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 Enhancement of Pressure Healing With Pulsatile Lavage (NCT00047619), a randomized phase 2 study. The primary outcome is Pressure Ulcer Geometry.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00047619 |
| Phase | Phase 2 |
| Condition | Spinal Cord Injury |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 28 |
| Arms in the primary outcome | n/a |
| Lead sponsor | US Department of Veterans Affairs |
| Results posted | Yes |
2. Clinical Question
Population
People with spinal cord injury and pelvic-region pressure ulcers were the intended study population. The registry lists spinal cord injury as the condition. It records enrollment of 28, while the brief summary describes a goal of recruiting 60 subjects. The final characteristics of the enrolled participants are not reported in the registry record.
Intervention
The intervention was pulsatile lavage therapy. The brief summary describes daily treatment over a 3 week period, alongside routine pressure-ulcer care. The registry does not report whether every participant received each planned treatment or give treatment-adherence information.
Comparator
The comparison group received sham pulsatile lavage. The brief summary describes daily sham treatment over a 3 week period and says participants continued routine pressure-ulcer care, including dressings and bedrest with a regular turning regime.
Primary question
The primary endpoint was pressure-ulcer geometry, measured through a linear assessment of wounds in cm and summarized as a mean with a 95% confidence interval. The study asked whether wound geometry differed with pulsatile lavage compared with sham lavage during study participation, described as up to 6 weeks. The endpoint results and the statistical comparison are not reported in the registry record.
3. Trial Design
The registry describes a randomized, parallel-group phase 2 trial with quadruple masking. Its two groups were pulsatile lavage and sham lavage. The brief summary calls the study a repeated-measures, double-blinded randomized controlled study. These descriptions are both recorded, but the registry does not explain how the masking labels correspond or which participants, clinicians, or assessors were masked.
The brief summary describes daily treatment and sham treatment for a 3 week period. Participants were also to receive routine pressure-ulcer care, described as dressings, bedrest, and a regular turning regime. The summary says participants would be monitored for a 3 week period and then followed until complete closure of the ulcer to assess the interval to final closure, including any surgical procedures. It also describes collecting information on admission duration, bedrest orders, and pressure-ulcer treatment from the Computerized Patient Record System. These are statements of study intent; completion and results for these measures are not reported in the registry record.
The registry records enrollment of 28. The brief summary states that 60 subjects would be recruited, so the record contains both an enrollment figure and a recruitment goal. It does not explain the difference or report how many participants were assigned to each group in the outcome analysis. The study status is completed. Its recorded start is 2002-06 and primary completion is 2008-05.
Two outcome measures are listed, but only the primary measure is described in the available record. No analyses are listed. The planned statistical analysis, allocation procedure, concealment method, and any changes to the design are not reported in the registry record.
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 | Pulsatile Lavage Group | Sham Lavage Group |
|---|---|---|
| STARTED | 14 | 14 |
| COMPLETED | 14 | 14 |
| NOT COMPLETED | 0 | 0 |
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 | Pulsatile Lavage Group | Sham Lavage Group | Total |
|---|---|---|---|---|
| Participants analysed | 14 | 14 | 28 | |
| Age, Customized: Number of subjects >=18 years | participants | 14 | 14 | 28 |
| Sex/Gender, Customized: male gender | participants | 14 | 14 | 28 |
6. Primary Endpoint
The registry lists the primary outcome as Pressure Ulcer Geometry, measured over study participation - up to 6 weeks.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | cm |
| Endpoint classification | Continuous Endpoint |
The primary endpoint, pressure-ulcer geometry, is described as a linear assessment of wounds. Its unit is cm, and the measure is summarized as a mean with a 95% confidence interval. In general, a geometric wound measure can describe a wound’s dimensions and can be used to track change over time. A linear measure captures dimensions rather than, for example, a clinical judgment about closure. The registry does not specify which linear dimensions were assessed, how measurements were taken, or whether the primary summary represents change from baseline or a measurement at a particular visit.
The endpoint timeframe is study participation, up to 6 weeks. The brief summary separately describes treatment and monitoring for a 3 week period, followed by monitoring until complete closure for determining total interval to final closure. These descriptions concern different time windows in the trial summary; the registry does not explain how the longer follow-up was incorporated into the primary endpoint analysis.
A mean provides a group-level summary of the measured values. A confidence interval expresses uncertainty around an estimated quantity under the statistical method used. Neither the observed means nor their confidence intervals are reported in the registry record. The record therefore identifies what the primary outcome was intended to measure, but does not establish the size, direction, or precision of any treatment-group difference.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies a randomized comparison of pulsatile lavage with sham lavage for pressure-ulcer healing in people with spinal cord injury. It names pressure-ulcer geometry as the primary outcome and gives a measurement unit, summary form, and timeframe. However, it does not report the observed endpoint values, a between-group estimate, a confidence interval for a treatment contrast, or a test result. Without those results, the record does not permit a statistical interpretation of whether the groups differed on the primary endpoint or how precisely any difference was estimated.
The endpoint is listed as a mean with a 95% confidence interval. In general, a confidence interval communicates a range of values compatible with the data and the method used, while its width conveys precision. It is not a guarantee that the true value lies within the interval, and it does not by itself establish the importance of a difference. Here, even the group-level confidence intervals are not reported, so the precision of the endpoint estimates cannot be assessed.
The trial is marked completed, but completion status is not a substitute for posted outcome findings. The record lists two outcome measures and zero analyses. It also gives no primary outcome result or account of how repeated measurements were modeled. Consequently, there is no basis in the registry record for judging the direction or magnitude of a treatment contrast, the role of measurement over time, or the uncertainty around a contrast.
The enrollment entry is 28, whereas the brief summary describes a goal of recruiting 60 subjects. The registry does not explain this distinction. Enrollment alone does not show how many participants contributed data to the primary endpoint, whether all randomized participants were analyzed, or whether withdrawals or missing measurements occurred. Those details are not reported in the registry record.
Safety counts are recorded separately: each group has 14 participants at risk for serious adverse events and zero affected, and each group has 14 at risk for other adverse events and zero affected. These counts describe the registry entries, not the missing primary efficacy analysis. Death counts are null and therefore are not reported in the registry record. The safety entries do not establish that no events occurred outside the reported categories or periods.
Overall, the record supports a description of the trial question, design labels, primary measurement, and recorded adverse-event counts. It does not support a conclusion about the comparative primary outcome. Sample-size calculations, when presented as planning illustrations based on an observed effect, are not observed power; no such numerical results are reported in the registry record.
9. Statistical Methods Explained
What does a randomized parallel-group design mean?
In general, randomization assigns participants to study groups through a chance-based process. Its purpose is to reduce systematic differences between groups at the point of assignment, although randomization cannot ensure that groups are identical in every respect, especially in a small trial. A parallel-group design means the assigned groups are followed as separate groups rather than each participant receiving both interventions in sequence. The registry labels this trial randomized and parallel. The actual sequence-generation and allocation-concealment methods are not reported in the registry record.
The listed masking designation is quadruple. The brief summary also describes a double-blinded study. Masking is intended to limit the influence of knowledge about treatment assignment on care, measurement, or reporting. Which roles were masked and how the two descriptions relate are not reported in the registry record. The labels alone do not establish that masking was maintained throughout the study.
What does a mean summarize?
In general, the mean is the arithmetic average of measured observations. It can be a useful summary when the outcome is continuous, as the registry classifies pressure-ulcer geometry. A mean does not show the full distribution: different sets of observations can share a mean while differing in spread or shape. The record does not provide the underlying observations, a measure of variability beyond the stated confidence interval, or information about the distribution of wound measurements.
The primary endpoint is described as a linear wound assessment in cm. The registry does not define the specific dimension or measurement procedure. Consistent measurement is important because differences in assessor technique or measurement conditions can affect the recorded values. The record does not describe assessor training, repeatability checks, or whether the assessors were masked.
How should a confidence interval be read?
In general, a confidence interval gives a range around an estimate using a specified statistical procedure. It reflects sampling uncertainty under that procedure and assumptions. A narrower interval indicates greater precision than a wider interval for the same kind of estimate, but precision is not the same as clinical importance. An interval for each group mean also differs from an interval for the between-group contrast: a direct contrast interval is what quantifies uncertainty about the comparison itself. The registry identifies a 95% confidence interval for the primary summary but does not post the values or describe a confidence interval for a treatment contrast.
A confidence interval should be interpreted together with the estimate, the endpoint definition, and the analysis population. It cannot compensate for incomplete outcome reporting or reveal how missing measurements were handled. Since endpoint estimates and analysis details are not reported, precision and robustness cannot be evaluated from this record.
What does repeated measurement involve?
In general, repeated measurements collect observations from the same participant at multiple times. Such observations are related: measurements from one person tend to share features that measurements from different people do not. An analysis that treats every observation as independent can misstate uncertainty. Methods for repeated data account for within-participant dependence and can estimate patterns over time, but the appropriate model depends on the measurement schedule and the study question.
The brief summary calls this a repeated-measures study, and the primary timeframe is study participation, up to 6 weeks. The registry does not state the measurement schedule, number of assessments per participant, model, covariance assumptions, or whether the primary comparison concerned a particular time point or change over time. No repeated-measures analysis is listed. It is therefore not possible to determine how the study’s longitudinal structure was handled.
Why can over-dispersion matter?
In general, over-dispersion occurs when observed variability is greater than a statistical model expects. It is especially relevant for count outcomes, where a simple model may assume a particular relationship between the average and variance. If over-dispersion is ignored, standard errors can be too small and confidence intervals too narrow. The listed primary outcome is continuous wound geometry, not a count outcome, and the registry does not describe a model or report a dispersion assessment. This general issue should not be mistaken for a reported analysis choice in this trial.
What can planning calculations say?
In general, sample-size planning asks how much information a future study might need to detect a chosen effect under specified assumptions. A planning illustration based on an observed effect is not a measure of the probability that the completed trial detected an effect, and it is not observed power. The record’s note describes a planning approach using a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the target effect expressed as a fraction of an observed effect. The actual planning outputs and the fraction values are not reported in the registry record. The original design justification and its assumptions are also not reported, so the planning note should not be treated as the trial’s own prespecified sample-size calculation.
10. Multiplicity, Missing Data and Analysis Populations
Multiplicity arises when a study conducts multiple statistical tests or evaluates multiple outcomes, time points, subgroups, or treatment contrasts. In general, more opportunities to identify a nominally unusual result can increase the chance of at least one false-positive finding unless the analysis plan accounts for the multiplicity. The registry lists two outcome measures, but only one is described in the record, and it lists no analyses. Whether any adjustment for multiple testing was planned or applied is not reported in the registry record.
The primary endpoint timeframe extends through study participation, up to 6 weeks. The brief summary also describes follow-up until complete closure and economic measures drawn from medical records. The registry does not clarify which measures were treated as primary or secondary in the final analysis, how many time points were analyzed, or whether any outcomes were changed. These missing details prevent assessment of the number and hierarchy of statistical comparisons.
Missing data can arise when participants do not complete follow-up or a measurement is unavailable. In general, the consequences depend on why values are missing and on the methods used to address them. Excluding participants with missing measurements can introduce bias if the missingness is related to outcome or treatment. The registry does not report missing endpoint values, withdrawals, reasons for missingness, imputation, or sensitivity analyses.
The analysis population is also not reported. The record does not say whether the primary analysis included all randomized participants, only participants who completed treatment, or another defined group. It does not report how participants were handled after discontinuation or whether analyses followed assigned treatment. These omissions limit evaluation of the primary comparison’s completeness and potential bias.
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 |
|---|---|---|---|
| Pulsatile Lavage Group | 0 | 14 | 0.0% |
| Sham Lavage Group | 0 | 14 | 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 |
|---|---|
| Pulsatile Lavage Group | 0 of 14 |
| Sham Lavage Group | 0 of 14 |
The registry records zero serious adverse events affecting participants in the pulsatile lavage group and zero in the sham lavage group. For both groups, the serious-event at-risk count is 14. The registry also records zero other adverse events affecting participants in either group, with 14 at risk in each group for that category.
These are registry counts, not a detailed safety analysis. A count of zero affected participants in the recorded category does not establish that no adverse experiences occurred in every setting or throughout all follow-up. The record does not give event terms, severity definitions, observation windows, or an explanation of how events were collected. No serious adverse event terms are listed. Death values are null, so death counts are not reported in the registry record; null should not be read as zero.
In general, adverse-event counts are descriptive and should be interpreted in relation to the population observed, the event definitions, follow-up, and completeness of reporting. The matching at-risk counts and zero affected counts in these entries do not substitute for the unreported primary outcome analysis, and they do not establish comparative safety beyond the registry entries.
12. What the Result Does, and Does Not, Mean
This trial’s recorded question concerns whether pressure-ulcer geometry differed between pulsatile lavage and sham lavage in people with spinal cord injury. The intervention and comparator are identified, and the registry describes the primary endpoint as a linear wound assessment in cm, summarized as a mean with a 95% confidence interval. These details make the intended comparison understandable at a high level.
The registry record does not include the primary endpoint values or a statistical analysis. It is therefore not possible to tell from this record which group had a larger or smaller mean, whether a contrast was estimated, or how precise an estimate might have been. No conclusion about the comparative effect on wound geometry can be drawn from the listed design and endpoint description alone.
The brief summary describes further monitoring until complete closure and planned collection of admission, bedrest, and treatment-duration information. It does not provide results for these measures. Their mention indicates intended follow-up questions, not evidence of a finding. The record likewise does not provide findings for the second listed outcome measure.
The registry’s enrollment entry is 28, while the brief summary describes a recruitment goal of 60 subjects. These figures do not, by themselves, indicate why enrollment differed from the stated goal or how many participants contributed to each endpoint. The analysis population, missing-data handling, and reasons for any noncompletion are not reported.
The adverse-event entries record zero affected participants for both serious and other adverse events in both groups, with death counts not reported. These entries are limited to what the registry records and do not answer the primary efficacy question. The most defensible interpretation is that the record documents a completed randomized study and its intended measurement, but does not post enough outcome or analysis information to assess the treatment contrast.
13. Why This Trial Matters Statistically
Statistically, this trial raises an important distinction between knowing a study’s question and knowing its answer. The registry identifies a randomized comparison, an active procedure, a sham comparator, and a continuous primary measurement. Those design details describe how the question was framed, but they cannot replace the endpoint estimates and analysis needed to evaluate the comparison.
The listed outcome is based on wound geometry and is described as a mean with a 95% confidence interval. For continuous outcomes, the difference between a group-level summary and a direct contrast matters: the contrast and its uncertainty address the comparative question. The registry does not report either. This makes the absence of analysis results consequential, not merely a missing detail.
The record also juxtaposes a repeated-measures description with an endpoint timeframe extending up to 6 weeks. Repeated observations from the same participant are correlated, so an appropriate analysis needs to account for that structure. The measurement schedule and model are not reported. This is a useful reminder that an endpoint label alone does not tell readers how longitudinal data were reduced or modeled.
Enrollment is recorded as 28, while the summary describes a goal of 60 subjects. That distinction underscores why study targets, actual enrollment, and analysis populations must be reported separately. A completed status does not reveal whether all enrolled participants contributed endpoint data, and the registry does not report the primary analysis population.
Finally, registry safety counts should be read with care: zero affected participants are recorded in the stated categories, while death counts are not reported. Clear definitions, follow-up periods, and outcome results are essential for interpreting both benefit and harm. This record illustrates how much statistical interpretation depends on transparent reporting beyond a trial’s design description.
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 central limitation of the registry record for interpretation is that it does not report primary outcome results or analyses. Although pressure-ulcer geometry is identified as the primary endpoint, observed means, confidence intervals, a treatment contrast, and a test result are absent. The direction, magnitude, and precision of the comparison therefore cannot be assessed.
The endpoint description is brief. It identifies a linear assessment of wounds in cm but does not specify which dimensions were measured, when measurements were taken, how assessors were trained, or whether measurements were made by masked assessors. The listed timeframe is up to 6 weeks, while the summary separately describes monitoring until complete closure. The relationship between these periods and the primary analysis is not explained.
The registry gives enrollment of 28, whereas the brief summary states a recruitment goal of 60. It does not explain the difference, describe participant flow, report group-specific analysis counts, or identify the population used for analysis. Withdrawals, missing outcomes, protocol deviations, and the handling of incomplete repeated measurements are not reported.
Design information is also incomplete for statistical appraisal. The registry labels the trial randomized, parallel, and quadruple-masked, while the brief summary describes a double-blinded repeated-measures study. The record does not explain those labeling differences or detail randomization, concealment, masking roles, measurement schedule, or the statistical model. The second listed outcome measure and any results for it are not described.
Safety entries are limited to category counts, without event terms or observation details, and deaths are not reported. Taken together, these gaps mean the registry record can describe the intended comparison and selected design features, but cannot support a full assessment of efficacy, precision, missing-data bias, or safety.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Enhancement of Pressure Healing With Pulsatile Lavage — NCT00047619.
- Registry record last updated 2015-10-05; status last verified 2015-09.
- Results first posted 2015-10-05.
- 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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Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
The registry identifies a completed, randomized, parallel-group phase 2 study of pulsatile lavage versus sham lavage for pressure-ulcer healing in people with spinal cord injury. It records quadruple masking and enrollment of 28. The brief summary describes a recruitment goal of 60 subjects, daily treatment or sham treatment for a 3 week period, and routine pressure-ulcer care.
The primary endpoint is pressure-ulcer geometry, defined as a linear wound assessment in cm and summarized as a mean with a 95% confidence interval over study participation, up to 6 weeks. The registry lists two outcome measures and no analyses. Primary outcome values, the comparative estimate, confidence intervals, analysis methods, and the analysis population are not reported in the registry record.
For both groups, the registry records zero participants affected by serious adverse events and zero affected by other adverse events, with 14 at risk for each category in each group. Death counts are not reported. The record does not provide enough outcome or analysis information to evaluate the primary treatment comparison.