. Such interpretation requires an appropriate denominator, defined follow-up, and information on ascertainment and completeness. The record provides some at-risk and affected counts, but it does not report these additional details or an uncertainty interval for the primary endpoint.
The completion status and enrollment figure are useful descriptive context, but neither replaces outcome reporting. In particular, the listed 651 is not a substitute for a result specific to the primary Safety Analysis Set or an analysis population for secondary outcomes. The registry record does not report whether all enrolled patients completed follow-up, how missing observations were handled, or whether any outcome analyses were adjusted. Conclusions should therefore remain limited to the design and the entries actually posted.
9. Statistical Methods Explained
Understanding the record requires distinguishing study design, outcome definition, and statistical result. The study is described as open-label postmarketing surveillance, with a single Pramipexole arm and no stated allocation method. It is not a randomized comparison. The primary outcome is a count of reported adverse-event cases, and the secondary outcomes are a symptom-scale change and two global-impression measures. These are different kinds of outcomes and would generally require different summaries and analysis choices. The record does not report the analyses used.
What does an open-label design imply?
As a general statistical concept, open-label means treatment assignment is not concealed from study participants or study personnel in the way it would be in a blinded design. Knowledge of treatment can influence reporting, observation, and assessment, particularly for outcomes that depend on subjective reports or clinical judgments. This does not establish that bias occurred in this study. The record does not describe the specific assessment procedures or safeguards, so the extent to which those influences could be relevant is not reported in the registry record.
Postmarketing surveillance describes the study context as stated in the registry. It does not by itself specify how participants were recruited, how outcomes were collected, or whether data collection was prospective or retrospective. Those details are not reported in the registry record. A single-arm design can describe outcomes observed among participants who received the intervention, but without a comparison group it cannot separate changes associated with treatment from other explanations such as changes over time, differences in who entered the study, or how outcomes were measured.
How should a count endpoint be understood?
As a general statistical concept, count outcomes take non-negative integer values and may be summarized as event counts, participant counts, or rates over a defined period. These quantities answer different questions. A case count concerns recorded cases; a participant count concerns how many people experienced an event; a rate additionally requires an appropriate measure of time at risk. The primary outcome is titled “Number of Reported Adverse Events” and uses cases as its unit, while the safety summary gives affected counts within serious and other categories. The record does not explain how those definitions relate or provide a numerical result for the primary endpoint.
Count data can also vary more than would be expected under simple models that assume events occur independently at a common rate. In general, over-dispersion means that observed variability exceeds that model’s expectation; ignoring it can make uncertainty estimates too small. Whether over-dispersion was assessed or relevant to the analysis of this study is not reported in the registry record. No count-model specification or uncertainty estimate is posted.
What do the secondary outcomes measure?
The registry lists IRLS change after 4 weeks, PGI-I, and CGI-I. The IRLS outcome is described as a change, so an analysis would need to define the baseline and follow-up measurements and how change is summarized. The registry does not report those details or a numerical result. PGI-I and CGI-I are global-impression outcomes, but their scoring, categories, and analysis approach are not reported in the registry record. The listing of an outcome indicates that it was included in the registry record; it does not establish that a result was posted.
As a general statistical principle, estimates should be accompanied by measures of uncertainty, such as confidence intervals, when the aim is to describe how precisely the data estimate a quantity. A confidence interval represents a range of values compatible with the observed data under the assumptions of the method. It does not account automatically for every source of bias, and it does not substitute for a suitable design. No confidence intervals or other uncertainty measures for the trial outcomes are reported in the registry record.
What can the posted counts establish?
The safety summary records 0 affected for serious adverse events and 0 affected for other adverse events, with 651 at risk in each category. These entries describe the posted categories, not an adjusted estimate or a comparative effect. The primary outcome’s total number of reported adverse-event cases is not reported in the registry record. The number of analyses is listed as 0, so no inferential analysis, modeled estimate, or test result is available in the record.
Planning calculations, when present in a statistical presentation, are not observed outcomes. In general, sample-size illustrations based on an observed effect explore what a future study might require under specified assumptions; they do not show that a study had a particular probability of detecting an effect after it has been conducted. No specific planning values or design justification are reported in the registry record, and no conclusion about the trial’s power can be drawn from the listed enrollment alone.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary safety outcome and three secondary outcomes: IRLS change after 4 weeks, PGI-I, and CGI-I. Considering several outcomes raises the general issue of multiplicity: if many hypotheses are tested, the chance of at least one apparently unusual result can increase unless the analysis plan addresses that possibility. This is a general statistical concern, not evidence that any particular adjustment was required or performed in this study.
The registry record does not report a multiplicity strategy, a hierarchy among secondary outcomes, or a prespecified testing procedure. The number of analyses is listed as 0, and numerical outcome analyses are not reported in the registry record. Therefore, there are no posted analysis results from which to assess how multiple outcomes or comparisons were handled. The protocol and statistical analysis plan are not reported in the registry record.
Missing data also affect interpretation because outcome summaries may depend on who was observed at each assessment. The primary safety population is described as patients who took at least one dose, but the record does not give a participant flow or state how many contributed data to each outcome. It does not report completion by outcome, reasons for missing observations, imputation methods, or sensitivity analyses. No assumption about the handling or absence of missing data can be made from the enrollment figure or completion status.
As a general principle, analysis populations should be defined clearly because safety, efficacy, and randomized-group populations can differ. Here, the primary endpoint names a Safety Analysis Set, while the analysis populations for secondary outcomes are not described. The registry record does not report whether the secondary outcomes used the same participants or another defined population. Thus, the scope of each intended analysis and the effects of missing observations cannot be evaluated from the posted record.
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 |
|---|---|---|---|
| Patients With Restless Legs Syndrome (RLS) | 0 | 651 | 0.0% |
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 |
|---|---|
| Patients With Restless Legs Syndrome (RLS) | 0 of 651 |
The safety summary lists 651 at risk and 0 affected for serious adverse events, and 651 at risk and 0 affected for other adverse events. Read these as the posted affected counts within those categories, not as a complete description of every adverse event or as the numerical result for the primary endpoint. The primary endpoint is the number of reported adverse-event cases; its numerical result is not reported in the registry record.
The death field is null, so a numerical death count is not reported in the registry record. No top serious adverse-event terms are listed. The absence of listed terms should not be interpreted as a separate count or as proof that no event could have occurred; the registry simply does not list terms in that field.
As a general statistical point, a zero count in a posted category describes the data as recorded, but does not by itself establish that the underlying risk is zero. Interpretation also depends on event definitions, follow-up completeness, reporting procedures, and the precision of the estimate. Those details and an uncertainty interval are not reported in the registry record. The summary also does not provide a comparator, so it cannot establish a relative safety difference between treatment groups.
12. What the Result Does, and Does Not, Mean
The record supports a limited descriptive account: it concerns an open-label, postmarketing surveillance study of pramipexole among Korean patients with RLS; it lists enrollment of 651; and it records 0 affected among 651 at risk in each of the serious and other adverse-event categories. The registry labels the study COMPLETED and lists the primary outcome as reported adverse-event cases, with secondary outcomes involving IRLS, PGI-I, and CGI-I.
It does not provide a numerical primary endpoint result or analyses for the listed outcomes. The count of affected participants in the safety summary is not the same measure as the primary outcome’s count of reported cases. The record does not explain their relationship. The death count is not reported in the registry record. These gaps prevent a complete statistical interpretation of the safety endpoint and prevent quantification of the secondary outcomes.
The record also does not support a causal comparison. There is no comparator arm described, the allocation method is not stated, and the study is not randomized. Observations from an open-label, single-arm surveillance study may be informative as descriptions of recorded experience, but they cannot by themselves show what would have happened to a comparable group without the intervention. This does not negate the descriptive information; it defines what kind of inference the design can support.
As a general statistical point, interpreting an estimate requires attention to its precision as well as its value. A result with no reported uncertainty measure cannot show how narrowly the study estimates the underlying quantity. Here, the numerical primary result and uncertainty measures are not reported in the registry record, so precision cannot be assessed. Nor does the listed enrollment establish how many participants contributed to each analysis.
The most defensible conclusion is therefore about the record’s contents, not a claim about benefit or harm: the registry describes the study and posts selected safety-category counts, but it does not report the primary outcome result or statistical analyses for the outcomes listed. Any stronger conclusion about symptom change, comparative effects, or the full adverse-event experience would require information not reported in the registry record.
13. Why This Trial Matters Statistically
This study is statistically notable because it illustrates the difference between a completed registry record and a complete outcome report. The record states that the study is COMPLETED and lists enrollment of 651, yet the number of analyses is 0 and numerical results for the primary outcome and secondary outcomes are not reported in the registry record. Completion status and enrollment provide context, but they do not supply estimates or measures of precision.
The design also makes the boundary of inference clear. The study is open-label and postmarketing, with one described intervention arm and no stated allocation method. It is not a randomized comparison. These features mean that the posted information is descriptive rather than a controlled estimate of comparative effects. This distinction is important whenever readers encounter outcome labels that may sound like direct evidence of a treatment effect.
The safety summary offers a further teaching point: the primary endpoint is a count of reported adverse-event cases, while the separate summary gives affected counts for serious and other adverse-event categories. The categories have zero affected counts in the record, but the relationship between these fields and the primary outcome is not explained. Keeping event counts, participant counts, and endpoint results conceptually separate prevents over-reading a registry entry.
Finally, the record shows why analysis populations, follow-up, and missing-data handling matter. The primary outcome names a Safety Analysis Set and specifies a follow-up period, but participant flow and outcome-specific analysis populations are not reported. Without those details, the denominator and completeness underlying an outcome cannot be independently evaluated. The statistical importance of this study record lies in clarifying what it documents and where inference stops, rather than in a treatment-effect estimate that is not posted.
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.
Several limitations are specific to the information recorded for this study. The primary endpoint is named and its timeframe is described, but its numerical result is not reported in the registry record. The record does not provide an analysis of the endpoint, an uncertainty interval, or details defining how reported adverse-event cases were counted. The summary’s serious and other adverse-event fields report affected counts, but their relationship to the primary endpoint is not explained.
The study has one described intervention arm and no stated allocation method. It is not a randomized comparison, and no comparator is described. As a result, the registry record cannot support a treatment-versus-control estimate. Its open-label, postmarketing surveillance description also leaves relevant procedures unspecified: the record does not report how patients were recruited, how events were ascertained, or what safeguards were used in outcome assessment.
The registry lists enrollment of 651 and gives a Safety Analysis Set definition for the primary endpoint, but does not report participant flow, outcome-specific denominators, or how many participants completed follow-up. It does not describe missing-data handling. The death field is null, and no top serious adverse-event terms are listed; neither entry supplies a numerical death result or a full event listing.
Although the secondary outcomes are named, numerical results and analysis details for IRLS change, PGI-I, and CGI-I are not reported in the registry record. The protocol, sample-size justification, statistical analysis plan, multiplicity strategy, and analysis populations for those outcomes are also not reported in the registry record. These omissions limit assessment of precision, completeness, and the prespecification of analyses. They do not justify filling gaps with assumptions about what the study may have done.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Safety and Effect of Mirapex(Pramipexole) Tablet Among Korean RLS — NCT01170091.
- Registry record last updated 2014-04-11; status last verified 2014-03.
- Results first posted 2012-09-11.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
The registry describes an open-label, postmarketing surveillance study of Mirapex (pramipexole) among Korean patients with RLS. Boehringer Ingelheim is listed as sponsor; the study is marked COMPLETED, with a start date of 2007-12, primary completion date of 2011-02, and enrollment of 651.
The primary outcome is the number of reported adverse-event cases during follow-up of up to 4 weeks, with another 4 weeks specified if dose titration occurs. Secondary outcomes are IRLS change after 4 weeks, PGI-I, and CGI-I. The safety summary lists 0 affected among 651 at risk for both serious and other adverse events. The death count is not reported in the registry record.
No numerical primary outcome result or outcome analyses are reported in the registry record; the number of analyses is listed as 0. No comparator is described, allocation is not stated, and the study is not a randomized comparison. Interpretation is therefore limited to the design and posted safety entries.