Procedural Discomfort Related to Number of Intradetrusor Botox Injections: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Procedural Discomfort Related to Number of Intradetrusor Botox Injections (NCT05652036), a randomized phase 4 study. The primary outcome is Participant Discomfort Related to BTX-A Injection.

2. Clinical Question

The registry record describes a randomized comparison of two ways to prepare and administer intradetrusor onabotulinumtoxinA for idiopathic overactive bladder. The clinical question is whether participant-reported discomfort around the procedure differs between the two injection approaches. The posted primary outcome is participant discomfort assessed using the Numeric Pain Scale, with higher scores indicating greater pain. The endpoint description says scores are collected before and immediately after the procedure, and that the comparison of interest is the change from before to after between groups.

The distinction between the treatment approaches is the reconstitution volume and the number of injections. Both descriptions specify the same total dose, and both include an injection at the trigone. The posted results show mean scores of 3.2 for the 5 mL Group and 3.6 for the 10 mL Group. Those values alone do not fully resolve the stated question about changes from before to after the procedure, because the result description does not identify the displayed means as change scores. The statistical comparison therefore needs to be read alongside that reporting ambiguity, rather than as an unqualified estimate of the pre-to-post difference.

3. Trial Design

This phase 4 study is recorded as a randomized, single-blind, parallel-group trial. The registry lists an enrollment of 108. The record says the study was completed. The sponsor is The Methodist Hospital Research Institute. Details about who was blinded, how randomization was implemented, and whether allocation was concealed are not reported in the registry record.

Participants were assigned to one of two injection approaches. In the 5 mL Group, 100 units of BTX-A were reconstituted in 5 mL normal saline and given in 5 separate injections of 1 mL. In the 10 mL Group, the same 100-unit dose was reconstituted in 10 mL normal saline and given in 10 separate injections of 1 mL. Each group description specifies one injection at the trigone. The registry identifies the intervention as intradetrusor Botox injections.

The primary outcome is participant discomfort related to BTX-A injection, measured with the Numeric Pain Scale immediately after the procedure, with the stated timeframe extending up to 45min after intradetrusor injections. The endpoint description also says participants assess discomfort before and immediately after the procedure, and that the intended evaluation compares the change in scores between groups. Secondary outcomes listed in the record include the Overactive Bladder Questionnaire Short-Form, overall treatment satisfaction, impression of clinical improvement, and procedural outcomes.

The registry lists the study start as 2022-07-07 and primary completion as 2023-04-06. Further information about recruitment, the allocation procedure, deviations from the planned protocol, and the analysis populations is not reported in the registry record. The posted results should therefore be interpreted from the available arm summaries and analysis entry, without assumptions about additional design or conduct details.

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

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 Participant Discomfort Related to BTX-A Injection, measured over Immediately post-procedure (up to 45min after intradetrusor BTX-A injections).

The primary endpoint concerns participant-reported discomfort around intradetrusor BTX-A injection. The registry specifies the Numeric Pain Scale, an 11-point scale from 0 to 10, on which higher scores indicate greater pain. It describes measurement before and immediately after the procedure, with the post-procedure assessment occurring immediately after the procedure and within the stated timeframe of up to 45min.

The stated comparison is not simply whether one group has a higher score at a single time. The endpoint description says the analysis evaluates the change from pre-procedure to post-procedure scores between study groups. A pre-procedure assessment can provide a reference for each participant’s starting discomfort, while a between-group comparison of change asks whether the shifts differ across the randomized approaches. That is the endpoint as described in the registry; the specific calculation or model used for this change comparison is not reported in the registry record.

The posted arm summaries list mean scores and standard deviations, but do not say whether the means represent post-procedure scores or changes from baseline. This reporting detail matters: a mean change and a mean post-procedure value answer related but distinct questions. The displayed values can describe the posted groups, but they should not automatically be treated as the change-score results named in the endpoint description.

Participant-reported discomfort is relevant to the stated procedural question because it captures the experience of the procedure directly. It is distinct from symptom relief or treatment satisfaction, which appear among the secondary outcomes. The registry does not report a clinically important difference threshold for the Numeric Pain Scale, so the size of the observed difference cannot be classified against such a threshold from this record.

7. Results Posted in the Registry

• 10 mL Group: mean 3.60 versus 3.20 on control; difference 0.40 (95% CI -0.43 to 1.23), standardized effect d = 0.18; z-test p = 0.346.

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a randomized, single-blind, parallel-group study, with one group receiving each injection approach. Random assignment is intended, in general, to make the groups comparable at the start of a study, on average, so that an outcome contrast can be interpreted as a comparison of the assigned approaches. The record does not report the sequence-generation procedure, concealment details, or which people were blinded. Those specifics cannot be inferred from the labels “randomized” and “single-blind.”

What does the mean summarize?

The posted primary outcome is continuous: it is a score on the Numeric Pain Scale, summarized as a mean with a standard deviation. A mean describes the group’s average score. A standard deviation describes spread among individual scores around that mean; it is not a confidence interval and does not directly describe uncertainty in the group average. The 5 mL Group has a mean of 3.2 and standard deviation of 2.3. The 10 mL Group has a mean of 3.6 and standard deviation of 2.1.

The endpoint description states that participants assess discomfort before and after the procedure and that the comparison concerns change in scores. A change score would be calculated for each participant from the measurements at the two times, then summarized or modeled for the group comparison. The registry does not identify whether the posted arm means are post-procedure values or participant-level changes. Nor does it describe an adjustment for the pre-procedure score. Because those details affect the interpretation of a group contrast, they should not be filled in by assumption.

What is a mean difference?

A mean difference expresses the contrast between two group averages in the original measurement units. Here, the posted contrast is 0.4 points, with the 10 mL Group listed as the comparison group against the 5 mL Group. Keeping the original scale makes the size of the contrast easier to relate to the Numeric Pain Scale than a standardized effect would be. The calculation does not by itself say whether a difference matters to participants; the registry does not report a threshold for meaningful change.

The confidence interval accompanying the recalculated contrast reflects uncertainty in that estimated mean difference under the calculation’s assumptions. General statistical explanation: a confidence interval is a range produced by a method that, over repeated studies under its assumptions, would cover the fixed underlying parameter at the stated rate. It is not a probability statement that the particular true value lies within this one interval. An interval that includes zero indicates that the summary data do not rule out a zero mean difference at the corresponding confidence level; it does not prove equality.

How should the p-values be read?

The recalculation reports an unadjusted p-value of 0.346. The registry’s analysis entry gives a two-sided t-test p-value of 0.21. A p-value describes how unusual results at least as incompatible with a null hypothesis would be under that hypothesis and the assumptions of the test. It is not the probability that the null hypothesis is true, and it does not measure the probability that the observed difference occurred by chance in a colloquial sense. The registry does not report a decision threshold or a fuller analysis description alongside its p-value.

A two-sided test considers differences in either direction, rather than specifying in advance that only one direction would count as evidence. “Unadjusted” means the recalculated p-value is not corrected for multiple outcome comparisons. It is based on the posted group summaries and is not a substitute for an analysis that uses participant-level data or the original study analysis plan. The calculation assumes the summaries are appropriate inputs for a simple comparison; the registry does not give enough detail to establish that this reproduces the study team’s exact endpoint analysis.

Why can a t-test be used, and what are its limits?

In general, a two-sample t-test compares means in two independent groups, using the observed variability and sample sizes to quantify uncertainty. Randomized parallel groups are independent in the sense that a participant belongs to one group, not both. The registry’s reported analysis is identified as a two-sided t-test. The recalculation also uses the posted means, standard deviations, and group sizes. The record does not say whether the study team used a pooled-variance version, a variance-unequal version, or a model that accounted for baseline measurements. A particular implementation should not be assumed from the term “t-test” alone.

General statistical explanation: t-based methods can be sensitive to strong departures from their assumptions, including unusual distributions or influential observations, especially when groups are small. A score on a bounded scale has limits by definition, and individual values need not follow a normal distribution. The record does not include participant-level distributions, diagnostic checks, or sensitivity analyses, so these features cannot be assessed. The means and standard deviations summarize the data but do not reveal the shape of each group’s score distribution.

Why does over-dispersion matter?

General explanation: over-dispersion refers to variability greater than a model expects. If variability is underestimated, standard errors may be too small and confidence intervals too narrow; if it is modeled appropriately, uncertainty estimates can better reflect the observed spread. This concept is most directly relevant to outcomes analyzed with models that specify a mean-variance relationship, such as counts. The primary endpoint is a continuous pain score and is summarized with means and standard deviations, so the registry does not report an over-dispersion model or a need for one. The available record also does not report any diagnostic assessment of variance assumptions.

What does the recalculation add?

The recalculated contrast is a simple, unadjusted summary-based analysis. It offers an estimate and confidence interval that are not included with the registry’s reported test entry. The posted analysis and recalculation do not match in p-value, and the reason is not reported in the registry record. The recalculation should therefore be read as a transparent, limited analysis of the displayed summaries, not as a correction to the study team’s analysis or a definitive reconstruction of it.

10. Confidence Intervals and Precision

The recalculated mean difference is 0.4 points, and its 95% confidence interval includes zero. In practical terms, the posted data do not isolate a single, precise value for the contrast. The interval allows for a range of effects that includes no average difference as well as differences in either direction. This is why the point estimate should not be read on its own as a definitive description of the underlying effect.

General statistical explanation: a confidence interval combines the observed estimate with its sampling uncertainty. A narrower interval indicates greater precision, while a wider interval indicates that a broader range of values remains compatible with the data and the method. The interval is not a guarantee that the true effect lies within its endpoints, and it does not describe individual participants’ scores. The standard deviations of 2.3 in the 5 mL Group and 2.1 in the 10 mL Group describe variation among scores, whereas the interval describes uncertainty around the contrast.

The result is limited in precision by the information available in the posted summaries. The group sizes are 52 and 56, and the observed mean difference is small relative to the within-group spread. No adjustment or alternative analysis can be reconstructed from aggregate means and standard deviations alone. The registry also does not clarify whether the group means refer to post-procedure scores or changes from pre-procedure scores, which makes the target of the interval less clear in relation to the endpoint’s stated definition.

The sponsor-reported analysis gives p = 0.21 but does not include an estimate or confidence interval in the registry entry. That p-value cannot by itself show how precisely the effect was estimated. The recalculated interval is useful for understanding uncertainty in the summary-based contrast, but it should not be assumed to be the interval from the sponsor’s analysis.

11. 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 sample-size table is a planning illustration based on the observed effect, not a report of the study’s original design calculations. Its entries give participants per arm for 80% power and participants per arm for 90% power. These are not total sample sizes. The table is not a count of observed participants and should not be confused with the enrollment of 108 in this completed study.

The listed planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is set as a stated fraction of the observed effect. For planning for 100% of the observed effect, The table shows 475 participants per arm for 80% power and 635 participants per arm for 90% power. For planning for 75% of the observed effect, it lists 844 participants per arm for 80% power and 1,129 participants per arm for 90% power. For planning for 50% of the observed effect, it lists 1,897 participants per arm for 80% power and 2,540 participants per arm for 90% power.

In plain terms, 80% power is the probability, under the planning assumptions and for the chosen effect, that the test would detect an effect at the specified significance level if that effect were the true one. The 90% column represents a higher target probability of detection under the same type of assumptions. Increasing that target generally requires more participants. The table also illustrates that smaller effects need more participants to detect: when planning for a smaller fraction of the observed effect, the listed per-arm requirements increase.

These values are not observed power. They are forward-looking illustrations that use the observed effect as an input, not evidence that this trial had a particular probability of finding a result. They do not establish that the original study was designed around these assumptions. The original sample-size justification and planning assumptions are not reported in the registry record. The sample-size curve should be read in the same way as the table: as a planning display conditional on its assumptions, not as an additional outcome result.

12. 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 = 0.400; pooled standard deviation σ = 2.198.
2. n = 2 × (1.96 + 0.842)² × 2.198² / 0.400² = 474.2, rounded up to 475 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 <- 0.4                      # observed difference in means
sigma <- 2.19849863006896                     # 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(5652036)
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 = 475 (80% power), 635 (90% power)
 75% of observed effect: n per arm = 844 (80% power), 1,129 (90% power)
 50% of observed effect: n per arm = 1,897 (80% power), 2,540 (90% power)
power.t.test: 475.2 
Simulated power at n = 475 per arm: 0.799 (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.

13. Analyses Reported by the Sponsor

The registry reports a two-sided t-test for the two groups with p = 0.21. It does not include the corresponding estimate, confidence interval, or enough detail to identify exactly how that test handled the before-and-after measurements described in the endpoint definition. The posted arm summaries give means, standard deviations, and sample sizes; a recalculated unadjusted comparison from those summaries gives a mean difference of 0.4 and p = 0.346.

The p-values differ, and the registry does not report why. The two results should therefore remain distinct. The summary-based recalculation is not a reconstruction of the study team’s full analysis: it uses aggregate data and does not account for any unreported model, baseline adjustment, endpoint derivation, or analysis-population choice. Those features may or may not explain the difference; the registry record does not say.

The sponsor’s analysis entry is the reported study analysis. The recalculation is a supplementary, simple comparison intended to make the posted summaries easier to interpret. Neither p-value alone gives the size and precision of the result. The recalculated contrast and interval add an estimate and uncertainty display for the summary data, while the sponsor’s entry does not supply those details. The available record does not establish that both analyses use an identical endpoint definition or set of participants, so they should not be treated as interchangeable.

14. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome and secondary outcomes that include the Overactive Bladder Questionnaire Short-Form, overall treatment satisfaction, impression of clinical improvement, and procedural outcomes. It also indicates multiple posted outcome measures and analyses. The registry record does not report whether the study used a formal strategy to control the chance of false-positive findings across multiple outcomes, time points, or comparisons. No adjustment for multiplicity is shown for the recalculated p-value.

General statistical explanation: when many hypotheses are tested, the chance of at least one apparently notable result can increase, even if no underlying effect exists. A multiplicity strategy may define a hierarchy of outcomes, adjust thresholds, or otherwise specify how several tests will be interpreted. Without such a strategy in the registry record, secondary results should be viewed as separate findings whose evidential status may differ from that of a prespecified primary analysis. The record does not report enough information to determine how the study team handled this issue.

Missing-data methods are not reported in the registry record. It does not state whether any primary outcome scores were missing, how missing scores were handled, whether participants were included according to their randomized group, or whether any imputation or sensitivity analysis was used. The posted group sizes for the primary summary are 52 and 56, but the record does not explain whether those are all randomized participants or the number with an available endpoint measurement. The registered enrollment is 108; that fact alone does not identify the analysis population.

The analysis population is also not described. The registry does not say whether the primary analysis followed an intention-to-treat principle, included only participants who completed the procedure, or used another population definition. Such choices can matter if participants do not receive the assigned procedure, withdraw, or lack outcome data. None of these circumstances should be assumed from the posted summary.

The record gives no detailed statistical analysis plan, protocol deviations, or interim analysis information. These items are not reported in the registry record. Their absence does not show that they did or did not occur; it limits the ability to evaluate prespecification, missingness, and the handling of multiple analyses.

15. 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 0% reporting threshold.

Most frequent non-serious adverse event terms

The registry’s safety summary lists zero serious adverse events in each group and zero deaths in each group. The serious-event figures are recorded among 36 participants at risk in the 5 mL Group and 43 participants at risk in the 10 mL Group. These at-risk counts differ from the primary-outcome summary sizes, and the record does not explain the difference. The safety figures should be read using their own listed at-risk groups rather than assumed to cover precisely the same participants as the discomfort analysis.

Zero reported serious adverse events means none were recorded in the listed groups for the registry summary. It does not establish that the risk is zero, and it does not show that the approaches have identical safety profiles. Rare events can be difficult to characterize from a trial of this size, and the record does not provide a follow-up duration or detailed event ascertainment information. The registry’s serious-event terms list is empty.

The adverse-event section also lists other adverse events, but those are distinct from serious adverse events. This page’s serious-event interpretation should not be extended to every possible discomfort, complication, or unwanted effect. The registry reports no deaths in either group. These are descriptive registry figures, not a basis for medical advice or a complete comparative safety assessment.

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

The posted results show mean Numeric Pain Scale scores of 3.2 in the 5 mL Group and 3.6 in the 10 mL Group, with standard deviations of 2.3 and 2.1. The recalculated mean difference is 0.4 points, and its confidence interval includes zero. The registry’s own analysis entry reports a two-sided p-value of 0.21. These findings describe the available record: the group means differ modestly, while the statistical summaries do not provide a precise, conclusive estimate of the between-group contrast.

The results do not establish that the two injection approaches are equivalent. Demonstrating equivalence or non-inferiority generally requires a prespecified margin and a suitable analysis; such a margin or analysis is not reported in the registry record. A non-significant result is not proof that the approaches have the same effect. Conversely, the positive point estimate does not establish that one approach causes greater discomfort, particularly given the uncertainty shown by the interval and the reporting ambiguity about whether the posted means are post-procedure values or changes from before the procedure.

The endpoint is participant-reported discomfort, not symptom response, treatment satisfaction, or long-term outcome. Secondary outcomes listed in the registry address some of those other domains, but this interpretation is limited to the primary discomfort result. It also does not establish which procedure participants would prefer or whether any score difference is important to them. A clinically meaningful difference threshold is not reported in the registry record.

The posted safety summary records no serious adverse events or deaths in either listed group. This is a descriptive observation and cannot rule out uncommon events or establish equal safety. The available record also does not report the analysis population, missing-data methods, or full statistical plan, limiting assessment of how the primary result was generated.

In short, the result is best read as an uncertain comparison of the posted discomfort summaries, not as a definitive demonstration for or against either injection approach. The conclusions are bounded by the reported data and by the information absent from the registry entry.

17. Why This Trial Matters Statistically

This trial is statistically interesting because it compares two procedural approaches while keeping the described total dose and injection-site feature the same. The 5 mL approach uses 5 injections, while the 10 mL approach uses 10 injections; both descriptions specify one injection at the trigone. That setup makes the procedure-related question concrete: whether participants report different discomfort around the procedure under the two templates.

The registry also illustrates why endpoint definitions matter. The stated primary endpoint is a comparison of pre-to-post change in pain scores, but the posted group summaries do not say whether their means are changes or post-procedure measurements. That distinction affects what the estimate means. Clear reporting of the derived endpoint, its timing, and the analysis used would make the result easier to interpret and reproduce.

The example also shows why estimates and confidence intervals are valuable alongside p-values. The registry reports a p-value but no effect estimate or interval for its own analysis. A summary-based recalculation supplies an estimate and an interval, making the uncertainty more visible, while still leaving unresolved whether the calculation matches the sponsor’s analysis. Keeping those analyses distinct is important for transparent interpretation.

Finally, the sample-size illustrations show how planning depends on the effect a study aims to detect and the desired power. They are not a replacement for the original design rationale and do not tell readers what the study was powered to find. Together, these features make the record a useful example of interpreting randomized clinical research while distinguishing observed summaries, reported tests, and planning illustrations.

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 limitations arise from the trial-specific information available in the registry. The primary outcome is described as a comparison of change from before to after the procedure, but the posted group means are not identified as change scores or post-procedure scores. That ambiguity makes it difficult to determine how directly the displayed estimate answers the primary question.

The registry reports a sponsor-analysis p-value but no corresponding effect estimate or confidence interval. A recalculated test from the posted summary data yields a different p-value, and the reason for the difference is not reported. Without participant-level data and a fuller analysis description, the recalculation cannot resolve that difference or verify the exact endpoint derivation.

The record does not state who was blinded, how allocation was generated or concealed, whether the analysis followed randomized assignment, or how missing outcome values were handled. It also does not report baseline characteristics, distributions of individual pain scores, a threshold for clinically important difference, or details of any sensitivity analyses. These are specific reporting gaps that constrain evaluation of this comparison.

The safety summary uses at-risk counts that are distinct from the primary-outcome group sizes, without explaining the difference. Serious-event follow-up duration and ascertainment methods are not reported. The registry lists zero serious adverse events and deaths, but those counts do not rule out uncommon events or establish equal safety.

Finally, the registry does not report the original sample-size justification or the planned strategy for multiple outcomes and analyses. The sample-size display is an illustration based on the observed effect, not evidence of the study’s original design assumptions. These limitations do not negate the posted data; they define how narrowly the result should be interpreted.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Procedural Discomfort Related to Number of Intradetrusor Botox Injections — NCT05652036.
• Registry record last updated 2025-04-13; status last verified 2025-03.
• Results first posted 2025-04-13.
• 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

NCT05652036 is a completed phase 4 randomized, single-blind, parallel-group trial of two intradetrusor BTX-A reconstitution and injection approaches for idiopathic overactive bladder. The registry lists enrollment of 108. One group received 100 units reconstituted in 5 mL normal saline as 5 injections; the other received the same dose in 10 mL normal saline as 10 injections. Each group description includes one trigone injection.

The primary outcome is participant-reported discomfort on the Numeric Pain Scale, described as a comparison of change from before to after the procedure. Posted mean scores are 3.2 and 3.6, with a recalculated mean difference of 0.4 and a confidence interval that includes zero. The registry reports a two-sided t-test p-value of 0.21; the summary-based recalculation gives p = 0.346. The record does not explain the difference or clarify whether the posted means are change scores. The registry reports zero serious adverse events and zero deaths in both listed safety groups.