Self-Management Intervention: Considering Needs & Preferences of Dementia Caregivers (Caregiver Career Study): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Self-Management Intervention: Considering Needs & Preferences of Dementia Caregivers (Caregiver Career Study) (NCT04603482), a randomized na study. The primary outcome is Change in Caregiver's Perceived Stress Scale.

2. Clinical Question

The study addresses whether involving caregivers in intervention selection in different ways is associated with changes in health risks and physical and mental health. Its three randomized arms distinguish assignment based on baseline data, assignment based on preference, and an attention-control condition. This makes the choice process part of the research question: the study compares not only intervention content with diversional activities, but also two approaches to choosing between the self-management options.

The primary outcome named in the registry is change in perceived stress. However, the registry record does not report arm-level outcome values, an estimated contrast between arms, or a statistical test for this outcome. It therefore does not establish the direction, magnitude, or precision of differences in perceived stress. Nor does the record provide results for the other outcome measures. The question can be described from the study plan, but its answer cannot be determined from the posted results in this record.

3. Trial Design

This is a randomized, parallel-group study with triple masking recorded in the registry. Enrollment is reported as 328, and the study status is completed. The listed phase is NA. Case Western Reserve University is the sponsor. The registry gives a start date of 2021-01-08 and a primary completion date of 2024-06-30.

Participants were assigned to one of three approaches. In the need-based arm, baseline data determined whether a participant received Resourcefulness Training or Biofeedback. In the preference-based arm, the participant’s preference determined which of those self-management interventions was received. The attention-control arm involved presentation of diversional activities. The registry does not describe the content, schedule, or delivery details of these interventions beyond those statements.

The primary outcome is a continuous score, summarized in the record as a mean with standard deviation. The stated measurement period runs from baseline T1 through T2 at 6 months and T3 at one year. The primary-outcome population description refers to people who completed the T3 questionnaire across the arms. It also reports 15 discontinuations in each arm between baseline and T3 and states that 45 participants dropped out over time. The description is truncated after mentioning a calculation involving 308 baseline-measure completers and 45 dropouts, so it does not provide a clear, complete final analyzed count.

The registry record does not report the randomization procedure, allocation concealment, which roles were masked, or how masking was maintained. It also does not report a protocol-level statistical plan or a sample-size justification. Those details should not be inferred from the labels for allocation, masking, or study design.

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: Enrolled participants may be excluded if they elect not to participate after enrolling.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The overall analyzed participants included all who completed the T3 questionnaire across the three arms. 15 participants in each arm discontinued their participation between baseline (T1) and T3. Thus, this number equals 308 (who completed baseline measures) minus 45 (who dropped out over time) which equals 263 at T3.

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: All participants who consented and completed the baseline questionnaire.

6. Primary Endpoint

The registry lists the primary outcome as Change in Caregiver's Perceived Stress Scale, measured over From T1 (baseline) to T2 (6 months) through T3 (one year).

The primary endpoint is change in the caregiver’s score on the Perceived Stress Scale. The registry describes a 14-item measure with a 3-point scale, scores ranging from 9-27, and higher scores indicating greater perceived stress. The outcome is recorded as a mean with standard deviation, making it a continuous measure rather than a count or time-to-event outcome.

Perceived stress is relevant to the study’s focus on family caregivers’ health risks and mental health. Tracking scores from baseline through later assessments allows the study to describe how reported stress changes over time and to compare those patterns across the randomized approaches. The registry specifies measurements at T1 (baseline), T2 (6 months), and T3 (one year).

The record does not explain how the change score was calculated, whether the main comparison used a particular follow-up point or the full sequence of assessments, or how repeated measurements were modeled. It also does not report the mean scores, standard deviations, estimated changes, or between-arm contrasts. Therefore, the endpoint’s meaning and scale can be described, but the observed change and its uncertainty cannot be evaluated from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a mean and standard deviation describe?

For a continuous outcome, the mean describes the average score among the participants included in a particular analysis. The standard deviation describes how spread out individual scores are around that average. Together, these summaries give information about the center and variability of the observed scores. They do not, by themselves, quantify the uncertainty in a comparison between randomized arms.

The registry labels the primary outcome as a mean with standard deviation, but it does not report those summaries for the outcome. No calculated comparison can therefore be interpreted from this record. The outcome scale is bounded, and higher scores indicate greater perceived stress; those properties help give context to scores when results are available, but they do not determine what the observed results were.

How should change over time be understood?

The listed assessment sequence is baseline T1, T2 at 6 months, and T3 at one year. A change score describes movement in a participant’s score between specified assessments. A comparison of change between randomized groups asks whether the groups’ average movements differ. These are distinct from comparing follow-up scores alone. The registry names change as the primary endpoint but does not explain the exact calculation or specify the statistical model used to account for repeated measurements.

In general, repeated observations from the same participant are related rather than independent. Statistical methods for longitudinal data account for this within-participant relationship when estimating change and uncertainty. The choice of method can affect the interpretation, particularly when some follow-up observations are missing. The registry record does not report which longitudinal method, if any, was used.

What does randomization contribute?

In general, random assignment is intended to make groups comparable in expectation at the point of assignment, including with respect to characteristics that were not measured. This supports a comparison of assigned strategies. It does not guarantee that the groups are identical in a particular study, and it does not remove the need to report the analysis population, outcome data, and uncertainty. The record identifies the study as randomized but does not describe how the random sequence was generated or concealed.

The parallel-group label means the arms are distinct assigned groups rather than a crossover sequence described in the registry. Triple masking is recorded, but the record does not say which people were masked or how masking applied to intervention delivery, outcome assessment, or analysis. No further interpretation of masking can be made from the label alone.

What information would quantify a treatment contrast?

A between-arm estimate would describe the observed difference in outcome, according to a defined comparison and analysis. A confidence interval would show the range of values compatible with the data under the model and its assumptions. In general, a narrower interval indicates greater precision, while a wider interval indicates less precision. A p-value addresses compatibility of the data with a specified null hypothesis under a statistical model; it does not measure the size or importance of an effect.

The registry record does not report an effect estimate, confidence interval, or p-value for the primary outcome. It also does not define a particular pairwise contrast or state whether the main inference concerns all three arms together, selected pairwise comparisons, or a pattern across follow-up. Accordingly, no estimate of magnitude, precision, or statistical evidence can be described.

What is the role of the sample-size assumptions?

The record describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. Such an illustration is a planning calculation, not an observed result and not observed power. It is also not the trial’s own design justification. The record does not report the trial’s sample-size rationale.

Because no observed primary-outcome effect is reported in this registry record, the assumptions alone cannot establish what effect was used in any numerical planning illustration or what sample size it would imply. The illustration should not be treated as evidence about whether the trial detected an effect. Its role, when calculated from available estimates, is to show how planning requirements depend on assumptions about the effect and statistical design.

Why does over-dispersion matter in general?

Over-dispersion is a general issue for certain outcome models when the observed variability is larger than the model assumes. If that extra variability is ignored, uncertainty may be understated and statistical tests may be poorly calibrated. The primary endpoint in this record is described as a continuous score summarized by a mean and standard deviation; the registry does not report an over-dispersion assessment or say that an over-dispersion adjustment was used. This concept therefore explains a general modeling concern, not a reported feature of this analysis.

10. Multiplicity, Missing Data and Analysis Populations

The study lists six outcome measures, but the registry record does not provide a statistical analysis plan specifying which outcomes were confirmatory, how multiple comparisons were handled, or whether any hierarchy of outcomes was prespecified. It also does not report numerical analyses for the primary outcome. The record’s note that the primary outcome has several categories or time points and was not reduced to one comparison means that a single comparison is not available in the posted results. No specific multiplicity adjustment or strategy can be inferred.

Multiplicity is a general concern when investigators assess several outcomes, time points, or pairwise contrasts. Conducting more tests can increase the chance of at least one apparently unusual result under a null scenario. Prespecified hypotheses and a stated adjustment or interpretation plan help readers understand how such results should be evaluated. The registry record does not report those details, so it is not possible to determine how the trial’s analyses addressed multiplicity.

For missing data, the primary-outcome description refers to participants who completed the T3 questionnaire. It reports 15 discontinuations in each arm between baseline and T3 and 45 dropouts over time, and it mentions 308 baseline-measure completers. The description is truncated, leaving its final statement incomplete. The final number analyzed, reasons for discontinuation, handling of partial questionnaires, and assumptions or methods for missing outcomes are not reported in the registry record.

These details matter because restricting an analysis to people with observed follow-up may produce a different estimate from an analysis that includes all randomized participants under a stated missing-data approach. The record identifies the analysis population only partially and does not state whether the primary analysis followed assignment regardless of intervention received. It does not report sensitivity analyses that would show how conclusions might change under alternative assumptions about missing outcomes.

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 registry reports zero serious adverse events among 105 participants at risk in the Need arm, zero among 100 at risk in the Preference arm, and zero among 103 at risk in Attention Control. It also reports zero other adverse events in each arm and zero deaths in each arm. The serious adverse-event terms list is empty.

These entries are counts as recorded in the registry. They do not provide event descriptions, definitions, severity criteria, or information about how actively events were collected. The record does not specify the safety follow-up period or describe whether event reporting was complete for every participant. The numbers at risk are the arm-specific figures shown in the registry and should not be interpreted as a complete account of exposure time.

A zero count in a registry entry means that no events are listed in that category for the reported arm; it does not establish that every possible adverse event was absent or that an intervention is safe in all settings. The safety data are also separate from the primary perceived-stress outcome. They cannot substitute for the missing outcome estimates or answer the study’s main effectiveness question.

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

The registry record establishes that the study was designed to compare a need-based approach to selecting a self-management intervention, a preference-based approach, and attention control among family caregivers of people with Alzheimer’s disease and other dementia disorders. It identifies perceived stress as the primary outcome and describes the measure, its direction, and the assessment schedule. It also reports arm-level adverse-event counts.

What the record does not establish is the result of the primary comparison. There are no reported means, changes, effect estimates, confidence intervals, or p-values for perceived stress. Without these, it is not possible to state whether scores changed, whether differences appeared between assigned approaches, or how precisely any differences were estimated. No result for the other outcome measures is reported either.

Even if an outcome estimate were available, its interpretation would depend on the analysis population, missing-data handling, selected comparison, and statistical model. Those aspects are incompletely described in the registry record. A numerical difference would also need to be judged in relation to the outcome scale and its practical meaning; the record does not provide a threshold for a clinically important change.

The trial’s completed status and enrollment figure are not outcome findings. Likewise, a planning illustration based on an observed effect, as described in the registry, would not be observed power and would not replace an analysis of the trial data. The reported zero adverse-event counts are limited to the registry’s entries and do not answer whether the self-management approaches changed stress or other health outcomes.

The appropriate reading is therefore descriptive: the record outlines a randomized comparison and names the main measure, but does not report enough primary-outcome data to evaluate the result. Any conclusion about benefit, lack of benefit, or equivalence would go beyond the information reported.

13. Why This Trial Matters Statistically

Statistically, this trial is notable for separating two ways of selecting a self-management option. One arm bases selection on baseline data; another uses caregiver preference. A third arm receives diversional activities as attention control. That structure makes the selection strategy itself relevant to interpretation, not merely the specific behavioral intervention named in an arm.

The primary endpoint is measured repeatedly, from baseline through follow-up at 6 months and one year. Longitudinal outcomes raise important analytic questions about how within-person measurements are handled, how change is defined, and what happens when follow-up data are missing. The registry names the time points but does not report the analysis model, missing-data method, or a fully specified contrast. Those omissions make it difficult to assess how the planned design was translated into statistical analysis.

The record also illustrates the difference between a trial’s design information and its result. Randomization, masking, enrollment, and outcome definitions describe how a study was organized. They do not show the estimated effect or its uncertainty. For this record, those outcome results are not reported, so the central statistical question remains unanswered in the posted information.

Finally, the listed planning assumptions should be distinguished from the trial’s own sample-size rationale and from observed evidence. A planning illustration can help explore design choices when an effect assumption is available, but it cannot establish what the trial found. Clear reporting of the primary estimate, uncertainty, analysis population, and missing-data approach would be needed to make the statistical evidence interpretable.

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 for interpreting this trial from the registry record is the absence of numerical results for the primary outcome. The record gives the scale and follow-up schedule but no arm-level scores, changes, estimated contrasts, measures of uncertainty, or statistical tests. It also does not report numerical results for the other listed outcome measures.

The primary-outcome population description is incomplete. It refers to T3 questionnaire completers and reports discontinuations and baseline-measure completers, but the statement is truncated. The final analysis count and the relationship between enrollment, baseline completion, and follow-up completion are not fully explained. The record does not describe reasons for dropout or methods for handling missing outcome data.

Important analysis details are not reported in the registry record. These include the exact change-score definition, the model used for repeated assessments, the primary between-arm contrast, the handling of multiple outcomes or comparisons, and whether the main analysis retained participants according to randomized assignment. The randomization method and the roles covered by triple masking are also not described.

The intervention descriptions are brief. The record identifies Resourcefulness Training, Biofeedback, and diversional activities, and explains how participants were assigned to the self-management options, but does not report implementation details or adherence. The safety entries give counts but not event definitions, ascertainment procedures, or a clear safety follow-up description. These limitations concern what can be learned from the registry record and should not be mistaken for evidence that the trial did not collect or analyze these data elsewhere.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Self-Management Intervention: Considering Needs & Preferences of Dementia Caregivers (Caregiver Career Study) — NCT04603482.
• Registry record last updated 2025-05-13; status last verified 2025-05.
• Results first posted 2025-03-18.
• 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 a completed, randomized, parallel-group study sponsored by Case Western Reserve University, with enrollment of 328 and triple masking recorded. The study compares self-management intervention selection based on baseline data or caregiver preference with attention control using diversional activities. The named self-management options are Resourcefulness Training and Biofeedback.

The primary outcome is change in the caregiver’s Perceived Stress Scale score from baseline T1 through T2 at 6 months and T3 at one year. Higher scores indicate greater perceived stress. The record lists six outcome measures but reports no analyses and gives no numerical result for the primary endpoint. The final analyzed population and missing-data approach are not fully described.

Registry safety entries report zero serious adverse events, zero other adverse events, and zero deaths in each arm. These counts do not resolve the missing primary-outcome results. The record describes study design and measurement, but does not allow estimation of the direction, magnitude, or precision of the intervention comparisons.