Enhancing & Mobilizing the POtential for Wellness & Emotional Resilience Among Surrogate Decision-Makers of ICU Patients: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Enhancing & Mobilizing the POtential for Wellness & Emotional Resilience Among Surrogate Decision-Makers of ICU Patients (NCT03276559), a randomized na study. The primary outcome is Change in Peritraumatic Distress Inventory.

2. Clinical Question

The clinical question concerns distress experienced by surrogate decision-makers during a highly stressful period. The registry description frames EMPOWER as a way to address experiential avoidance of difficult thoughts and feelings about a patient’s death. It also describes aims involving advance care planning, patient quality of life, and surrogate coping. Those aims are not themselves evidence that the intervention achieved these outcomes.

The primary outcome is change in Peritraumatic Distress Inventory score, with assessment at baseline and after the intervention. The endpoint description says the between-group comparison is at the post-intervention assessment. The record does not report the comparison estimate, its confidence interval, or a test result. It therefore does not establish the size or direction of any difference in distress between the groups.

3. Trial Design

The registry record describes a study with randomized, parallel groups and single masking, with an enrollment of 63. It lists the study status as completed, with a start date of 2017-07-12 and a primary completion date of 2023-05-22. The identity of the party or parties who were masked is not reported in the registry record.

The randomized controlled trial compared EMPOWER with enhanced usual care. The EMPOWER arm was described as six 15 minute modules delivered one-to-one with the same interventionist, followed by 2 phone boosters of approximately 45 minutes each. Enhanced usual care included regular ICU caregiver support, such as social work and chaplaincy, as recorded in the patient’s medical record, a general information packet, and a site-specific resource list.

The record also includes an open-trial COVID-19 phase. That phase did not include randomization or a control arm, and all participants received EMPOWER. Its assessments were planned before intervention, immediately after intervention, and at later follow-up points. For the primary-outcome population, the record says the randomized EMPOWER arm and open-trial COVID-19 phase arm were combined because there were no procedural differences between them apart from randomization to the EMPOWER arm in the randomized phase.

This combination means the stated primary population includes participants from both a randomized comparison and an open phase without a control group. The registry record does not report results separately for those phases. It also does not report the allocation procedure, masking details, or a full analysis plan. The trial is listed as phase NA.

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.

Before assignment: 81 caregivers consented. 16 were not eligible (eligibility's determined by a brief screening assessment conducted after participants sign consent form). 2 were loss to follow-up prior to sending the T1 assessment. 63 participants completed the first assessment (T1). After T1 is completed, participants are randomized to study groups. 60 caregivers were randomized because 1 patient died (patients were not considered enrolled in the study), 1 patient was discharged, and 1 was loss to follow-up.

T1 Assessment

Randomization

EMPOWER Only

Randomization

Analysis population for the primary outcome, as defined in the registry: As pre-specified in the analysis plan, "Randomized Controlled Trial EMPOWER Arm" and "Open Trial COVID-19 Phase Arm" are combined because there were no procedural differences for subjects in both groups, besides the "Randomized Controlled Trial EMPOWER Arm" subjects were randomized to that group instead of the usual care group. Subjects in both the "Randomized Controlled Trial EMPOWER Arm" and "Open Trial COVID-19 Phase Arm" received the EMPOWER intervention and were thus analyzed together.

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.

6. Primary Endpoint

The registry lists the primary outcome as Change in Peritraumatic Distress Inventory, measured over At baseline (T1) and in the week following the intervention (T2).

The primary endpoint is change in Peritraumatic Distress Inventory score, measured at baseline and in the week following the intervention. The inventory was adapted to fit the ICU experience and consists of 13 Likert-style items. Its total score can range from 0 to 52; higher scores represent greater symptom burden, while lower scores represent better outcomes.

Peritraumatic distress is relevant to the study because surrogate decision-makers may face potentially traumatic experiences while making decisions for critically ill patients. A questionnaire score provides a structured way to describe reported symptoms across participants, rather than relying on an informal impression of distress. Comparing scores between groups after the intervention could address whether measured distress differed between participants assigned to EMPOWER and those assigned to enhanced usual care.

The endpoint description specifies a post-intervention between-group comparison, with baseline and post-intervention assessments. However, the registry record does not report the group means, the estimated difference, or the confidence interval for this comparison. The primary outcome is also identified as having several categories or time points and is not reduced in the posted results to a single comparison. Without those estimates, the endpoint’s observed pattern and precision cannot be described.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods help turn participant measurements into estimates that can be interpreted in light of uncertainty. In this record, the primary endpoint is a continuous score, and its listed summary is a mean with a 95% confidence interval. The registry record does not report the mean values or confidence interval for the primary comparison, nor does it specify the statistical model used to produce them.

What a mean describes

General explanation: a mean is an average score across the participants included in an analysis. It can summarize the overall level of a continuous measure, but it does not show how widely individual scores vary. For this endpoint, lower scores indicate less reported symptom burden and higher scores indicate more. A group mean can be useful for comparing average scores, but the underlying distribution and the individual experiences are not captured by the mean alone.

The endpoint description identifies measurements at baseline and after intervention, and says the groups are to be compared at the post-intervention assessment. The registry record does not state whether the intended analysis adjusts for baseline scores, uses change scores, accounts for repeated measurements, or includes other covariates. Those details are not reported in the registry record, so the comparison method cannot be reconstructed from the endpoint description alone.

How to read a confidence interval

General explanation: a confidence interval expresses the uncertainty around an estimate under the assumptions of the statistical method used. A narrower interval indicates greater precision, while a wider interval indicates less precision. The interval’s location relative to values representing no difference can help readers assess which effects are compatible with the data. It does not show that a particular effect is certain, and it does not describe the range of individual participant outcomes.

The primary endpoint lists a 95% confidence interval as its dispersion measure, but no interval is reported with an outcome estimate. Without the estimate and interval, readers cannot assess how precisely the group comparison was measured. The registry record also does not report a p-value for this outcome, so there is no reported test result to interpret.

Why analysis details matter

General explanation: a statistical model states how the outcome is related to group assignment and any other information used in the analysis. The model matters because different choices can produce different estimates or uncertainty, particularly when data are incomplete, measurements are repeated, or participant groups differ. The registry record does not report the model, whether an adjusted analysis was planned, or which assumptions were checked.

The record describes a randomized parallel-group phase and a separate open-trial phase without randomization or a control arm. The primary-outcome population combines the randomized EMPOWER arm and the open-trial COVID-19 phase arm. Combining data can be reasonable when the study’s stated conditions support it, but the record does not report phase-specific estimates or details of how phase membership was handled in analysis. Readers therefore cannot assess whether the combined estimate would be similar to an estimate restricted to the randomized comparison.

Planning illustrations are not trial findings

The sample-size assumptions describe illustrations based on a fraction of the observed effect. They use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. These are planning assumptions, not a description of observed participant outcomes. The registry record does not report the observed effect estimate alongside the assumptions, so the size of the effect underlying those illustrations cannot be assessed from the record.

General explanation: sample-size planning asks how many participants would be needed under chosen assumptions to detect a specified effect with a specified probability, if those assumptions hold. Such a calculation does not measure the probability that the completed study’s result is correct. It is not observed power, and it cannot demonstrate that the trial detected an effect. Interpreting the illustrations requires the effect size and other assumptions used in the calculation; the record does not report all of that detail.

The registry record lists no analyses and does not report inferential results for the primary endpoint. Statistical methods can clarify how a reported estimate should be read, but they cannot recover missing outcome results. In this case, the design and endpoint information are available, while the analysis estimate and its uncertainty are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The record lists seven outcome measures and names three secondary outcomes: change in anticipatory grief, change in experiential avoidance, and change in post-traumatic stress disorder. It does not report numerical results for these outcomes. The primary outcome is flagged as involving several categories or time points and is not reduced to one comparison in the posted results.

Multiplicity arises when a study assesses several outcomes, time points, groups, or statistical comparisons. General explanation: the more comparisons researchers make, the greater the chance that some results may appear noteworthy by chance alone. Statistical plans can address this concern by identifying a primary comparison in advance, adjusting for multiple testing, or interpreting secondary findings as exploratory. The registry record does not report a multiplicity adjustment or a detailed strategy for interpreting multiple outcomes and time points.

The primary population description refers to an analysis plan as pre-specified, but the plan’s details are not reported in the registry record. The record does not state how missing outcome measurements were handled, whether all randomized participants were included in the analysis, or which analysis populations were used. It also does not report reasons for missing measurements or the number of participants contributing to each endpoint analysis.

These omissions limit the interpretation of any potential comparison, beyond the fact that the primary outcome estimate itself is not reported. Readers cannot determine from the registry record whether the analysis followed an intention-to-treat approach, how incomplete follow-up was addressed, or whether planned multiplicity procedures were applied. Such details are not reported in the registry record.

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.

The adverse-event figures list three groups: the randomized controlled trial EMPOWER arm, the randomized controlled trial enhanced usual care arm, and the open-trial COVID-19 phase arm. The numbers at risk for serious adverse events are 18, 17, and 25, respectively. The number affected by serious adverse events is 0 in each group. The record also lists 18, 17, and 25 at risk for other adverse events, with 0 affected in each group. Deaths are listed as 0 for all three groups.

These figures are counts, not comparative estimates. They show that no affected participants or deaths are recorded among the listed numbers at risk. They do not establish that the interventions have equivalent safety, because the record does not provide a comparative analysis or uncertainty estimates for these counts. The open-trial phase also had no control arm.

The registry record does not report event definitions, the method or duration of safety surveillance, or details of adverse-event ascertainment. The listed zero counts should therefore be read as the safety information recorded for these groups, not as proof that no unrecorded events occurred.

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

The record describes an intervention study focused on surrogate decision-makers of critically ill ICU patients and identifies peritraumatic distress as the primary outcome. It also sets out the intervention format and the enhanced usual care comparison. These details clarify the question the study was designed to address, but they do not show what happened to participants’ distress scores.

The primary outcome comparison is not reported as a single analyzable result. No group means, effect estimate, confidence interval, or p-value are included in the posted results, and the record lists no analyses. As a result, the record does not show whether scores were higher or lower in either group, or how precise any difference might be. The study’s stated aims should not be interpreted as observed effects.

The inclusion of an open-trial phase also matters to interpretation. That phase had no randomization or control arm, while the primary population combines that phase with the randomized EMPOWER arm. The record gives a reason for combining the two EMPOWER groups but does not report phase-specific outcome estimates. It therefore does not allow readers to assess the result within the randomized comparison alone.

The safety counts record no serious adverse events, other adverse events, or deaths among the participants listed at risk. Those counts address safety reporting, not whether the intervention changed distress. The record does not describe the completeness of safety monitoring or provide statistical comparisons for the counts.

In practical statistical terms, the registry record establishes that a clinical question was studied and identifies how the main outcome was defined. It does not supply the outcome estimates needed to quantify the result. The record therefore supports description of the study and its measurement approach, but not a conclusion about the direction, size, or precision of an effect on peritraumatic distress.

13. Why This Trial Matters Statistically

This study addresses a population facing consequential decisions in the ICU: surrogate decision-makers for critically ill patients who may be unable to communicate. The intervention’s rationale focuses on emotional responses to the possibility of patient death and on support for value-directed end-of-life care. Measuring distress in this setting makes the outcome clinically relevant to the study’s stated aims.

The record also illustrates why a clear endpoint definition is not enough for statistical interpretation. It describes the Peritraumatic Distress Inventory, its score range, the timing of measurement, and the intended between-group comparison. Yet it does not report the estimate or its uncertainty. Without those results, readers cannot distinguish a potentially small difference from a larger one, or a precise estimate from an imprecise one.

The inclusion of a randomized phase alongside an open-trial COVID-19 phase creates an additional interpretive issue. The primary population combines EMPOWER participants from both phases, while the open phase had no randomization or control arm. The record explains the reason for combining the groups but does not report phase-specific results. Statistical readers therefore need to keep the combined population’s composition in mind when assessing what the primary comparison would represent.

The listed planning assumptions also underline the difference between design calculations and observed findings. Planning illustrations can explore sample-size requirements under stated assumptions, but they are not a substitute for the completed study’s estimated effect and confidence interval. In this record, the main result needed to evaluate precision is not reported.

For biostatisticians and clinical researchers, this is a useful example of how registry information can clarify the design and outcome framework while leaving key inferential details unavailable. The distinction between the question, the planned measurement, and the reported result is essential when describing what a trial contributes statistically.

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 for interpretation is that the registry record does not report a single primary-outcome comparison. It identifies the endpoint and the assessment schedule but does not provide group estimates, an effect estimate, a confidence interval, or a p-value. The record lists no analyses. This prevents assessment of the direction and precision of the primary result.

The primary population combines the randomized EMPOWER arm with the open-trial COVID-19 phase arm. The latter had no randomization or control arm. Although the record explains that the groups had no procedural differences apart from randomized assignment in the randomized phase, it does not report phase-specific estimates or detail how the combined analysis was conducted. The contribution of the randomized and open-trial participants to the primary result therefore cannot be evaluated.

The registry record lists enrollment as 63, while the safety figures give separate numbers at risk for the three groups. It does not report the number contributing to each primary outcome analysis, reasons for missing measurements, or methods used to handle missing data. These details are important for evaluating whether the analyzed participants represent the intended study population.

The record does not identify who was masked, describe the allocation procedure, or give the full statistical analysis plan. It does not report whether the primary analysis adjusted for baseline score, how multiple outcomes or time points were handled, or whether any sensitivity analyses were performed. These limitations concern what can be established from the registry record and do not, on their own, show that the study procedures were inadequate.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Enhancing & Mobilizing the POtential for Wellness & Emotional Resilience Among Surrogate Decision-Makers of ICU Patients — NCT03276559.
• Registry record last updated 2024-08-20; status last verified 2024-07.
• Results first posted 2024-08-20.
• 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 registry record describes EMPOWER, a cognitive-behavioral, acceptance-based intervention for surrogate decision-makers of critically ill ICU patients. It lists a randomized parallel-group comparison with enhanced usual care and a separate open-trial COVID-19 phase without randomization or a control arm. The record lists an enrollment of 63 and a completed study.

The primary endpoint is change in Peritraumatic Distress Inventory score, assessed at baseline and in the week after intervention. The record describes the scale and direction of scoring, but does not report a single primary-outcome estimate or its uncertainty. It lists no analyses. The primary population combines the randomized EMPOWER arm and the open-trial phase arm.

Safety figures record 0 serious adverse events, 0 other adverse events, and 0 deaths in each of the three listed groups. The record does not report detailed analysis methods, missing-data handling, or phase-specific outcome estimates. Thus, the study’s question and design are described, but its primary statistical result is not reported in the registry record.