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 Evaluation of a Novel Post-Surgical Dressing (NCT01831596), a na na study. The primary outcome is Frequency of Complaints About Device Use and Operation.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01831596 |
| Phase | NA |
| Condition | Post Surgical Wound |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 59 |
| Arms in the primary outcome | n/a |
| Lead sponsor | KCI USA, Inc |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns people with a post-surgical wound. The registry record lists enrollment as 59, but does not give further eligibility details or a description of the analyzed population. The primary endpoint description says efforts to contact the principal investigator and study team were unsuccessful and that no study data are available.
Intervention
The intervention is the ciSNaP device, identified in the registry as a device. The study purpose is described as evaluating the safety and efficacy of the Closed-Incision SNaP Device. Details of how the device was applied, how long it was used, or what care accompanied it are not reported in the registry record.
Comparator
The study is listed as a single-group model, with no comparator group described. Allocation and masking are recorded as NA and NONE, respectively. Consequently, the registry record does not support a like-for-like comparison between the device and another treatment or care approach.
Primary question
The primary endpoint is the frequency of complaints about device use and operation during 30 days. This endpoint is intended to describe reported difficulties or concerns related to using or operating the device. However, the registry record says no study data are available, so the posted information cannot answer how often complaints occurred or characterize their pattern.
3. Trial Design
The registry record describes an interventional study of the ciSNaP device, classified as a single-group study. Enrollment is listed as 59. The record gives the condition as post-surgical wound and describes the study purpose as evaluating safety and efficacy of the Closed-Incision SNaP Device. It does not describe a separate control group, random allocation, or masking. Allocation is recorded as NA and masking as NONE.
The record lists a start date of 2010-11 and a primary completion date of 2012-06. Its status is TERMINATED. The primary endpoint description says that the study was terminated by Spiracur. It also says efforts were made to contact the principal investigator and study team members, but were unsuccessful, and that no study data are available. The registry record does not report the reason for termination, so no conclusion about why the study ended is warranted.
The primary outcome is frequency of complaints about device use and operation, with a 30-day timeframe. The record lists one outcome measure but no analysis records. It does not provide methods for recruiting participants, applying the device, collecting complaints, or defining a complaint. It also does not describe follow-up procedures beyond the endpoint timeframe.
Because the study has a single group and no comparator, its design is descriptive rather than a controlled contrast between treatment strategies. Even if outcome data had been available, results from a single group would not by themselves distinguish device-related effects from other influences on observed outcomes. In this record, the absence of primary study data further limits interpretation: the intended endpoint cannot be summarized from the posted information.
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 | ciSNaP |
|---|---|
| STARTED | 59 |
| COMPLETED | 51 |
| NOT COMPLETED | 8 |
Reasons for not completing this period:
| Reason | ciSNaP |
|---|---|
| Other | 8 |
Analysis population for the primary outcome, as defined in the registry: The study was terminated by Spiracur. Efforts were made to contact the PI/study team members, but were unsuccessful. No study data are available.
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 | ciSNaP |
|---|---|---|
| Participants analysed | 51 | |
| Age, Continuous | years | 68 (SD 11.8) |
| Sex: Female, Male: Female | Participants | 18 |
| Sex: Female, Male: Male | Participants | 33 |
| Race/Ethnicity, Customized: Ethnicity (White) | Participants | 41 |
| Race/Ethnicity, Customized: Ethnicity (Non-White) | Participants | 10 |
| Region of Enrollment: United States | Participants | 51 |
6. Primary Endpoint
The registry lists the primary outcome as Frequency of Complaints About Device Use and Operation, measured over 30 days.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the frequency of complaints about device use and operation during 30 days. It is intended to capture how often participants reported concerns or difficulties related to using or operating the ciSNaP device. Such an endpoint can be relevant to evaluating device experience because it focuses on reports about use rather than on a clinical event alone. The registry record does not define what qualifies as a complaint, how complaints were elicited, whether a participant could report multiple complaints, or how the frequency was to be summarized. Those details are not reported in the registry record.
Most importantly, the endpoint description states that no study data are available. There is therefore no posted complaint count, rate, estimate, or uncertainty interval to interpret. The 30-day timeframe identifies the intended observation period; it does not establish that complete observations were obtained for that period. The record cannot show whether complaints were absent, present, or incompletely collected. It also cannot establish whether a complaint was attributed to the device, since an attribution rule is not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central interpretive fact is that the registry record does not contain study data for the primary endpoint. Although the endpoint is defined as frequency of complaints about device use and operation over 30 days, no result is posted. The record therefore cannot quantify complaints, describe their severity or type, or estimate the precision of an observed complaint frequency. The absence of a posted result is not evidence that no complaints occurred.
The record does include adverse-event figures for the ciSNaP group: 51 participants are listed as at risk for serious adverse events, with 0 serious events; 51 are listed as at risk for other adverse events, with 6 events; deaths are listed as 0. These figures should be read as the registry's reported counts, not as a complete account of all possible safety outcomes. The record does not provide event descriptions for the other adverse events, exposure time, ascertainment details, or an explanation for the difference between the listed enrollment of 59 and the at-risk population of 51. That difference cannot be resolved from the registry record.
The study is single-group, so there is no concurrent comparator against which to interpret the observed counts. A count in an intervention group alone cannot establish whether an outcome was more or less frequent than it would have been under another approach. Likewise, the absence of reported serious events in the listed at-risk group does not establish that the device has no serious risks. The record's status is TERMINATED, but the reason for termination is not reported in the registry record.
Statistical precision also cannot be assessed for the primary endpoint because there is no posted estimate or denominator tied to a complaint result. The adverse-event counts are not accompanied by confidence intervals or a statistical comparison. They should not be read as proof of safety or harm. The registry information is best understood as a limited record of the intended study question and a small set of posted safety counts, with the primary complaint outcome unavailable.
9. Statistical Methods Explained
The registry record lists a single-group model, the primary endpoint of complaint frequency over 30 days, and no analysis records. It does not report a statistical analysis plan, the planned summary measure for the primary endpoint, or a statistical test. Accordingly, any explanation of statistical ideas below is general context, not a description of methods confirmed to have been used in this study.
How would a complaint-frequency endpoint be summarized?
In general, a frequency outcome may be reported as a count, as the number of participants with at least one complaint, or as a rate over a defined period of observation. These quantities answer different questions. A count of complaints can include repeated complaints by the same participant, while a count of participants with a complaint treats each participant as having the outcome or not. A rate also depends on how observation time is defined and accumulated. The registry record does not say which definition was intended for this endpoint, whether repeat reports were possible, or how missing follow-up would be handled. Since no endpoint data are available, none of these summaries can be calculated from the posted results.
Why does the single-group design matter?
In general, a single-group study can describe outcomes observed among participants receiving the intervention, but it does not directly estimate a difference from a control condition. Without a comparator, changes or events cannot be attributed uniquely to the device rather than to participants' underlying condition, other care, or the circumstances of observation. This is a design limitation, not a problem that can be fixed by choosing a more elaborate statistical test. The registry record lists no comparator and therefore offers no direct between-group estimate.
What does a confidence interval ordinarily add?
In general, a confidence interval expresses the statistical uncertainty around an estimate under the assumptions of the analysis. A narrow interval indicates greater precision than a wide interval, but it does not remove bias or resolve limitations in how data were collected. For this study's primary endpoint, neither an estimate nor an interval is posted. The registry record therefore does not permit assessment of precision. The adverse-event counts also have no posted confidence intervals, and the record does not identify an analysis from which one could be reconstructed without making assumptions.
How should count outcomes be analyzed in general?
General methods for counts depend on whether events are independent, whether participants can experience repeated events, and whether observation time differs. A simple count model may be inadequate when event variability exceeds the model's assumptions; this is known generally as over-dispersion. Methods that account for over-dispersion can produce more appropriate uncertainty estimates when their assumptions fit the data. If the outcome is instead the number of participants with any event, a binary-outcome approach may be more appropriate. The registry record does not say whether complaints were counted as repeated events or as participants with at least one complaint, and it does not report a model or test. It would be inappropriate to attribute any particular method to the investigators.
What do the planning illustrations represent?
Any sample-size figures associated with the posted results are planning illustrations based on an observed effect, not observed power from this trial. The stated illustration assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect defined as a stated fraction of the observed effect. For time-to-event outcomes, the illustration concerns the total number of events; for other outcomes, it concerns participants per arm. These are hypothetical planning conventions and do not change the actual single-group design. Because no primary endpoint effect is available in the registry record, the record cannot establish an observed effect for the complaint outcome or make a data-based interpretation of its precision.
In general, planning calculations describe what a future study might require under specified assumptions. They are not evidence that the current study had a particular probability of detecting an effect, and they do not substitute for an analysis of observed data. The registry record does not report the trial's sample-size justification or its own statistical plan. Any such rationale is not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists one outcome measure and no analysis records. The primary measure concerns complaint frequency over 30 days. The absence of analysis records means that the registry does not show how this endpoint was analyzed, whether the analysis followed a prespecified plan, or whether additional outcomes or subgroup analyses were evaluated. Those details are not reported in the registry record.
Multiplicity refers generally to the interpretive challenge that arises when several outcomes, comparisons, time points, or analyses are tested. Repeated testing can increase the chance of finding an apparently notable result by chance. Statistical plans may address multiplicity by defining a primary outcome, setting an order for testing, or adjusting inference. The registry record does not describe any such procedures. Since no primary outcome result is available, it is not possible to assess whether reported findings were affected by multiple analyses.
Missing-data handling is also not described. The endpoint description says no study data are available and notes unsuccessful efforts to contact the principal investigator and study team. This means the posted record does not permit assessment of completeness, reasons for missing observations, or whether missingness could be related to participant experience. The registry does not give an analysis population, such as all enrolled participants or participants with complete follow-up. It also does not explain how the listed adverse-event risk population relates to enrollment.
In general, missing observations can affect both the estimate and its uncertainty, especially when the chance of missing data is related to the outcome. A method for handling missingness cannot be selected or evaluated without information about what was collected and why observations are absent. No imputation, sensitivity analysis, or other missing-data method is reported in the registry record.
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 |
|---|---|---|---|
| ciSNaP | 0 | 51 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| ciSNaP | 0 of 51 |
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 |
|---|---|
| ciSNaP | 6 of 51 |
Most frequent non-serious adverse event terms
| Event term | Organ system | ciSNaP |
|---|---|---|
| Stitch granuloma | Skin and subcutaneous tissue disorders | 3 of 51 |
| Minor dehiscence | Skin and subcutaneous tissue disorders | 3 of 51 |
| Blister | Skin and subcutaneous tissue disorders | 2 of 51 |
| Mild surgical infection | Infections and infestations | 2 of 51 |
| Congestive Heart Failure exacerbation | Cardiac disorders | 1 of 51 |
| Hemarthrosis | Blood and lymphatic system disorders | 1 of 51 |
| Lymphocele | Blood and lymphatic system disorders | 1 of 51 |
The registry record lists 51 participants at risk for serious adverse events and 0 serious events. It lists 51 at risk for other adverse events and 6 other events, with deaths listed as 0. These are posted counts for the ciSNaP group. The record does not give the terms describing the other events, the seriousness criteria, the observation time for these safety figures, or the method used to collect them.
These counts should not be interpreted as proving that serious events could not occur or that the device is free of risk. A zero count means no serious events are recorded in this registry summary for the listed at-risk group; it does not establish the absence of unrecorded events or quantify the frequency with high precision. Likewise, the 6 other events cannot be characterized without event descriptions, and the record does not state whether they occurred in separate participants or included repeated events.
Enrollment is listed as 59, while the safety at-risk figures use 51. The registry record does not explain that difference, so the counts should be read with that denominator limitation in mind. The available safety figures are not a substitute for the unavailable primary complaint data or for a comparison group.
12. What the Result Does, and Does Not, Mean
The registry record establishes what the study intended to examine: the ciSNaP device in a single group, with the primary endpoint focused on complaints about device use and operation during 30 days. It also records that the study was terminated and that no study data are available for the primary endpoint. Therefore, the posted information does not show the frequency of complaints and cannot support a conclusion about the endpoint's magnitude or precision.
The safety summary reports 0 serious adverse events among 51 listed at risk, 6 other adverse events among 51 listed at risk, and 0 deaths. These counts are descriptive. They do not establish whether the device caused any event, whether an observed count differs from what would occur under another approach, or whether all events were captured. The absent event descriptions and unexplained difference between enrollment and the safety denominator further constrain interpretation.
The single-group design does not provide a controlled comparison. Even if the primary results were available, an outcome observed in a group receiving the device would not by itself show what would have happened under a comparator. The registry record does not report a comparison group or a strategy for estimating a treatment contrast.
Thus, the record cannot establish efficacy, comparative safety, or the absence of device-related complaints. It also cannot show that the endpoint was measured completely or that the study was stopped for a particular reason. What it does document is a terminated study, the intended complaint endpoint and timeframe, the lack of available primary data, and limited adverse-event counts. These distinctions separate the study's stated purpose from conclusions that the posted results can support.
13. Why This Trial Matters Statistically
This study is statistically instructive because its registry record separates an intended endpoint from an analyzable result. A clearly named outcome and timeframe do not themselves provide evidence about the outcome: the record specifies complaints about use and operation during 30 days, but says no study data are available. Without an estimate, there is no frequency to interpret and no basis for discussing its statistical precision.
The record also illustrates why study design shapes the questions statistical analysis can answer. A single-group study can describe observed experience in that group, but it cannot directly compare outcomes with a control condition. Statistical sophistication cannot create a comparator that the design did not include. This distinction matters when reading statements about safety or efficacy, especially when the record's stated purpose includes both.
The adverse-event summary shows a further practical issue: denominator context matters. Enrollment is recorded as 59, while the safety figures use 51 at risk. The record does not explain the difference. Reporting the counts without that context could make the safety summary seem more complete than the registry information allows. Clear reporting should connect populations, outcomes, and observation periods so readers can understand what each count represents.
Finally, termination and unavailable data constrain what can be learned from a registry record. The reason for termination is not reported, and no analysis records are listed. These registry entries do not establish why the study ended or what its unposted results would have shown. Statistically careful interpretation therefore requires distinguishing documented counts from missing endpoint results, and intended aims from conclusions that the available record can support.
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 is that no study data are available for the primary endpoint. The registry record therefore offers no complaint frequency, estimate, or measure of uncertainty for the outcome that was designated primary. It does not explain whether data were never collected, were collected but unavailable, or were unavailable for another reason; the cause is not reported in the registry record.
The study is described as single-group and has no comparator. The record does not support a controlled estimate of differences in complaints or safety outcomes. Allocation is listed as NA and masking as NONE, but further design details are not reported in the registry record. The registry also does not describe eligibility criteria, the procedure for applying the device, other care, complaint definitions, or how outcomes were ascertained.
The study status is TERMINATED, and the primary endpoint description says termination was by Spiracur. The reason for termination is not reported in the registry record. Efforts to contact the principal investigator and study team were unsuccessful. This limits the available context for interpreting the missing results, but does not establish why the data are unavailable.
The posted safety information is limited to counts. There are no serious adverse event terms listed, and the other adverse events are not described. The record does not provide the event collection method, observation time, or explanation of the safety denominator. Enrollment is listed as 59, whereas the safety figures list 51 at risk; the relationship between these figures is not reported in the registry record. No analysis population, missing-data strategy, statistical plan, or sample-size justification is reported.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Evaluation of a Novel Post-Surgical Dressing — NCT01831596.
- Registry record last updated 2024-11-25; status last verified 2024-11.
- Results first posted 2020-09-28.
- 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
The registry record concerns Evaluation of a Novel Post-Surgical Dressing, a single-group study of the ciSNaP device for post-surgical wounds. Enrollment is listed as 59. The study started in 2010-11, has a primary completion date of 2012-06, and is listed as TERMINATED. The primary endpoint is frequency of complaints about device use and operation during 30 days.
The endpoint description states that the study was terminated by Spiracur, contact efforts with the principal investigator and study team were unsuccessful, and no study data are available. The record lists 0 serious adverse events among 51 at risk, 6 other adverse events among 51 at risk, and 0 deaths. It does not provide descriptions of the other adverse events or explain the difference between enrollment and the safety denominator. No analysis records are listed.