Study of Median Lobe Prostatic UroLift Procedure: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study of Median Lobe Prostatic UroLift Procedure (NCT02625545), a na na study. The primary outcome is At 6 Months, the 95% Lower Confidence Limit of the Mean Percent Improvement in IPSS Over Baseline for the UroLift System Must be ≥ 25%..

2. Clinical Question

IPSS is described as a standardized questionnaire about BPH symptoms and quality of life. The primary endpoint focuses on change relative to baseline rather than a comparison with another treatment group. Its criterion is framed in terms of the lower limit of a confidence interval, so it concerns both the estimated mean improvement and the precision of that estimate. The record states the endpoint and its threshold, but not the observed mean percent change, the confidence interval, or whether the threshold was met. Accordingly, the registry entry alone does not resolve the primary question.

3. Trial Design

The study, NCT02625545, is titled “Study of Median Lobe Prostatic UroLift Procedure.” It is listed as completed and as a single-group study of the UroLift System procedure in subjects with BPH and median lobe enlargement. The registry lists enrollment as 45. The start date is 2016-02-17, and the primary completion date is 2017-05-30. The phase is recorded as not applicable.

All eligible, enrolled subjects were to undergo the UroLift procedure. There is no separately listed control arm. Allocation is recorded as not applicable, and masking is listed as none. This design can describe outcomes in the treated group, but it does not provide a concurrent treatment comparison. Differences between baseline and follow-up measurements are within-group changes, not randomized between-group effects.

The primary endpoint is the mean percent improvement in IPSS over baseline at 6 months, evaluated against a criterion based on its 95% lower confidence limit. The primary population is identified as intent to treat. Listed secondary outcomes include IPSS, quality of life, BPHII, and peak flow rate at baseline and 12 Month Follow-up, along with percent changes for those measures. The registry lists 11 outcome measures and 0 analyses.

The sponsor is NeoTract, Inc. Further details about recruitment, eligibility criteria, procedure delivery, follow-up completion, protocol deviations, and statistical analysis planning are not reported in the registry record. In particular, the enrollment entry should not be interpreted as a measure of how many participants contributed data to each endpoint; endpoint-specific denominators are not reported.

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: Intent to treat Population

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

Population: Intent to Treat (analysis population)

6. Primary Endpoint

The registry lists the primary outcome as At 6 Months, the 95% Lower Confidence Limit of the Mean Percent Improvement in IPSS Over Baseline for the UroLift System Must be ≥ 25%., measured over 6 months.

The primary endpoint is the mean percent improvement in International Prostate Symptom Score (IPSS) over baseline at 6 months. The registry sets a criterion: the 95% lower confidence limit for that mean percent improvement must be at least 25%. It identifies the measure as a mean and the dispersion as a 95% confidence interval. The numerical mean, confidence interval, and assessment of whether the criterion was met are not reported in the registry record.

IPSS is a standardized tool described as having 8 questions: 7 symptom questions and 1 quality-of-life question. It concerns symptoms experienced in the last month. Each answer is scored from 0 to 5, for a maximum score of 35 points. The registry notes that scores of 7 or below are generally considered mildly symptomatic, while scores of 20 or above are considered severely symptomatic. These interpretive bands describe the score; they do not provide the study’s baseline or follow-up results.

As a general statistical concept, measuring change from baseline can describe whether the average score shifted over follow-up among the analyzed participants. Expressing that change as a percent relates the change to baseline, but interpretation depends on the calculation and the baseline values. Those calculation details are not reported in the registry record. Using a confidence-limit criterion makes precision part of the endpoint: a mean estimate alone would not establish whether the lower limit reached the stated threshold. The registry entry does not report enough numerical result information to judge either the estimate or its precision.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The endpoint is expressed as a mean, and its uncertainty is described with a 95% confidence interval. The record does not provide the numerical estimate or interval. The following explanations are general statistical context; they do not fill in missing study results or specify methods that are not reported in the registry record.

What does a mean describe?

A mean is a measure of the average value in the analyzed observations. For a change endpoint, it summarizes the changes across participants included in the analysis. It does not show the full distribution of individual responses: people may have changes above or below the average, and the average alone does not describe that variation. A mean can also be influenced by extreme values. The registry identifies a mean percent improvement but does not report the individual observations, their distribution, or further details of the calculation.

What does a confidence interval describe?

General: a confidence interval expresses sampling uncertainty around an estimate under the model and assumptions used to calculate it. Its lower and upper limits define a range of values compatible with the data under that procedure. It is not a guarantee that the true value lies in the interval, nor does it describe the range of individual participant outcomes. The registry specifies a 95% confidence interval and focuses on its lower limit, but the actual limits and the method used to calculate them are not reported in the registry record.

In this study’s endpoint rule, the criterion concerns the lower limit rather than only the estimated mean. This makes both the estimate and its uncertainty relevant to determining whether the rule was satisfied. A mean above the stated threshold would not alone establish that its lower confidence limit also reached that threshold. Because neither the mean nor interval is reported, the criterion cannot be evaluated from the registry entry.

What does percent change add?

General: a percent change expresses change in relation to a reference value, commonly a baseline measure. It can aid interpretation when the starting level matters, but its meaning depends on the precise formula, the direction of scoring, and the baseline distribution. The primary endpoint calls for percent improvement over baseline. Its exact computational definition, handling of baseline values, and treatment of missing follow-up values are not reported in the registry record. No percent change should be inferred from the questionnaire description alone.

What does a single-group design allow?

General: repeated measurements in a single group can describe how observed outcomes vary from baseline to follow-up. A comparator group can help distinguish changes associated with an intervention from changes that might also occur over time or under other influences. This study has no separately listed comparator and no randomized allocation. As a result, its design does not provide a randomized between-group estimate. A before-and-after difference, if reported, would remain a within-group description and would not by itself identify the cause of that change.

The record lists masking as none. In general, masking can reduce some forms of influence on treatment delivery, assessment, or reporting, depending on who is masked and how outcomes are measured. The registry does not provide details about outcome assessment procedures or any steps used to limit measurement influence. No further conclusion about these procedures is supported by the entry.

How should the planning illustrations be read?

The sample-size assumptions describe planning illustrations based on a fraction of the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. They are not the study’s own design description: the registered study is single-group and has no listed comparator. The assumptions say that non-time-to-event illustrations are expressed as participants per arm for 80% power, while time-to-event illustrations use total events. Such planning quantities are not observed power and do not establish that the study had a particular probability of detecting an effect. The illustration values themselves are not reported in the registry record.

General: power calculations depend on the target effect, variability, analysis method, and design assumptions. A calculation using a hypothetical two-arm comparison cannot be read as evidence that a single-group study made that comparison. The record does not report a sample-size justification for the registered study, an interim analysis plan, or a statistical analysis plan. It would be inappropriate to infer those details from the planning assumptions.

Why can over-dispersion matter?

General: over-dispersion means that observed variability is greater than a statistical model assumes. When a model underestimates variability, standard errors and confidence intervals can be too small, making uncertainty appear less than it is. This is a general issue for data analyzed with distributional models; the primary endpoint is described as a mean of a continuous measure. The registry does not report a model choice, a dispersion assessment, or a correction for over-dispersion, so no claim about its presence or handling in this study is warranted.

More broadly, the registry entry names outcome measures and the primary endpoint criterion but does not provide the numerical results or detailed analysis procedures needed to independently evaluate assumptions, reproducibility, or robustness. Statistical explanations clarify what the stated quantities mean; they cannot substitute for unreported estimates, denominators, or analytic details.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 11 outcome measures. These include the primary six-month IPSS endpoint and secondary outcomes concerning IPSS, quality of life, BPHII, and peak flow rate at baseline and 12 Month Follow-up, including percent changes. It also lists 0 analyses. Numerical results for the outcome measures, including estimates and uncertainty, are not reported in the registry record.

Multiplicity arises when several outcomes or statistical tests are considered. General: assessing many outcomes can increase the chance of at least one apparently notable result if each is interpreted without accounting for the wider set of analyses. Approaches to multiplicity can include prespecifying a primary outcome, adjusting inference, or treating secondary findings as exploratory. The registry record does not report a multiplicity strategy, a hierarchy among secondary outcomes, or which results were tested. No adjustment or absence of adjustment can be assumed.

The primary population is identified as intent to treat. That label alone does not specify which participants had usable measurements at each time point, how protocol deviations were handled, or whether all enrolled participants were included in each analysis. Endpoint-specific denominators are not reported in the registry record.

Missing-data methods are also not reported in the registry record. The entry does not state how missing baseline or follow-up scores were handled, whether any imputation was used, or whether sensitivity analyses were conducted. General: missingness can affect an estimate when the availability of measurements is related to participant characteristics or outcomes. The direction and extent of any such effect cannot be assessed without information on missing measurements and the analysis approach. The enrollment entry is not a substitute for those details.

11. 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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: bradycardia/heartblock (2.2%), cervical spinal stenosis (2.2%), pain in hip (2.2%), urinary tract infection (2.2%), aspiration pneumonitis (2.2%).

The registry reports a UroLift System Procedure group with 45 listed as at risk for serious adverse events and 5 listed as affected. For other adverse events, it lists 45 at risk and 36 affected. Deaths are recorded as 0. These are descriptive figures in the registry record; the entry does not provide event-level timing, duration, severity grading beyond the serious-event category, or causal attribution details.

The listed serious adverse event terms are Bradycardia/Heartblock, Cervical spinal stenosis, Pain in hip, Urinary tract infection, and Aspiration pneumonitis. Each is reported as 2.2%. The registry does not provide further information about the number of events corresponding to each term, their timing, or whether they were considered related to the procedure. The terms and percentages should therefore be read as the listed safety information, not as proof of causation or as a complete clinical account.

General: an “at risk” count identifies the group used as the denominator for a reported safety summary, while an “affected” count describes those recorded as having the corresponding type of event. Such summaries do not by themselves indicate how long participants were observed or whether all participants had the same follow-up. Safety comparisons between treatments are not available in a single-group record without a comparator. The safety figures do not establish comparative risk, and they should not be combined with unreported context to infer a treatment effect.

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

The registry record establishes the study’s focus: the UroLift System procedure in subjects with median lobe enlargement due to BPH. It identifies a single-group design and a primary endpoint based on mean percent improvement in IPSS at 6 months. The decision rule requires the 95% lower confidence limit to be at least 25%. These details clarify what the study set out to assess, but the numerical primary result is not reported in the registry record.

Without the mean and its confidence interval, the posted information does not show whether the endpoint criterion was met or how precise the estimate was. Without a comparator, a within-group change cannot establish how outcomes would have differed in a group not receiving the procedure. This does not negate the value of describing outcomes in the study group; it limits the conclusions that can be drawn about cause and comparative effects.

The record lists secondary outcome domains and safety figures, but does not include numerical secondary outcome results or detail the ascertainment and analysis for those measures. The adverse event summary reports affected counts and serious-event terms, but does not establish that the procedure caused any event. The listed deaths figure is 0, within the registry’s safety summary; the record does not provide further follow-up context.

Accordingly, this registry entry supports a description of the study question, design, specified endpoint, and reported safety summary. It does not support a complete assessment of the primary endpoint result, comparative effectiveness, uncertainty around secondary outcomes, or causal attribution of adverse events. Those judgments require outcome estimates, denominators, analytic details, and context that are not reported in the registry record. The design and endpoint should be interpreted separately from any conclusion about whether the procedure benefits or harms patients.

13. Why This Trial Matters Statistically

Statistically, the study is notable for stating a threshold-based primary endpoint rather than only naming a symptom measure. The endpoint specifies the mean percent improvement in IPSS at 6 months and makes the 95% lower confidence limit central to the criterion. This framing underscores that a point estimate and its precision answer related but different questions. The registry, however, does not report the numerical estimate or interval, so the criterion cannot be assessed from the entry.

The single-group design is also central to interpretation. Baseline and follow-up measures can describe within-group change, but without a comparator they do not supply a randomized contrast. This distinction matters when readers move from describing observed changes to attributing those changes to an intervention. Allocation is recorded as not applicable, and the study has no listed control group.

The entry also illustrates the difference between a registry’s outcome descriptions and a statistical results report. It identifies 11 outcome measures and the intent-to-treat population for the primary endpoint, but lists 0 analyses and does not report the endpoint estimates or detailed methods. The outcome names alone cannot establish whether results were analyzed, how missing values were addressed, or how multiple outcomes were interpreted.

Finally, planning assumptions should not be confused with the study’s registered design or with observed power. The assumptions describe illustrations for a two-arm allocation, whereas the study is single-group. Keeping those distinctions clear helps readers avoid treating planning quantities as trial findings. The record is statistically informative about the intended question and important design constraints, while leaving key result and analysis details unreported.

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 for interpretation is the absence of a separately listed comparator. The study is single-group, allocation is recorded as not applicable, and masking is listed as none. The record can therefore describe outcomes in the procedure group but does not provide a like-for-like control comparison. Any change from baseline, if reported elsewhere, would not on its own establish that the procedure caused the change.

The primary endpoint is defined through a mean percent improvement in IPSS at 6 months and a 95% lower confidence-limit criterion. However, the numerical mean, confidence limits, and conclusion against the criterion are not reported in the registry record. The endpoint-specific denominator and the handling of missing follow-up values are also not reported. The enrollment entry alone cannot resolve those issues.

Although several secondary outcomes are named, their numerical results and analysis details are not reported in the registry record. The entry does not state how multiplicity was addressed, whether any sensitivity analyses were conducted, or how outcome assessment was performed. The safety summary supplies affected counts and listed serious-event terms but does not provide detailed timing, duration, causal assessment, or additional follow-up context.

Eligibility criteria beyond the description of median lobe enlargement due to BPH, procedural details, and further information about participant characteristics are not reported in the registry record. This limits assessment of how broadly the study group represents other populations. The record lists a completed study, but completion status does not substitute for numerical endpoint results or a detailed analysis report.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Study of Median Lobe Prostatic UroLift Procedure — NCT02625545.
• Registry record last updated 2019-02-26; status last verified 2019-02.
• Results first posted 2019-02-26.
• 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.

18. Record Summary

NCT02625545 is a completed, single-group study of the UroLift System procedure in subjects with median lobe enlargement due to BPH. The registry lists enrollment as 45, records the phase as not applicable, allocation as not applicable, and masking as none. The start date is 2016-02-17, and the primary completion date is 2017-05-30. NeoTract, Inc. is listed as sponsor.

The primary endpoint is mean percent improvement in IPSS over baseline at 6 months, with a criterion based on the 95% lower confidence limit reaching at least 25%. The numerical primary result and its confidence interval are not reported in the registry record. Secondary outcomes include IPSS, quality of life, BPHII, and peak flow rate. The safety summary lists 5 affected for serious adverse events, 36 affected for other adverse events, and deaths recorded as 0. The record lists 11 outcome measures and 0 analyses.