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 Bipolar Plasmakinetic TURP Vs Monopolar TURP in the Treatment of Lower Urinary Tract Symptoms (NCT03936244), a randomized na study. The primary outcome is International Prostate Symptom Score (IPSS).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03936244 |
| Phase | NA |
| Condition | Prostatic Hyperplasia, Lower Urinary Tract Symptoms, Transurethral Resection of Prostate |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Single |
| Enrollment | 100 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Hospital Universitario de Fuenlabrada |
| Results posted | Yes |
2. Clinical Question
Population
The trial concerns people with lower urinary tract symptoms due to benign prostatic hyperplasia who underwent transurethral resection of the prostate. The registry describes a tertiary-care public institution and follow-up over one year. Further eligibility criteria and participant characteristics are not reported in the registry record.
Intervention
The intervention was bipolar plasmakinetic transurethral resection of the prostate, abbreviated PK-TURP. The record describes a resectoscope, camera system, saline irrigation fluid, a generator unit, and a platinum-iridium superloop. The extent to which procedural details varied between operators is not reported in the registry record.
Comparator
The comparison was monopolar transurethral resection of the prostate, abbreviated M-TURP. The recorded procedure uses a resectoscope, camera system, glycine irrigation fluid, a generator unit, and a stainless steel loop. The trial compares these procedural approaches; the registry record does not provide detailed information about operator experience or any additional care received.
Primary question
The primary outcome was the International Prostate Symptom Score (IPSS), measured at 1, 3, 6, and 12 months after surgery. The listed primary timeframe is 12 months. The registry record does not report group-level IPSS results, an effect estimate, a confidence interval, or a statistical test, so the size and precision of any between-group difference cannot be assessed from this record.
In statistical terms, the question is whether the symptom-score patterns following the two procedures differed over follow-up, with particular attention to the listed 12-month timeframe. Because measurements are described at several follow-up times, a complete account would need to clarify whether the main comparison concerns only the 12-month score, change from baseline, or a model using repeated measurements. The analysis approach and the baseline IPSS values are not reported in the registry record.
3. Trial Design
The registry describes a randomized controlled trial with a parallel-group design. Participants were allocated to PK-TURP or M-TURP, and masking is recorded as single. The identity of the people who were masked, and how masking was maintained for these procedures, are not reported in the registry record. Random allocation can help balance prognostic factors across groups on average, but it does not ensure that every characteristic is balanced in a particular trial.
The record lists enrollment of 100. It does not report how many participants were assigned to each arm, how many received the assigned procedure, or how many contributed primary outcome data at each follow-up. These details matter because the analyzed group sizes can differ from enrollment when participants withdraw, miss visits, or have outcomes that cannot be measured.
The trial is marked completed. Its recorded start date is 2014-12-05, and its primary completion date is 2017-12-12. The brief description specifies one-year follow-up and comparison of intraoperative, perioperative, and postoperative outcomes in a tertiary-care public institution. The primary outcome is IPSS at 1, 3, 6, and 12 months after surgery, with 12 months identified as the primary timeframe.
Several secondary outcomes are listed, including quality of life, sexual activity, erectile function, prostate volume, operative time, irrigation volume, and changes in plasmatic sodium and haemoglobin after surgery. The record also lists 31 outcome measures. A randomized design establishes the intended allocation method; it does not, on its own, show how well follow-up was maintained or how the outcome data were analyzed. Participant flow, adherence, and the analysis populations 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
| Stage | M-TURP | PK-TURP |
|---|---|---|
| STARTED | 57 | 43 |
| COMPLETED | 45 | 39 |
| NOT COMPLETED | 12 | 4 |
Reasons for not completing this period:
| Reason | M-TURP | PK-TURP |
|---|---|---|
| Lost to Follow-up | 5 | 1 |
| Physician Decision | 7 | 3 |
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
| Characteristic | Unit | M-TURP | PK-TURP | Total |
|---|---|---|---|---|
| Participants analysed | 45 | 39 | 84 | |
| Age, Continuous | years | 64.9 (SD 7.2) | 66.2 (SD 7.1) | 65.5 (SD 7.2) |
| Sex: Female, Male: Female | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Male | Participants | 45 | 39 | 84 |
| Race and Ethnicity Not Collected | Participants | — | — | 0 |
| Body mass index (BMI) | kg/m^2 | 27.9 (SD 4.2) | 26.8 (SD 4.2) | 27.4 (SD 4.2) |
| Hypertension | Participants | 27 | 18 | 45 |
| Diabetes mellitus | Participants | 7 | 6 | 13 |
| Smoker | Participants | 7 | 6 | 13 |
| ASA classification: ASA I | Participants | 1 | 1 | 2 |
| ASA classification: ASA II | Participants | 38 | 33 | 71 |
| ASA classification: ASA III | Participants | 6 | 5 | 11 |
| Serum PSA | ng/mL | 2 (SD 3) | 1.3 (SD 0.9) | 1.7 (SD 2.2) |
| Creatinine | mg/dL | 0.9 (SD 0.3) | 0.9 (SD 0.1) | 0.9 (SD 0.3) |
| Serum sodium | mEq/L | 140.8 (SD 2.3) | 140.5 (SD 2.5) | 140.7 (SD 2.4) |
| Hemoglobin | g/dL | 14.7 (SD 1.3) | 15.1 (SD 1.1) | 14.9 (SD 1.2) |
| IPSS | units on a scale | 24.7 (SD 6.1) | 23.8 (SD 4.8) | 24.3 (SD 6.1) |
| QoL score | units on a scale | 5.2 (SD 0.8) | 4.8 (SD 1.3) | 5.1 (SD 1.1) |
6. Primary Endpoint
The registry lists the primary outcome as International Prostate Symptom Score (IPSS), measured over 12 months.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | points |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is the International Prostate Symptom Score (IPSS), a seven-question measure of lower urinary tract symptoms. The registry identifies the score as a mean continuous measure in points and describes assessment at 1, 3, 6, and 12 months after surgery. The primary timeframe is 12 months. The score is described as ranging from 0 to 35 points, with mild symptoms defined as 0-7 points, moderate symptoms as 8-19 points, and severe symptoms as 20-35 points.
A symptom score offers a structured way to quantify participants’ reported symptom burden, rather than relying only on an overall impression of improvement or worsening. As a continuous outcome, the mean can describe the average score in a group. A comparison of group means would need to be interpreted alongside its uncertainty and the analysis method, particularly if the question concerns differences over time rather than one follow-up measurement.
The registry record does not report the observed IPSS means, standard deviations, baseline scores, or between-group estimates. It also does not describe how missing questionnaire responses were handled or whether the primary comparison used the 12-month measurement alone or incorporated the other listed timepoints. Thus, the endpoint’s definition is available, but the record does not provide the numerical outcome information needed to judge the observed difference or its precision.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a primary symptom outcome and a follow-up schedule, but it does not report the numerical results for IPSS. There are no posted group means or standard deviations in the record summarized for this analysis, and no effect estimate, confidence interval, or p-value is reported. Consequently, the direction, magnitude, and statistical precision of the primary comparison cannot be described from this registry record.
The record lists the primary outcome at 1, 3, 6, and 12 months, while naming 12 months as the primary timeframe. It also indicates that the primary outcome has several categories or timepoints and is not reduced to one comparison. This is important for interpretation: a set of measurements over time can be analyzed in more than one way, and a result at one visit is not interchangeable with a result representing the overall trajectory. The exact primary contrast and analysis are not reported in the registry record.
The registry record lists zero analyses. That does not establish what analyses were performed outside the record; it means that this record does not supply a statistical analysis to interpret. In particular, it provides no basis for saying whether a difference was statistically significant, whether the groups were similar, or whether an observed difference would be clinically important. Those judgments require reported outcome estimates and adequate information about how they were obtained.
General statistical interpretation distinguishes an estimated effect from its precision. An estimate describes the observed contrast in the trial, while a confidence interval describes a range of values compatible with the data under the stated model and assumptions. A narrow interval indicates greater precision than a wide interval, but neither width nor location can be assessed without the result. The registry record does not report a confidence interval for IPSS.
The adverse-event information is available as counts, but it is a separate part of the record and does not substitute for the symptom endpoint. The serious-event counts and the listed other-event counts should be read as recorded, with their respective at-risk denominators; they do not establish the comparative effect on symptoms. Likewise, the listed serious event term, Need for reintervention, is not a report of the primary IPSS outcome.
Overall, the record supports a description of the randomized comparison, outcome definition, follow-up schedule, and selected safety counts. It does not support a conclusion about which procedure had lower symptom scores or about the statistical strength of any difference. The sponsor’s primary outcome analysis is not reported in the registry record, so there is no sponsor analysis in this record to take precedence over a recalculation.
9. Statistical Methods Explained
The registry describes randomized allocation, a parallel-group structure, and single masking. Those features concern how participants were assigned and how the trial was organized. They do not specify the statistical model used to compare the outcome. The primary IPSS endpoint is identified as a mean continuous measure with standard deviation, but the registry record does not report an analysis method, an effect estimate, or a test statistic.
What does a mean and standard deviation describe?
General explanation: A mean summarizes the average of measured scores within a group. A standard deviation describes how dispersed individual scores are around that mean. These answer different questions: the mean concerns the group’s average score, while the standard deviation concerns variability among measured scores. Neither alone shows how precisely the difference between groups has been estimated. For that, the analysis would also need to account for the number of observations and the comparison method.
The record names IPSS as the primary measure and provides its scoring range and symptom categories. It does not give the group means or standard deviations at any visit. Without those results, a reader cannot determine the observed average scores or how variable they were. Nor can a comparison be reconstructed from the endpoint definition alone.
Why does the schedule of measurements matter?
The endpoint description names measurements at 1, 3, 6, and 12 months, with 12 months listed as the primary timeframe. Repeated measurements on the same participant are related: a participant’s score at one visit may be associated with that participant’s score at another. General statistical explanation: an analysis of repeated measures may account for this within-participant relationship, whereas separate comparisons at each visit may treat each timepoint as its own question. The appropriate interpretation depends on the planned contrast and model.
Possible questions include the difference between groups at the 12-month visit, the change from an earlier measurement to 12 months, or a difference in score patterns across visits. These are not equivalent estimands. An estimand is the precise treatment effect a statistical analysis aims to describe, including the population, outcome, timepoint, and handling of events such as discontinuation. The registry record does not report the estimand or analysis model, so it is not possible to identify which of these questions the trial’s analysis addressed.
How should uncertainty be evaluated?
General explanation: A confidence interval communicates uncertainty around an estimated effect. Its interpretation depends on the estimate, the data, and the statistical method. A p-value, when reported, addresses compatibility of the data with a specified null hypothesis under a statistical model; it does not describe the size or importance of an effect. Both measures are most informative when reported with the actual effect estimate and a clear account of the comparison.
No IPSS confidence interval or p-value is reported in the registry record. There is therefore no numerical basis to characterize uncertainty or to make a significance statement. The record also does not describe any covariate adjustment, variance assumptions, or sensitivity analyses. Those details should not be inferred from the randomized design or from the fact that the outcome is continuous.
What does the record say about power and planning?
General explanation: A sample-size calculation is a planning exercise based on assumed effect size, variability, significance level, allocation, and other design choices. It is not evidence that a trial had a particular probability of detecting an effect after the data have been collected. A post hoc “observed power” calculation based on the observed result is not a substitute for an estimate and its confidence interval.
The registry record does not report the trial’s own sample-size justification or its statistical assumptions. A planning illustration based on an observed effect is conceptually different from the original design calculation. Any sample-size values in such an illustration should be read as hypothetical planning quantities, not as observed results or as proof that the trial was adequately powered. The record does not provide a primary outcome effect from which to assess the precision of the comparison.
What can be concluded from the listed analyses?
The registry record lists zero analyses and does not give a statistical plan. It does not state whether the primary analysis followed intention-to-treat principles, used only participants with complete follow-up, or applied another population definition. General explanation: intention-to-treat analysis typically compares groups according to randomized assignment, while a per-protocol analysis focuses on participants meeting specified adherence criteria. These approaches answer different questions and can be affected differently by non-adherence and missing outcomes. Neither can be attributed to this trial based on the registry record.
The record also lists multiple outcomes and several primary endpoint timepoints. If multiple comparisons are made, the chance of finding at least one apparently unusual result can increase. General explanation: multiplicity procedures can control or otherwise address this issue, but the choice depends on which outcomes and contrasts were prespecified and how they are related. No multiplicity strategy is reported in the registry record. The primary endpoint is therefore defined, but the registered information does not establish how repeated measurements or the wider set of outcomes were incorporated into a formal statistical analysis.
10. Multiplicity, Missing Data and Analysis Populations
The record lists the primary IPSS outcome at 1, 3, 6, and 12 months, with 12 months as the primary timeframe, as well as multiple secondary outcomes. It also lists 31 outcome measures. Considering several outcomes or timepoints can create multiplicity: the interpretation of a collection of statistical tests differs from the interpretation of one prespecified comparison. General statistical explanation: adjustment methods or a hierarchy of testing may be used to manage multiplicity, but the approach should be specified and interpreted in light of the questions being tested. A multiplicity plan is not reported in the registry record.
Missing data can also affect interpretation. The record does not report attendance at each follow-up, the number of missing IPSS measurements, reasons for missingness, or the method used to handle missing values. General explanation: analyses based only on participants with observed scores may be vulnerable to bias if having a missing score is related to the outcome or to treatment assignment. Statistical methods can address some missing-data patterns under assumptions, but those assumptions and methods need to be described. They cannot be inferred from the follow-up schedule.
The analysis populations are not reported in the registry record. The record does not state whether participants were analyzed as randomized, according to procedure received, or under another defined rule. It also does not report how crossovers, withdrawals, or protocol deviations were treated. The registry lists zero analyses, so no analysis population or missing-data procedure can be confirmed from its results record. These omissions limit reproducibility and make it difficult to determine how the outcome estimates, if reported elsewhere, relate to the original randomized groups.
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 |
|---|---|---|---|
| M-TURP | 2 | 45 | 4.4% |
| PK-TURP | 1 | 39 | 2.6% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| M-TURP | 0 of 45 |
| PK-TURP | 0 of 39 |
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 |
|---|---|
| M-TURP | 4 of 45 |
| PK-TURP | 4 of 39 |
Most frequent serious adverse event terms
| Event term | Organ system | M-TURP | PK-TURP |
|---|---|---|---|
| Need for reintervention | Renal and urinary disorders | 2 of 45 | 1 of 39 |
Most frequent non-serious adverse event terms
| Event term | Organ system | M-TURP | PK-TURP |
|---|---|---|---|
| Stenotic events without the need for surgery | Renal and urinary disorders | 4 of 45 | 4 of 39 |
Serious events with the highest arm-level rate: need for reintervention (4.4%).
The adverse-event record gives serious-event counts and other adverse-event counts separately for each group. For M-TURP, 2 participants were affected by serious events among 45 at risk, and 4 were affected by other events among 45 at risk. For PK-TURP, 1 participant was affected by serious events among 39 at risk, and 4 were affected by other events among 39 at risk. The recorded death count is 0 in each group.
The registry also lists Need for reintervention as a top serious event term, with 4.4% recorded. The record does not give a group-specific breakdown for that term in the information. The term should therefore not be assigned to one group or treated as an additional count beyond the listed group totals without further detail.
These are descriptive registry counts. The at-risk numbers are the denominators recorded for the event listings; they are not the trial’s enrollment total. Counts alone do not adjust for follow-up duration, event severity beyond the registry classification, or differences in participant characteristics. The registry record does not provide event timing, detailed definitions, relatedness assessments, or a statistical comparison of safety outcomes. These figures can describe what was recorded, but they do not establish a causal or comparative safety conclusion.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a randomized, single-masked, parallel-group trial compared PK-TURP with M-TURP for lower urinary tract symptoms due to benign prostatic hyperplasia. It identifies IPSS as the primary measure, describes follow-up at 1, 3, 6, and 12 months, and names 12 months as the primary timeframe. It also records selected adverse-event counts and lists a range of secondary outcomes.
It does not report the primary IPSS results. Without the group-level values and a comparison estimate, the record cannot show whether the scores differed, which group had a higher or lower mean, or how large any difference was. Without an interval estimate, the precision of a comparison cannot be assessed. The record also does not provide a test result that would support a statistical significance statement.
This absence of reported results is not evidence that the groups had identical outcomes, nor is it evidence that one procedure had better outcomes. It means the registry record does not contain the results needed to distinguish those possibilities. Similarly, the selected adverse-event counts do not establish a comparative safety effect: further details about event definitions, timing, and analysis are not reported in the registry record.
General statistical explanation: statistical evidence is best interpreted by considering the estimated effect, its uncertainty, the prespecified question, and the quality and completeness of outcome measurement. A numerical result can be statistically compatible with a range of effects, and the clinical importance of that range is a separate consideration. Here, those outcome estimates and uncertainty measures are not reported, so neither statistical nor clinical importance can be evaluated from this record.
The practical meaning is therefore limited to the study’s design and the information actually registered. The record describes an intended comparison and a symptom measure, but it does not answer the comparison’s primary outcome question. Conclusions about relative symptom outcomes require results and analysis details that are not reported in the registry record.
13. Why This Trial Matters Statistically
This trial is statistically informative as an example of why a clearly identified endpoint and a completed randomized design are not, by themselves, enough to interpret comparative effectiveness. The registry specifies an IPSS endpoint, a primary timeframe of 12 months, and measurements at several visits. Those details help define what was intended to be measured. Yet the absence of group results, an effect estimate, and an analysis description prevents readers from evaluating the primary comparison.
The multiple scheduled measurements raise an important analytical distinction. A visit-specific contrast and a comparison of symptom trajectories answer different questions. Reporting which contrast was prespecified, how repeated measurements were handled, and how uncertainty was quantified would make the result more interpretable. These methods are not reported in the registry record.
The record also highlights the value of transparent reporting for missing data and analysis populations. A completed trial can still have incomplete follow-up, and readers need to know how missing observations and departures from assigned treatment were addressed. Without participant flow and analysis-population details, the relationship between randomization and the analyzed outcome cannot be assessed.
Finally, a registry can provide useful descriptions of design, outcome definitions, and selected safety counts without providing enough information to judge an effect. Separating what the record establishes from what it leaves unknown avoids treating absence of a reported result as a finding of no difference. For this trial, the design and measurement plan are documented more fully than the statistical results needed to answer its primary question.
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 principal limitation of the registry record for interpretation is that it does not report the primary IPSS results or a statistical comparison. Means, standard deviations, effect estimates, confidence intervals, and p-values are not reported in the registry record. As a result, the direction and precision of the primary comparison cannot be assessed.
The endpoint description includes multiple follow-up times, but the record does not specify the precise primary contrast or how repeated measurements were modeled. The participant-level number contributing data at each visit, baseline outcome values, and missing-data handling are also not reported. The record does not identify the analysis population or provide a statistical analysis plan.
Although the trial is marked completed and enrollment is recorded as 100, the registry information does not provide a participant-flow account or group allocation counts. Eligibility criteria, participant characteristics, operator experience, and details of masking are not reported in the registry record. These omissions limit assessment of how representative the trial population was and how the intended comparison was implemented.
The adverse-event information is limited to recorded counts and one serious-event term with a percentage. Event timing, detailed definitions, severity beyond the registry classification, and group-specific information for the listed term are not reported. The registry record also does not report a multiplicity strategy for the several outcomes and timepoints. These limitations concern what can be learned from this record; they do not establish that the trial did not collect or analyze the information elsewhere.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Bipolar Plasmakinetic TURP Vs Monopolar TURP in the Treatment of Lower Urinary Tract Symptoms — NCT03936244.
- Registry record last updated 2020-11-12; status last verified 2020-10.
- Results first posted 2020-10-19.
- 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
The registry record describes a completed randomized, single-masked, parallel-group trial comparing PK-TURP with M-TURP for lower urinary tract symptoms due to benign prostatic hyperplasia. Enrollment is recorded as 100, and the brief description specifies one-year follow-up at a tertiary-care public institution. The primary outcome is IPSS, with measurements at 1, 3, 6, and 12 months and a primary timeframe of 12 months.
The record lists several secondary outcomes and selected adverse-event counts. It does not report the primary outcome values, a statistical comparison, an analysis plan, analysis populations, or missing-data methods. Consequently, the registry record describes the planned comparison and measurement but does not establish the direction, magnitude, or precision of the primary outcome result.