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 Botulin-A Toxin Instillations and Overactive Bladder (NCT00583219), a na phase 1, phase 2 study. The primary outcome is Median Number of Incontinent Episodes During 24 Hours.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00583219 |
| Phase | Phase 1, Phase 2 |
| Condition | Overactive Bladder, Detrusor Instability, Detrusor Hyperreflexia |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 25 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Mayo Clinic |
| Results posted | Yes |
2. Clinical Question
Population
Women with symptoms of overactive bladder and secondary urinary incontinence were the intended population. The registry lists overactive bladder, detrusor instability, and detrusor hyperreflexia as conditions. Enrollment was 25; further details about participant characteristics are not reported in the registry record.
Intervention
Participants received bladder instillations of botulinum-A toxin with dimethyl sulfoxide (DMSO), delivered through a catheter system. The stated objective was to assess safety and efficacy, with attention to urinary incontinence symptoms after treatment. The available arm description gives some dosing details but does not fully describe the regimen for all participants.
Comparator
There was no separate control group. The design is listed as single-group, with allocation not applicable and no masking. Outcomes were assessed at baseline and follow-up, but changes over time in this design do not constitute a randomized comparison against another treatment or against no treatment.
Primary question
The primary outcome was the median number of incontinent episodes during 24 hours, assessed at baseline, one month, and three months. The study objective was to estimate the percentage of women with improved urinary incontinence symptoms at one month and three months. Numerical primary outcome results and the stated improvement definition are not reported in the registry record.
This question is framed as a pilot evaluation of a bladder instillation technique rather than as a comparative-effectiveness question. The endpoint follows participants over time, so it can describe whether reported episodes changed after instillation. Without a comparison group, however, such observations cannot separate a treatment-associated change from other explanations for change over time. The registry record does not report a threshold defining improvement, a hypothesis test for the primary question, or a numerical estimate of the proportion with improvement.
3. Trial Design
The study is listed as Phase 1 and Phase 2, completed, and single-group, with enrollment of 25. The registry dates the study start to 2006-03 and primary completion to 2008-05. Allocation is not applicable, and masking is listed as none. These design features mean that outcomes were not collected as a blinded, randomized comparison between treatment groups. The record does not describe a concurrent control group.
The intervention is described as botulinum-A toxin and DMSO solution instilled into the bladder by catheter. The available arm description says the first 3 subjects in Phase 1 received 50 cc of solution using 200 units of botulinum-A toxin and 50cc DMSO. It then says the next 6 subjects in Phase 1 received 300 units of botulinum-A toxin and 50, but the remainder of that dosing description is not reported in the registry record. The regimen for all participants and details about any Phase 2 dosing are not fully reported in the registry record.
The primary outcome was the median number of incontinent episodes during 24 hours, with baseline, one-month, and three-month assessment times. The record also lists secondary outcomes that include pad weight, a continence score, pads per day, postvoid residual, urine culture, and urinary urgency. Across the record, there are 14 outcome measures and 20 analyses. Those counts indicate multiple measures or analyses, but do not establish how any particular analysis was specified or prioritized.
Because this was a single-group study, each follow-up assessment is interpreted relative to the participants’ own baseline rather than against a separately assigned comparison group. The record does not report the statistical analysis plan, the handling of changes in dosing, or whether all enrolled participants contributed to every follow-up analysis. It also does not report a sample-size justification for the trial’s actual design.
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.
Phase 1
| Stage | Botox/DMSO Solution |
|---|---|
| STARTED | 9 |
| COMPLETED | 9 |
| NOT COMPLETED | 0 |
Phase 2
| Stage | Botox/DMSO Solution |
|---|---|
| STARTED | 22 |
| COMPLETED | 21 |
| NOT COMPLETED | 1 |
Reasons for not completing this period:
| Reason | Botox/DMSO Solution |
|---|---|
| Withdrawal by Subject | 1 |
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 | Botox/DMSO Solution |
|---|---|---|
| Participants analysed | 25 | |
| Age, Continuous | years | 74 (37 to 86) |
| Sex: Female, Male: Female | Participants | 25 |
| Sex: Female, Male: Male | Participants | 0 |
| Region of Enrollment: United States | participants | 25 |
| Body Mass Index | kg/m^2 | 26.6 (18.4 to 40.0) |
6. Primary Endpoint
The registry lists the primary outcome as Median Number of Incontinent Episodes During 24 Hours, measured over baseline, 1 month, 3 months.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Inter-Quartile Range |
| Unit | number of incontinent episodes |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the median number of incontinent episodes recorded during a 24-hour period. The study coordinator instructed participants to keep a record of any incontinence episodes during the 24-hour period before baseline and follow-up visits. The planned assessment times were baseline, one month, and three months.
A count of episodes is a direct way to describe the frequency of the symptom targeted by the study. A median summarizes the middle of the observed values and is less influenced by unusually high counts than an arithmetic mean can be. The interquartile range is listed as the measure of dispersion; it describes the spread of the middle portion of observations. These are general statistical interpretations of the selected summaries, not evidence about the size or direction of an outcome in this study.
The endpoint’s repeated assessment schedule allows a descriptive account of how episode counts varied from baseline to follow-up. The registry record does not report the median values, interquartile ranges, participant counts at each time point, or a statistical comparison among time points. It therefore does not establish the magnitude or precision of any observed change in the primary endpoint. The brief study objective refers to estimating the percentage of women who experienced improvement, but the improvement criterion and its numerical results are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a clinically focused, repeated-measures question: whether urinary incontinence symptoms changed after bladder instillation of botulinum-A toxin and DMSO. It specifies the primary measure and assessment schedule, but does not report the numerical primary outcome results. Without those values, the direction, magnitude, and precision of change in the median number of incontinent episodes cannot be described. The stated objective of estimating the percentage of women with symptom improvement also cannot be evaluated from the reported information because neither an improvement definition nor a result is given.
Enrollment was 25, and the study is listed as a single-group trial without masking. These characteristics shape what any results could establish. A baseline-to-follow-up difference in a single group is a temporal association, not a direct estimate of how outcomes would differ under an alternative treatment or no instillation. General methodological considerations include natural variation in symptoms, changes in reporting, expectations, and other events during follow-up. The registry record does not say whether any such factors occurred or how they were addressed.
The outcome is based on a participant-kept record of episodes over the 24-hour period before visits. That approach focuses on a defined observation window, but the registry record does not report how diary completion was checked, whether incomplete diaries were accepted, or how missing entries were handled. Nor does it report how many participants had usable endpoint data at each visit. Consequently, the enrolled count should not be treated as the number included in every outcome analysis.
The endpoint was summarized using a median and interquartile range. These summaries are appropriate descriptions when counts are skewed or include unusually large observations, as a general statistical matter. They do not by themselves indicate whether a change is statistically distinguishable from chance, whether it is clinically important, or how precisely it was estimated. The record does not provide the values needed to assess those questions.
The record lists 14 outcome measures and 20 analyses. Multiple outcomes and analyses can raise questions about selective emphasis and the chance of false-positive findings when many hypotheses are tested. The counts alone do not show how many hypothesis tests were performed, whether outcomes were prespecified, or whether any multiplicity adjustment was used. Those details are not reported in the registry record.
Safety information records 0 serious adverse events among 25 participants at risk and 18 participants with other adverse events among 25 at risk. These figures describe the registry’s recorded safety counts; they do not establish that no unrecorded events occurred. The types of serious events are not listed, and deaths are not reported in the registry record. Interpretation of safety is limited by the absence of event descriptions and follow-up detail.
Overall, the available information supports describing the design, planned endpoint, and recorded adverse-event counts, but not drawing a conclusion about symptom benefit. The primary outcome results, analysis details, missing-data approach, and improvement estimate are not reported in the registry record.
9. Statistical Methods Explained
The study’s central statistical feature is its single-group structure. Outcomes were measured at baseline and again at one month and three months. In a design of this kind, a within-participant comparison can describe how measurements changed over time. As a general statistical principle, that comparison does not supply the counterfactual outcome: what the same participants’ symptoms would have been at follow-up without the instillation. A concurrent comparison group is usually needed to estimate that contrast more directly.
Why report a median and interquartile range?
The primary endpoint is a count of incontinent episodes in a 24-hour window, summarized by its median and interquartile range. The median identifies the middle of the ordered observations. The interquartile range describes the spread across the middle half of the distribution. As a general matter, these summaries can be informative for skewed data or data with extreme values, where the mean and standard deviation may be strongly influenced by a small number of observations. The registry record does not report the endpoint values or distribution, so it is not possible to assess the data’s shape in this study.
Reporting a median and interquartile range is descriptive. A comparison over time would require an inferential method appropriate to the paired or repeated observations and to the distribution of the endpoint. The method used for such comparisons is not reported in the registry record. The record also does not state whether analyses used all available observations at each visit or required participants to have measurements at every visit.
What does a confidence interval describe?
In general, a confidence interval gives a range of estimates compatible with the data under a specified statistical procedure. Its width reflects precision: a wider interval indicates greater uncertainty about the estimated quantity, while a narrower interval indicates greater precision. An interval does not resolve limitations in design, remove bias, or establish that an effect matters clinically. The registry record does not report confidence intervals for the primary endpoint or for the improvement estimate.
A p-value, in general, describes how unusual data at least as discrepant as those observed would be under a specified null model and its assumptions. It is not the probability that a treatment effect is real, and it does not measure the size or clinical importance of an effect. The statistical tests and p-values for the primary endpoint are not reported in the registry record. With no numerical outcome results or inferential statistics, there is no basis for describing statistical significance.
Why can count outcomes require special care?
Counts are nonnegative and may have distributions unlike continuous measurements. A basic count model may assume that variability is linked to the mean in a particular way. General statistical guidance is that over-dispersion—more variability than a model allows—can make standard errors too small if it is ignored. The registry record does not describe a count model, report a dispersion assessment, or state that a model-based analysis was used. These are general considerations, not claims about the methods applied in this study.
Because the same participants were assessed repeatedly, measurements from one participant may be related. General methods for repeated data account for that within-participant dependence; treating repeated measurements as independent can misstate uncertainty. The analysis method and its handling of within-participant correlation are not reported in the registry record. No particular repeated-measures model should therefore be attributed to this trial.
How should planning calculations be read?
Any sample-size figures associated with planning assumptions are illustrations, not observed power and not the trial’s actual enrollment justification. The stated illustration assumes a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. Time-to-event illustrations are described as total event counts; other illustrations are described as participants per arm. These assumptions do not match the listed single-group design, which has no two-arm allocation. The registry record does not report a sample-size justification for the trial’s own design. No planning illustration can substitute for the missing primary outcome values or an analysis of precision based on those results.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 14 outcome measures and 20 analyses. This indicates that the record covers more than the primary endpoint alone, but the counts do not reveal which analyses were confirmatory, exploratory, or repeated versions of the same outcome. The registry record does not report a multiplicity strategy, such as adjustment of significance thresholds, hierarchical testing, or a prespecified prioritization of outcomes. It also does not report whether the primary endpoint or analysis changed during the study.
When many outcomes or tests are considered, the chance of at least one apparently unusual result can increase. This is a general statistical concern, not evidence that a false-positive result occurred in this trial. Without analysis-level results and a stated plan, readers cannot determine how multiplicity should affect interpretation.
The endpoint diary covered the 24-hour period before each assessment. The registry record does not report the number of missing diaries, missing values at follow-up, reasons for missingness, or any method used to handle missing data. It also does not report whether participants who stopped follow-up were included in analyses or how the analysis population was defined. Enrollment of 25 does not establish that all participants contributed data at every time point.
The record does not describe an intention-to-treat population, a per-protocol population, or another analysis set. It does not report interim analyses, imputation, sensitivity analyses, or procedures for participants with incomplete follow-up. These omissions prevent assessment of whether missingness or analysis-population choices could have influenced the endpoint estimates. They also limit reproducibility: the endpoint and time points are identified, but the analytic decisions needed to reproduce an estimate are not reported in the registry 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 |
|---|---|---|---|
| Botox/DMSO Solution | 0 | 25 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Botox/DMSO Solution | 18 of 25 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Botox/DMSO Solution |
|---|---|---|
| Dysuria after 24 hours | Renal and urinary disorders | 4 of 25 |
| Urinary tract infection after 24 hours | Renal and urinary disorders | 3 of 25 |
| Bladder spasms in first 24 hours | Renal and urinary disorders | 2 of 25 |
| Urethral discomfort in first 24 hours | Renal and urinary disorders | 2 of 25 |
| Dysuria in first 24 hours | Renal and urinary disorders | 2 of 25 |
| Pelvic tenderness after 24 hours | Renal and urinary disorders | 2 of 25 |
| Pelvic soreness in first 24 hours | Renal and urinary disorders | 1 of 25 |
| Positional light-headedness in first 24 hours | General disorders | 1 of 25 |
| Anxiety in first 24 hours | Psychiatric disorders | 1 of 25 |
| Perineal rash 7 days after injection | Reproductive system and breast disorders | 1 of 25 |
The registry records 0 serious adverse events among 25 participants at risk. It also records 18 participants with other adverse events among 25 at risk. These figures are counts of participants affected, not a description of event severity beyond the serious-versus-other classification. The record lists no top serious-event terms, so the types of serious events are not reported. Deaths are not reported in the registry record.
A recorded count of zero serious adverse events does not establish that the intervention is free of serious risks. General interpretation depends on the size and duration of follow-up, how events were collected and classified, and whether all participants were monitored. Those details are not fully reported in the registry record. Likewise, the count for other adverse events does not identify what happened, when it happened, or whether an event was considered related to the instillation.
These safety counts come from a single-group study. They do not provide a comparative estimate of adverse-event risk against another treatment or a control group. The registry record does not report event-level descriptions or a statistical comparison. The figures should therefore be read as the recorded counts in this study, with substantial limits on what they establish about the nature or comparative frequency of harms.
12. What the Result Does, and Does Not, Mean
The record describes a completed pilot study intended to evaluate bladder instillations of botulinum-A toxin and DMSO in women with symptoms of overactive bladder and secondary urinary incontinence. It specifies a primary symptom measure based on the number of incontinent episodes recorded over 24 hours and assessments at baseline, one month, and three months. It also records adverse-event counts. Those details define the study question and its measurement approach.
The registry record does not report numerical results for the primary endpoint, the proportion of participants with improved symptoms, or the secondary outcomes. It therefore does not show the size or direction of symptom change, the precision of an estimate, or whether any observed change was statistically distinguishable from chance. The record also does not state the criterion used to classify a participant as improved. No conclusion about symptom benefit can be drawn from the objective alone.
The single-group design places an additional limit on causal interpretation. In general, change from baseline may be associated with receiving an intervention, but without a comparison group the change cannot be attributed to the intervention alone. This design does not show how outcomes would compare under another treatment or no instillation. The absence of masking may also matter for participant-reported measures as a general design consideration; the registry record does not report whether expectations affected reporting.
The safety record reports 0 serious adverse events and 18 participants with other adverse events among 25 at risk. These counts do not provide event descriptions or a comparative safety estimate. The study’s enrollment and recorded counts should not be treated as evidence that all possible harms were captured or that risks would be similar in a different population.
In short, the registry record documents a pilot study’s design, endpoint, timing, and some safety counts, but not the efficacy results needed to judge changes in symptoms. It does not establish a causal treatment effect, comparative benefit, or comprehensive safety profile.
13. Why This Trial Matters Statistically
This trial is statistically notable for the gap between a clearly stated clinical aim and the limited outcome information recorded. The primary measure is specified as a median count of episodes over a defined 24-hour window, and follow-up is planned at one month and three months. Those details show how a symptom-focused pilot question can be translated into a measurable endpoint. Yet without the medians, interquartile ranges, or improvement estimate, the central statistical question remains unanswered in the registry record.
The single-group design illustrates the distinction between describing change and estimating a comparative treatment effect. Baseline and follow-up measurements can reveal temporal patterns within a cohort. General causal reasoning, however, requires considering what might have happened to participants in the absence of the intervention. A control group can help address that question; this study’s listed design does not include one. This matters when interpreting any before-and-after result, even if numerical results were available.
The record also highlights the importance of transparent analysis reporting. It identifies multiple outcome measures and analyses, but does not report a multiplicity plan, missing-data methods, analysis populations, or the statistical procedure for the primary endpoint. These details are essential for understanding how estimates were produced and how much confidence to place in them.
Finally, the safety counts demonstrate why event totals need context. Counts without event descriptions, follow-up detail, or a comparison group have limited interpretive reach. The study can be described as a completed pilot with an identified symptom endpoint and recorded safety observations, but the registry information does not support a quantitative assessment of its primary outcome.
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 most immediate limitation is that numerical results for the primary endpoint are not reported in the registry record. The median number of incontinent episodes and its interquartile range are not available, nor is the proportion of participants reported as improved. The improvement definition is also not reported. Without these items, neither the size nor the precision of the primary result can be assessed.
The study is listed as single-group, with no masking and no separate control group. This restricts interpretation to outcomes observed over time within the cohort and limits causal comparisons. The registry record does not report participant characteristics that would clarify how broadly the study population represents women with the listed conditions.
The available intervention description is incomplete. It gives dosing information for some Phase 1 participants but ends before the later regimen is fully described. The complete regimen and details of Phase 2 dosing are not reported in the registry record. The record also does not explain how participants were assigned to any dosing sequence or how regimen differences were handled analytically.
Further limitations arise from missing reporting on endpoint completeness, analysis populations, statistical methods, multiplicity, and the handling of missing data. Although the primary endpoint has defined assessment times, the number of participants contributing at each time point is not reported. The registry record does not describe how the diary records were checked or how incomplete records were treated.
Safety reporting is limited to aggregate counts. Serious-event terms are not listed, deaths are not reported in the registry record, and event-level details are unavailable. These limitations mean the counts cannot characterize event types, timing, attribution, or comparative risk. Together, these reporting gaps prevent a full appraisal of efficacy, precision, and safety.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Botulin-A Toxin Instillations and Overactive Bladder — NCT00583219.
- Registry record last updated 2014-04-21; status last verified 2014-03.
- Results first posted 2014-04-21.
- 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
NCT00583219 is a completed Phase 1 and Phase 2, single-group study sponsored by Mayo Clinic, with enrollment of 25. It assessed bladder instillations of botulinum-A toxin and DMSO in women with symptoms of overactive bladder and secondary urinary incontinence. The primary endpoint was the median number of incontinent episodes during 24 hours, assessed at baseline, one month, and three months.
The registry record does not report numerical primary outcome results, an improvement estimate, or the statistical analysis method. It lists 14 outcome measures and 20 analyses, but does not report how multiplicity or missing data were handled. Safety counts are 0 serious adverse events among 25 at risk and 18 participants with other adverse events among 25 at risk. Serious-event terms are not listed, and deaths are not reported in the registry record.