Family Support Intervention in Intensive Care Units: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Family Support Intervention in Intensive Care Units (NCT05280691), a randomized na study. The primary outcome is Satisfaction With Care (Quality of Family Care) - Total Score.

2. Clinical Question

The trial was registered as a superiority study: its stated purpose was to test whether the intervention improved the primary endpoint relative to usual care. That describes the research question, not a finding. The registry record does not report group means, a between-group estimate, a confidence interval, or a test result for satisfaction with care, so it cannot establish from the posted information whether the groups differed or how precisely any difference was estimated.

3. Trial Design

The registry describes a multicenter, parallel, cluster-randomized controlled superiority trial. The ICU, rather than each family member individually, was the unit of randomization. The planned design included eight ICU clusters per study arm. This matters because families cared for within the same ICU may share staff, routines, and communication practices. Their outcomes may therefore be more alike than outcomes from families in different ICUs.

The trial compared a family support intervention added to usual care with usual care alone. The intervention was described as nurse-led and multicomponent: specialist nurse support was planned at defined time points along the patient pathway, including follow-up, alongside nurse-coordinated liaison and structured communication among ICU professionals. The registry does not provide further operational detail about usual care or the actual delivery and uptake of each intervention component.

Masking was listed as none. In this setting, the registry does not report masking of participants, clinical staff, or outcome assessors. The primary outcome was family-reported satisfaction, assessed using the German FS-ICU-24R at a time tied to the patient’s ICU discharge. The trial was marked completed; its recorded start date was 2022-05-12 and its primary completion date was 2024-03-31.

The registry lists enrollment of 885 and describes a projected sample size of 896 family members in the trial summary. Those are different registry figures, and the record does not explain the difference. Enrollment should not be confused with the number of ICU clusters or with the number of family members included in a particular outcome analysis. The analyzed population and the number contributing primary outcome data 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

Analysis population for the primary outcome, as defined in the registry: No difference.

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 Satisfaction With Care (Quality of Family Care) - Total Score, measured over Assessed at a single time point no earlier than 24 hours prior to and no later than 14 days following the discharge of the patient from ICU..

The primary endpoint was satisfaction with ICU care, treated as a continuous total score on a scale from 0-100. The registry identifies the German version of the Family Satisfaction in ICU questionnaire, FS-ICU-24R, as the measure. It covers satisfaction with care and satisfaction with involvement in decision-making; the record describes 16 items for care and ten items for decision-making. A score of 100 indicates maximal satisfaction.

This endpoint was chosen to operationalize quality of family care from the family member’s perspective. Family members experience communication, support, and involvement directly, so a satisfaction measure can capture aspects of care that may not be represented by patient clinical outcomes alone. The score is a measure of reported experience, however, and should not be treated as a direct measure of every element of care or of patient health.

Assessment was scheduled at a single time point, no earlier than 24 hours before and no later than 14 days following the patient’s ICU discharge. This window anchors the report to the ICU stay while allowing assessment around discharge. The registry does not report the actual assessment timing for participants, the score distribution, group means, standard deviations, or the treatment-effect estimate. It therefore supplies the endpoint definition but not the result needed to judge the observed between-group difference or its precision.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The trial’s statistical design begins with how allocation occurred. This was a cluster-randomized study, with ICUs as clusters and family members as the people whose outcomes were measured. In a cluster design, participants within a shared setting can have related outcomes because they encounter common teams, policies, and routines. This dependence is called intracluster correlation. As a general statistical principle, when outcomes are correlated within clusters, an analysis must account for that structure to quantify uncertainty appropriately. The registry record does not report the specific method used to account for clustering in the primary analysis.

Why does cluster randomization matter?

Randomizing whole ICUs can make sense when an intervention changes how staff communicate or organize support, because those practices occur within the care setting and may affect multiple families. But the number of clusters, not only the number of individuals, informs how much independent information the trial contains. Cluster size and within-cluster similarity also affect precision. The record describes a plan for eight clusters per arm, but does not report the number of clusters actually analyzed, cluster sizes by arm, or a measure of within-cluster similarity. No individual-level re-analysis is reported; the registry notes that such a simple re-analysis would be misleading for this design.

What does the continuous endpoint imply?

Satisfaction with care was measured as a continuous score on a scale from 0-100, and the registry specifies a mean and standard deviation as its summary measures. A mean describes the central average score in a group, while a standard deviation describes how spread out individual scores are around that average. Comparing group means can summarize an average difference, but the difference alone does not show its uncertainty. A confidence interval communicates uncertainty in an estimate under the assumptions of the analysis. A p-value, if reported, addresses compatibility between the data and a specified null hypothesis under a statistical model; it is not a measure of the size or importance of an effect.

The registry record gives no group means, standard deviations, confidence interval, or p-value for the primary endpoint. Consequently, no numerical effect can be interpreted from the registry information. The registry’s stated primary population entry is “No difference.” That wording does not supply an estimated result or an analysis method, and its intended statistical meaning is not explained in the record.

What do the planning assumptions mean?

The record describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between the arms, and a normal approximation. For outcomes other than time-to-event outcomes, those illustrations are expressed as participants per arm. Such calculations can show how a hypothetical study size would vary under specified assumptions about the effect to detect. They are planning illustrations, not observed power, and they do not establish that the completed trial had adequate power. The registry’s description says the effect to detect is a stated fraction of the observed effect, but the effect and the numerical planning rows are not reported in the registry record.

General statistical caution is especially important when a planning illustration uses an observed effect. An observed effect is itself uncertain, and planning calculations based on it inherit that uncertainty. A smaller target effect would generally require more information to detect than a larger target effect, all else equal, but the actual numerical requirements depend on the assumptions and design. Cluster randomization adds dependence and cluster-level considerations beyond a simple individual-level calculation. The registry record does not state that its planning illustration was the original trial’s design justification; in fact, it describes it as separate from the trial’s own design.

What analysis information is missing?

The registry lists 0 analyses and does not report the sponsor’s numerical primary analysis. It does not state the model, covariates, method for handling clustering, missing-data approach, or analysis population. Nor does it report whether the treatment effect was adjusted or unadjusted. These omissions prevent assessment of model assumptions, the handling of departures from the intended design, and the relationship between planned and analyzed populations. Statistical methods can clarify how an estimate should be read, but they cannot recover an unreported estimate or substitute for the trial’s analysis results.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Family Support Intervention & Usual Care", "Usual Care")
n   <- c(412, 473)
m   <- c(81.78, 79.39)
sp  <- c(14.64, 15.12)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Family Support Intervention & Usual Care  412  81.780  14.640  80.362  83.198
CARM  Usual Care  473  79.390  15.120  78.024  80.756

11. Multiplicity, Missing Data and Analysis Populations

The registry lists the primary satisfaction-with-care measure and a set of secondary outcomes spanning communication, nurse cognitive and emotional support, family functioning, resilience, life satisfaction, well-being, quality of life, and psychological distress. It records 12 outcome measures and 0 analyses. The record does not report a multiplicity strategy, such as whether secondary outcomes were treated as exploratory, whether testing was adjusted across outcomes, or which outcomes formed any prespecified family of hypotheses. Without results and a stated strategy, readers cannot judge how multiple outcome testing may affect interpretation.

Missing-data methods are not reported in the registry record. The number of participants with primary outcome measurements, the extent and pattern of missingness, and any imputation or other handling are also not reported. These details matter because missing outcome data can affect both the estimated group comparison and its uncertainty, particularly if missingness differs between arms or is related to outcomes.

The analysis population is not specified in the posted record. It does not say whether the primary analysis included all allocated clusters and participants, or whether exclusions were made. Nor does it report how participants were assigned to the analysis if their exposure or follow-up differed from the intended intervention. Those choices affect the interpretation of the estimate and its relation to the randomized comparison.

For a cluster-randomized trial, the analysis must also address the ICU-level allocation and possible correlation among families in the same ICU. The registry identifies the design but does not report the analytic method. These absences are not proof that the trial team did not make such decisions; they mean the decisions are not reported in the registry record.

12. 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 registry’s adverse-event record lists 0 serious events in the Family Support Intervention group and 0 in the Usual Care group. It also lists 0 other events for each group, and deaths of 1 in each group. The record gives at-risk counts of 412 for the intervention group and 473 for usual care. These are the registry’s listed fields; they should not be treated as a complete safety analysis or as evidence about causes of events.

The death entries are reported separately from the serious-event and other-event counts. The record does not give causes, timing, relationship to the intervention, or further clinical descriptions for the deaths. It also does not list serious adverse event terms. The fact that the event fields are recorded as 0 does not clarify how events were collected, what reporting window was used, or whether every participant was assessed in the same way.

These counts are descriptive registry entries, not a comparison adjusted for the cluster-randomized design. No statistical estimate or uncertainty measure for safety outcomes is reported in the registry record. They should be read alongside the limits of the reporting rather than interpreted as demonstrating that either care approach is safe or unsafe.

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

The registry record establishes what the trial was designed to compare: a nurse-led, multicomponent family support intervention added to usual care versus usual care alone, with family satisfaction with ICU care as the primary endpoint. It also identifies the cluster-randomized, parallel, multicenter design and the timing and instrument for measuring satisfaction. These details allow readers to understand the intended question and the context in which a reported result would need to be interpreted.

However, the record does not report the primary outcome results or any analysis entries. It therefore does not show whether satisfaction scores were higher, lower, or similar between the groups, nor does it show the estimated size or precision of a difference. Trial completion, enrollment, and the existence of a planned intervention cannot stand in for those results. The absence of a reported analysis also means that no conclusion about secondary outcomes can be drawn from their inclusion in the registry.

The study addresses family experience and support in a setting where family members may face uncertainty and distress. The trial summary notes that guidelines recommend structured family inclusion, communication, and support, while describing the existing evidence base for protocolized interventions as modest and in need of substantiation. That background explains the motivation for studying the intervention; it is not an outcome of this trial. The summary’s statement that about 20-60% of family members experience post-traumatic distress post-ICU is background context and should not be confused with a trial estimate.

Even if numerical results were reported, interpretation would depend on the size and uncertainty of the treatment-effect estimate, the handling of clustering and missing data, and the analysis population. The posted record does not report those details. Accordingly, the trial’s stated question can be described, but its effectiveness cannot be determined from the registry information available in this record.

14. Why This Trial Matters Statistically

This trial is statistically notable because the intervention was delivered in a setting where practices are organized at the ICU level, and randomization was by ICU cluster. That feature aligns the allocation unit with the setting in which staff support and communication take place. It also means that the analysis cannot safely treat every family member’s response as independent without accounting for possible similarities within the same ICU. The registry itself flags why an uncomplicated individual-level re-analysis would be misleading.

The primary outcome captures family members’ reported experience of care rather than a clinical measure of the critically ill patient. This makes the endpoint directly relevant to the trial’s stated family-support question, while also requiring care in describing what it represents: satisfaction with care and involvement in decision-making, measured using the FS-ICU-24R, is not interchangeable with every aspect of family well-being or ICU quality.

The registry describes a projected sample size and records enrollment, but those quantities alone cannot reveal how much information the trial’s cluster structure and outcome availability provided. The number and size of clusters, within-cluster similarity, missingness, and the analysis method all bear on precision. Those details and the actual primary analysis are not reported in the registry record. The record therefore illustrates why design information is essential but insufficient without results and methods.

The listed secondary outcomes broaden the intended assessment beyond satisfaction, including family functioning, resilience, well-being, and psychological distress. That breadth can help describe different dimensions of family experience, but it also makes transparent reporting of analysis choices important. Since the registry lists no analysis entries, those outcomes cannot be used to support conclusions about intervention effects.

15. 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 principal limitation of interpretation is that the registry record contains no reported analysis results. It provides no primary outcome means, standard deviations, treatment-effect estimate, confidence interval, or p-value. As a result, the direction and precision of the primary comparison cannot be assessed. The record’s completed status does not resolve this limitation.

Several features needed to assess the analysis are also not reported: the number of clusters actually analyzed, cluster sizes by arm, the primary analysis method, adjustment for clustering, the analysis population, missing-data handling, and multiplicity procedures. The record lists 0 analyses. These are limits of what can be concluded from the registry record, not evidence that no analyses were conducted outside it.

The enrollment entry of 885 and the projected sample size of 896 are both recorded, but the registry does not explain the difference or state how many participants contributed to the primary endpoint. Nor does it report implementation or adherence information that would show how the multicomponent intervention was delivered in practice. Usual care is not described in detail, making it difficult to characterize variation in the comparator across participating ICUs.

The registry lists no masking. It does not specify which parties, if any, were masked during outcome assessment or analysis. Because the primary endpoint is a family-reported satisfaction measure, interpretation would benefit from knowing how it was collected and whether completion differed by arm. Those details are not reported. The adverse-event fields also lack event timing, causes, and relatedness information, limiting what can be inferred from their counts.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Family Support Intervention in Intensive Care Units — NCT05280691.
• Registry record last updated 2026-06-30; status last verified 2026-05.
• Results first posted 2026-06-30.
• 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.

19. Record Summary

NCT05280691 is a completed, multicenter, parallel, cluster-randomized superiority trial titled “Family Support Intervention in Intensive Care Units.” It compared a nurse-led Family Support Intervention added to usual care with usual care alone among family members of adult, critically ill patients in the German-speaking part of Switzerland. The planned target included families whose patient was expected to remain in the ICU for 48 hours or longer.

The primary endpoint was family satisfaction with ICU care, measured with the German FS-ICU-24R on a 0-100 scale at a time from 24 hours before through 14 days after ICU discharge. The registry records enrollment of 885 and describes a projected sample size of 896. It lists 12 outcome measures and 0 analyses. Primary and secondary outcome results, analysis methods, missing-data methods, and analysis populations are not reported in the registry record.