Tailored Health Self-Management Interventions for Highly Distressed Family Caregivers: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Tailored Health Self-Management Interventions for Highly Distressed Family Caregivers (NCT03023332), a randomized na study. The primary outcome is Change in Caregiver Health - Health Risks.

2. Clinical Question

The central design question concerns the degree of caregiver involvement in choosing a self-management approach. One arm assigned an option based on need, another used the caregiver’s preference, and the other arms provided no intervention or bipolar education. This arrangement allows the trial to examine the assigned strategies as described in the record; it does not, by itself, establish whether the strategies differed in outcome.

The primary outcome is change in health-risk behavior, measured with the Change in Health Risk Behavior Scale. The record indicates that higher scores represent greater risk. It does not provide the observed scores, the direction or size of any between-group differences, uncertainty intervals, or significance tests. Consequently, the clinical question is identifiable, but its answer is not available from the posted results.

3. Trial Design

The registry describes a randomized, double-masked, parallel-group trial with four arms: self-management need, self-management preference, control, and usual care. Enrollment is recorded as 310. Randomization indicates assignment to trial groups by chance, as opposed to choosing an arm based on participant characteristics; the record does not give further details about how the random sequence was generated or implemented. The meaning of double masking is not specified: the registry does not identify which people involved in the trial were masked or how masking was maintained.

The self-management need arm could involve bipolar education, resourcefulness training, HRV-focused biofeedback training, or no intervention, according to the stated need. The self-management preference arm could involve the same options, selected according to preference. The control arm is described as no intervention or treatment, while usual care is described as bipolar education. The registry also lists resourcefulness training, biofeedback training, and bipolar education as behavioral interventions.

The trial record lists the start date as 2017-06-12 and the primary completion date as 2021-06-30. Its status is completed. Phase is listed as NA. The primary outcome timeframe is 12 months, and its population is described as all participants completing T1 and T3. The record does not explain what those assessment labels refer to, how assessments were scheduled, or whether all randomized participants completed them.

The registry lists five outcome measures and names three secondary outcomes: change in Bipolar Knowledge Assessment Scale, change in Heart Rate Variability, and change in Resourcefulness. It lists zero analyses, and no primary-outcome numerical results are reported. Details such as allocation concealment, recruitment procedures, intervention delivery, adherence, and the statistical analysis plan 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.

Before assignment: The only participants excluded from assignment signed a consent form but withdrew or did not respond to requests to complete T1. We do not report their subdivision into self-management interventions as, per our study Aims, we were not looking at the effects of the individual self-management interventions.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: All participants completing T1 and 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: Participants who completed the baseline T1 questionnaire

6. Primary Endpoint

The registry lists the primary outcome as Change in Caregiver Health - Health Risks, measured over 12 months.

The primary endpoint is change in caregiver health risks, measured with the Change in Health Risk Behavior Scale. The registry describes a score on a scale, analyzed as a mean with standard deviation, with a 12-month timeframe. It identifies the outcome population as participants completing T1 and T3. The scale has 9 items measured on a 3-point scale; scores range from 9-27, and higher scores indicate greater risk.

A health-risk behavior measure can capture changes in behaviors relevant to health, rather than only a single clinical event. In general, using a continuous score retains gradations across participants and can make average changes between assigned groups a useful summary. The mean describes the group’s average score, while the standard deviation describes the spread of individual scores around that mean. Those summaries would help characterize both the typical score and variation within a group, but neither is reported for this endpoint.

The registry does not provide the scale’s individual item wording, scoring instructions, or evidence about its measurement properties in this study population. It also does not report the observed change, a contrast between groups, or an uncertainty interval. Since higher scores indicate greater risk, the direction of a change would be interpretable only alongside the actual scores and a clear description of the comparison. The endpoint definition alone does not show whether risk scores changed or whether any assigned approach differed from another.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies a randomized, double-masked, parallel-group design and a continuous primary outcome summarized as a mean and standard deviation. These labels describe aspects of the planned study structure and outcome summaries; they are not a substitute for the analysis results. The record does not report a statistical analysis plan or any primary-outcome estimates.

What does randomization contribute?

In general, randomization assigns participants to groups using chance. When implemented successfully, it helps make groups comparable at the point of assignment, on average, including with respect to measured and unmeasured factors. This supports interpretation of between-group comparisons as effects of assignment, subject to adherence, follow-up, analysis choices, and other sources of bias. The registry says the allocation was randomized, but details about sequence generation, concealment, and implementation are not reported.

A parallel-group design means that participants are assigned to one of the groups and the groups are compared. The four arms are described as self-management need, self-management preference, control, and usual care. The record does not report the planned pairwise or overall comparisons, or whether any particular comparison was designated as the main contrast. The trial question can involve several meaningful comparisons, but the analysis plan needed to define and prioritize them is not reported.

How should a mean change be understood?

In general, a mean is the arithmetic average of participant scores in a group. A standard deviation describes how dispersed those scores are around the mean. For a change outcome, an analysis needs to define the score difference being summarized and the assessment occasions used. The registry names change in health risks, gives a 12-month timeframe, and identifies participants completing T1 and T3, but it does not explain the exact calculation or report the resulting group summaries.

A comparison between groups is generally more informative about an intervention than separate descriptions of change within each group. For example, when each group has a change estimate, the comparative question concerns how those changes differ. That comparison should be accompanied by an uncertainty measure, commonly a confidence interval. In general, an interval communicates both the estimated effect and the range of values reasonably compatible with the data and assumptions. No such estimate or interval is reported in this registry record.

The scale runs from 9-27 and higher values indicate greater risk. Those details give the score a direction and range, but they do not determine the direction of a group’s change or its clinical importance. The registry does not report a threshold for an important change, a validated interpretation of score differences, or observed scores. No conclusion about the meaning of a specific change can be drawn without such information.

What do significance tests and precision tell readers?

In general, a significance test assesses the compatibility of data with a specified null hypothesis under a statistical model. A p-value is not the probability that the null hypothesis is true, and it does not describe the size of an effect. A confidence interval complements a test by showing the estimate’s uncertainty and the range of effects compatible with the data under the model. Neither a p-value nor a confidence interval is reported for the primary endpoint.

Precision depends on factors such as the amount of outcome information, variability, and the analysis. Enrollment alone does not show the precision of an endpoint estimate: the primary-outcome population is specified as participants completing T1 and T3, and the number analyzed is not reported. The registry also does not state the variability observed in the endpoint or the planned comparison. Thus, precision cannot be evaluated from enrollment alone.

Why does over-dispersion matter in general?

Over-dispersion is a general concern for outcomes analyzed as counts when the observed variability exceeds what a chosen count model assumes. If it is ignored, uncertainty estimates can be too small and tests can appear more decisive than warranted. This primary endpoint is described as a continuous scale score summarized by a mean and standard deviation, not as a count outcome. The registry does not report a model or analysis that would allow assessment of whether over-dispersion was relevant to any other outcome.

How should planning illustrations be read?

In general, a sample-size planning illustration asks how many participants per arm might be needed to detect an effect under stated assumptions. It is a planning calculation, not a measure of the study’s observed power and not evidence that an effect occurred. The registry’s stated assumptions for such illustrations are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is described as a stated fraction of the observed effect. These are planning assumptions, not a reported statistical plan for this trial. The sample-size justification used by the investigators is not reported in the registry record.

The record does not provide numerical planning results or the observed effect needed to contextualize an effect-based illustration. It would therefore be inappropriate to infer a required sample size, observed power, or design adequacy from the information available. The key methodological distinction is between a calculation that illustrates a hypothetical future design and an analysis of observed trial outcomes; the latter is not reported.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists five outcome measures. It identifies the primary outcome as change in caregiver health risks and names three secondary outcomes: change in Bipolar Knowledge Assessment Scale, change in Heart Rate Variability, and change in Resourcefulness. The two other outcome measures are not identified in the listed details. The record lists zero analyses and does not report results for these outcomes.

When a study assesses multiple outcomes or makes multiple group comparisons, general statistical practice considers multiplicity: the more tests conducted, the greater the chance that at least one result may appear statistically notable by chance. Researchers may define a primary comparison in advance or use an adjustment or other strategy. The registry record does not report how multiplicity was addressed, which comparisons were planned, or whether analyses were selected after examining results. The analysis plan is not reported.

The primary-outcome population is described as all participants completing T1 and T3. This does not tell readers how missing data were handled, whether participants with incomplete assessments were excluded, or whether a model used available observations. The record does not report missing-data counts, reasons for missingness, imputation, sensitivity analyses, or an analysis population defined by randomized assignment. As a result, the extent to which the reported outcome population may differ from the randomized population cannot be assessed.

In general, missing outcome data can affect both the amount of information available and the validity of a comparison, especially when the likelihood of missingness differs across groups or relates to outcomes. The registry does not provide enough information to determine whether such concerns arose in this trial. It also does not describe interim analyses, prespecified stopping rules, or a statistical plan; these 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 record lists serious adverse events affected as 0 in each of the four groups. Other adverse events affected are also listed as 0 in each group. The record lists one death in the self-management need group and zero deaths in each of the other groups. No serious-event terms are listed.

These figures should be read as the adverse-event information entered in the registry, not as proof that no unrecorded events occurred. The record does not provide details about how events were defined, how they were collected, the period during which they were monitored, or whether events were judged related to an intervention. It also does not describe the circumstances or cause of the death. The death count should not be interpreted as evidence that an assigned approach caused or prevented a death.

The figures are presented by assigned group, but they do not establish comparative safety. A meaningful comparison would require clear event definitions and observation periods, as well as information about exposure and follow-up. The registry does not report those details or statistical comparisons. The adverse-event counts therefore provide a limited account of what was recorded, not a complete safety assessment or a causal conclusion.

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

The record shows that investigators registered a randomized, double-masked, parallel-group trial comparing four approaches for family caregivers of people with bipolar disorder. Its central design feature was varying whether a self-management option was assigned according to need or selected according to preference, alongside a no-intervention control and bipolar education as usual care. The named primary outcome was change in health-risk behavior over a 12-month timeframe.

That design defines a question, not an answer. The registry does not report the primary-outcome means, standard deviations, changes, or between-group comparisons. It also does not report confidence intervals or p-values. Readers therefore cannot determine from the posted results whether any arm had higher or lower scores, whether the groups differed, or how precise any estimated difference was. The record does not support a conclusion that any approach did or did not affect health-risk scores.

The outcome’s scale direction is available: higher scores indicate greater risk. This helps interpret a numerical result if one is reported, but it cannot replace the missing numerical result. Similarly, the trial’s completed status and enrollment entry do not establish that all enrolled participants contributed to the primary outcome or that a planned comparison was adequately precise.

The adverse-event entries list no affected participants for serious or other adverse events in the groups, and list one death in the self-management need group. Those entries alone do not establish comparative safety or causation. Event definitions, monitoring details, attribution, and the circumstances of the death are not reported in the registry record.

What the record can support is a description of the registered design, intervention options, and intended outcome. It cannot support an estimate of comparative benefit, a claim about the effectiveness of an intervention, or an assessment of the statistical strength of the primary result. Those interpretations require outcome data and analysis details that are not reported.

13. Why This Trial Matters Statistically

This trial addresses a design question that is distinct from simply comparing an intervention with no intervention: whether caregiver involvement in selecting a self-management option is structured around assessed need or personal preference. The registry also includes a control group and a usual-care group, which it describes as bipolar education. This creates a potentially informative framework for examining different ways of organizing behavioral support, provided the comparisons and results are reported.

Statistically, the design makes clear why the comparison needs to be specified. The four arms represent different assignment strategies, and the two self-management arms can involve several possible options. The record does not state which group contrasts were planned as primary or how multiple comparisons would be handled. Without that information, readers cannot identify the intended inferential priority among the possible comparisons.

The registered primary outcome is a continuous health-risk behavior score, with a stated direction and range. A well-reported analysis could show average changes, variability, between-group differences, and uncertainty. Those elements would help readers distinguish an estimated effect from its precision and judge whether the data are informative. The registry record does not report those results, so the trial’s statistical contribution cannot be assessed from the posted information.

The record also makes visible a common reporting distinction: a completed trial and a registered outcome are not the same as an interpretable result. Enrollment, intervention descriptions, and outcome definitions clarify what was planned, but they do not reveal what the data showed. For this trial, reporting arm-level results, analysis populations, missing-data handling, and prespecified comparisons would be necessary to evaluate the randomized evidence.

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 main limitation for interpretation is that the registry record does not report primary-outcome results or statistical analyses. There are no group-specific scores, changes, comparative estimates, confidence intervals, or p-values. Although the record names five outcome measures, it lists zero analyses. The registry therefore describes the trial design and endpoint but does not permit assessment of the primary question.

The primary-outcome population is described as participants completing T1 and T3, but those assessment labels are not explained. The number contributing to the endpoint and the handling of participants without complete assessments are not reported. The record does not say whether the analysis followed randomized assignment, how missing data were addressed, or whether sensitivity analyses were conducted. This limits assessment of the relationship between randomized allocation and the analyzed population.

Intervention assignment involved options based on need or preference, including education, resourcefulness training, HRV-focused biofeedback training, or no intervention. The registry does not report how need or preference was assessed, how the options were delivered, whether participants adhered to their assigned approach, or whether the interventions were delivered consistently. These omissions make it difficult to evaluate implementation and distinguish the effect of assignment from the effects of receiving a particular option.

Further design and analysis details are not reported in the registry record, including allocation concealment, the identities of masked parties, the statistical analysis plan, planned comparisons, multiplicity handling, and sample-size justification. The adverse-event record does not give monitoring periods, event definitions, or attribution. These are limitations of the available registry information and should not be treated as evidence that the trial itself lacked these procedures.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Tailored Health Self-Management Interventions for Highly Distressed Family Caregivers — NCT03023332.
• Registry record last updated 2023-11-15; status last verified 2023-11.
• Results first posted 2023-11-15.
• 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 describes NCT03023332, Tailored Health Self-Management Interventions for Highly Distressed Family Caregivers, sponsored by Case Western Reserve University. The trial is listed as randomized, double-masked, and parallel-group, with status completed and enrollment of 310. Its start date is 2017-06-12, and its primary completion date is 2021-06-30.

Four groups are described: self-management need, self-management preference, control, and usual care. The primary outcome is change in caregiver health risks on the Change in Health Risk Behavior Scale, with a 12-month timeframe. Higher scores indicate greater risk, and the record describes the outcome as a mean with standard deviation among participants completing T1 and T3.

The record lists five outcome measures and zero analyses. It does not report primary-outcome estimates, comparative analyses, or details of missing-data handling. Adverse-event entries list 0 serious and 0 other affected participants in every group, and one death in the self-management need group. These entries do not establish causation or comparative safety.