Prostatic Artery Embolization vs Medication for Benign Prostatic Hyperplasia: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Prostatic Artery Embolization vs Medication for Benign Prostatic Hyperplasia (NCT04398966), a na na study. The primary outcome is Mean Change in IPSS at 6 Months.

2. Clinical Question

3. Trial Design

The registry lists NCT04398966 as a study of PAE versus medication for BPH, with an official title describing a single-subject study design. The registered model is single group, allocation is listed as NA, and masking is listed as none. The study summary describes a single-arm, uncontrolled, non-blinded study using HydroPearl Beads. The single-group designation is important: it does not indicate a randomized comparison with a concurrent medication group.

The study summary describes planned enrollment of 30 men across 3 sites, while registry enrollment is 12. The registry lists the study status as terminated. The dates recorded are a start date of 2020-09-23 and a primary completion date of 2023-05-08. A reason for termination is not reported in the registry record. These details describe the conduct and status recorded in the registry; they do not establish why enrollment differed from the planned figure or whether all planned procedures and visits were completed.

The summary describes 6 visits: enrollment and baseline, the PAE procedure, and follow-up at 1 day, 3 months, 6 months, and 12 months. Questionnaires and uroflowmetry were planned at baseline and follow-up, with MRI at baseline and the 6-month follow-up. The primary endpoint uses baseline and 6-month data. Whether all participants completed each visit, and how departures from the planned schedule were handled, is not reported in the registry record.

The record lists secondary outcomes involving quality of life, urine flow, prostate volume, prostate infarction, and treatment-related adverse events. Outcome titles indicate intended areas of assessment, not reported findings. A statistical analysis plan, sample-size justification for the actual study, and details of any interim analyses are not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Analysis population for the primary outcome, as defined in the registry: Data are reported for all participants with both baseline and Month 6 data.

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 Mean Change in IPSS at 6 Months, measured over baseline to 6 months following the procedure.

The primary endpoint is mean change in IPSS from baseline to 6 months following PAE. IPSS is a written screening tool for assessing, tracking, and helping guide management of BPH symptoms. It includes 7 Likert-type questions, each scored from 0 to 5, with 0 indicating less severe symptoms. The registry describes total scores as Mild (1-7), Moderate (8-19), or Severe (20-35).

A change score represents how a participant’s recorded symptom score differs between the two measurement times. The endpoint’s mean summarizes those changes for the participants included in the analysis. The registry does not specify in the posted outcome description whether change is calculated as the 6-month value minus baseline or the reverse. Therefore, the direction associated with a positive or negative change should not be inferred from the record alone.

Using the same symptom measure at baseline and follow-up makes it possible to describe change over time in the participants with both measurements. It does not, by itself, separate a procedure’s effect from natural change, other care, expectations, or measurement variation. The registry specifies that the primary endpoint population includes participants with both baseline and Month 6 data. The mean change, its standard deviation, and the number of participants included in that endpoint analysis are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the primary outcome as a continuous measure summarized by a mean, with standard deviation as the stated dispersion measure. These labels describe the intended form of the result, not an analysis result. The posted record does not include the mean change, standard deviation, confidence interval, or a listed analysis. It is therefore not possible to assess the estimated change or its precision from the registry entry.

What does a mean change represent?

In general, a change score is calculated by comparing a participant’s measurement at follow-up with that participant’s baseline measurement. A mean change then summarizes those participant-level changes. This can be useful for describing how a measured outcome shifts over time within a study group. The exact subtraction order matters for interpreting the sign. The registry states the timeframe as baseline to 6 months following the procedure, but the posted outcome description does not state the subtraction convention. Interpretations that assign a particular clinical direction to a positive or negative value would therefore require information not reported in the registry record.

The standard deviation describes how spread out individual change scores are around their mean. It is not a confidence interval and does not directly express the uncertainty in the estimated mean. In general, a confidence interval gives a range of values compatible with the data and the assumptions of a specified statistical procedure. A narrow interval indicates greater precision than a wide interval, but neither can be evaluated because no interval or endpoint estimate is reported.

What can a within-group analysis establish?

General statistical interpretation distinguishes change over time in a single group from a difference between treatment groups. Participants serve as their own baseline reference in the study summary, which can account for stable differences between people when describing paired measurements. However, before-and-after change can also reflect factors that change over time, such as other care, changing circumstances, expectations, or measurement variability. Without a concurrent comparator, those influences cannot be separated from the effect of the procedure by a simple within-group change estimate.

The study’s stated non-inferiority purpose requires a treatment comparison and a criterion for how much difference would still be considered non-inferior. The registry record does not report a non-inferiority margin, a medication-group estimate, or a comparative analysis. Its single-group design and posted outcome information therefore do not permit a non-inferiority conclusion. This is a design and reporting limitation, not a claim about the procedure’s performance.

How should the planning illustration be read?

The registry’s sample-size illustration is described as a planning calculation based on the observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It considers detecting a stated fraction of the observed effect. The illustration is not the trial’s own design and does not describe an observed power calculation. Participants per arm are the unit for non-time-to-event illustrations; time-to-event illustrations use a total number of events. The record does not report numerical values for those illustrations in the material available for interpretation.

In general, a planning sample size depends on assumptions about the effect to detect, variability, the chosen significance level, allocation, and analysis method. A planning illustration is conditional on those assumptions; it is not evidence that a study had a particular probability of detecting an effect after completion. In particular, it should not be called observed power. Because the registry describes a single-group study, a hypothetical equal-allocation, two-arm calculation should not be mistaken for the actual enrolled design.

Why does outcome distribution matter?

For a continuous outcome, a mean and standard deviation are common summaries. Their usefulness for inference depends on the data and analysis assumptions. If observations are highly skewed or contain influential extreme values, the mean and standard deviation may not fully convey the distribution. General methods can address distributional concerns, but the analysis method and diagnostic checks used for IPSS are not reported in the registry record.

Over-dispersion is a general concern for count data when variability exceeds what a simple count model assumes. It is not a direct description of the continuous IPSS mean-change endpoint. It could matter for some event-count analyses, depending on the outcome and statistical model. The record does not provide an event-count model or an analysis plan. The posted safety figures should therefore be read as reported counts and percentages, not as results from a model adjusted for over-dispersion or other factors.

The registry lists 7 outcome measures and 0 analyses. The listed outcomes indicate intended measurement domains, while the absence of analyses means that the registry entry does not provide analysis results for interpretation. The statistical methods used for the primary and secondary outcomes, including any covariate adjustment or sensitivity analyses, are not reported in the registry record.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("PAE Procedure")
n   <- c(11)
m   <- c(-9.64)
sp  <- c(9.04)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  PAE Procedure  11  -9.640  9.040  -15.713  -3.567

11. Multiplicity, Missing Data and Analysis Populations

The record lists a primary endpoint and 7 outcome measures, including secondary outcomes for quality of life, urine flow, prostate volume, prostate infarction, and treatment-related adverse events. When a study assesses multiple outcomes, the chance of finding at least one apparently notable result can depend on how many comparisons are made and how they are analyzed. General approaches may prespecify a hierarchy or adjust for multiple testing. Whether any such approach was planned or used is not reported in the registry record. No outcome analysis is listed, so the record does not permit review of multiplicity procedures or their consequences.

The primary endpoint population is defined as participants with both baseline and Month 6 data. This is a complete-measurement definition for the endpoint, but it does not explain how many participants met it or why measurements might be missing. The number analyzed, reasons for missing baseline or follow-up measurements, and methods for handling missing data are not reported in the registry record. The enrollment figure cannot be treated as the endpoint analysis size.

In general, restricting an analysis to participants with measurements at both time points can yield a result that differs from one based on all enrolled participants, particularly if missingness is related to symptoms, treatment experience, or other factors. This is a methodological consideration, not evidence that a particular pattern of missingness occurred in this study. The record does not report imputation, sensitivity analyses, or a broader analysis population definition.

The record also does not report a statistical analysis plan, prespecified interim analyses, or a sample-size justification for the actual study. These omissions prevent assessment of whether the posted endpoint and analysis population were handled according to a detailed prespecified plan.

12. 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 serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: gastrointestinal bleeding (8.3%), failure to thrive (8.3%), dysphagia (8.3%).

The registry lists safety counts for the PAE Procedure group. Serious events affected 1 of 12 participants at risk, and other events affected 11 of 12 at risk. Deaths are listed as 1. These entries describe the counts recorded in the registry; they do not establish that the procedure caused an event or death. The record does not report the cause of death or its relationship to the procedure.

The top listed serious-event terms are gastrointestinal bleeding, failure to thrive, and dysphagia, each reported as 8.3%. The posted record does not provide enough detail to determine the timing, duration, severity beyond the serious-event classification, or clinical circumstances for each listed term. Nor does it identify whether any particular event was judged treatment-related. The separate outcome titles for treatment-related adverse events do not, by themselves, show how the listed serious events were attributed.

These figures should not be read as a comparison with medication: the registered design is single-group, and no concurrent medication safety group is reported. They are descriptive registry safety information, with limited context for judging attribution or comparative risk.

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

The registry record establishes that the study was intended to assess PAE using HydroPearl microspheres in men with BPH, with mean IPSS change from baseline to 6 months as the primary endpoint. It also records a single-group, uncontrolled, non-blinded design and a terminated status. The registry lists safety counts and several secondary outcome domains. These are useful descriptions of the study’s focus and the information posted.

The record does not report the primary mean change, its standard deviation, the number included in the endpoint analysis, or a medication comparison. It therefore does not show whether the symptom score changed, how precisely any change was estimated, or whether PAE was non-inferior to medication. The stated study purpose is not itself evidence that the comparative aim was achieved. A within-participant baseline-to-follow-up assessment cannot substitute for a reported randomized or otherwise concurrent treatment comparison.

The listed serious and other adverse-event counts provide descriptive safety information, but they do not establish causation or comparative safety. The record does not give enough clinical detail to interpret individual events, and it does not report a medication group for comparison. The death count should be understood as a registry entry without an available cause or attribution in the record.

The appropriate interpretation is bounded by what is posted: design, planned measurement, enrollment and status information, and safety counts. No medical decision follows from these entries alone. The registry does not provide the outcome analysis required to quantify symptom change or answer the stated comparison with medication.

14. Why This Trial Matters Statistically

This trial is statistically notable because its stated purpose is comparative, while the registered design is single-group and uncontrolled. The summary describes comparing participants with themselves, and the primary endpoint is a change from baseline. That approach can describe within-participant change, but it does not directly estimate how outcomes under PAE compare with outcomes under medication. The distinction between a change over time and a treatment contrast is central to interpreting the study’s question.

The record also illustrates why the analysis population matters. The primary endpoint is defined for participants with both baseline and Month 6 data, while the registry lists enrollment of 12 and planned enrollment of 30 in the study summary. The endpoint analysis count is not reported. Without that count and an account of missing data, readers cannot determine how much of the enrolled group contributes to the primary endpoint or assess possible selection associated with missing measurements.

Finally, the posted registry information contains a named primary endpoint and safety counts but no listed analyses or primary endpoint estimate. Statistical interpretation depends not only on outcome definitions and study design, but also on reported estimates and uncertainty. The record makes clear what was intended to be measured while leaving the principal efficacy result unavailable. This separation between study aim, design, and reported analysis is important when reading clinical trial registries.

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 main limitation for interpretation is that the registry does not report the primary endpoint estimate or its standard deviation. It also does not report a confidence interval, endpoint analysis count, or statistical test. The primary outcome therefore cannot be quantified from the posted record.

The registered model is single group, with allocation listed as NA and masking as none. The summary describes an uncontrolled, non-blinded study. These features limit causal and comparative interpretation, particularly for the stated non-inferiority question against medication. A concurrent medication comparison, non-inferiority margin, and comparative result are not reported in the registry record.

The summary’s planned enrollment of 30 differs from registry enrollment of 12, and the study status is terminated. A reason for termination and details on recruitment, adherence, or completion of visits are not reported in the registry record. The number of participants with both baseline and Month 6 measurements is also not reported, nor are missing-data methods or sensitivity analyses.

Safety entries lack detail on timing, cause, and treatment attribution. The record does not report a statistical analysis plan, multiplicity approach, or analysis methods for the primary and secondary outcomes. These limitations mean the registry information can describe the study structure and selected safety counts, but cannot support a full assessment of efficacy, precision, or comparative safety.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Prostatic Artery Embolization vs Medication for Benign Prostatic Hyperplasia — NCT04398966.
• Registry record last updated 2024-05-07; status last verified 2023-10.
• Results first posted 2024-04-03.
• 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

NCT04398966 is registered as a single-group study of PAE for BPH. The study summary describes planned enrollment of 30 men across 3 sites; registry enrollment is 12. The registry lists the status as terminated, with a start date of 2020-09-23 and primary completion date of 2023-05-08.

The primary endpoint is mean IPSS change from baseline to 6 months following the procedure, among participants with both measurements. The estimate, standard deviation, and analysis population count are not reported in the registry record. The registry lists 7 outcome measures and 0 analyses. Safety entries report serious events affecting 1 of 12 at risk, other events affecting 11 of 12 at risk, and 1 death. The record does not provide a reported medication comparison or a reason for termination.