Pressure Injury Prevention in the ICU With Multi-Layer Foam Dressings: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Pressure Injury Prevention in the ICU With Multi-Layer Foam Dressings (NCT02962882), a non-randomized na study. The primary outcome is User Friendliness of Both Sacrum and Heel (Left & Right) Dressings: Comfort, Conformability, Acceptability, the Handling at Application and Ease of Inspection of the Dressings as Well as Reapplication.

2. Clinical Question

This is a practical-use question rather than a controlled test of comparative effectiveness. The stated focus is staff experience with applying, inspecting and reapplying the dressings, alongside wear time. The primary endpoint counts dressing changes evaluated, with assessments relevant to different actions and visits. Because a dressing change was not required at every visit and some questions applied only to particular activities, the number of evaluations could vary across user-friendliness variables.

The registry notes that the intended study period was not completed by all participants: patients typically left the ICU earlier than expected. It says that the protocol stipulated leaving the test dressing in place for 3 days or longer, while patients typically left the ICU department after one day. Consequently, the investigation’s question must be interpreted in the context of incomplete observation and the absence of a control group. Numerical primary-endpoint findings are not reported in the registry record.

3. Trial Design

This was a completed, multi-centre, open, non-controlled clinical investigation sponsored by Molnlycke Health Care AB. The registry lists an enrollment of 50 and dates the study start to 2016-09-09 and primary completion to 2016-11-21. Its allocation is classified as non-randomized, masking as none, and model as parallel. These design features describe an investigation without blinded assessment or a randomized control comparison; they do not establish that outcomes would differ from those under another approach.

The device intervention is listed as Mepilex Border. The described uses distinguish a sacrum dressing from heel dressings intended for both heels. The registry’s main focus is user friendliness for the sacrum and heel dressings, judged by site staff. Its listed secondary outcome is wear time, in days, for the first dressing. The primary endpoint is framed as a count of dressing changes evaluated, not as a single participant-level rating or a comparison between randomized groups.

The stated primary-outcome timeframe is 4-6 days. The record explains that the test dressing was intended to remain in place for 3 days or longer, but patients typically left the ICU department after one day. It also notes that not all participants completed the full study period or all assessment visits. This means the intended period and the observations actually available did not necessarily align.

The registry identifies an ITT population for the primary outcome, but a detailed definition of that population is not reported in the registry record. A full protocol, a statistical analysis plan, and the methods used to summarize or test the outcome are not reported in the registry record. The design is therefore best understood as an observational evaluation of use and staff judgments, not as a controlled efficacy comparison.

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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: ITT population As a dressing change was not required at all visits, the total number of dressing changes evaluated vary for each variable and a question was perhaps not relevant at a given visit (some questions were only relevant for dressing applications, some were only relevant for dressing removals or only relevant for dressing inspections).

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.

Population: ITT population

6. Primary Endpoint

The registry lists the primary outcome as User Friendliness of Both Sacrum and Heel (Left & Right) Dressings: Comfort, Conformability, Acceptability, the Handling at Application and Ease of Inspection of the Dressings as Well as Reapplication, measured over 4-6 days.

The primary endpoint concerns staff-rated user friendliness of the sacrum and heel dressings. Its named aspects are ability to stay in place, facilitation of inspection, ease of reapplication, conformability to the body and overall impression. The registry describes the endpoint as the count of dressing changes evaluated. That framing matters: the unit being counted is an evaluated dressing change, and the count may differ from the number of participants or from the number of completed visits.

This type of endpoint is used to capture practical aspects of device use. Staff observations can address whether a dressing remains positioned, can be inspected, and can be handled during application or reapplication. Such judgments are relevant to evaluating usability in the ICU setting. They are not, on their own, evidence of comparative clinical benefit or of a reduction in pressure injuries.

The registry states that some questions were relevant only to dressing applications, some only to removals, and some only to inspections. It also says that some visits did not involve a dressing application or removal, and that not all assessment visits were completed. Therefore, the total count of visits can exceed the count for an individual variable, and variable-specific evaluation counts can differ. Numerical values for the primary endpoint are not reported in the registry record, so the direction and precision of staff ratings cannot be described.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the primary endpoint count?

The primary outcome is described as a count of dressing changes evaluated. The evaluations cover staff judgments about whether the dressings stayed in place, facilitated inspection, were easy to reapply, conformed to the body and made a favorable overall impression. A count of evaluated changes is not automatically a count of participants: a participant may contribute assessments at different visits, while a visit may not include every activity or question.

The registry explicitly notes that different questions applied to different circumstances. Some concerned application, some removal, and some inspection. Where no dressing change was required, an evaluation of a dressing change might not occur. As a result, variable-specific counts can differ. Any interpretation of a reported average, proportion or count would need to account for the unit and denominator used; numerical summaries and their denominators are not reported in the registry record.

Why does the design affect interpretation?

In general, random allocation helps balance known and unknown influences between comparison groups, while masking can reduce the influence of knowledge about treatment assignment on assessment. This investigation is classified as non-randomized and open, with no controlled comparator and no masking. It therefore describes experience with the dressings in the observed setting, rather than estimating a randomized contrast. The registry does not report an alternative comparator group or a statistical method to adjust for differences in patient circumstances.

In general, repeated observations from the same person can be related to one another. A statistical analysis of repeated assessments may need to account for that dependence rather than treating every assessment as independent. The registry mentions multiple visits and varying counts by assessment variable, but it does not report whether repeated observations were modeled or how they were summarized. No particular count model or repeated-measures method should be inferred.

What does missing observation mean in this investigation?

The record gives a specific reason that not all participants completed the full study period or every assessment visit: patients typically left the ICU earlier than expected. It says the protocol stipulated that the dressing should remain in place for 3 days or longer, while patients typically left the ICU department after one day. It also explains that not every visit required a dressing change and that some questions were not relevant at every visit.

These circumstances distinguish a missing assessment from an assessment that was not applicable or not triggered by a dressing change. In general, those situations can have different meanings for analysis. The registry does not report how they were coded, whether any missing-data method was used, or whether results were compared across participants with different amounts of follow-up. The detailed handling of missing observations is not reported in the registry record.

What statistical analysis is reported?

The registry identifies an ITT population for the primary outcome, but its detailed membership and analysis procedures are not reported. It lists 3 outcome measures and 0 analyses. Numerical primary-outcome results, estimates of uncertainty, hypothesis tests and adjustment methods are not reported in the registry record. It is therefore not possible to assess a reported p-value or confidence interval for the primary endpoint.

In general, a confidence interval describes a range of values compatible with data and a specified statistical procedure; it communicates precision as well as the estimate’s scale. A p-value, when used appropriately, describes how unusual data would be under a specified null model. Neither can be interpreted without the estimate, analysis method and assumptions. Those inferential results are absent from this registry record.

How should planning illustrations be distinguished from results?

The record describes a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It specifies that the effect to detect is a stated fraction of the observed effect. For time-to-event illustrations, it specifies a total event count using the Schoenfeld approach; other illustrations are expressed as participants per arm.

These are planning assumptions, not evidence that the investigation used those methods for its analysis. The record explicitly distinguishes the illustration from the trial’s own design. A planning sample size is a hypothetical design quantity, not observed power and not a result from this non-controlled investigation. The numerical sample-size illustration values are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 3 outcome measures, identifies user friendliness as the primary outcome, and names wear time for the first dressing as a secondary outcome. The other outcome measures are not described in the registry record. It lists 0 analyses, and does not report an inferential analysis plan, the number of statistical tests performed, or a method for handling multiple comparisons. Consequently, any adjustment for multiplicity is not reported in the registry record.

Multiplicity matters in general when many outcomes, variables or time points are examined: interpreting each test without considering the full set can make chance findings more likely. This investigation includes several user-friendliness variables, with questions relevant to different activities. The record does not state whether these variables were treated as separate outcomes, how they were prioritized in analysis, or whether any multiplicity procedure was planned.

The registry describes incomplete study periods and visits because patients typically left the ICU earlier than expected. It also notes that not all visits involved a dressing change and that some questions were not relevant at some visits. These are distinct reasons that an assessment may be absent. The registry does not report how these situations were distinguished in the analysis, whether missingness was imputed, or whether sensitivity analyses were performed.

The primary-outcome population is identified as ITT, but its detailed definition and the handling of participants with incomplete assessments are not reported in the registry record. Without those details and numerical outcome results, the effect of incomplete observation on the reported endpoint cannot be quantified.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: death (8.0%), prolongation of existing hospitalization (4.0%), bowel perforation (2.0%).

The registry lists a group titled Mepilex Border Dressing All, with 50 at risk. It reports 7 serious events, 1 other event and 4 deaths. The serious-event terms listed include Death at 8.0%, Prolongation of existing hospitalization at 4.0%, and Bowel perforation at 2.0%. These are registry-reported safety figures, not a controlled comparison.

The record does not describe a comparator group or provide a basis for estimating how these event figures differ from another treatment or from usual care. It also does not report the causal relationship between individual events and the dressing. The event counts and listed percentages should not be combined or interpreted as evidence that the device caused or prevented an event. The registry does not provide additional detail about event timing, severity criteria, or attribution in the information.

In general, adverse-event data describe events observed and reported during a study; they do not by themselves establish causation. Interpretation also depends on the population, observation period, event definitions and completeness of follow-up. The early ICU departures and incomplete visits described for this investigation are relevant context, but the record does not explain how they affected safety follow-up.

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

The investigation addresses a practical question: how site staff judged the use of sacrum and heel dressings in ICU patients considered prone to pressure injuries, and how long the first dressing was worn. The record names several specific aspects of staff experience, including staying in place, inspection, reapplication, conformability and overall impression. It also documents that the intended observation period was not completed by all participants.

Those features can make the study relevant to understanding device use in the setting described. However, numerical findings for the primary endpoint and the secondary wear-time outcome are not reported in the registry record. The record therefore does not establish how staff rated the dressings or what wear time was observed. It cannot support a quantitative statement about the magnitude or precision of those outcomes.

The non-randomized, open, non-controlled design also limits what can be concluded. There is no like-for-like control comparison from which to estimate a relative effect. Staff assessments may describe experiences in this investigation, but they do not establish that the dressings perform better or worse than another option. The design and reported data also do not support a causal conclusion about pressure-injury prevention.

Likewise, adverse-event counts are not a comparative risk estimate, and the registry does not report event attribution. The results must be interpreted within the stated population and study conditions, with early ICU departure and incomplete assessment visits in mind. The most defensible conclusion is that the registry documents an evaluation focused on usability and wear time, while leaving the numerical outcome findings and inferential analysis unavailable in the registry record.

13. Why This Trial Matters Statistically

This investigation illustrates why endpoint definitions and units of analysis matter. “User friendliness” covers several distinct judgments, and the registry counts dressing changes evaluated rather than describing a single uniform participant-level outcome. Because the relevant questions differ between application, removal and inspection, evaluation counts can vary by variable. A reader needs those distinctions to understand what a summary represents.

It also highlights how study setting can shape data availability. The record says patients typically left the ICU earlier than expected, before the intended period was complete, and that not all visits involved a dressing change. These practical circumstances can affect which observations are collected. Statistical interpretation depends not only on the outcome definition but also on who contributed data and how incomplete or inapplicable assessments were handled.

The design is another key lesson. Open, non-randomized, non-controlled studies can document use and staff experience, but they do not provide the protection against confounding that a randomized comparator is intended to offer. The absence of numerical outcome results further prevents assessment of estimate size and precision. A complete interpretation requires both transparent design information and analyzable results.

Finally, planning illustrations should not be confused with analysis results. The registry’s stated planning assumptions describe a hypothetical sample-size framework, not a method known to have been used for the trial’s own analysis. Separating planning, observation and inference is essential when reading a clinical study record.

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 most direct limitation is the absence of numerical results for the primary user-friendliness endpoint and the secondary first-dressing wear-time outcome. Without these values, the direction, magnitude and precision of the findings cannot be assessed. The registry lists 3 outcome measures but does not describe all of them, and it lists 0 analyses.

The study was open, non-randomized and non-controlled. It therefore lacks a like-for-like comparator and does not support a controlled estimate of relative performance. The registry does not report whether staff ratings were collected with a validated instrument, how rating categories were defined, or whether assessment procedures were standardized across sites.

Follow-up was incomplete for some participants because patients typically left the ICU earlier than expected. The record says the test dressing was intended to remain in place for 3 days or longer, while patients typically left after one day. Not all assessment visits were completed, and a dressing change was not required at every visit. The analysis approach for these circumstances is not reported in the registry record.

The primary-outcome population is labeled ITT, but its detailed definition is not given. The registry also does not report the statistical analysis plan, missing-data methods, multiplicity handling, or inferential results. Safety figures are presented without a controlled comparison or reported event attribution. These limitations restrict conclusions to the study’s stated purpose and design, rather than comparative effectiveness or causation.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Pressure Injury Prevention in the ICU With Multi-Layer Foam Dressings — NCT02962882.
• Registry record last updated 2018-03-26; status last verified 2018-03.
• Results first posted 2018-03-26.
• 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.

18. Record Summary

The completed investigation, NCT02962882, evaluated Mepilex Border multi-layer foam dressings with Safetac® for pressure-injury prevention in the ICU. The registry lists enrollment of 50, a study start date of 2016-09-09, and primary completion on 2016-11-21. The design is described as multi-centre, open, non-randomized and non-controlled.

The primary outcome concerns site-staff judgments of user friendliness for sacrum and heel dressings, counted as dressing changes evaluated. The secondary outcome is wear time for the first dressing. The record notes early ICU departures and incomplete assessment visits, and says that questions were not relevant at every visit.

Numerical primary and secondary outcome results and inferential analyses are not reported in the registry record. The registry lists safety events for the Mepilex Border Dressing All group, but does not provide a controlled basis for attributing them to the dressing.