Photoselective Vaporization of the Prostate With the GreenLight XPS™ Laser System vs TURP for the Treatment of BPH: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Photoselective Vaporization of the Prostate With the GreenLight XPS™ Laser System vs TURP for the Treatment of BPH (NCT01218672), a randomized na study. The primary outcome is International Prostate Symptom Score (IPSS).

2. Clinical Question

In practical statistical terms, the posted primary result compares the average recorded symptom score between the treatment groups at the stated follow-up. It does not report a change from baseline: baseline IPSS values and a change-score analysis are not reported in the registry record. Nor does this comparison, on its own, describe every participant’s experience or the full course of symptoms after treatment.

The study also tracked procedural and post-procedural outcomes. Listed secondary outcomes include maximum urinary flow rate, freedom from complications, prostate volume, immediate and later post-treatment outcomes, health status, tolerability measures, and subject satisfaction. Those outcomes give other perspectives on the comparison, but they are not substitutes for the primary symptom-score question.

3. Trial Design

The registry describes a prospective, multicenter, randomized study comparing photoselective vaporization of the prostate with TURP for benign prostatic hyperplasia. The study used a parallel-group design and had no masking. The registry lists enrollment of 291 and marks the study as completed. It lists the phase as NA.

The treatment arms were GreenLight XPS photoselective vaporization and TURP using monopolar or bipolar systems. Random allocation is part of the recorded design, but the primary outcome population is described as an as-treated analysis: participants were analyzed according to treatment received, and only those who received a study treatment and had an available outcome measure were included. That differs from simply assuming that every randomized participant contributed to the primary-outcome comparison.

The primary outcome was IPSS at 6 months. The registry also lists secondary outcomes that address urinary flow, prostate volume, complications, immediate post-treatment outcomes, health status, tolerability, and satisfaction. Numerical results for some secondary measures are posted, with outcome-specific analysis counts that differ. The detailed reasons for those differences are not reported in the registry record.

The study began in 2011-04, and its primary completion date is 2014-10. These are registry dates, not a description of the timing of every participant’s follow-up. The original protocol’s sample-size justification, statistical analysis plan, allocation-concealment procedures, and any interim analyses are not reported in the registry record. The record does not state whether masking was considered feasible; it records no masking.

Randomization can support a fair comparison when maintained through conduct and analysis, but the reported as-treated population may not preserve all the protections of comparing participants strictly according to their randomized assignment. The record does not provide enough detail to assess departures from assigned treatment or the consequences of any such departures.

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.

Before assignment: Ten subjects were determined to be ineligible for the study procedure and were withdrawn before randomization (i.e., study procedure not performed).

Overall Study

Analysis population for the primary outcome, as defined in the registry: The analysis includes all subjects who received a study treatment and for whom the outcome measure is available. Subjects were analyzed according to treatment received (as-treated analysis).

5. Baseline Characteristics

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

6. Primary Endpoint

The registry lists the primary outcome as International Prostate Symptom Score (IPSS), measured over 6 months.

The primary endpoint is the International Prostate Symptom Score (IPSS), measured at 6 months. IPSS is a patient-administered seven-question instrument used to classify the severity of benign prostatic hyperplasia symptoms. Its total score ranges from 0 to 35, from asymptomatic to very symptomatic. The posted outcome is a mean, accompanied by a standard deviation for each treatment group.

As a general measurement concept, a symptom score puts several patient-reported experiences into a consistent scale. A group mean offers a compact description of the average recorded score, while the standard deviation describes how spread out scores are within that group. Neither measure reveals the full distribution or shows how many participants experienced a particular degree of symptom burden.

The endpoint is relevant to the clinical question because the study concerns urinary symptoms associated with benign prostatic hyperplasia. It gives a patient-reported perspective alongside the procedure-focused and other post-treatment outcomes. The registry specifies an as-treated analysis among participants who received treatment and had an available IPSS result. Baseline scores, change from baseline, and the handling of missing endpoint data beyond that population description are not reported in the registry record.

7. Results Posted in the Registry

• TURP: mean 5.60 versus 6.80 on control; difference -1.20 (95% CI -2.42 to 0.02), standardized effect d = -0.24; z-test p = 0.053.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Maximum Urinary Flow Rate (Qmax)

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • TURP: mean 24.30 versus 23.30 on control; difference 1.00 (95% CI -1.76 to 3.76), standardized effect d = 0.09; z-test p = 0.478.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between TURP and the control. The interval gives the range of effects that remain compatible with the data.

Prostate Volume

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • TURP: mean 20.50 versus 23.00 on control; difference -2.50 (95% CI -5.35 to 0.35), standardized effect d = -0.21; z-test p = 0.086.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between TURP and the control. The interval gives the range of effects that remain compatible with the data.

Immediate Post Treatment Outcomes of PVP and TURP

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • TURP: mean 97.80 versus 65.50 on control; difference 32.30 (95% CI 17.07 to 47.53), standardized effect d = 0.51; z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically higher for TURP than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

The registry lists nine posted secondary outcomes spanning urinary flow, prostate volume, complications, immediate and later post-treatment outcomes, health status, tolerability, and satisfaction. Numerical results available in the record cover several different kinds of measures and follow-up timings. Their analysis counts vary by outcome, so each comparison is based on the participants with data for that measure rather than necessarily the same analysis population as the primary endpoint.

Across the continuous secondary results with recalculated comparisons, the observed directions are not uniform. The flow-rate comparison and the immediate post-treatment outcome have positive estimated differences for TURP relative to GreenLight XPS, while the prostate-volume estimate is negative. Their confidence intervals and unadjusted p-values differ in width and position. These comparisons add context but do not alter what the primary IPSS estimate says: the primary endpoint is a distinct patient-reported measure at 6 months, whereas the secondary outcomes measure other features and may use different time frames.

As a general statistical concern, multiple outcome comparisons create more opportunities for apparently notable findings to arise by chance. The registry does not report a multiplicity adjustment or a hierarchy for interpreting secondary outcomes. It also lists no reported analyses. For that reason, unadjusted secondary results should carry less weight than a prespecified, appropriately controlled analysis would, particularly when considered one at a time. The record does not say which secondary outcomes were intended to support confirmatory conclusions.

Secondary findings should therefore be treated as descriptive evidence about the outcomes measured, not as a single overall verdict on the procedures. Differences in outcome definitions, follow-up times, and available analysis counts also mean that the results do not all answer the same question. The registry record does not provide enough information to determine whether missing data or additional analysis choices affected their comparisons.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Maximum Urinary Flow Rate (Qmax)
• Freedom From Complications
• Prostate Volume
• Post Treatment Outcomes of PVP and TURP
• Immediate Post Treatment Outcomes of PVP and TURP
• Health Status of PVP and TURP
• Tolerability of PVP and TURP Assessed Using International Index of Erectile Function (IIEF-5) and International Consultation on Incontinence Questionnaire - Short Form (ICIQ-SF)
• Subject Satisfaction of PVP and TURP

9. Statistical Interpretation

10. Statistical Methods Explained

The primary comparison is a difference between group means for a continuous measure. In the posted results, the two group means are IPSS values at 6 months. The comparison is expressed as TURP minus GreenLight XPS, so a negative estimate means the observed mean was lower in the TURP group. This direction describes the arithmetic contrast; its clinical meaning depends on the instrument and context, and a threshold for a meaningful difference is not reported in the registry record.

What does a mean describe?

As a general statistical concept, a mean is the sum of measured values divided by the number of values contributing to that estimate. It describes a group’s average, not the score of a typical individual in every respect. The standard deviation describes the spread of participant scores around the mean. A larger standard deviation indicates more variability in the measured scores. For the primary endpoint, the reported means were 6.8 and 5.6, and the reported standard deviations were 5.2 and 4.9. These summaries do not reveal skewness, outliers, or the number of participants at each score.

What does the mean difference show?

The estimated mean difference was -1.2, with TURP as the comparison arm relative to GreenLight XPS. This is a difference in average endpoint scores, not a relative percentage change and not an estimate of the difference between each participant’s own before-and-after values. Baseline values are not reported in the registry record. The comparison also does not adjust for additional variables, based on the recalculated summary-statistic analysis.

How should the standardized effect be read?

A standardized effect expresses a group difference in units of pooled standard deviation. As a general concept, this can help describe the size of a mean contrast when measures use different scales, but it does not replace interpretation in the original units. The recalculated standardized effect for the primary outcome was -0.237. The sign follows the direction of the mean difference. The registry record does not state a clinical-importance threshold for this standardized value.

What does the p-value address?

The unadjusted p-value was 0.053. In general, a p-value measures how compatible the observed data are with a specified null model, under the assumptions of the test. It is not the probability that the null model is true, and it does not measure the probability that the result will replicate. A p-value also does not tell whether a difference is large enough to matter. The registry’s original statistical plan and its intended testing threshold for the primary analysis are not reported in the registry record, so the posted p-value should not be treated as evidence of a protocol-defined decision rule.

Why report a confidence interval?

A confidence interval communicates uncertainty around an estimate. In general, a 95% confidence interval is generated by a method that, under repeated use of its assumptions, would cover the target parameter in 95% of such intervals. It is not a range that assigns a 95% probability to the fixed true value after observing these data. The interval for the primary mean difference extends from -2.416 to 0.016. Its width reflects the precision of the estimate, and its inclusion of no difference means the data do not pin down the direction with the same precision as a narrow interval entirely on one side of no difference.

What does recalculation mean?

The displayed comparison and standardized effect are simple unadjusted recalculations from the posted group summaries. They are not described as the sponsor’s original analysis. The discrepancy indicator is false, so no conflict with a sponsor analysis is identified in the registry record. However, the record lists no reported analyses, and the method used for any original analysis is not described. The recalculated comparison should therefore be read as a transparent summary-statistic comparison rather than as a reconstruction of every element of the trial’s analysis plan.

What can the outcome counts tell us?

The primary endpoint counts were 134 for GreenLight XPS and 131 for TURP. These are counts contributing to the reported outcome summaries, not necessarily a complete account of the randomized population. The registry’s primary-outcome description says that participants had to have received treatment and have an available outcome, and that they were analyzed according to treatment received. Reasons for missing values and the methods, if any, used to address them are not reported in the registry record.

11. Confidence Intervals and Precision

The primary mean difference is -1.2 IPSS units, and its 95% confidence interval runs from -2.416 to 0.016. The interval is the clearest compact account of precision: it shows that the estimated contrast is uncertain enough to include no difference, as well as values on the negative side. The point estimate alone would hide that uncertainty. Conversely, the interval should not be read as a list of equally likely values or as proof that every value within it is plausible under every analysis.

In general, confidence intervals combine an estimate with its sampling uncertainty. Their width depends on factors such as variability in the measured outcome, the amount of information available, and the analysis method. Here, the endpoint standard deviations were 5.2 and 4.9, with outcome counts of 134 and 131. Those summaries help contextualize the estimate, but they do not remove uncertainty or establish clinical importance.

The unadjusted p-value of 0.053 and the interval are consistent descriptions of uncertainty for this recalculated comparison. Neither alone establishes equivalence or a clinically meaningful advantage. The registry does not report a threshold for clinical importance or a prespecified statistical analysis plan, so the intended interpretation of the boundary around no difference is not reported in the registry record.

These are unadjusted results based on posted summary statistics. The interval does not account for any multiplicity adjustment or additional covariate adjustment. Such procedures are not reported in the registry record. Thus, the interval gives precision for the recalculated comparison as stated, not a complete accounting of all uncertainties related to trial conduct, missing outcomes, or analysis choices.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning figures are participants per arm for the continuous-outcome comparisons. They are not total event counts. They use a planning illustration based on the observed effect, a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The target effect is set to the stated fraction of the observed effect. These assumptions describe the illustration, not the trial’s original design assumptions; the original sample-size justification and design assumptions are not reported in the registry record.

The 80% power column gives the illustrated number of participants per arm for a design with an 80% chance of detecting the specified effect under the stated assumptions, if that effect and those assumptions hold. The 90% power column represents a higher chance of detecting that same specified effect, and therefore generally calls for more participants per arm. For example, the primary-outcome planning figures are 279 participants per arm for 80% power and 373 participants per arm for 90% power when planning for 100% of the observed effect. Planning for 75% of the observed effect gives 496 and 663 participants per arm, respectively; planning for 50% gives 1,114 and 1,492.

Smaller effects are harder to distinguish from sampling variation, so the illustrated requirement rises as the assumed effect becomes smaller. The values are planning illustrations, not observed power. They do not show the probability that the completed trial’s result is correct, and they do not establish what the trial was originally designed to detect. The record does not report the protocol’s original target effect or planned sample-size calculation.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -1.200; pooled standard deviation σ = 5.054.
2. n = 2 × (1.96 + 0.842)² × 5.054² / -1.200² = 278.4, rounded up to 279 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- -1.2                      # observed difference in means
sigma <- 5.05393721457057                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(1218672)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 279 (80% power), 373 (90% power)
 75% of observed effect: n per arm = 496 (80% power), 663 (90% power)
 50% of observed effect: n per arm = 1,114 (80% power), 1,492 (90% power)
power.t.test: 279.4 
Simulated power at n = 279 per arm: 0.798 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

The registry record does not report a statistical analysis plan describing how multiple outcomes or repeated comparisons were to be handled. It lists nine posted secondary outcomes and no reported analyses. A multiplicity adjustment, testing hierarchy, or distinction between confirmatory and exploratory outcomes is not reported in the registry record. Without that context, individual unadjusted secondary p-values should be interpreted cautiously rather than treated as independent confirmatory evidence.

The primary endpoint is described as an as-treated analysis of participants who received treatment and for whom IPSS was available. Participants were analyzed according to treatment received. The record does not report an intention-to-treat result, a per-protocol result, or a comparison based strictly on randomized assignment. Nor does it describe how many randomized participants lacked an endpoint or why outcomes were missing. The outcome counts vary across measures, but the record does not explain the reasons for those differences or the method used to handle missing data.

Randomization is intended to create comparable groups at assignment, but analyzing participants according to treatment received can affect that comparability if treatment received differs from assigned treatment. Whether that occurred, and whether it affected the results, is not reported in the registry record. No conclusions about the extent or impact of such differences can be drawn from the posted summaries.

The record does not report interim analyses, the original sample-size justification, or the protocol’s planned statistical methods. It also does not give details of allocation concealment or adjustments for baseline characteristics. These omissions limit assessment of whether the reported comparisons follow prespecified methods and whether the available outcome population represents the randomized groups. They do not by themselves demonstrate that a particular bias occurred; they identify information needed to judge the analysis more fully.

15. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: bleeding (6.0%), stricture (5.9%), urinary retention (4.5%), urinary incontinence (4.4%), urinary tract infection (2.2%).

The registry lists serious adverse events among 24 of 136 participants at risk in the GreenLight XPS group and 25 of 133 at risk in the TURP group. Other adverse events are listed as affecting 68 of 136 at risk in the GreenLight XPS group and 57 of 133 at risk in the TURP group. These are posted counts with their corresponding at-risk denominators; they should not be treated as a complete account of event timing, severity beyond the listed categories, or causal relationship to treatment.

The record also lists serious-event terms and percentages: Bleeding, 6.0%; Stricture, 5.9%; Urinary Retention, 4.5%; Urinary Incontinence, 4.4%; Urinary Tract Infection, 2.2%; and Other, 0.8%. Those terms are not assigned to a treatment group in the listed summary. Deaths are not reported in the registry record.

Adverse-event counts are descriptive. The registry record does not provide further details needed to compare event rates with adjustment, clarify event definitions, or assess whether events were considered related to treatment. They should be read alongside, not substituted for, the efficacy outcomes.

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

The posted primary result describes average IPSS values at 6 months among participants who received treatment and had an available outcome, analyzed according to treatment received. The observed mean was lower in the TURP group, with a recalculated mean difference of -1.2 relative to GreenLight XPS. The confidence interval extends from -2.416 to 0.016, and the unadjusted p-value is 0.053. Together, these statistics show an estimated difference with uncertainty that includes no difference; they do not establish equivalence or a clinically important difference.

The result does not describe change from baseline, because baseline scores and a change analysis are not reported in the registry record. It does not show how every participant’s symptoms changed, or whether the average contrast applies equally across different participants. A threshold for a meaningful IPSS difference is also not reported.

The trial’s randomized, parallel design provides a framework for comparing the procedures, but the posted primary analysis is as-treated rather than described as an analysis of everyone according to randomized assignment. The registry record does not provide details of missing outcomes, departures from assigned treatment, or the analysis plan. Those gaps limit how completely the posted estimates can be interpreted.

The secondary measures and adverse-event summaries add information about other observed outcomes, but they do not combine into a single overall measure of benefit or harm. Multiple unadjusted comparisons may be less reliable as confirmatory evidence, and the record does not report a multiplicity plan. These results should be understood as summaries of the outcomes and populations recorded, not as treatment advice or a guarantee about outcomes for an individual.

17. Why This Trial Matters Statistically

This trial is statistically informative because it places a patient-reported symptom measure alongside a randomized comparison of two procedures and a range of other outcomes. The primary endpoint is not a procedural surrogate alone: it is a score based on participant responses to questions about symptoms. The other listed measures broaden the scope to urinary flow, prostate volume, complications, immediate post-treatment outcomes, health status, tolerability, and satisfaction.

The primary result also illustrates why a point estimate should not be read without its uncertainty. The mean difference favors a lower observed score in the TURP group, while the confidence interval reaches across no difference. The p-value of 0.053 cannot by itself determine whether the difference matters, and no clinical-importance threshold is reported. The estimate, interval, and outcome scale answer related but distinct questions.

The record offers a useful example of how analysis population affects interpretation. Although allocation was randomized, the primary outcome is described as an as-treated analysis among participants with an available result. Outcome counts differ across measures, and the record does not explain missingness or report an intention-to-treat result. These are important details when assessing whether the comparison retains the protections expected from random allocation.

Finally, the registry’s missing statistical-plan details matter. The original sample-size assumptions, multiplicity handling, interim analyses, and reported sponsor analyses are not described. Planning illustrations based on observed effects cannot replace the original design rationale. These features make careful separation of posted observations, recalculated comparisons, and unreported protocol choices essential to statistical interpretation.

18. 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.

Several trial-specific limitations of interpretation follow from the registry record. The primary endpoint is reported for an as-treated population with an available IPSS result, rather than explicitly for all participants according to randomized assignment. The record does not report how many participants lacked IPSS results, why data were unavailable, or how missing outcomes were handled. The reported analysis counts also vary by outcome, with no explanation of the variation.

The primary result is a comparison of endpoint means at 6 months. Baseline IPSS values and changes from baseline are not reported, so the summaries do not show how scores shifted within each treatment group. A clinical-importance threshold is not reported either. The registry’s original analysis plan and sample-size justification are absent, as are details about interim analyses, multiplicity adjustment, and any planned covariate adjustment.

The record states that the study was randomized and had no masking, but it does not report allocation-concealment procedures or details of how treatment assignment and treatment received related to each other. It also does not report a participant-flow account. These gaps prevent a complete assessment of potential departures from assigned treatment and their impact.

Safety summaries provide counts and a list of serious-event terms, but the listed terms are not attributed to treatment groups in the summary. Further details on event definitions, timing, seriousness assessment, and treatment relationship are not reported in the registry record. The available results therefore support a limited descriptive reading rather than a comprehensive safety comparison.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Photoselective Vaporization of the Prostate With the GreenLight XPS™ Laser System vs TURP for the Treatment of BPH — NCT01218672.
• Registry record last updated 2020-09-03; status last verified 2020-07.
• Results first posted 2020-09-03.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

22. Record Summary

NCT01218672 is a completed, prospective, multicenter randomized parallel-group study comparing GreenLight XPS photoselective vaporization with TURP for benign prostatic hyperplasia. The registry records no masking and enrollment of 291. The primary outcome is mean IPSS at 6 months among participants who received treatment and had an available result, analyzed according to treatment received.

The posted mean IPSS values were 6.8 for GreenLight XPS and 5.6 for TURP. The recalculated unadjusted mean difference, TURP relative to GreenLight XPS, was -1.2, with a 95% confidence interval from -2.416 to 0.016 and an unadjusted p-value of 0.053. The record also posts secondary outcomes and adverse-event summaries, but does not report the original statistical plan, multiplicity approach, or missing-data methods.