ProACT Therapy for the Treatment of Stress Urinary Incontinence in Males: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for ProACT Therapy for the Treatment of Stress Urinary Incontinence in Males (NCT00277095), a na na study. The primary outcome is Primary Efficacy: Demonstrate the Efficacy of the ProACT Device in Reducing Incontinence as Measured by the 24-hour Pad Weight at 18 Months Compared to Baseline. A Subject is a Success if he Demonstrates a 50% Reduction..

2. Clinical Question

3. Trial Design

NCT00277095 is a completed, single-group clinical investigation of ProACT adjustable continence therapy. The registry lists Uromedica as sponsor and classifies the intervention as a device. The study concerns urinary incontinence, specifically stress urinary incontinence following prostate surgery. The stated purpose was to evaluate safety and effectiveness in men with intrinsic sphincter deficiency after prostate surgery for cancer or benign prostatic hyperplasia.

The intervention is implantation of two adjustable balloons, positioned one on each side of the urethra. The registry describes one arm: ProACT implantation. It does not identify a concurrent control group. Allocation is listed as NA, masking as NONE, and the model as SINGLE GROUP. Accordingly, the primary efficacy question is framed as a within-participant comparison between baseline pad weight and pad weight at follow-up, rather than as a comparison of outcomes between randomized groups.

The registry reports enrollment of 123. Its brief summary describes the intended study as involving up to 109 male patients. These are distinct figures in the record; the registry does not explain the difference. The study started in 2005-08, had primary completion in 2009-02, and is listed as COMPLETED. Phase is recorded as NA.

The primary outcome is assessed at 18 month follow-up. Success is defined as a reduction of at least 50% in 24-hour pad weight relative to baseline. The specified analysis population is treated participants who reached the 18-month visit, described as an “As followed” analysis. The registry record does not report the number in that population, the number with outcome data, or a numerical efficacy result. It lists one outcome measure and zero analyses.

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:

Analysis population for the primary outcome, as defined in the registry: As followed analysis of all patients who were treated and reached the 18 month follow-up visit

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 Primary Efficacy: Demonstrate the Efficacy of the ProACT Device in Reducing Incontinence as Measured by the 24-hour Pad Weight at 18 Months Compared to Baseline. A Subject is a Success if he Demonstrates a 50% Reduction., measured over 18 month follow-up.

The primary endpoint is the percentage of participants with at least a 50% reduction in 24-hour pad weight at 18 months compared with baseline. Pad weight is an objective measure used in this study to quantify urinary leakage over a defined collection period. The endpoint turns each participant’s change into a binary classification: success if the reduction reaches the stated threshold, and not success otherwise.

A binary endpoint can give a straightforward summary of how many participants meet a clinically specified response criterion. The threshold also makes the definition of success explicit, rather than relying only on a change in the average pad weight. However, a yes-or-no classification does not describe the size of every participant’s change. Participants with reductions of different magnitudes may be counted alike if both meet the threshold, while a participant just short of the threshold is classified differently from one just over it.

The analysis population is described as treated participants who reached the 18-month visit. This defines a follow-up-based group, not necessarily everyone enrolled or treated. The registry record does not report the number reaching that visit, the observed percentage meeting the threshold, or the associated 95% confidence interval. Thus, the endpoint definition is available, but its estimated result and precision cannot be assessed from the recorded efficacy information.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The statistical interpretation starts with the endpoint’s structure. It is binary: a participant either meets the defined threshold for success or does not. The threshold is at least a 50% reduction in 24-hour pad weight at the 18-month visit compared with baseline. A percentage for this endpoint would describe the share of the analysis population meeting the criterion. The registry record identifies the measure and timeframe, but does not report the observed percentage.

What does a confidence interval describe?

A confidence interval expresses uncertainty around an estimated quantity. For a binary percentage, it gives a range of values compatible with the observed data under the method used to calculate the interval. A narrower interval indicates greater precision; a wider interval indicates less precision. The interval does not describe the range of individual participants’ outcomes, and it does not correct for limitations in study design or missing follow-up. The registry lists a 95% confidence interval as the endpoint’s dispersion measure, but does not report the interval’s limits or the estimate it would accompany. Therefore, neither the endpoint’s estimated level nor its precision can be evaluated from the efficacy entry.

Why does the single-group design matter?

In a single-group study, a baseline measurement can serve as a reference for later measurements in the same participants. This allows a description of change over time among those followed. It does not provide the same basis for comparison as a concurrent control group, because the observed change may reflect influences other than the intervention. General examples include changes in measurement conditions or participants’ circumstances over time; the registry record does not say whether any particular influence occurred in this study. This distinction is important: a change from baseline is a within-group observation, not by itself an estimate of the difference that would have occurred with another treatment or no intervention.

The design is recorded as SINGLE GROUP, allocation as NA, and masking as NONE. No randomized comparison is reported. There is consequently no between-arm treatment contrast to interpret in the registry’s primary efficacy entry. The word “success” refers to meeting the protocol-defined pad-weight threshold, not to a demonstrated comparison against another group.

What does the analysis population imply?

The primary population is described as an “As followed” analysis of all patients who were treated and reached the 18-month follow-up visit. This means the stated denominator is limited by both treatment and attendance at that visit. It is not automatically the same as the enrollment count. The registry record does not state how many participants reached the visit or had a valid pad-weight measurement. It does not describe how missing measurements were handled, whether any participants were excluded after reaching the visit, or how incomplete records were treated.

In general, missing outcome data can affect both the estimate and its interpretation if participants with observed follow-up differ from those without it. The direction and magnitude of any such effect cannot be determined without information about follow-up and the missing-data approach. No method for imputing missing values, sensitivity analysis, or alternative analysis population is reported in the registry record.

How should sample-size planning be read?

Sample-size calculations are planning tools. They estimate how many participants a future comparison would require under specified assumptions; they are not a measure of the probability that a completed study’s result is correct, and they do not establish that a study had adequate power after the fact. The planning assumptions described for the accompanying illustration are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The illustration is based on a stated fraction of an observed effect. No sample-size output or numeric observed efficacy estimate is reported in the registry entries available for this analysis, so a numerical planning result cannot be interpreted.

There is also an important distinction between that generic two-arm planning framework and this registry’s recorded single-group design. A planning illustration based on two arms does not turn the actual study into a randomized or controlled comparison. Any such calculation should be understood as a conditional planning exercise, not as an observed result or evidence of a treatment effect. The record does not report the study’s own sample-size justification or design assumptions.

What can be said about multiplicity?

The registry lists one outcome measure and zero analyses. That tells readers what is recorded in this entry, not whether the study protocol included additional endpoints, time points, interim looks, or analytical choices. The registry record does not report a multiplicity adjustment or a plan for controlling false-positive findings across multiple analyses. No statistical analysis plan is reported. With no numerical efficacy analysis posted, there is no reported test statistic or p-value to interpret.

These methods considerations frame the information available: a defined binary endpoint, a specified follow-up-based population, and a single-group design, with no posted efficacy estimate or interval. General statistical concepts explain what the intended summaries would mean, but they cannot fill in results that are not reported in the registry record.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Urine Loss ( in Grams)")
n      <- c(99)
events <- c(60)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Urine Loss ( in Grams)  99  60  60.6  50.3  70.3  50.8  69.7  50.7  69.7

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome measure and zero analyses. The primary measure is the percentage of treated participants who reached the 18-month visit and had at least a 50% reduction in pad weight from baseline. The record does not report a multiplicity plan, such as how inference would be handled if several outcomes, time points, subgroups, or analyses were considered. It also does not report whether interim analyses were planned or conducted. The absence of these details in the registry record should not be read as evidence that no such plans existed.

The stated primary population is “As followed”: treated participants who reached the 18-month follow-up visit. This approach does not necessarily include every enrolled participant. The record gives enrollment as 123, but does not report how many participants received the intervention, reached the visit, or had evaluable pad-weight data. It does not describe reasons for missed visits, withdrawals, or missing measurements.

No missing-data method is reported. In particular, the registry does not describe imputation, assumptions about missing outcomes, sensitivity analyses, or comparisons between participants with and without follow-up data. These omissions limit assessment of how representative the followed population may be of those enrolled or treated. They also prevent evaluation of whether missingness could influence the estimated percentage meeting the success threshold.

The record does not report a statistical analysis plan or numerical analysis results. It is therefore not possible to determine from the registry entry whether the outcome definition, population, and analysis approach were prespecified in a detailed plan or whether other analyses were performed.

12. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: cva (0.8%), low heart rate (0.8%), ulcerative colitis (0.8%), sepsis (0.8%).

The registry’s safety listing reports one ProACT group, with 124 at risk in both the serious-event and other-event entries. It records 4 affected under serious events and 112 affected under other events. These are the counts as listed in the registry; the entry does not provide event-level timing, duration, recurrence, or a detailed account of how affected participants were counted.

Four serious-event terms are listed: CVA, Low Heart Rate, Ulcerative Colitis, and Sepsis. Each term is accompanied by 0.8%. These percentages should be read as the registry’s reported values for the listed terms, not added together to make a total. The record does not explain whether a participant could contribute to more than one term or provide additional detail on the clinical course of these events.

The serious and other-event categories are distinct registry listings and should not be treated as measures of the primary efficacy outcome. The entry does not state whether events were considered related to the device or procedure. Deaths are not reported in the registry record. These safety figures are descriptive and do not, on their own, establish comparative risk because no control group is reported.

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

The registry record establishes what the investigators intended to measure: the percentage of treated participants reaching 18-month follow-up who achieved at least a 50% reduction in 24-hour pad weight compared with baseline. It also describes the device procedure and reports selected safety counts. It does not provide the observed primary efficacy percentage or its 95% confidence interval. Without those values, readers cannot assess the recorded magnitude or statistical precision of the primary endpoint result.

The endpoint’s threshold provides a clear definition of success, but it is not a complete account of every participant’s outcome. It does not show the amount of pad-weight change for each participant, or distinguish degrees of improvement among those who meet the threshold. The registry record also does not provide a continuous summary of pad-weight change or additional time-point results.

The single-group design permits a description of outcomes among participants followed after treatment, but does not provide a concurrent control comparison. A baseline-to-follow-up difference, if reported, would not alone establish what would have happened under an alternative approach. This is a general interpretation of the design, not a statement about the cause of any individual outcome.

The safety entries indicate that serious and other events were recorded among the ProACT group, including the four serious-event terms listed at 0.8% each. They do not give a full safety profile, comparative rates, or causal attribution. The registry record also does not report the number of participants followed for the primary endpoint or its handling of missing data.

Accordingly, the record supports a description of the study design, endpoint definition, analysis population, and selected adverse-event entries. It does not support a numerical interpretation of primary efficacy, an assessment of its precision, or a comparative conclusion about the device.

14. Why This Trial Matters Statistically

This study illustrates how a registry can define an endpoint more fully than it reports the endpoint’s result. The primary measure is specific: a threshold reduction in 24-hour pad weight at 18 months relative to baseline. That definition allows readers to understand what was intended to count as success. But the registry’s listed outcome metadata is not accompanied by the observed percentage or its confidence interval, so the principal efficacy estimate cannot be evaluated.

The study also highlights the difference between a within-participant comparison and a controlled comparison. Each participant’s baseline measurement is the reference for the endpoint, but there is no concurrent comparator arm in the recorded design. This distinction matters when describing an observed change: it is a change over time in a followed group, not a direct estimate of how outcomes differ between treatment strategies.

The choice of an “As followed” population makes follow-up information essential for interpretation. The registry states that the analysis concerns participants who were treated and reached the 18-month visit, yet does not report how many reached that visit or how missing measurements were addressed. These details affect a reader’s ability to understand the denominator and assess how much the result might depend on follow-up.

Finally, the safety listings show why counts and event terms need context. The registry records serious and other affected counts and names four serious-event terms, but does not supply event narratives, causality assessments, or a control group for comparison. Statistical interpretation requires not only a defined measure, but also a reported estimate, its uncertainty, the analysis population, and enough design information to clarify what comparisons the data can support.

15. 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 direct limitation of the registry entry is that it does not report a numerical primary efficacy result. Although the endpoint is defined and a 95% confidence interval is identified as the dispersion measure, neither the estimated percentage nor the interval limits appear in the recorded outcome information. The number of participants in the stated 18-month analysis population is also not reported.

The study is recorded as single-group, with no concurrent comparator. This limits the kinds of comparisons that can be made: the registry entry does not provide a randomized contrast or a control-group estimate. Its primary endpoint compares follow-up with baseline within participants, which is a different question from comparing outcomes under alternative groups.

The enrollment figures are not explained in relation to one another. The registry lists enrollment of 123, while the brief summary describes an intended study of up to 109 male patients. The record does not clarify why these figures differ. It also does not report how many participants were treated, how many reached the 18-month visit, or how many contributed a valid endpoint measurement.

Additional limitations include the absence of a reported statistical analysis plan, missing-data approach, multiplicity strategy, interim-analysis information, or sample-size justification. These items are not reported in the registry record; their absence from the entry does not establish what was or was not done outside the record. Safety reporting is also limited to the listed counts and terms, without event narratives, causality assessments, or a reported death count.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: ProACT Therapy for the Treatment of Stress Urinary Incontinence in Males — NCT00277095.
• Registry record last updated 2018-05-31; status last verified 2018-04.
• Results first posted 2016-02-03.
• 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.

19. Record Summary

NCT00277095 is a completed, single-group device study sponsored by Uromedica, evaluating ProACT adjustable continence therapy for stress urinary incontinence after prostate surgery. The intervention is implantation of two adjustable balloons, one on each side of the urethra. The registry lists enrollment of 123 and describes an intended study of up to 109 participants; it does not explain the difference. Study start is recorded as 2005-08 and primary completion as 2009-02.

The primary endpoint is the percentage of treated participants reaching 18-month follow-up with at least a 50% reduction in 24-hour pad weight from baseline. The registry identifies a 95% confidence interval but does not report the efficacy estimate, interval, or analysis population size. It lists 4 affected under serious events and 112 under other events among 124 at risk, with four serious-event terms listed at 0.8% each. No concurrent comparator is reported.