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 Therapeutic Merit of Solifenacin in the Mitigation of Ureteral Stent-induced Pain and Lower Urinary Tract Symptoms (NCT01381120), a randomized phase 4 study. The primary outcome is Change in Post-ureteroscopy Stent-induced Pain.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01381120 |
| Phase | Phase 4 |
| Condition | Flank Pain, Urinary Bladder, Overactive |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 84 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Barrie Urology Associates |
| Results posted | Yes |
2. Clinical Question
Population
People undergoing ureteroscopy for stone management who had a ureteral stent inserted. The registry lists flank pain and overactive urinary bladder among the conditions. It does not report detailed eligibility criteria or a fuller description of the population included in the primary outcome analysis.
Intervention
Solifenacin, described by the brand name VESIcare, alongside oxycodone and acetaminophen. The registry describes solifenacin as a 5 mg tablet taken daily for three months, with the painkiller described as a 10 mg tablet taken every 6 hours for 5 - 8 days while the stent was inserted.
Comparator
Oxycodone and acetaminophen alone, described as a 10 mg tablet taken every 6 hours for 5 - 8 days while the stent was inserted. The registry does not report a placebo or masking; the trial is listed as having no masking.
Primary question
What change in ureteral stent-associated pain was reported for each treatment group? Pain was measured using the ureteral stent symptom questionnaire on a 0-to-10 scale, with higher values representing greater pain. The outcome is described as the mean difference between baseline and 3 months, calculated as baseline minus the later measurement.
3. Trial Design
The registry describes a randomized, parallel-group, unmasked, phase 4 trial sponsored by Barrie Urology Associates. The recorded enrollment is 84. The trial started in 2010-10, reached primary completion in 2012-06, and is listed as completed. The registry record does not report the randomization method, allocation concealment, or a rationale for the enrollment target.
Participants were assigned to one of two groups: VESIcare plus a narcotic painkiller, or a narcotic painkiller alone. The listed painkiller was oxycodone and acetaminophen. In the combination group, the registry describes VESIcare as a 5 mg film-coated tablet taken daily for three months. The painkiller is described as a 10 mg film-coated tablet taken every 6 hours for 5 - 8 days while the stent was inserted. The comparator group received the painkiller on the same described schedule.
The registry describes stents as being used after ureteroscopy for stone management, with usual removal 5 to 8 days after insertion. It notes that special accommodations would be made in the study if stenting lasted greater than 8 days. These statements describe the study context, not an outcome result.
The primary outcome concerns change in pain, and one secondary outcome is change in stent-induced lower urinary tract symptoms. The registry lists two outcome measures but posts no secondary outcome results in the record. For the primary outcome, results are reported for 39 participants in the combination group and 18 in the painkiller-only group. The registry record does not explain the difference between the recorded enrollment and the numbers reported for this outcome, or identify the analysis population used.
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 | VESIcare + Narcotic Painkiller | Narcotic Painkiller |
|---|---|---|
| STARTED | 50 | 27 |
| COMPLETED | 39 | 18 |
| NOT COMPLETED | 11 | 9 |
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 | VESIcare + Narcotic Painkiller | Narcotic Painkiller | Total |
|---|---|---|---|---|
| Participants analysed | 50 | 27 | 77 | |
| Age Continuous | years | 50.81 (SD 12.36) | 57.54 (SD 18.73) | 53 (SD 15.52) |
| Sex: Female, Male: Female | Participants | 33 | 13 | 46 |
| Sex: Female, Male: Male | Participants | 17 | 14 | 31 |
6. Primary Endpoint
The registry lists the primary outcome as Change in Post-ureteroscopy Stent-induced Pain, measured over Baseline and 3 months..
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | units on a scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is change in post-ureteroscopy stent-associated pain, measured with the ureteral stent symptom questionnaire. The questionnaire asks patients to rate pain on a scale from 0 to 10, where 0 means absence of pain and 10 means the most excruciating pain of their life. The registry reports the mean change, defined as baseline minus the later score, in units on that scale.
The outcome description gives the timeframe as baseline and 3 months. It also says the questionnaire was administered a couple days after surgery and again several weeks later. These descriptions do not give a fully consistent account of when the later measurement occurred. The registry record does not clarify this timing difference.
A pain rating is a continuous measure: it can take values across a scale rather than representing a simple event count. A change score expresses how a participant's reported pain rating differs between measurement times. With baseline minus later score as the stated direction, a positive change corresponds to a lower later pain score than the baseline score, as a matter of the endpoint's definition. The reported mean summarizes the change scores in each group; it does not show how much individual participants varied unless additional distribution information is reported.
Repeated pain measurement is used to describe change over time in a symptom that may vary between people. The registry record does not report a threshold for what would constitute a clinically important change, or a separate analysis comparing the groups' change scores. The group means therefore describe the posted endpoint results but do not, on their own, establish the size or precision of a treatment-group contrast.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry reports a mean pain change of 4.61 units on the 0-to-10 scale in the VESIcare plus narcotic painkiller group, with a 95% confidence interval from 3.75 to 5.46. For the narcotic painkiller group, it reports a mean change of 3.11 units, with a 95% confidence interval from 1.63 to 4.6. These are within-group summaries of the outcome defined as baseline minus the later pain score.
The confidence intervals describe uncertainty around each reported group mean under the statistical procedure used to construct them. They do not show the range of individual participants' changes. Their width reflects the precision of the group mean estimates: a narrower interval indicates greater precision than a wider interval, all else equal. The registry does not name the calculation method or report an adjusted comparison between groups.
The outcome sample sizes reported alongside these means are 39 for the combination group and 18 for the painkiller-only group. The overall recorded enrollment is 84, and the registry record does not explain why the reported outcome sample sizes differ from enrollment. It also does not state whether participants without outcome measurements were excluded, how missing observations were handled, or whether the outcome analysis followed an intention-to-treat approach.
Although the two group means can be read as descriptive results, the registry does not post a between-group effect estimate, confidence interval for a group contrast, or p-value for this continuous outcome. The record also lists no analyses. The observed group means and their separate confidence intervals should therefore not be treated as a formal test of whether the groups differed. Separate intervals do not directly quantify uncertainty in the difference between groups.
The trial is randomized, which can support a fair comparison when allocation and follow-up are appropriately handled. However, the record does not describe the randomization procedure or analysis details. It also lists no masking. Because the endpoint is a patient-reported pain rating, knowledge of treatment assignment could influence reporting or other aspects of care; the registry record does not report whether or how this possibility was addressed.
These results describe the registered outcome and its reported precision. They do not establish a causal effect or tell readers how the findings would apply beyond the trial population. The absence of a posted comparative analysis is particularly important: a difference between the displayed group means cannot be assigned a statistical uncertainty from the two separate intervals alone. No efficacy conclusion should be drawn from the within-group summaries alone.
9. Statistical Methods Explained
A continuous endpoint records a quantity on a scale. Here, the questionnaire score ranges from 0 to 10, and the endpoint is a mean change score. A mean is the arithmetic average of the participant-level measurements included in an analysis. It offers a compact description of a group, but it does not show whether changes were similar across participants or whether a small number of values influenced the average. The registry record does not report a standard deviation or other measure of participant-level spread.
What does a confidence interval describe?
A confidence interval is an estimate of the uncertainty around a statistic, such as a group mean. In repeated use of the same method under its assumptions, intervals constructed at a stated confidence level would cover the target quantity at the corresponding rate. This is a general explanation of confidence intervals, not a claim about the specific calculation procedure used in this trial. The record gives a 95% confidence interval for each group mean, but it does not report the interval method or assumptions.
The reported interval for the VESIcare plus narcotic painkiller group is 3.75 to 5.46 around a mean change of 4.61. The reported interval for the narcotic painkiller group is 1.63 to 4.6 around a mean change of 3.11. Each interval concerns its own group mean. It is not an interval for the difference between treatment groups. A direct comparison would require an estimate of the between-group contrast and its uncertainty, neither of which is posted in the registry record.
Why does the direction of the change score matter?
The registry defines change as baseline minus 3 months. Direction determines how to read a positive or negative value. Under this definition, a positive change means the later pain score is lower than the baseline score. Reversing the subtraction would reverse that interpretation. The registry also describes administration a couple days after surgery and again several weeks later, so the stated assessment timing is not entirely consistent with the baseline and 3 months timeframe. The record does not clarify the intended timing used for the posted results.
What does randomization contribute?
As a general statistical concept, random assignment is intended to make treatment groups comparable, on average, with respect to measured and unmeasured factors at the point of allocation. It does not guarantee that groups are identical, particularly in a trial of limited size, and it cannot correct problems introduced by missing outcomes or analysis choices after assignment. The registry lists this trial as randomized but does not report the method used to generate or conceal assignments. It does not report a prespecified statistical analysis plan, adjusted analysis, or analysis population.
The parallel-group design means participants were assigned to one treatment group rather than crossing between treatments, according to the registry's design classification. The trial is listed as unmasked. In general, masking can reduce the influence of treatment knowledge on participant reports, clinician behavior, and outcome assessment. This matters for a questionnaire-based pain outcome, but the registry does not describe any steps to reduce reporting or assessment bias.
Why can the reported counts differ?
The record lists enrollment of 84, while the primary outcome results are reported for 39 participants in the combination group and 18 in the painkiller-only group. These are reported figures for different parts of the record; they should not be silently reconciled. The registry does not explain the difference, say how many participants had missing measurements, or describe whether the posted outcome results include all randomized participants. Missing outcome data can reduce precision and can bias a comparison if availability of measurements is related to treatment or pain.
For a continuous outcome, an analysis might compare group means, adjust for baseline values, or model repeated measurements. These are general options, not descriptions of what this trial did. The registry does not report which approach was used, whether baseline pain was included in a model, or whether other covariates were considered. It does not post a comparative estimate, p-value, or analysis details. Consequently, readers can interpret the group means and their intervals as descriptive summaries, but cannot reconstruct the trial's inferential comparison from the registry record.
Why does over-dispersion matter?
Over-dispersion is a general concern for count outcomes when observed variability exceeds what a chosen count model expects. It can make standard errors too small and confidence intervals too narrow if the model fails to allow for that extra variability. This trial's primary endpoint is continuous, not a count, so over-dispersion is not the central issue for interpreting the posted pain means. More generally, statistical methods should match the outcome type and its distribution. The registry record does not describe the distributional assumptions used for the continuous endpoint.
Finally, a statistical result and a clinical interpretation answer different questions. Statistical uncertainty concerns how precisely an estimate is known under the analysis assumptions. Clinical importance concerns whether a change matters in context. The registry does not report a clinically important threshold for the pain scale, and the posted group means do not by themselves supply one.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists two outcome measures: the primary outcome of change in post-ureteroscopy stent-induced pain and a secondary outcome of change in stent-induced lower urinary tract symptoms. It posts results for the primary outcome but no secondary outcome results. The registry record does not report whether additional outcomes were assessed, how outcome priorities were set, or whether any multiplicity adjustment was planned or applied.
Multiplicity arises when several outcomes, time points, subgroups, or statistical tests are considered. As a general principle, testing more hypotheses can increase the chance of a nominally unusual result occurring by chance unless the analysis accounts for the testing strategy. The record does not report a testing hierarchy, correction procedure, or statistical analysis plan, so the handling of multiplicity cannot be evaluated.
The primary outcome results are reported for 39 participants in the combination group and 18 in the painkiller-only group, while recorded enrollment is 84. The registry record does not explain the difference or describe how missing observations were handled. It does not identify the analysis population, state whether all randomized participants were included, or describe any imputation or sensitivity analyses. These details matter because missing outcomes can affect both the precision and the validity of a group comparison.
The record also does not report whether the outcome analysis was prespecified, whether the analysis included baseline adjustment, or how deviations from the assigned treatment were handled. These details are not inferable from the posted group means and confidence intervals. Without them, readers cannot assess the robustness of the results to analysis choices or missing data assumptions.
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 |
|---|---|---|---|
| VESIcare + Narcotic Painkiller | 0 | 50 | 0.0% |
| Narcotic Painkiller | 0 | 27 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| VESIcare + Narcotic Painkiller | 0 of 50 |
| Narcotic Painkiller | 0 of 27 |
The registry reports zero serious adverse events among 50 participants at risk in the VESIcare plus narcotic painkiller group, and zero among 27 participants at risk in the narcotic painkiller group. It also reports zero other adverse events among 50 participants at risk in the combination group, and zero among 27 participants at risk in the painkiller-only group. The record lists no serious adverse event terms.
These figures describe events recorded in the registry within the stated at-risk groups. A zero count means no events of that category were reported for the group in this record; it does not establish that no adverse events occurred outside the recorded definitions, observation period, or reporting process. The registry record does not provide details of event definitions, severity assessment, follow-up duration for safety, or the method used to collect adverse events.
The record does not report death counts. That absence should not be read as a zero count. Nor do these safety figures establish a comparative safety profile: the registry does not post a statistical comparison or provide context on completeness of event reporting. The at-risk figures differ from the group counts reported for the pain endpoint, and the record does not explain the relationship between these populations.
12. What the Result Does, and Does Not, Mean
The posted results describe mean change in pain ratings in two randomized groups following ureteroscopy and stent placement. The combination group has a reported mean change of 4.61, with a 95% confidence interval from 3.75 to 5.46. The painkiller-only group has a reported mean change of 3.11, with a 95% confidence interval from 1.63 to 4.6. Because the endpoint is defined as baseline minus the later score, positive values indicate lower later scores relative to baseline.
These are within-group summaries, not a reported estimate of the difference between treatments. The registry does not post a between-group confidence interval, p-value, or other comparative analysis. Separate group means and their separate intervals cannot replace a direct estimate of the contrast. The record therefore does not establish whether any apparent difference between the group summaries is compatible with chance variation, nor how precisely a treatment-group contrast was estimated.
The results also do not show how individual participants' pain changed. A group mean can conceal variation in responses, and no participant-level distribution or measure of spread is reported. The record does not identify a threshold for a clinically important change, so the numerical scale change cannot be classified as clinically important based on the registry information alone.
Because the trial is listed as randomized, the design is intended to support comparison between treatment groups. However, the record does not describe the allocation procedure, analysis population, missing-data handling, or statistical model. It also lists no masking, which is relevant because pain was self-reported. The difference between recorded enrollment and outcome sample sizes is not explained.
The findings should be read as the outcome summaries recorded for this trial, not as a standalone conclusion about treatment benefit or harm. The record does not provide secondary outcome results, a complete statistical analysis, or enough information to assess all potential sources of bias and uncertainty. It also does not establish how well the results apply to people or settings beyond those represented in the trial.
13. Why This Trial Matters Statistically
This trial illustrates why the type of result matters as much as the value itself. The registry reports a mean change for each treatment group, but not a direct comparison between them. A reader can see the group-level summaries and their confidence intervals, yet cannot use those separate intervals as a substitute for the uncertainty around a between-group effect. Distinguishing descriptive estimates from comparative inference is central to reading randomized-trial results.
It also demonstrates the importance of tracking the outcome definition and measurement timing. The endpoint is a patient-reported pain score on a 0-to-10 scale, defined as baseline minus the later score. The registry names baseline and 3 months as the timeframe, but the description also refers to a measurement a couple days after surgery and another several weeks later. Those descriptions leave uncertainty about the exact timing represented by the reported change.
The record highlights the need to understand who contributes to each result. Enrollment is recorded as 84, while the pain outcome summaries have different group sample sizes. The registry does not explain this discrepancy or say how missing data were addressed. A complete interpretation requires not only an estimate, but also clarity about the analysis population and follow-up.
Finally, this example shows how trial design features intersect with the outcome. Randomization is listed, while masking is not. For a self-reported symptom, awareness of treatment assignment may be relevant to how outcomes are reported. The record does not describe procedures or analyses that address this concern. These are not reasons to disregard the results; they are reasons to distinguish what is documented from what remains uncertain.
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 registry record leaves important details about the primary outcome analysis unreported. It does not state the method used to calculate the confidence intervals, provide a direct between-group estimate, or report a p-value. It also does not identify the analysis population, explain how missing measurements were handled, or state whether the analysis included all randomized participants.
There is a difference between the recorded enrollment of 84 and the group sample sizes reported for the primary endpoint, 39 and 18. The record does not explain this difference. The safety figures use separate at-risk counts, and the registry does not explain how these relate to the outcome analysis groups. These distinctions limit assessment of completeness and comparability across results.
The timing description is not fully consistent: the timeframe is given as baseline and 3 months, while the outcome description refers to a couple days after surgery and several weeks later. The record does not clarify which measurement times were used for the reported values. The record also does not report a clinically important threshold for the pain scale, making it difficult to interpret the practical importance of the mean changes.
Randomization is listed, but its method and allocation concealment are not reported. Masking is listed as none. Since pain is reported by participants, treatment awareness may affect reporting; the record does not describe how this was addressed. No statistical analysis plan or details on adjustment for baseline values are reported. The secondary outcome is listed, but its results are not posted. Finally, the registry does not provide safety event definitions, a description of monitoring, or death counts.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Therapeutic Merit of Solifenacin in the Mitigation of Ureteral Stent-induced Pain and Lower Urinary Tract Symptoms — NCT01381120.
- Registry record last updated 2012-08-30; status last verified 2012-08.
- Results first posted 2012-08-22.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
This completed phase 4 trial is listed as randomized, parallel-group, and unmasked, with Barrie Urology Associates as sponsor. Recorded enrollment was 84, with a start date of 2010-10 and primary completion in 2012-06. It compared solifenacin plus oxycodone and acetaminophen with oxycodone and acetaminophen alone after ureteroscopy and ureteral stent placement.
The primary outcome was mean change in post-ureteroscopy stent-associated pain on a 0-to-10 questionnaire scale, defined as baseline minus the later score. The registry reports group means and 95% confidence intervals, but no direct comparative estimate or p-value. One secondary outcome is listed, with no result posted. The record does not explain the outcome sample sizes, missing-data handling, or the difference between the stated assessment timeframe and the timing described in the outcome narrative.