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 Prostate Artery Embolization (PAE) for Lower Urinary Tract Symptoms (LUTS) Due to Benign Prostatic Hyperplasia (BPH) (NCT02930889), a na na study. The primary outcome is Number of Adverse Events Reported.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02930889 |
| Phase | NA |
| Condition | Benign Prostatic Hyperplasia |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 21 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Minnesota |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns people with benign prostatic hyperplasia (BPH), a condition associated in the registry description with lower urinary tract symptoms (LUTS). The registry record lists an enrollment of 21. It does not report further eligibility details or a description of the participants’ baseline symptom severity.
Intervention
The intervention was prostate artery embolization (PAE), listed as a device intervention. The registry describes it as a procedure in which embolizing particles are injected into a target blood vessel to occlude blood flow. The study is described as an investigator-initiated evaluation of safety and efficacy.
Comparator
There was no reported comparator group. The registry identifies the study model as single group, and allocation is not reported in the registry record. The PAE group therefore cannot be read as a randomized comparison with another treatment or with no treatment.
Primary question
The primary endpoint was the total number of adverse events reported during a timeframe of 3 Months. Events were to be collected through self-report and medical records and reviewed. The study also lists a secondary outcome concerning efficacy measured by a Medical Therapy of Prostatic Symptoms Questionnaire or flow rate change, but results for that outcome are not reported in the registry record. The primary outcome describes reported events; by itself it does not establish whether PAE caused them or how its safety compares with another approach.
3. Trial Design
The registry describes a completed, single-group study of prostate artery embolization for lower urinary tract symptoms due to benign prostatic hyperplasia. The listed sponsor is the University of Minnesota. The study began on 2016-10-01, and its primary completion date is 2020-10-31. Enrollment is listed as 21. The record does not describe a randomized allocation or a separate control group, so the design does not support a direct treatment-versus-control comparison.
PAE is listed as the intervention, with a description of particles being injected into a target blood vessel to occlude blood flow. Masking is recorded as none. The phase is listed as NA, which is not a reported phase designation. Additional details about recruitment, eligibility, treatment delivery, follow-up visits, and protocol deviations are not reported in the registry record.
The primary outcome is the number of adverse events reported over 3 Months. Collection is described as using self-report and medical records, with all events collected and reviewed. The registry also lists an efficacy outcome assessed by a Medical Therapy of Prostatic Symptoms Questionnaire or flow rate change. The corresponding outcome results are not reported in the registry record. Although five outcome measures are listed, the record does not provide five outcome results in the information summarized for this analysis.
The registry lists no analyses. It does not report the statistical analysis plan, a sample-size justification, interim analyses, or the approach to incomplete follow-up. The enrollment count is not evidence that a particular sample-size target was met, since the rationale and target are not reported in the registry record. The single-group structure is central to interpretation: event counts can describe what was recorded among participants assessed, but they cannot separate treatment-related events from events that might have occurred for other reasons.
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 | Prostate Artery Embolization |
|---|---|
| STARTED | 21 |
| COMPLETED | 5 |
| NOT COMPLETED | 16 |
Reasons for not completing this period:
| Reason | Prostate Artery Embolization |
|---|---|
| Lost to Follow-up | 2 |
| Withdrawal by Subject | 6 |
| Did not meet inclusion/exclusion criteria | 8 |
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: All participants from whom data was collected are included.
| Characteristic | Unit | Prostate Artery Embolization |
|---|---|---|
| Participants analysed | 5 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 2 |
| Age, Categorical: >=65 years | Participants | 3 |
| Age, Continuous | years | 67.2 (SD 9.3) |
| Sex: Female, Male: Female | Participants | 0 |
| Sex: Female, Male: Male | Participants | 5 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 5 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | participants | 5 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Adverse Events Reported, measured over 3 Months.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | adverse events |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the total number of adverse events reported during 3 Months. The registry says events are collected by self-report and medical record and reviewed. This endpoint is a count: it describes the recorded volume of events, rather than a change in symptoms or a comparison between treatment groups. The registry does not provide a breakdown of all events, their timing, severity, duration, or whether they were judged related to PAE.
Counting adverse events is one way to describe safety experience during a defined follow-up period. It can capture more than one event for a participant, so an event count is not automatically the same as a count of participants who experienced an event. A participant-level count answers how many people had at least one event; an event-level count answers how many events were recorded. The primary endpoint is explicitly described as the total number of events, but the total result is not reported in the registry record.
For this reason, the posted safety figures for participants affected should not be substituted for the primary endpoint’s total event count. Nor do the available figures establish the event rate over time: the registry does not report person-time or sufficient follow-up detail to characterize that quantity. The endpoint can help characterize reported safety experience, but without a comparator and fuller event details it cannot by itself establish causation or comparative safety.
The listed secondary outcome concerns efficacy measured by a Medical Therapy of Prostatic Symptoms Questionnaire or flow rate change. Results for that outcome are not reported in the registry record. Consequently, the primary endpoint should be read as a safety-focused count outcome, not as a measure of symptom improvement.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a single-group study with enrollment of 21 and a primary adverse-event timeframe of 3 Months. The safety figures list 5 participants at risk in the PAE group for serious adverse events and 1 affected; for other adverse events, 5 were at risk and 4 were affected. Deaths are listed as 0. These figures describe the posted safety record, but the small at-risk group means they represent a limited set of participants rather than the full enrollment listed for the study. The reason for that difference is not reported in the registry record.
The serious adverse event listing names Prostate Cancer at 20.0% among the top serious terms. The record does not provide enough detail to determine how the term was defined, when it occurred, whether it was judged related to PAE, or how the percentage was calculated. It should therefore be read as a registry-reported term and percentage, not as evidence that PAE caused the event. The affected count and the event term also describe different kinds of information: one is a participant count, while the other is a coded event category.
There is no control group against which to compare these observations. Even a clear count of events in a single group would not show what the count would have been without PAE or under another treatment. Differences in underlying health, background events, ascertainment, or follow-up could affect what was recorded; details to evaluate those factors are not reported in the registry record. No causal or comparative conclusion follows from the event counts alone.
The primary endpoint is a total number of adverse events, but the total result is not reported in the registry record. The safety summary gives participant counts affected by serious and other adverse events, which is useful but is not interchangeable with a total event count. The registry also lists a secondary efficacy outcome based on a symptom questionnaire or flow rate change, but its result is not reported in the registry record. Thus the available information supports a description of the design and selected safety counts, not a complete assessment of the primary endpoint or efficacy.
The registry lists no analyses. It does not report confidence intervals, hypothesis tests, adjusted estimates, or an analysis population for these outcomes. Without those details, the precision of the results cannot be fully evaluated. A small number at risk also means that each participant’s experience can substantially shape the observed counts, while the registry’s limited reporting prevents a fuller account of outcome completeness. These limitations argue for a restrained reading: the posted figures document events recorded in the study, but do not establish treatment effect, comparative safety, or the likelihood of similar outcomes in a broader population.
9. Statistical Methods Explained
The registry identifies the study model as single group. In general, a single-group study observes outcomes among participants who receive the intervention without a concurrent control group. Such a design can describe what was recorded during the study, but it cannot directly estimate how outcomes would differ under another treatment or no treatment. This distinction matters for adverse events: an event observed after an intervention is not automatically an event caused by it. The registry does not report a comparative analysis or a method for attributing events to PAE.
What a count endpoint describes
The primary outcome is a count of adverse events reported during 3 Months. In general, a count records how many events occur, not necessarily how many people experience them. One person may contribute more than one event, while another may contribute none. A participant-level measure such as the number affected answers a different question from the total number of events. The registry gives selected participant counts for serious and other adverse events, but the total primary outcome result is not reported in the registry record.
Counts can vary according to the period of observation and the way events are identified and coded. The registry says collection used self-report and medical records and that all events would be reviewed. Details on coding rules, event adjudication, severity grading, relatedness assessment, and completeness of collection are not reported in the registry record. Without those details, readers cannot determine how consistently events were classified or whether some events may have been missed.
Why over-dispersion can matter
In general, count data may vary more than a simple statistical model expects, a feature called over-dispersion. For example, events can cluster in a small number of people rather than being evenly distributed. When over-dispersion is present, a model that assumes less variability may give uncertainty estimates that are too small. Appropriate choices depend on the data structure and analysis plan. The registry does not report a count model, dispersion estimate, or statistical method for the primary outcome, so it is not possible to tell whether over-dispersion was assessed or how it was handled.
For event counts, exposure time can also matter: participants followed for different lengths of time may have different opportunities to report events. In general, an analysis may account for person-time when that information is available and relevant. The registry specifies a 3 Months timeframe for the primary outcome but does not report participant-level follow-up durations or person-time. No event rate should be inferred from the listed counts alone.
Precision and statistical evidence
In general, a confidence interval describes a range of values compatible with the observed data under the assumptions of the analysis. It conveys uncertainty, rather than a guarantee about where the true value lies. No confidence interval for the primary outcome or the posted safety counts is reported in the registry record. The record also lists no analyses and does not report a hypothesis test or p-value. Statistical significance therefore cannot be assessed from the registry information.
Precision depends on the amount and variability of the observed information, as well as on the design and analysis. The safety figures list 5 participants at risk for each of the serious and other adverse-event categories. Those counts are limited in scope, and the record does not explain why the at-risk group differs from the enrollment of 21. Without an analysis population definition or account of missing follow-up, the relationship between the at-risk counts and the full study enrollment remains unclear.
Design and analysis choices
Random allocation, when used, can help balance participant characteristics between comparison groups on average. This study is not reported as a randomized comparison, and there is no comparator group. Statistical adjustment cannot fully replace a concurrent control when the goal is a causal treatment comparison, especially when relevant covariates and the adjustment strategy are not reported. The record does not state whether any covariate adjustment was planned or performed.
Enrollment is listed as 21, but the sample-size justification and target are not reported in the registry record. A study’s enrollment count alone does not show that it had adequate precision for every outcome. Any sample-size planning illustration based on an observed effect is not observed power and does not establish that the study was designed to detect a particular clinically meaningful difference. No protocol-based power calculation is reported in the registry record.
The listed secondary outcome involves a Medical Therapy of Prostatic Symptoms Questionnaire or flow rate change. In general, a questionnaire outcome and a flow measure can capture different aspects of a clinical question and require clear outcome definitions, assessment timing, and analysis rules. Those details and the results are not reported in the registry record. Accordingly, the statistical evidence available for interpreting efficacy is insufficient to describe an effect estimate or its precision.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists five outcome measures, including the primary count of adverse events and a secondary efficacy outcome involving a Medical Therapy of Prostatic Symptoms Questionnaire or flow rate change. It lists no analyses. The statistical plan, including whether outcomes or analyses were prioritized beyond the primary designation, is not reported in the registry record.
In general, multiplicity arises when several outcomes, timepoints, subgroups, or statistical tests are examined. Considering many results can increase the chance of finding an apparently notable result by chance. Methods such as prespecifying a primary outcome or adjusting for multiple tests can help interpret this issue, but the registry does not report a multiplicity strategy. The presence of several listed outcome measures does not establish that all were analyzed or that any adjustment was applied.
Missing-data handling is also not reported in the registry record. The enrollment is 21, while the safety summary lists 5 participants at risk for serious adverse events and 5 at risk for other adverse events. The record does not explain why these counts differ, whether they refer to a defined analysis population, or whether follow-up or outcome information was incomplete. The reason should not be inferred from the counts alone.
The registry does not report an intention-to-treat population, a per-protocol population, exclusions, withdrawals, or imputation methods. In general, these choices affect which participants contribute to an estimate and how incomplete observations are handled. Without these details, the completeness and representativeness of the reported safety figures cannot be assessed. Results for the listed secondary efficacy outcome are not reported in the registry record, so its missingness and analysis population also cannot be evaluated.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Prostate Artery Embolization | 1 | 5 | 20.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Prostate Artery Embolization | 0 of 5 |
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 |
|---|---|
| Prostate Artery Embolization | 4 of 5 |
Most frequent serious adverse event terms
| Event term | Organ system | Prostate Artery Embolization |
|---|---|---|
| Prostate Cancer | Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 1 of 5 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Prostate Artery Embolization |
|---|---|---|
| Loose Stool | Gastrointestinal disorders | 1 of 5 |
| Burning Sensation While Urinating | Renal and urinary disorders | 1 of 5 |
| Post Procedure Penile Pain | Reproductive system and breast disorders | 1 of 5 |
| Blood in Urine | Renal and urinary disorders | 1 of 5 |
Serious events with the highest arm-level rate: prostate cancer (20.0%).
The serious adverse event summary lists 5 participants at risk, 1 affected, and 0 deaths for the PAE group. The other adverse event summary lists 5 at risk and 4 affected. These are participant counts in the posted safety record, not a complete description of every event. The primary outcome is a total event count, and that total is not reported in the registry record.
The serious-event term shown is Prostate Cancer at 20.0%. The registry does not report the event’s timing, clinical details, severity criteria, attribution to treatment, or the method used to calculate this percentage. The term should be read as a coded safety listing, not as proof that the intervention caused the condition. The record also does not explain why only 5 participants are listed at risk when enrollment is 21.
In general, serious adverse events and other adverse events are distinct categories, and a participant count does not indicate how many events each person experienced. The figures do not provide a comparison with another group. They also do not establish the frequency of events in a larger population, particularly when the analysis population and follow-up completeness are not reported. The zero deaths entry means that no deaths are listed in this safety summary; it does not answer other safety questions or resolve the missing details.
12. What the Result Does, and Does Not, Mean
The record documents a completed, single-group evaluation of PAE for BPH-related LUTS, with enrollment of 21 and a primary adverse-event timeframe of 3 Months. Its safety listing records 1 participant affected by a serious adverse event among 5 at risk, 4 affected by other adverse events among 5 at risk, and 0 deaths. Prostate Cancer is listed as a serious adverse event term at 20.0%. These observations describe what the registry reports, not a comparison of PAE with another intervention.
The posted figures do not establish whether PAE caused any reported event. A single-group study cannot show how many events would have occurred under a different treatment or without the intervention. The record does not report event attribution, detailed event histories, or an analysis adjusting for other factors. It also does not explain why the safety at-risk counts are smaller than the enrollment count.
The primary endpoint is the total number of adverse events, but that result is not reported in the registry record. Participant counts affected are not a substitute for the total event count, because one person may have more than one event. The registry also lists a secondary efficacy outcome based on a symptom questionnaire or flow rate change, but results for it are not reported in the registry record. The available information therefore does not support a conclusion about symptom or flow-rate change.
Nor does the record establish the precision of the safety observations. Confidence intervals, hypothesis tests, and the analysis population are not reported. The small at-risk count means the posted participant counts represent a limited group, while missing follow-up and outcome handling cannot be evaluated from the record. The study can be read as a description of selected reported safety data, but not as evidence of comparative effectiveness, a causal safety estimate, or a definitive account of outcomes for people with BPH more broadly.
13. Why This Trial Matters Statistically
This trial is statistically notable for the contrast between the listed enrollment of 21 and the safety summary’s at-risk count of 5 for each event category. That difference makes clear why denominators and analysis populations matter. A participant count is interpretable only in relation to who was assessed, during what period, and how missing observations were handled. Those explanations are not reported in the registry record.
The study also illustrates a distinction between event counts and participant counts. Its primary endpoint is the total number of adverse events, while the posted safety summary reports how many participants were affected. Those measures answer different questions. Keeping them distinct prevents participant-level figures from being mistaken for a total number of events.
A single-group safety evaluation can contribute descriptive information, but it cannot provide a randomized treatment contrast. This matters because events observed after a procedure may have causes other than the procedure, and there is no control group to help estimate the background rate. The registry does not report an attribution method or a comparative analysis.
Finally, the record lists a secondary efficacy outcome but does not report its results, and it lists no analyses. This shows why registration details and outcome results are both needed to judge what a study establishes. The design and event listings can be described, while conclusions about efficacy, uncertainty, and comparative safety remain unavailable from the registry record.
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 trial has no reported comparator group and is identified as single group. As a result, the event counts cannot establish a treatment difference or isolate the effect of PAE from other influences. Allocation is not reported in the registry record, and masking is listed as none. The record does not report a method for attributing events to the procedure.
Although enrollment is listed as 21, the safety figures list 5 participants at risk for serious adverse events and 5 at risk for other adverse events. The registry does not explain this difference, define the safety analysis population, or report withdrawals and missing follow-up. It is therefore unclear how representative these safety counts are of all enrolled participants.
The primary endpoint is a total adverse-event count over 3 Months, but the total result is not reported in the registry record. Event-level details, coding procedures, seriousness criteria, timing, and relatedness assessments are also not reported. The posted participant counts cannot fill these gaps or provide an event rate.
The registry lists five outcome measures and no analyses. The statistical plan, multiplicity approach, sample-size justification, and methods for missing data are not reported in the registry record. The secondary efficacy outcome is listed, but its results are not reported. Consequently, the information available is insufficient to assess efficacy, precision, or whether the reported safety findings reflect complete follow-up. These limitations are specific to the design and registry reporting and should shape any interpretation of the observed counts.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Prostate Artery Embolization (PAE) for Lower Urinary Tract Symptoms (LUTS) Due to Benign Prostatic Hyperplasia (BPH) — NCT02930889.
- Registry record last updated 2021-12-02; status last verified 2021-10.
- Results first posted 2021-11-15.
- 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
NCT02930889 is a completed, single-group study titled “Prostate Artery Embolization (PAE) for Lower Urinary Tract Symptoms (LUTS) Due to Benign Prostatic Hyperplasia (BPH).” The sponsor is the University of Minnesota. Enrollment is listed as 21, with a start date of 2016-10-01 and primary completion date of 2020-10-31. PAE is the listed intervention, and masking is recorded as none.
The primary outcome is the total number of adverse events reported during 3 Months, collected by self-report and medical record. The total primary outcome result and results for the listed secondary efficacy outcome are not reported in the registry record. The safety summary lists 5 at risk and 1 affected for serious adverse events, 5 at risk and 4 affected for other adverse events, and 0 deaths. The registry lists no analyses, and it does not report a comparator group or the reason for the difference between enrollment and the at-risk counts.