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 Penile Nerve Stimulation for Treatment of Delayed Ejaculation (NCT04115540), a na na study. The primary outcome is International Index of Erectile Function (IIEF) Scale Score.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04115540 |
| Phase | NA |
| Condition | Delayed Ejaculation |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 20 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Stanford University |
| Results posted | Yes |
2. Clinical Question
Population
Men with delayed ejaculation were the intended population. The primary outcome description specifies participants with data at baseline and week 12, but the number meeting that condition is not reported in the registry record. The registry lists enrollment of 20.
Intervention
The intervention was transcutaneous electrical nerve stimulation of penile nerves. The arm description identifies electrode pads placed at the base of the penis and perineum. The brief summary describes the intended use as before or during sexual activity; the detailed use instructions in the arm description are incomplete in the registry record.
Comparator
There was one treatment group and no like-for-like control group. Allocation is listed as NA, masking as none, and the design as single group. Consequently, the study does not provide a randomized between-group comparison.
Primary question
The stated primary objective in the study summary is whether participants subjectively reduce ejaculatory latency time. However, the registry record identifies International Index of Erectile Function (IIEF) scale score as the primary outcome, assessed at baseline and 12 weeks. The record does not report results for either latency time or IIEF score, so the size and precision of any change cannot be assessed.
3. Trial Design
This was a completed, single-group clinical trial of transcutaneous electrical nerve stimulation (TENS) of penile nerves for delayed ejaculation. The registry lists an enrollment of 20 and a status of completed. The recorded start date is 2019-01-10, and the primary completion date is 2024-01-31. The study is listed as phase NA.
The intervention group is described as receiving penile nerve stimulation using electrode pads placed at the base of the penis and perineum. The device is identified in the arm description as the TENS 7000. The summary describes the research aim as testing safety and feasibility and hypothesizes that stimulation before or during sexual activity might reduce intra-vaginal ejaculatory latency time. The detailed arm instructions are cut off in the registry record, so the complete treatment schedule cannot be established from that description.
There was no randomized allocation and no masking. With only one group, any before-and-after outcome comparison would describe changes observed among participants receiving the intervention; it would not, by itself, separate an intervention-associated change from other influences over time. There is no control-group estimate in this design.
The registry identifies IIEF score at baseline and 12 weeks as the primary outcome, while the study summary calls subjective reduction in ejaculatory latency the primary objective. That difference in emphasis is important when interpreting the trial: the registry’s listed primary endpoint and the stated objective are not the same measure. The registry record does not report the statistical analysis plan, the rationale for the enrollment target, or whether any interim analyses were planned.
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 | TENS Penile Nerve Stimulation Group |
|---|---|
| STARTED | 20 |
| COMPLETED | 6 |
| NOT COMPLETED | 14 |
Analysis population for the primary outcome, as defined in the registry: Participants with data at baseline and week 12.
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 | TENS Penile Nerve Stimulation Group |
|---|---|---|
| Participants analysed | 14 | |
| Age, Continuous | years | 64.5 (SD 12.96) |
| Sex: Female, Male: Female | Participants | 0 |
| Sex: Female, Male: Male | Participants | 14 |
| Race/Ethnicity, Customized: White | Participants | 12 |
| Race/Ethnicity, Customized: Asian | Participants | 1 |
| Race/Ethnicity, Customized: Other | Participants | 1 |
| Region of Enrollment: United States | Participants | 14 |
6. Primary Endpoint
The registry lists the primary outcome as International Index of Erectile Function (IIEF) Scale Score, measured over Baseline and 12 weeks.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | score on a scale |
| Endpoint classification | Continuous Endpoint |
The registry’s listed primary endpoint is the International Index of Erectile Function (IIEF) scale score, measured at baseline and 12 weeks. The record describes it as a validated multidimensional questionnaire for erectile and ejaculatory function in men, with three questions scored from 0 to 5 each. It states that the total score ranges from 0 to 15, with higher scores representing a better outcome.
A questionnaire score can provide a structured way to describe participants’ reported sexual function at different assessment times. Using the same measure at baseline and follow-up allows the study to characterize whether scores changed among participants with data at both times. The record states that the primary outcome population consists of participants with data at baseline and week 12, but does not report how many participants contributed data or the resulting scores.
The stated primary objective in the study summary concerns subjective reduction in ejaculatory latency time, whereas the listed primary endpoint is IIEF score. Those measures address related but distinct questions: a questionnaire score is not itself a measured latency time. The registry record does not report a latency-time result, an IIEF summary result, or an estimate of change with an uncertainty interval. Therefore, the endpoint definition explains what was intended to be measured, but does not establish what the results were.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The record describes a small, single-group study with a listed enrollment of 20. Its design can describe outcomes observed during the study, but it does not include a randomized control group against which to compare those outcomes. This limits causal interpretation: a change from baseline may reflect the intervention, but a before-and-after observation alone cannot rule out other explanations, such as changes over time or factors related to measurement and participation.
The primary outcome listed in the registry is IIEF score at baseline and 12 weeks. The registry record does not report the baseline score, the week-12 score, a change estimate, a measure of variability, or a confidence interval. It therefore does not allow a reader to assess the direction, size, or precision of the primary endpoint result. The summary’s stated primary objective concerns subjective reduction in ejaculatory latency time, but a result for that outcome is also not reported in the registry record.
There are six outcome measures listed and no analyses reported. That does not establish that no analyses were conducted; it means the registry record does not present analysis results. Nor does it establish which outcome was emphasized in any analysis beyond the endpoint designation in the record. The record does not report whether a multiplicity procedure was used or how missing measurements were handled.
The safety entry reports zero serious adverse events among 14 participants at risk, zero other adverse events among 14 at risk, and zero deaths. These are descriptive counts for the listed group and do not establish that no adverse events occurred outside the categories or ascertainment captured in the record. The number at risk for these safety summaries differs from the listed enrollment, and reasons for that difference are not reported.
Overall, the posted information supports a description of the design, planned endpoint, and recorded safety counts, but not an estimate of treatment-associated change. Without outcome summaries, analysis details, and a comparator, the magnitude and precision of efficacy-related findings cannot be determined from the registry record.
9. Statistical Methods Explained
What does a single-group design estimate?
In a single-group study, participants receive the intervention without a parallel control group. If a measure is collected at baseline and again later, the observed change describes the difference between those measurements among participants with data at both times. It is not automatically an estimate of what would have happened without the intervention. A control group can help address that counterfactual question, particularly when assignment is randomized; this study is not listed as randomized and has no like-for-like control comparison.
The registry lists baseline and 12-week assessment for the IIEF score. For this endpoint, a complete paired observation requires data at both assessment times. The registry describes the primary outcome population in those terms, but does not report the number with complete data, the analysis method used to combine their scores, or the resulting estimate. It is therefore not possible to reconstruct the primary analysis from the registry record.
What does a mean and standard deviation describe?
The primary endpoint is characterized as a mean with standard deviation. A mean describes the central level of a continuous measure across observations; a standard deviation describes how dispersed individual observations are around that mean. These summaries do not, on their own, show the uncertainty in an estimated treatment effect. A confidence interval is a general statistical tool for expressing uncertainty around an estimate: narrower intervals indicate greater precision under the assumptions of the analysis, while wider intervals indicate less precision. No mean, standard deviation, change estimate, or confidence interval for the primary outcome is reported in the registry record.
For a before-and-after study, the variability of individual changes can differ from the variability of scores at either assessment time. An analysis of paired changes therefore needs information about the paired observations or their change-score variability. Separate baseline and follow-up summaries alone may not be enough to reproduce an exact paired analysis. In this case, the registry record does not report either set of score summaries or a paired-change analysis.
Why do allocation and masking matter?
Random allocation, when used, is intended to make comparison groups similar on average with respect to both measured and unmeasured influences. This study is listed as single group, with allocation NA, so it has no randomized treatment contrast. Masking can reduce some forms of expectation or assessment influence. Masking is listed as none. These design characteristics do not mean that an observed measurement is invalid, but they affect how strongly a difference can be attributed to the intervention rather than other influences.
What do the planning assumptions mean?
The registry’s planning description refers to an illustrative calculation based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. Such a calculation is a hypothetical planning exercise: it asks how many participants per arm might be required under specified assumptions to detect an assumed effect. It is not an observed outcome and is not observed power.
Those planning assumptions describe a two-arm comparison, while the recorded trial design is single group. This means the assumptions should not be read as evidence that this study actually randomized participants between two arms or had a control group. The registry record does not report the values of any planning illustrations or the trial’s own sample-size justification. In general, planning estimates depend on the effect size assumed, outcome variability, allocation, significance level, and analysis approach; changing those assumptions changes the resulting estimate.
Why can over-dispersion matter?
As a general statistical concept, over-dispersion occurs when observed variability is greater than a model assumes. If a model underestimates variability, its uncertainty estimates can be too small, making evidence appear more precise than it is. The primary endpoint is a continuous score described using a mean and standard deviation; the registry record does not report a model or indicate that over-dispersion was assessed. This general concept should not be mistaken for a finding about this study.
What can be concluded from the posted analysis record?
The record lists six outcome measures but no analyses. It does not report the statistical methods used for the primary endpoint, any adjustment for baseline values, an analysis population beyond the stated availability of baseline and week-12 data, or the handling of incomplete observations. Without those details and numerical results, readers cannot evaluate the fitted analysis, its assumptions, or the precision of an estimated effect. Statistical methods explain how an estimate is produced; they cannot substitute for the missing outcome summaries and analysis results.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists six outcome measures and zero analyses. Multiple measured outcomes can raise a multiplicity question because, when many statistical hypotheses are tested, the chance of at least one apparently notable result can increase. General approaches include designating a primary outcome in advance, using a prespecified hierarchy, or adjusting inference across a family of tests. The registry identifies IIEF score as the primary outcome, but does not report whether a multiplicity strategy was specified or applied. The summary’s emphasis on subjective reduction in ejaculatory latency time is another reason to distinguish the stated study objective from the endpoint listed as primary.
The record does not report the results for the listed outcomes or the number of outcome measures with available data. It also does not report how missing observations were handled, whether the analysis used only participants with complete baseline and week-12 data, or whether any other analysis population was defined. The primary outcome description refers to participants with data at both times, but does not state how many participants met that criterion.
For the safety summaries, the registry reports 14 participants at risk in the group, compared with listed enrollment of 20. The reason for the difference is not reported in the registry record. It cannot be assumed that the difference reflects withdrawal, missing data, or any particular eligibility or follow-up process. These gaps mean that the extent and potential influence of missing outcome information cannot be evaluated from the posted record.
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 |
|---|---|---|---|
| TENS Penile Nerve Stimulation Group | 0 | 14 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| TENS Penile Nerve Stimulation Group | 0 of 14 |
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 |
|---|---|
| TENS Penile Nerve Stimulation Group | 0 of 14 |
The registry reports zero serious adverse events among 14 participants at risk in the TENS penile nerve stimulation group. It also reports zero other adverse events among 14 at risk and zero deaths. No serious adverse-event terms are listed. These are the recorded counts for the safety categories and group in the registry record; they are not estimates of comparative risk because there is no control group.
The safety denominator is 14, while the listed enrollment is 20. The reason that the safety group at risk is smaller than the enrollment is not reported in the registry record. The record does not describe the duration or completeness of safety follow-up, or provide details about event collection beyond assessment by survey for treatment-related adverse events. Those omissions limit what can be inferred from a zero count.
A recorded count of zero means that no events in that category were reported in the stated group at risk. It does not establish that the intervention is free of risk, nor does it describe events that may not have been captured by the registry summary. Because there is no comparator, the counts cannot show whether event occurrence differed from another treatment or from no intervention.
12. What the Result Does, and Does Not, Mean
The trial record documents an investigation of penile nerve stimulation in men with delayed ejaculation, with the stated aims of assessing safety and feasibility and exploring changes in ejaculatory latency and IIEF score. The registry lists enrollment of 20 and a completed, single-group design. It also records safety counts for 14 participants at risk, including zero serious adverse events, zero other adverse events, and zero deaths.
Those design and safety details do not provide a numerical account of the primary outcome. The registry identifies IIEF score at baseline and 12 weeks as the primary endpoint, but does not report scores, a change estimate, variability, or a confidence interval. It also does not report a result for subjective ejaculatory latency time, the objective emphasized in the study summary. Therefore, the direction and size of any observed change, and the precision with which it was estimated, are not reported in the registry record.
The absence of a control group matters independently of the missing results. Even if a before-and-after change were available, a single-group comparison would not by itself establish that the change was caused by stimulation. Changes over time, expectations, measurement conditions, and other influences could also contribute. The registry record does not provide an estimate that separates these possibilities.
The posted information can be used to understand what the investigators intended to study and how the registry characterizes the design and endpoint. It cannot establish whether the primary objective was met, how large any outcome change was, or how precisely it was measured. The safety counts are limited to their recorded categories and denominator and are not a comparative safety assessment.
13. Why This Trial Matters Statistically
This trial is statistically notable for the gap between its stated objective and its registered primary endpoint. The summary describes subjective reduction in ejaculatory latency time as the primary objective, while the registry lists IIEF score as the primary outcome. Because these measures are distinct, readers need outcome-specific results to determine what was measured and how the reported findings relate to each aim. Those results are not reported in the registry record.
The single-group design also defines the kind of evidence the study can produce. It can describe outcomes among people receiving the intervention, but cannot supply a randomized contrast with a control group. This distinction is useful for interpreting early or feasibility-oriented research: a within-participant change can be informative as a description, yet it does not isolate the intervention’s contribution in the way a controlled comparison is intended to do.
The record also illustrates why outcome definitions and analysis details matter. The IIEF score is described with a scale range and direction, but no score summaries or uncertainty estimates are posted. Without those results, readers cannot assess magnitude or precision. The lack of reported analyses, missing-data methods, and multiplicity information further limits assessment of how the outcomes were handled.
Finally, safety counts need their denominator and context. The record lists 14 participants at risk for safety summaries and enrollment of 20, but does not explain the difference. Reporting the reason and follow-up completeness would help readers understand the scope of those counts. The record therefore offers design and endpoint information, while leaving central statistical questions about outcome estimates and their interpretation unanswered.
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 main trial-specific limitation is the single-group design. There is no randomized control group, so a comparison of measurements over time cannot distinguish an intervention-associated change from other explanations. Masking is listed as none, which can also leave subjective reports susceptible to expectations or assessment influences. These are features of the design, not proof that any particular bias occurred.
The registry does not report numerical results for the listed primary endpoint. It identifies IIEF score at baseline and 12 weeks, but provides no scores, change estimate, standard deviation, confidence interval, or analysis result. The study summary’s stated primary objective concerns subjective ejaculatory latency time, and no result for that measure is reported either. The difference between the summary’s stated objective and the registered endpoint complicates interpretation of what result would directly answer the main question.
The enrollment is listed as 20, while safety summaries use 14 participants at risk. The reason for this difference is not reported in the registry record. The number with complete baseline and week-12 IIEF data is also not reported, and missing-data handling is not described. As a result, the completeness and representativeness of the analyzed outcome data cannot be evaluated.
The detailed intervention instructions are incomplete in the registry record, so the full treatment schedule cannot be determined from the arm description. The record does not report the analysis plan, sample-size justification, multiplicity approach, or interim analysis plan. These missing details limit appraisal of the intended inference and the treatment exposure. The safety summary is also restricted to recorded categories and does not provide a comparator or fuller follow-up context.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Penile Nerve Stimulation for Treatment of Delayed Ejaculation — NCT04115540.
- Registry record last updated 2025-03-20; status last verified 2025-03.
- Results first posted 2025-03-20.
- 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, single-group study of transcutaneous electrical nerve stimulation of penile nerves for delayed ejaculation. Enrollment is listed as 20; the study is unmasked, with allocation NA, and is listed as phase NA. The recorded start date is 2019-01-10, and the primary completion date is 2024-01-31.
The summary states that the study aimed to assess safety and feasibility and to examine subjective ejaculatory latency and IIEF score. The registered primary outcome is IIEF score at baseline and 12 weeks. Numerical outcome results and analyses are not reported in the registry record. Safety summaries report zero serious adverse events and zero other adverse events among 14 participants at risk, and zero deaths. The record does not explain the difference between enrollment and the safety denominator.