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 Evaluation of the Coloplast Titan® IPP for Maintaining Penile Length While Treating Erectile Dysfunction (ED) (NCT00731666), a na na study. The primary outcome is The Study's Primary Objective Will Assess the Change in Penile Length..
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00731666 |
| Phase | NA |
| Condition | Erectile Dysfunction |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 40 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Coloplast A/S |
| Results posted | Yes |
2. Clinical Question
Population
People with erectile dysfunction who were enrolled in the study. The registry record lists an enrollment of 40. Further eligibility criteria and participant characteristics are not reported in the registry record.
Intervention
Implantation of the Coloplast Titan® inflatable penile prosthesis (IPP). The study description also refers to modified cylinder sizing during implantation and a max-inflate technique after implantation.
Comparator
There is no separate comparator group in the registered design. The study is listed as non-randomized and single-group, so it does not provide a like-for-like comparison with another treatment or a control condition.
Primary question
What change in penile length, measured as a mean in centimeters, is observed at the 12-month timeframe after implantation? The numerical result and the precise reference measurement used to define change are not reported in the registry record.
The study concerns whether penile length is maintained or increased after implantation. Its official title describes a prospective, multicenter assessment of that question, and its brief description links the evaluation to a modified cylinder-sizing method and a max-inflate technique. The primary outcome is continuous: length is measured on a numeric scale, and the registry identifies the mean and standard deviation as the intended summary statistics.
The registry also names participant satisfaction with penile length at baseline, 12 months, and 24 months as a secondary outcome, measured by questionnaire. Another secondary outcome is the rate of change in male stress urinary incontinence. Results for these secondary outcomes are not reported in the registry record. Because the study has no randomized control group, its central question is descriptive: what change was recorded in the enrolled group, rather than whether the device caused a difference compared with another approach.
3. Trial Design
The record describes a prospective, non-randomized, multicenter clinical trial, with one study group receiving the Titan® IPP. Allocation is listed as NA, masking as none, and the model as single group. The study is marked completed, with enrollment of 40. The sponsor is Coloplast A/S. The recorded study start is 2007-12 and primary completion is 2010-05. The phase is listed as NA.
The registered intervention is an inflatable penile prosthesis, described in the group as the Titan® IPP. The brief summary says the study was designed to assess maintenance or increase in penile length after implantation and that it would incorporate modified cylinder sizing during implantation and a max-inflate technique after implantation. The record does not report enough procedural detail to establish how consistently these techniques were implemented or whether any participants received a different approach.
A prospective design means outcomes are intended to be assessed as the study proceeds, rather than solely reconstructed from past records. It does not, by itself, establish that measurements were complete or that assessment procedures were unbiased. Multicenter indicates that the study was conducted across more than one center, but the number and identities of centers are not reported in the registry record.
With a single group, the observed outcome can describe what happened among participants treated in the study, but there is no concurrent control group to separate treatment-associated change from other explanations. Such explanations can include natural variation, measurement variability, changes over time, and differences in participant circumstances. The design therefore cannot provide a randomized estimate of the contrast between the IPP and an alternative. The registry record does not report a detailed protocol, eligibility criteria, follow-up completeness, or a statistical analysis plan.
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 | Titan® IPP |
|---|---|
| STARTED | 40 |
| COMPLETED | 28 |
| NOT COMPLETED | 12 |
Reasons for not completing this period:
| Reason | Titan® IPP |
|---|---|
| Adverse Event | 2 |
| Lost to Follow-up | 8 |
| Withdrawal by Subject | 2 |
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 | Titan® IPP |
|---|---|---|
| Participants analysed | 40 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 17 |
| Age, Categorical: >=65 years | Participants | 23 |
| Age Continuous | years | 66.2 (SD 11.4) |
| Sex: Female, Male: Female | Participants | 0 |
| Sex: Female, Male: Male | Participants | 40 |
| Region of Enrollment: United States | participants | 40 |
6. Primary Endpoint
The registry lists the primary outcome as The Study's Primary Objective Will Assess the Change in Penile Length., measured over 12 months.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | cm |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is described as change in penile length, with results intended to be summarized as a mean and standard deviation in centimeters at the 12-month timeframe. Penile length is a continuous measurement: it can take values along a scale, rather than being limited to categories such as improved or not improved. A mean describes the central level of the observed measurements, while a standard deviation describes how spread out those measurements are around the mean.
Change is useful because it focuses on how a measurement differs over time, rather than describing length only at a single assessment. To interpret a change estimate, readers need to know the reference measurement, the follow-up measurement, how measurements were obtained, and which participants contributed data. The registry title and primary-objective description identify change and a 12-month timeframe, but the specific comparison point, measurement procedure, and analysis population are not reported in the registry record.
A mean change can make the overall direction and average magnitude of change easier to describe, but it does not show whether every participant had a similar experience. The standard deviation can indicate the variability of individual measurements, but it does not describe the precision of the mean in the same way as a confidence interval. No numerical endpoint result, standard deviation, or confidence interval is reported in the registry record, so the endpoint cannot be interpreted for direction, magnitude, or precision from this record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies the primary outcome and its planned summary, but it does not report a numerical result for change in penile length at 12 months. Consequently, the direction and magnitude of the observed mean change cannot be described. There is also no reported standard deviation or confidence interval with which to assess the spread of participant measurements or the precision of an estimated mean.
This absence of a posted primary result is distinct from a result showing no change. Without the estimate, it is not possible to determine whether the recorded mean change was positive, negative, or close to zero. Nor is it possible to assess whether the data were compatible with a range of clinically meaningful changes. The registry record does not report a hypothesis test or p-value for the primary outcome, and no analysis is listed. A conclusion about statistical significance or an estimated treatment effect would therefore go beyond the information recorded.
The single-group design also affects what any observed change could establish. In general, a before-and-after measure can describe change within the group, but without a concurrent control it cannot distinguish the effect of the intervention from other influences on measurements over time. This is a design limitation, not a claim that any particular alternative explanation occurred in this study. The record does not describe an adjustment strategy that would address such influences.
The secondary outcomes do not fill this gap in the registered record. Satisfaction with penile length was planned for assessment at baseline, 12 months, and 24 months by questionnaire, and change in male stress urinary incontinence was also named. Their numerical results, measurement details beyond the stated questionnaire and time points, and analysis methods are not reported in the registry record.
The appropriate reading is therefore limited: the registry describes a completed, prospective, non-randomized, single-group study with enrollment of 40 and a continuous primary endpoint at 12 months, but does not post the outcome estimate. No statement about the size, direction, precision, or clinical importance of the result can be made from the recorded information. The record also does not establish whether all enrolled participants contributed measurements at the primary time point.
9. Statistical Methods Explained
The primary outcome is a continuous measure summarized by a mean and standard deviation. In general, a mean is the arithmetic average of the measurements included in an analysis. It gives a compact description of the group’s central value, but can be influenced by unusually high or low observations. A standard deviation describes how much observed values vary around the mean. It is a description of variability among measurements, not a measure of how precisely the mean has been estimated.
What would a confidence interval add?
In general, a confidence interval expresses uncertainty around an estimated quantity under the assumptions of the analysis. For a mean change, it would help readers assess which values are reasonably compatible with the observed data and the analysis method. A narrow interval indicates greater precision than a wide interval, but precision alone does not establish clinical importance or remove potential bias. No confidence interval for the primary outcome is reported in the registry record.
Why does the comparison point matter?
A change score depends on the measurements being compared. The primary objective names change in penile length and gives a 12-month timeframe, but does not specify in the registry record the exact baseline or reference value used for the primary calculation. In general, a change score is interpretable only when the measurement occasions and their procedures are clear. Measurement position, instrument, assessor training, and consistency of technique can affect the values. Those details are not reported in the registry record, so they cannot be evaluated for this study.
What can a single-group analysis estimate?
For a single group, an analysis may describe the mean change among participants with relevant measurements. That estimate is a within-group description. It is not the same as a difference between treatment groups, because the registered study has no separate comparator group. In general, changes over time can reflect both the intervention and other influences, including measurement error, natural variation, or changes in participants’ circumstances. Without a control group or a reported strategy that addresses these possibilities, the record cannot isolate a causal effect.
Why can variability affect inference?
In general, the variability of a continuous outcome matters because greater spread makes the group mean less precise when other features of the data are held constant. The standard deviation describes observed spread; the standard error and confidence interval address uncertainty in the estimate of the mean. These quantities answer related but different questions. The registry record identifies standard deviation as the dispersion measure but does not report the observed value or an uncertainty interval.
Some continuous data may also have a distribution that is asymmetric or includes influential observations. In general, analysts may examine distributions and consider methods suited to the data and the estimand. Over-dispersion is especially relevant when a statistical model assumes less variability than the data exhibit; ignoring it can make uncertainty appear too small. The record does not report distributional checks, model assumptions, or an approach to over-dispersion, so there is no basis to say which methods were used or whether these issues arose.
What does the design imply for statistical testing?
The design is described as non-randomized and single-group. A statistical test of change, if performed, would address a question framed around a within-group estimate and its uncertainty under the chosen model. It would not create a randomized comparison or establish that the intervention caused the observed change. The registry lists zero analyses, and a statistical analysis plan, test specification, adjustment method, and p-value are not reported in the registry record. Accordingly, the posted information does not support a reconstruction of the sponsor’s analysis.
The sample-size assumptions recorded for a planning illustration describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect described as a fraction of the observed effect. These are planning assumptions, not evidence of the trial’s analysis plan. They do not match the registered single-group design’s structure, and the registry does not report that they were used to design this study. Any sample-size figures associated with such assumptions are planning illustrations, not observed power. No trial-specific sample-size justification is reported in the registry record.
Finally, interpretation of a mean change depends on which participants were analyzed and how incomplete measurements were handled. An analysis of participants with observed follow-up measurements can differ from an analysis that accounts for missing outcomes. In general, missingness can affect both the estimate and its precision, particularly if the likelihood of missing data is related to outcomes or participant characteristics. The registry record does not describe the analysis population, missing-data handling, or sensitivity analyses. These omissions limit assessment of the reliability and generalizability of any unreported estimate.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary outcome and secondary outcomes: participant satisfaction with penile length assessed at baseline, 12 months, and 24 months by questionnaire, and the rate of change in male stress urinary incontinence. The primary outcome is change in penile length at 12 months. Numerical findings for these outcomes are not reported in the registry record.
When a study examines multiple outcomes, time points, or statistical comparisons, the chance of at least one apparently unusual result can increase if each is tested separately without accounting for multiplicity. In general, a prespecified hierarchy or adjustment can help clarify which findings are confirmatory and how multiple tests are handled. The registry record does not report a multiplicity strategy, a hierarchy among secondary assessments, or the planned statistical tests. It is therefore not possible to assess whether any adjustment was planned or applied.
The record also does not report how missing measurements were handled, whether participants were analyzed according to a defined analysis population, or whether sensitivity analyses were performed. These details matter because follow-up may be incomplete, and the analyzed group can differ from the enrolled group. The registry lists enrollment of 40, but does not state how many participants had primary-outcome measurements at the 12-month timeframe or contributed to a particular analysis. No assumptions about completion or missingness can be made from enrollment alone.
Outcome definitions beyond the brief descriptions, the questionnaire’s scoring approach, and the method for evaluating change in stress urinary incontinence are not reported in the registry record. Without analysis and missing-data details, neither the handling of multiple assessments nor the robustness of any findings can 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 |
|---|---|---|---|
| Titan® IPP | 1 | 40 | 2.5% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Titan® IPP | 0 of 40 |
Most frequent serious adverse event terms
| Event term | Organ system | Titan® IPP |
|---|---|---|
| Infection | Surgical and medical procedures | 1 of 40 |
Serious events with the highest arm-level rate: infection (2.5%).
The registry’s adverse-event summary lists 40 at risk for serious adverse events and 1 affected. It lists 40 at risk for other adverse events and 0 affected. Infection is listed among the serious adverse-event terms at 2.5%. These figures describe the registry record’s safety entries; the record does not provide event narratives, timing, severity details beyond the serious classification, or an explanation of how events were attributed to the intervention.
The listed number at risk is the denominator for the corresponding safety summary, not necessarily the number with complete follow-up for every other outcome. The number affected describes participants with an event in that category as reported; it should not be read as a count of all event episodes unless the record explicitly defines it that way. The listed infection percentage is a registry entry, not a separately calculated estimate.
Deaths are recorded as null. This means a death count is not reported in the registry record; it should not be interpreted as confirmation that no deaths occurred. Safety summaries are also limited by the scope of event collection and reporting. The record does not describe surveillance procedures or the duration over which these adverse events were assessed. These entries alone do not support a broader comparison of safety with another treatment.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a prospective, non-randomized, multicenter, single-group study was completed, with enrollment of 40, and that its primary objective concerned change in penile length at the 12-month timeframe after Titan® IPP implantation. It also records intended assessments of participant satisfaction and male stress urinary incontinence. These details clarify the study question and the type of outcome planned.
The record does not report the primary outcome estimate, its standard deviation, or an interval expressing its precision. It therefore cannot show how much penile length changed on average, whether the mean change was an increase or decrease, or how variable individual measurements were. It also does not report results for the named secondary outcomes. Missing results should not be interpreted as evidence of no change or no effect.
Even if a within-group change estimate were available, the single-group design would support a description of change among observed participants, not a randomized comparison with an untreated group or an alternative intervention. General influences over time and measurement variability would remain possible explanations. The record does not report an analysis capable of separating these influences from the intervention.
The study’s description of modified cylinder sizing and a max-inflate technique gives context for the planned approach, but the registry does not provide detailed implementation data or establish whether the methods were applied uniformly. The safety entries report serious and other adverse-event counts, but do not provide enough information to characterize event timing, follow-up, or comparative risk.
Overall, the record is informative about design, the stated endpoint, and some safety reporting, but not about the study’s efficacy findings. A conclusion about benefit, absence of benefit, clinical importance, or comparative safety would require results and methodological details not reported in the registry record. No medical decision should be inferred from the design description alone.
13. Why This Trial Matters Statistically
This trial is statistically notable because its primary question concerns change in a continuous measurement, while its registered design has a single group and no randomized comparator. That combination determines what the data could answer. A mean change can describe the group’s average trajectory, and a standard deviation can describe variation across measurements, but neither alone identifies what would have happened over the same period without the intervention.
The design also makes careful reporting of the measurement process particularly important. In general, a change estimate is sensitive to how the initial and follow-up measurements are defined and collected. If measurement procedures vary, observed differences may reflect both actual change and measurement variation. The registry specifies centimeters and a 12-month timeframe, but does not report the detailed measurement or analysis procedures needed to assess those sources of uncertainty.
Statistical interpretation requires more than a point estimate. The mean, standard deviation, confidence interval, analyzed population, and handling of missing follow-up together help readers judge the scale and precision of a result. The registry identifies the intended mean and standard deviation but does not report the numerical outcome or the related analysis details. Consequently, the record cannot support an assessment of whether the estimate is precise or how representative it is of enrolled participants.
The discrepancy between a single-group registered design and planning assumptions describing equal allocation between two arms is also relevant. Such assumptions are planning illustrations and do not establish how the study was designed or analyzed. They should not be mistaken for observed power or for evidence of a trial-specific sample-size rationale. Overall, the record illustrates why transparent outcome reporting and design-appropriate interpretation are both essential: the stated question is clear, but the posted information is insufficient to estimate the primary result or draw a causal comparison.
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 trial-specific limitation is the absence of a posted numerical primary outcome. The registry describes the endpoint as mean change in penile length at 12 months, but does not report the estimate, its standard deviation, a confidence interval, or a test result. The endpoint’s reference measurement and detailed measurement procedures are not reported in the registry record, limiting assessment of what the change represents and how reproducibly it was measured.
The single-group, non-randomized design has no concurrent control. Thus, any within-group change cannot by itself separate intervention-associated change from other influences over time. The record does not describe adjustment methods that could address this limitation. Masking is listed as none; who performed outcome measurement and whether assessors knew the treatment status are not reported in the registry record.
The record gives enrollment of 40 but does not report the number with primary-outcome data at the relevant follow-up or explain whether all enrolled participants were analyzed. Eligibility criteria, baseline characteristics, missing-data procedures, and sensitivity analyses are also not reported. These gaps prevent assessment of participant selection, follow-up completeness, and the robustness of a result.
The study description mentions modified cylinder sizing and a max-inflate technique, but the record does not provide implementation details. The number and identity of participating centers are not reported. No statistical analysis plan or multiplicity approach is reported, and the named secondary outcomes have no posted numerical findings. These limitations restrict both statistical evaluation and interpretation of how broadly the findings could apply.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Evaluation of the Coloplast Titan® IPP for Maintaining Penile Length While Treating Erectile Dysfunction (ED) — NCT00731666.
- Registry record last updated 2013-11-28; status last verified 2013-09.
- Results first posted 2013-11-28.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
The registry record describes NCT00731666, a completed prospective, non-randomized, multicenter, single-group study sponsored by Coloplast A/S. It lists enrollment of 40, an inflatable penile prosthesis intervention, and the Titan® IPP group. The recorded study start is 2007-12, and primary completion is 2010-05.
The primary objective is change in penile length, measured in centimeters and summarized as a mean with standard deviation at the 12-month timeframe. The brief description refers to modified cylinder sizing during implantation and a max-inflate technique after implantation. Secondary outcomes include participant satisfaction with penile length at baseline, 12 months, and 24 months by questionnaire, and the rate of change in male stress urinary incontinence.
Numerical results for the primary and secondary outcomes, the statistical analysis plan, and details on missing data and analysis populations are not reported in the registry record. Safety entries list 1 affected by a serious adverse event and 0 affected by other adverse events; infection is listed at 2.5%. The death count is not reported in the registry record.