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 Barbed Suture Versus Non-Barbed Suture for Posterior Colporrhaphy (NCT04658784), a randomized na study. The primary outcome is Post-operative Posterior Compartment Pain Scores - Posterior Repair.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04658784 |
| Phase | NA |
| Condition | Rectocele |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 72 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Wake Forest University Health Sciences |
| Results posted | Yes |
2. Clinical Question
Population
Participants undergoing posterior colporrhaphy for rectocele were enrolled. The trial record reports an enrollment of 72. It does not provide further eligibility details or a description of participant characteristics in the information available for this analysis.
Intervention
The intervention was posterior colporrhaphy closure using a standardized technique with barbed 2-0 V-Loc 90TM suture from Medtronic. The trial description identifies the material as a delayed absorbable barbed suture.
Comparator
The comparator was posterior colporrhaphy closure using a standardized technique with conventional 2-0 PDS® Ethicon suture, described as non-barbed and delayed absorbable. Both arms therefore concerned suture choice within posterior repair, rather than different repair procedures.
Primary question
At week 6, how did postoperative posterior compartment pain, measured with a visual analog scale and reported in pain categories, compare between participants assigned to barbed suture and those assigned to non-barbed suture? The registry record does not report the category counts or a single comparative result for this primary outcome.
3. Trial Design
The registry record describes a randomized, double-masked, parallel-group trial. Participants were assigned to posterior repair using either barbed or non-barbed suture. The record lists 72 participants as enrolled. The allocation ratio, the method used to generate the random sequence, and the process used to conceal allocation before assignment are not reported in the registry record. The record says the trial was double masked but does not identify which participants, clinicians, assessors, or other personnel were masked, or how masking was maintained.
The intervention descriptions specify a standardized closure technique in both arms. The barbed arm used 2-0 V-Loc 90TM, Medtronic; the control arm used conventional 2-0 PDS® Ethicon. The record describes both as delayed absorbable sutures. It characterizes the study as a randomized controlled trial and lists the phase as not applicable. The sponsor is Wake Forest University Health Sciences.
The trial status is completed. The record lists a start date of 2020-08-14 and a primary completion date of 2021-11-05. These dates describe the registry record and do not establish when results were analyzed or reported. A protocol description beyond the summary, the original sample-size justification, and details of the planned statistical analysis are not reported in the registry record. The listed planning assumptions are illustrations based on the observed effect, not documentation of the trial's original design rationale.
The registry lists postoperative posterior compartment pain as the primary outcome, assessed at week 6. Secondary outcomes include posterior compartment pain scores, operative time, suture burden, changes in bowel function, pelvic organ prolapse symptoms and postoperative sexual function, early anatomic recurrence, and subjective failure. The record lists 11 outcome measures and 7 analyses, but those totals alone do not specify how outcomes were tested or how analyses were selected.
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.
Enrollment to 6-week Follow-up
| Stage | Intervention | Control |
|---|---|---|
| STARTED | 36 | 36 |
| COMPLETED | 36 | 36 |
| NOT COMPLETED | 0 | 0 |
6-month Follow-up
| Stage | Intervention | Control |
|---|---|---|
| STARTED | 36 | 36 |
| COMPLETED | 34 | 31 |
| NOT COMPLETED | 2 | 5 |
Reasons for not completing this period:
| Reason | Intervention | Control |
|---|---|---|
| Lost to Follow-up | 2 | 5 |
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 | Intervention | Control | Total |
|---|---|---|---|---|
| Participants analysed | 36 | 36 | 72 | |
| Age, Continuous | Years | 57.6 (SD 10.5) | 58.2 (SD 11.0) | 57.9 (SD 10.7) |
| Sex/Gender, Customized: Female | Participants | 36 | 36 | 72 |
| Race/Ethnicity, Customized: White | Participants | 34 | 34 | 68 |
| Race/Ethnicity, Customized: Black | Participants | 2 | 1 | 3 |
| Race/Ethnicity, Customized: Other | Participants | 0 | 1 | 1 |
| BMI kg/m^2 | kg/m^2 | 27.8 (SD 3.9) | 28.3 (SD 4.9) | 28.0 (SD 4.4) |
| Tobacco use | Participants | 1 | 1 | 2 |
| Sexually active | Participants | 22 | 27 | 49 |
| Vaginal estrogen use | Participants | 3 | 7 | 10 |
| Total Pelvic Organ Prolapse Quantification (POP-Q) Stage: POP-Q Stage 0 | Participants | 0 | 0 | 0 |
| Total Pelvic Organ Prolapse Quantification (POP-Q) Stage: POP-Q Stage I | Participants | 0 | 1 | 1 |
| Total Pelvic Organ Prolapse Quantification (POP-Q) Stage: POP-Q Stage II | Participants | 27 | 16 | 43 |
| Total Pelvic Organ Prolapse Quantification (POP-Q) Stage: POP-Q Stage III | Participants | 8 | 16 | 24 |
| Total Pelvic Organ Prolapse Quantification (POP-Q) Stage: POP-Q Stage IV | Participants | 1 | 3 | 4 |
| Posterior Compartment Pelvic Organ Prolapse Quantification (POP-Q) Stage (0-IV): POP-Q Stage 0 | Participants | 2 | 1 | 3 |
| Posterior Compartment Pelvic Organ Prolapse Quantification (POP-Q) Stage (0-IV): POP-Q Stage I | Participants | 8 | 4 | 12 |
| Posterior Compartment Pelvic Organ Prolapse Quantification (POP-Q) Stage (0-IV): POP-Q Stage II | Participants | 26 | 25 | 51 |
| Posterior Compartment Pelvic Organ Prolapse Quantification (POP-Q) Stage (0-IV): POP-Q Stage III | Participants | 0 | 5 | 5 |
| Posterior Compartment Pelvic Organ Prolapse Quantification (POP-Q) Stage (0-IV): POP-Q Stage IV | Participants | 0 | 1 | 1 |
| Prior pelvic reconstructive surgery | Participants | 3 | 2 | 5 |
6. Primary Endpoint
The registry lists the primary outcome as Post-operative Posterior Compartment Pain Scores - Posterior Repair, measured over Week 6.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is postoperative posterior compartment pain after posterior repair, assessed at week 6. The registry describes measurement with the visual analog scale, a validated scale ranging from 0-100mm. A score of 0mm corresponds to no pain, while 100mm corresponds to the worst possible pain. The record reports the outcome in four categories: no pain, VAS 0; low pain, VAS 1-33; moderate pain, VAS 34-66; and high pain, VAS 67-100.
In general, a pain scale gives participants a structured way to report a subjective experience. Grouping scores into categories can make a distribution easier to describe, but it also retains less detail than reporting each score across the full scale. A comparison of categories could describe whether participants fell into different levels of reported pain, but the particular method used to compare categories depends on the analysis plan.
The registry record does not report how many participants were in each pain category in either arm, nor does it provide a single summary comparison for the primary outcome. It also does not report the handling of missing week 6 assessments. Without category counts or a comparative estimate, the outcome definition explains what was intended to be measured, but does not show the observed pain distribution or the precision of a treatment contrast.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The key interpretive limitation is that the registry record describes the primary endpoint but does not report its results. There are no posted week 6 counts for the four pain categories, and no single comparative estimate is reported. Consequently, the posted record does not establish how pain categories were distributed between the randomized groups or how precisely any difference was estimated. No conclusion about a difference in postoperative pain can be drawn from the primary outcome information available in the registry record.
The categorical endpoint matters to interpretation. A reader would need to know the number of participants with no pain, low pain, moderate pain, and high pain in each arm, along with the analysis used to compare the groups. An overall contrast alone might not show whether any difference was concentrated in one category or reflected a broader shift. Conversely, category counts without an uncertainty estimate would not communicate how precisely the between-group pattern was measured. Neither the category counts nor a corresponding uncertainty estimate is reported in the registry record.
The record does provide enrollment and safety counts, but those do not substitute for the primary endpoint results. The safety information lists 36 participants at risk in each arm, one serious adverse event in each arm, and zero deaths in either arm. It also lists other adverse events in affected participants. These observations concern adverse events and cannot be used to infer the week 6 pain distribution.
In general, randomized assignment helps support a comparison between assigned groups because allocation is intended to reduce systematic differences in prognostic factors. That design feature does not itself reveal the results, guarantee that all randomized participants contributed outcome data, or resolve uncertainty about the analysis. The registry record does not report the analysis population, missing-data approach, or statistical model for the primary endpoint. The description of double masking is useful design context, but details about who was masked are not reported.
The trial is listed as completed, but completion status is not evidence of a particular result. The registry lists several secondary outcomes and multiple analyses; it does not report enough detail to determine how those analyses relate to the primary comparison or whether any multiplicity adjustment was planned. Overall, the available record supports a description of the question, design, and selected safety counts, but not an estimate of the primary pain outcome or its precision.
9. Statistical Methods Explained
The design is randomized and parallel group. In general, randomization assigns participants to treatment groups using a chance process, with the aim of making the groups comparable on average at the start of a trial. It does not ensure identical groups, especially in a trial of this size, and it does not prevent bias arising after assignment. The registry record identifies randomization but does not report the sequence-generation method, allocation concealment, or the allocation ratio. These details are relevant to evaluating how assignment was implemented, and they are not reported in the registry record.
What does double masking tell the reader?
The registry identifies the trial as double masked. In general, masking is intended to limit the influence of knowledge about assigned treatment on care, outcome assessment, or participant reporting. For a self-reported pain outcome, participants' awareness of assignment could affect their reports, while assessors' awareness could influence how information is collected or interpreted. The record does not identify who was masked, whether the two suture approaches could be distinguished in practice, or how masking was maintained. The label alone therefore does not establish which potential sources of knowledge were controlled.
How should the pain categories be understood?
The primary measure uses a visual analog scale from 0-100mm and reports pain in four ordered categories. In general, categorization turns a scale into groups that can be counted and compared. The ordering conveys that one category represents more pain than another, but the categories do not describe the exact score of every participant. Results would ideally be interpreted with the category counts and an appropriate contrast, including uncertainty. The registry record does not give those counts or identify the statistical method used for the primary outcome. It also does not report whether the original scale scores were analyzed in another way.
A confidence interval, in general, expresses the uncertainty around an estimated quantity under a specified statistical procedure. It can show which effect sizes are reasonably compatible with the data and model. A p-value, in general, measures how surprising data at least as extreme as those observed would be under a specified null hypothesis and model; it is not the probability that the null hypothesis is true. Neither a confidence interval nor a p-value for the primary comparison is reported in the registry record. Without an estimate and its uncertainty, statistical precision cannot be assessed.
What is known about the analysis plan?
The registry lists 11 outcome measures and 7 analyses. Those counts do not identify which outcomes were included in each analysis, which contrasts were prespecified, or which models were used. The statistical analysis plan, model specifications, adjustment variables, and rules for selecting analyses are not reported in the registry record. The primary outcome is described in multiple pain categories, and the registry notes that it has not been reduced to one comparison. It would therefore be inappropriate to assume that a particular binary, ordinal, or continuous model was used.
Multiplicity is a general concern when several outcomes or comparisons are examined: the chance of observing at least one apparently unusual result can increase as the number of tests increases. Appropriate responses depend on the aims and analysis plan. The registry record does not report whether multiplicity was addressed or how the primary endpoint was distinguished analytically from the secondary outcomes. The number of analyses by itself is not enough to determine whether adjustment was needed or applied.
What do the planning assumptions mean?
The registry describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. These are assumptions for an illustrative calculation, not evidence about the trial's original sample-size justification or a report of observed power. The original sample-size justification is not reported in the registry record. In general, sample-size planning asks how much information a proposed design might produce under specified assumptions; it does not replace estimation from the observed data.
Any sample-size figures should be read as planning illustrations, not as observed power and not as a description of the actual outcome estimates. In general, observed power calculated from an estimated effect is not a substitute for the effect estimate and its confidence interval. The primary endpoint results needed to interpret the observed effect are not reported in the registry record, so no further conclusion about planning calculations can be drawn from the available details.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 11 outcome measures and 7 analyses, including the primary pain outcome and several secondary outcomes. It does not report a statistical analysis plan describing which comparisons were prespecified, how the primary endpoint was analyzed, or whether any adjustment for multiple outcomes or analyses was used. The number of outcomes and analyses does not by itself show that a multiplicity problem occurred, but it makes the missing plan important for interpreting any reported findings. No complete set of outcome results is present in the registry record for assessing selective reporting.
The primary pain outcome is divided into four categories. The registry record does not report a single primary comparison, category counts, or an analysis that combines or contrasts the categories. It also does not explain whether an overall test or category-specific comparisons were intended. The listed 7 analyses should not be treated as evidence of any particular model or testing strategy.
Missing-data procedures are not reported in the registry record. The record does not state how many participants completed the week 6 assessment, how missing pain scores were handled, or whether analyses followed assigned treatment regardless of what participants received. The analysis population and any exclusions after randomization are also not reported. In general, missing outcomes can affect interpretation when the availability of measurements differs between groups or is related to participants' outcomes. Without the relevant counts and methods, the direction or magnitude of any such effect cannot be assessed.
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 |
|---|---|---|---|
| Intervention | 1 | 36 | 2.8% |
| Control | 1 | 36 | 2.8% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Intervention | 0 of 36 |
| Control | 0 of 36 |
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 |
|---|---|
| Intervention | 14 of 36 |
| Control | 13 of 36 |
Most frequent serious adverse event terms
| Event term | Organ system | Intervention | Control |
|---|---|---|---|
| Nerve entrapment | Nervous system disorders | 1 of 36 | 1 of 36 |
| Pelvic pain | Nervous system disorders | 1 of 36 | 1 of 36 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Intervention | Control |
|---|---|---|---|
| De novo dyspareunia | Reproductive system and breast disorders | 4 of 36 | 5 of 36 |
| Urinary tract infection (UTI) | Infections and infestations | 5 of 36 | 3 of 36 |
| New or worsening pelvic pain > 3months | Nervous system disorders | 1 of 36 | 4 of 36 |
| New or worsening constipation | Gastrointestinal disorders | 2 of 36 | 1 of 36 |
| Surgical site infection | Infections and infestations | 1 of 36 | 1 of 36 |
| New fecal incontinence | Gastrointestinal disorders | 1 of 36 | 1 of 36 |
| Other | Blood and lymphatic system disorders | 1 of 36 | 0 of 36 |
Serious events with the highest arm-level rate: nerve entrapment (2.8%), pelvic pain (2.8%).
The registry reports serious adverse events for 36 participants at risk in each arm. It lists 1 participant affected by a serious adverse event in the intervention arm and 1 in the control arm. Deaths are recorded as 0 in each arm. The registry also lists other adverse events in 14 intervention participants and 13 control participants. These are counts of affected participants, not estimates of the primary pain outcome.
Nerve entrapment and pelvic pain are listed among the top serious adverse event terms, each at 2.8%. The record does not provide the event-level detail needed to determine from these figures alone how each term was distributed by arm, whether participants experienced more than one event, or the clinical context of the events. The percentages should be read as registry-reported values rather than as a basis for a new calculation.
In general, adverse-event counts describe what was recorded during the specified study period; they do not by themselves establish that an intervention caused an event. Interpretation depends on definitions, ascertainment, follow-up, and the number of participants with available safety information. Details of those procedures are not reported in the registry record. The counts are small and are not accompanied by a comparative statistical estimate or uncertainty interval, so they should not be treated as proof that the arms have equivalent or different safety profiles.
12. What the Result Does, and Does Not, Mean
This trial addresses a focused procedural question: whether barbed or non-barbed suture used for posterior colporrhaphy is associated with a different pattern of postoperative posterior compartment pain at week 6. The randomized, parallel-group design provides a framework for comparing the assigned approaches. The registry record also identifies a standardized closure technique and reports selected adverse-event counts.
The primary outcome results are not reported in the registry record. There are no category counts, treatment contrast, confidence interval, or p-value for the week 6 pain outcome in the information available. The trial's completion status and enrollment do not fill that gap. The available record therefore does not show whether the pain distributions differed, how large a difference might have been, or how precisely it was estimated.
In general, a statistically detectable difference and a clinically important difference are distinct ideas. Statistical evidence concerns compatibility between data and a specified model or hypothesis; clinical importance concerns whether the size and nature of an outcome difference matter in context. The registry record does not report the primary result or a threshold for interpreting a clinically important difference. Neither kind of conclusion can be reached from the endpoint description alone.
The reported safety counts offer limited descriptive information. One serious adverse event was recorded in each arm, and zero deaths were recorded in each arm, while other adverse events were recorded in 14 intervention participants and 13 control participants. Those counts do not establish causation, equivalence, or a comparative safety effect. The registry does not provide enough detail to assess the events' timing, severity beyond the serious classification, or relationship to treatment.
Accordingly, the record is informative about the trial question, intervention, comparator, design, and the way pain was categorized. It is not sufficient to determine whether one suture approach produced lower pain, whether any observed difference was important, or whether the approaches had comparable safety. Such conclusions require outcome estimates and transparent information about the analysis and missing data.
13. Why This Trial Matters Statistically
The statistical value of this trial lies in the structure of the comparison. Random assignment and a parallel-group design are intended to support a direct comparison of two suture approaches used with a standardized posterior repair technique. The primary endpoint is also defined in advance in a specific clinical context: postoperative posterior compartment pain assessed at week 6. A clear endpoint and assessment time help readers understand what the study was designed to measure.
The endpoint's categorical reporting makes transparent results especially important. The four pain categories communicate levels of reported pain, but their meaning depends on the distribution across categories in each randomized arm and on the method used to compare those distributions. Counts alone would not show the precision of a contrast, while a single contrast could obscure the pattern across categories. The registry record does not report the category results or a comparative estimate, so readers cannot evaluate that statistical evidence.
The record also illustrates why trial design details and result reporting answer different questions. Randomization and masking describe features intended to reduce bias; they do not establish the direction or size of an outcome difference. Similarly, safety counts provide descriptive information but do not replace a comparative analysis. The missing analysis plan, missing-data approach, and analysis-population details limit assessment of how the trial's design was translated into its reported results.
For biostatistical interpretation, a completed trial is most useful when the outcome estimates, uncertainty, and analytic decisions are reported alongside the design. Here, the available registry entries identify the question and several important design features, but do not support an estimate of the primary outcome. That distinction is important: an understandable design is not itself evidence for an outcome effect.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The main limitation for interpreting this trial is the absence of reported primary outcome results in the registry record. The endpoint is specified, including the week 6 assessment and pain categories, but the record does not provide category counts or a between-arm estimate. The precision of any comparison therefore cannot be evaluated. The secondary outcomes are listed, but their results are not included in the information available for this analysis.
Several design and analysis details are also not reported in the registry record. These include the random sequence-generation method, allocation concealment, the identity of the people masked, and the procedures used to maintain masking. The record does not describe the primary statistical model, the analysis population, handling of missing week 6 pain assessments, or any multiplicity strategy. It does not report a protocol-based sample-size justification or the threshold, if any, used to interpret a clinically important difference.
The registry reports an enrollment of 72 and adverse-event counts, but the information available does not include participant characteristics, detailed follow-up, or event-level descriptions by arm. The listed serious event terms and percentages do not provide enough context to assess event timing, overlap among participants, or causal attribution. The other adverse-event counts are descriptive and cannot be interpreted as a formal between-arm safety comparison.
These limitations concern what can be concluded from the registry record, not proof that the trial itself lacked procedures or analyses. Details not reported in the registry record may exist elsewhere, but they cannot be assumed for interpretation. In particular, the completed status does not establish that every outcome was measured for every participant or that the posted record contains the complete analysis.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Barbed Suture Versus Non-Barbed Suture for Posterior Colporrhaphy — NCT04658784.
- Registry record last updated 2023-05-06; status last verified 2023-03.
- Results first posted 2022-10-05.
- 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
NCT04658784 is a completed randomized, double-masked, parallel-group trial sponsored by Wake Forest University Health Sciences. It enrolled 72 participants and compared standardized posterior colporrhaphy closure with barbed 2-0 V-Loc 90TM, Medtronic, versus conventional non-barbed 2-0 PDS® Ethicon. The registry lists the start date as 2020-08-14 and the primary completion date as 2021-11-05.
The primary outcome was postoperative posterior compartment pain at week 6, measured using the visual analog scale and reported in four categories. The registry record does not report the primary outcome category counts or a single comparative result. It lists 11 outcome measures and 7 analyses, but does not report the analysis plan or missing-data procedures.
For safety, 1 serious adverse event was recorded in each arm, with 0 deaths in either arm. Other adverse events were recorded in 14 intervention participants and 13 control participants. These descriptive counts do not provide a comparative estimate of the primary outcome or establish a causal safety difference.