Treatment of Incontinence Without Memory Problems: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Treatment of Incontinence Without Memory Problems (NCT02436889), a randomized phase 4 study. The primary outcome is The Number of Participants Who Completed and Discontinued the Study.

2. Clinical Question

The trial asks a feasibility question about retaining participants through an 8-week comparison of mirabegron and tolterodine tartrate. Its primary outcome is the number of participants who completed and discontinued the study from baseline to Week 8, described in the registry as an assessment of retention rates. This outcome concerns whether participants remain in the study; it is not itself a measure of change in urinary incontinence or memory.

The population is described as elderly women with urgency urinary incontinence. The registry title refers to incontinence without memory problems, and the listed conditions are urge incontinence and urinary incontinence, urge. The record does not give a fuller eligibility description or demographic breakdown, so the population cannot be characterized more specifically from the registry record.

Participants were assigned to mirabegron or tolterodine tartrate, identified in the brief summary as Detrol LA and a standard anticholinergic therapy. The study also listed changes in cognitive test scores, physical performance, and urinary incontinence frequency as secondary outcomes. Those measures indicate that the trial assessed more than retention, but their numerical results are not reported in the registry record.

The question should therefore be read as a pilot feasibility comparison, not as a complete assessment of comparative clinical effects. The registry record does not report the completion and discontinuation counts by arm, a single primary comparison, or numerical secondary-outcome findings. Without those results, the posted information does not establish how retention differed between groups or how the measured secondary outcomes changed.

3. Trial Design

This was a Phase 4, randomized, triple-masked, parallel-group pilot clinical trial. The brief summary describes an 8-week controlled comparison of mirabegron with standard anticholinergic therapy in elderly women with urgency urinary incontinence. The listed interventions are mirabegron and tolterodine tartrate. The registry gives the sponsor as the University of California, San Francisco, and records the study status as completed.

The trial enrolled 23 participants. The adverse-event listings identify 12 participants at risk in the mirabegron group and 11 in the tolterodine tartrate group. Those figures describe the denominators used for the posted adverse-event counts; the registry record does not provide a separate account of participant flow, withdrawals, or the number completing each outcome assessment.

Random allocation is intended, in general, to reduce systematic differences between groups at enrollment. Masking is intended, in general, to limit the influence of expectations on care, reporting, or assessment. The registry labels the trial randomized and triple-masked, but details of the allocation sequence, concealment, and which parties were masked are not reported in the registry record. The parallel-group designation means the two treatment groups were compared over the study period rather than described as successive treatment periods for each participant.

The registry lists six outcome measures and six analyses, including the primary retention outcome and secondary measures of cognition, physical performance, and urinary symptoms. The statistical analysis plan, analysis populations, and methods used for those analyses are not reported in the registry record. Enrollment and study dates are recorded as 2016-02 for study start and 2017-12 for primary completion. No further design rationale or sample-size justification is 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

Reasons for not completing this period:

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as The Number of Participants Who Completed and Discontinued the Study, measured over Baseline to Week 8.

The primary endpoint is titled “The Number of Participants Who Completed and Discontinued the Study.” Its measurement unit is participants, and its stated timeframe is baseline to Week 8. The registry describes the purpose as assessing feasibility through retention rates. In practical terms, the endpoint is intended to describe whether participants remained in the study or discontinued during the specified period.

A retention outcome is useful in a pilot study because it helps characterize whether participants can be followed through the planned study period. In general, completion and discontinuation counts can also help readers understand how much outcome information may be available for later comparisons. Counts alone, however, do not explain why participants discontinued, when discontinuation occurred, or whether missing outcome measurements were handled in a particular way.

The posted registry record does not report the number who completed or discontinued in either group, nor does it give a single numerical comparison for this primary outcome. It therefore does not support a numerical estimate of retention by treatment group. The outcome title refers to both completion and discontinuation, while the stated purpose refers to retention; the exact categories and their reporting format are not further described in the registry record. The primary endpoint should not be mistaken for an efficacy measure of urinary symptoms or cognition.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Randomization, masking, and a parallel-group structure describe different parts of a trial’s design. Randomization assigns participants to groups by chance, with the general aim of limiting systematic differences at the start of a comparison. Masking is intended to reduce the influence of knowledge about assignment on treatment, assessment, or reporting. A parallel-group design compares participants assigned to separate groups over the study period. The registry identifies this study as randomized, triple-masked, and parallel, but does not report the sequence-generation method, concealment procedures, or the identities of the masked parties.

What does the primary outcome measure?

The primary outcome is a count of participants who completed and discontinued the study, with a baseline-to-Week 8 timeframe. The registry describes it as a feasibility assessment of retention. A count is a direct way to describe how many participants fall into a category, but its interpretation depends on clearly defined categories and denominators. The registry record does not provide the group-specific counts, explain the category definitions in further detail, or report reasons for discontinuation. It also does not state whether the primary comparison used counts, a retention rate, or another summary.

How should counts and comparisons be distinguished?

General statistical context: a count reports how many observed participants or events fall into a category. A rate or proportion relates a count to a specified denominator. A comparison between groups requires a stated estimand and analysis method; merely listing counts does not show whether any observed difference is compatible with chance variation. The registry reports adverse-event counts and the numbers at risk, but does not report a statistical comparison for those counts. For the primary endpoint, even the group-specific counts are not reported.

What can uncertainty estimates add?

General statistical context: a confidence interval describes a range of values compatible with the data and the method used to calculate it. Its width conveys precision: a wider interval generally reflects greater uncertainty, while a narrower interval reflects greater precision under the assumptions of the analysis. A confidence interval does not by itself prove that an effect is real or important. The registry record does not report confidence intervals for the primary or secondary outcomes, so precision cannot be assessed from the posted results.

What does the sample-size planning information mean?

The record describes a planning illustration based on an observed effect, rather than the trial’s own design justification. Its stated assumptions include a two-sided significance level of 0.05, equal allocation between groups, and a normal approximation. The illustration describes the effect to detect as a stated fraction of the observed effect. It also distinguishes planning quantities for time-to-event outcomes, which are total event counts, from other outcomes, which are participants per arm. No numerical planning results or specific effect fractions are reported in the registry record. Such planning quantities are illustrations, not observed trial outcomes, and do not establish the trial’s actual power or explain how its enrollment was selected.

Why can outcome distributions matter?

General statistical context: statistical methods rely on assumptions about the form and variability of the data. For count outcomes, values may be more variable than a simple model expects; this is called over-dispersion. If over-dispersion is present and not accommodated, standard errors may be too small and uncertainty may be understated. The registry record does not report the distributions of the outcome data or whether over-dispersion was assessed. It therefore does not support a conclusion about which count model, if any, would have been appropriate.

What is not specified about the analyses?

The registry lists six outcome measures and six analyses, but does not report the model specifications, covariates, handling of repeated measurements, missing-data methods, or analysis populations. It also does not identify whether the analyses followed an intention-to-treat approach or another population definition. These choices can affect both the estimate and its interpretation. They should not be inferred from the trial’s randomized design or from the outcome names. The statistical plan and sample-size justification are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists six outcome measures and six analyses, including a primary retention outcome and secondary cognitive, physical-performance, and urinary-symptom outcomes. When a study examines multiple outcomes or makes multiple comparisons, the chance of at least one apparently unusual result can increase. General statistical context: multiplicity procedures can address this issue by adjusting how evidence is evaluated or by defining a hierarchy of outcomes in advance. The registry record does not report a multiplicity strategy, an outcome hierarchy beyond identifying the primary outcome, or which analyses were considered confirmatory.

Missing data matter because participants may not complete every assessment, and outcome values may be unavailable even for participants who remain in a study. The primary outcome itself concerns completion and discontinuation, but the registry does not report those counts by group. It also does not describe missingness for the secondary outcomes, reasons for missing measurements, or methods used to handle missing data. General statistical context: methods for missing data rely on assumptions about why information is absent; different assumptions can lead to different estimates. No such assumptions are reported in the registry record.

The registry does not specify the analysis population for any outcome. In general, an analysis population defines which participants contribute to a particular estimate and how deviations from assigned treatment or incomplete follow-up are handled. Randomization alone does not tell readers which population was analyzed. The statistical analysis plan, the treatment of protocol deviations, and the handling of incomplete observations are not reported in the registry record. These omissions limit assessment of how the listed outcomes were analyzed and how robust any unreported findings might be.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent non-serious adverse event terms

The registry reports serious adverse events separately from other adverse events. In the mirabegron group, 12 participants were listed as at risk, 0 as affected by a serious adverse event, and 5 as affected by another adverse event. In the tolterodine tartrate group, 11 participants were listed as at risk, 0 as affected by a serious adverse event, and 6 as affected by another adverse event. The registry reports 0 deaths in each group.

These figures are counts, not estimates of comparative risk. The record does not provide a statistical comparison, event-level descriptions for the other adverse events, or serious-event terms; the list of top serious terms is empty. It is therefore not possible to characterize the nature or severity of the other events from this record or to determine whether the groups differ. Zero reported serious adverse events means none were recorded in the posted group listings; it does not establish that no event could occur or that risks are equivalent. The small enrollment also means these counts provide limited information about uncommon events. Safety interpretation should remain descriptive and confined to the categories and counts recorded.

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

The posted information establishes that this was a completed, randomized, triple-masked, parallel-group pilot trial of mirabegron versus tolterodine tartrate in elderly women with urgency urinary incontinence. The study enrolled 23 participants and followed a stated 8-week treatment period. Its primary outcome was designed to assess feasibility through study completion and discontinuation from baseline to Week 8. The registry also lists cognitive, physical-performance, and urinary-symptom outcomes.

What the record does not establish is the actual primary outcome result. It does not give the number completing or discontinuing in each group, or a single numerical comparison for retention. It also does not report the numerical findings for the listed secondary outcomes. Without those estimates, there is no basis in the posted results for describing the size, direction, or precision of comparative changes in memory testing, physical performance, or urinary symptoms.

The adverse-event listings show no reported serious adverse events and no deaths in either group, alongside other adverse events affecting 5 participants receiving mirabegron and 6 receiving tolterodine tartrate. These descriptive counts do not demonstrate that one treatment is safer, nor do they establish an absence of risk. The registry does not provide detailed event terms or statistical comparisons.

General statistical context: a pilot trial can inform the feasibility of conducting a larger study, but its results do not automatically settle questions about comparative benefit or harm. Here, the record does not provide retention results, outcome estimates, precision measures, or a statistical analysis plan. It should therefore be read as a record of a small comparative pilot with incomplete posted outcome detail, rather than as sufficient evidence for conclusions about treatment effects. No treatment recommendation follows from these registry entries.

13. Why This Trial Matters Statistically

This trial is statistically notable because its stated primary aim is feasibility and retention, while the registry also lists outcomes spanning cognition, physical performance, and urinary symptoms. Those measures represent distinct domains and may require different summaries and analysis methods. A clear distinction between the retention question and the secondary clinical measurements is important: completion is an aspect of study conduct, whereas symptom and test-score changes describe participant outcomes.

The enrolled population was 23 participants. In a pilot of this size, estimates can be uncertain, especially for outcomes that are divided between treatment groups or for uncommon events. General statistical context: uncertainty is best evaluated using estimates alongside measures of precision, such as confidence intervals, rather than by treating a count or a significance threshold as definitive. The registry record does not report such precision measures for the listed outcomes.

The record also illustrates why outcome reporting needs more than outcome names. To interpret a primary retention endpoint, readers need the group-specific counts, clear category definitions, and information about participant flow. To interpret secondary outcomes, readers need the observed estimates, analysis populations, missing-data handling, and methods used for comparison. Those details are not reported in the registry record.

Finally, the listed outcomes create a multiplicity question because several measures were analyzed, yet the record does not state how multiple comparisons were handled. This does not establish that the analyses were inappropriate; it means their inferential framework cannot be evaluated from the posted information. The trial’s statistical importance lies partly in these reporting needs: feasibility studies can be informative when their aims, denominators, uncertainty, and analysis choices are described transparently.

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 registry record does not report the primary outcome counts by group, despite identifying completion and discontinuation as the primary outcome. It also does not provide numerical results for the cognitive, physical-performance, or urinary-symptom outcomes. This prevents assessment of effect direction, magnitude, or precision for the outcomes named in the record.

Participant flow is not described in detail. The record does not report when or why participants discontinued, how many completed each assessment, or how missing outcome data were handled. The adverse-event denominators are listed, but they do not substitute for a full accounting of follow-up and analysis populations.

The record identifies the trial as randomized and triple-masked, but does not describe the randomization procedure, allocation concealment, or which parties were masked. It does not report the statistical analysis plan, sample-size justification, model choices, covariate adjustments, or multiplicity strategy. These omissions make it difficult to assess the planned inferential approach or whether outcome analyses followed a prespecified plan.

The enrollment of 23 participants limits the amount of information available, particularly for uncommon events and for comparisons across multiple outcomes. The safety record is descriptive and gives no event terms for the other adverse events or comparative analysis. Study dates, sponsor, design labels, and outcome listings are available, but these do not resolve the missing result and methods details. These limitations concern what can be learned from the registry record; they do not establish that unreported procedures or analyses were not conducted.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Treatment of Incontinence Without Memory Problems — NCT02436889.
• Registry record last updated 2019-04-16; status last verified 2019-03.
• Results first posted 2019-04-16.
• 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.

18. Record Summary

The registry record describes NCT02436889, “Treatment of Incontinence Without Memory Problems,” as a completed Phase 4 randomized, triple-masked, parallel-group pilot trial sponsored by the University of California, San Francisco. It enrolled 23 participants and compared mirabegron with tolterodine tartrate over an 8-week period in elderly women with urgency urinary incontinence.

The primary outcome was the number of participants who completed and discontinued the study from baseline to Week 8, intended to assess retention. Six outcome measures and six analyses are listed, including cognitive, physical-performance, and urinary-symptom outcomes. Group-specific primary results and numerical secondary-outcome results are not reported in the registry record.

The adverse-event listings report 0 serious adverse events and 0 deaths in each group. Other adverse events affected 5 participants in the mirabegron group and 6 in the tolterodine tartrate group. The statistical plan, missing-data methods, analysis populations, and sample-size justification are not reported in the registry record.