A Home-based Training Program for Elderly Patients With Dementia: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Home-based Training Program for Elderly Patients With Dementia (NCT02667951), a randomized na study. The primary outcome is Caregivers' Self-efficacy.

2. Clinical Question

The trial also listed caregivers’ quality of life and depressive symptoms as secondary outcomes. The posted numerical secondary result is for depressive symptoms. A numerical result for quality of life is not reported in the registry record. The study description frames the comparison around the costs and effectiveness of two care models, but cost results are not reported in the registry record.

The primary outcome is a caregiver-reported measure of confidence in managing agitation, rather than a direct measure of agitation frequency or the care recipient’s clinical status. The comparison therefore addresses one aspect of caregiver experience at the stated follow-up time. It does not by itself describe all consequences of either care model or establish how the result might apply to caregivers outside the population and setting represented in the trial.

3. Trial Design

The registry record describes a randomized, single-masked, parallel-group study. Enrollment was 129, and the study status is completed. The recorded study start is 2009-06, with primary completion in 2010-09. The registry labels the phase as NA. The meaning of the single-masked designation, including who was masked, is not reported in the registry record.

Caregivers in the intervention group received support directed at managing behavioral problems in people with dementia. This included solutions for behavioral problems, referrals to community services, telephone consultation, and monthly telephone follow-ups that offered further assurance and consultation. Progress in behavior management was evaluated. The control group received general dementia-care information and follow-up phone calls intended to maintain contact, but did not receive training to create a behavioral problem-management plan or strategies.

The primary outcome was caregivers’ self-efficacy, measured with the Agitation Management Self-efficacy Scale at 18 months. The registry also lists caregivers’ quality of life and depressive symptoms as secondary outcomes. Arm-level primary outcome results are reported for 45 control participants and 40 intervention participants. The depressive-symptom results use the same arm-specific counts. How those outcome counts relate to the full enrollment, including whether any participants lacked outcome data or were excluded from an analysis, is not reported in the registry record.

Details of the randomization procedure, allocation concealment, masking procedures, follow-up schedule beyond the reported outcome timeframe, and analysis population are not reported in the registry record. The registry record does not describe a prespecified statistical analysis plan or the trial’s original sample-size justification. The enrollment figure alone does not establish the intended statistical power or the assumptions used when the trial was designed.

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

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 Caregivers' Self-efficacy, measured over 18 months.

The primary endpoint is caregivers’ self-efficacy for managing agitation associated with dementia, assessed at 18 months with the Agitation Management Self-efficacy Scale. The measure asks caregivers how confident they are about handling each identified behavioral problem and whether they believe they could manage behaviors that had not occurred. Scores range from 42 to 210, with higher scores representing greater caregiver self-efficacy. The registry reports Cronbach’s alphas ranging from 0.98 to 0.99 at different time points.

Self-efficacy is a measure of perceived confidence. In general, such a measure can capture a caregiver’s sense of capability in handling difficult situations, which may be relevant when comparing a program that provides training and consultation with routine care. It is distinct from a direct count of behavioral events, an objective assessment of caregiving skill, or a measure of the person with dementia’s symptoms. A change in confidence should therefore be interpreted as a result about caregivers’ reported confidence, not as proof that agitation itself changed.

The endpoint is expressed as a mean on a continuous scale, with standard deviations reported for each group. The registry record does not report the scale’s minimally important difference or a threshold defining a clinically important change. The result can describe the direction and precision of the group contrast, but the registry information does not establish how large a difference caregivers would regard as important in practice.

7. Results Posted in the Registry

• Intervention Group: mean 178.00 versus 155.00 on control; difference 23.00 (95% CI 10.21 to 35.79), standardized effect d = 0.75; z-test p = <0.001.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Caregivers' Depressive Symptoms

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Intervention Group: mean 8.00 versus 13.00 on control; difference -5.00 (95% CI -9.12 to -0.88), standardized effect d = -0.50; z-test p = 0.017.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for Intervention Group than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

The secondary outcomes place caregiver well-being alongside the primary focus on confidence in managing agitation. The registry lists caregivers’ quality of life and depressive symptoms. A numerical result is posted for depressive symptoms; a numerical quality-of-life result is not reported in the registry record. The available secondary evidence is therefore incomplete across the outcomes named in the registry.

The posted depressive-symptom comparison has a direction consistent with a lower group mean in the intervention arm, whereas the primary self-efficacy comparison has a direction consistent with a higher group mean in that arm. These are distinct constructs measured on different scales. Taken together, the directions are compatible with a pattern in which the training program is associated with higher reported confidence and fewer reported depressive symptoms, but the registry information does not establish a common mechanism or show that one outcome caused a change in the other.

Secondary findings carry less weight than the primary result when the analysis plan and multiplicity handling are not reported. If several outcomes or comparisons are examined, the chance of at least one apparently noteworthy result can rise unless the interpretation accounts for the broader set of tests. The registry lists six outcome measures, but does not report a testing hierarchy, adjustment strategy, or complete set of formal analyses. The posted unadjusted secondary finding should consequently be regarded as supportive or exploratory rather than as a stand-alone confirmation of the primary result.

The registry record reports no formal analyses in its reported-analyses listing. It also does not report whether the secondary outcomes were prespecified at the same level as the primary endpoint, how missing secondary measurements were handled, or whether all time points were considered. The pattern across outcomes is therefore informative as a description of the posted results, but it is not enough to establish consistency across every planned outcome or to resolve the risk of selective reporting.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Caregivers' Quality of Life
• Caregivers' Depressive Symptoms

9. Statistical Interpretation

10. Statistical Methods Explained

The outcome is continuous and is reported as a mean with a standard deviation for each group. A mean describes the arithmetic average of the recorded scores. In general, the standard deviation describes how dispersed individual scores are around their group mean; it is not the uncertainty interval for the mean itself. For caregivers’ self-efficacy, the posted group means are 155.0 for control and 178.0 for intervention, with standard deviations of 34.0 and 26.0, respectively.

The reported mean difference is 23.0 units on a scale, with the intervention group as the comparison group and control as the reference. In general, a mean difference keeps the scale’s original units and expresses the contrast between group averages. Positive values in this direction indicate a higher mean in the intervention group; negative values would indicate a lower mean. The reported estimate is an unadjusted contrast in the posted comparison. Whether the trial’s own analysis used an adjusted model is not reported in the registry record.

The registry also reports a pooled standard deviation of 30.5 and a standardized effect size, d, of 0.754 for the primary comparison. In general, a standardized effect expresses a mean contrast relative to a measure of variability, allowing the contrast to be described without relying only on the outcome’s original scale. It is not a different clinical endpoint and does not replace the scale-unit estimate. Its interpretation still depends on the outcome, study context, and variability in the measured scores.

The unadjusted p-value for the primary comparison is <0.001. In general, a p-value is calculated under a null model that specifies no group difference, along with assumptions about the data and analysis. It describes the compatibility of the observed data with that model; it is not the probability that the treatment or care model has no effect. The statistical test used, its assumptions, and whether any prespecified adjusted test was conducted are not reported in the registry record. The unadjusted label is important because it does not account for a stated multiplicity adjustment.

The record reports arm-specific outcome counts of 45 for control and 40 for intervention. Those are the counts associated with the primary means and the depressive-symptom means. They are not identical to the total enrollment of 129, and the record does not explain the difference. It does not state whether the counts reflect missing measurements, a defined analysis population, exclusions, or another reporting process. In general, unequal or incomplete outcome availability can affect both precision and the interpretation of a group comparison, particularly if availability is related to participant characteristics or outcomes.

Randomization is intended, in general, to create groups that are comparable on average at the point of assignment, including for characteristics that were not measured. However, the registry record does not describe how the random sequence was generated or concealed. It also does not report baseline outcome values or the method used to account for baseline measurements. A randomized designation alone does not reveal the details of implementation or analysis.

The study is described as single-masked, but the masked party and procedures are not reported in the registry record. In general, masking can reduce the influence of expectations on assessment or behavior, depending on who is masked and what outcomes are measured. Because the primary endpoint is based on caregivers’ reported confidence and the intervention is a training and consultation program, the available record does not clarify whether caregivers or outcome assessors could have been unaware of group assignment. No conclusion about the extent of protection from reporting or assessment bias can be drawn from the masking label alone.

The registry lists six outcome measures and two secondary outcomes, and the primary endpoint is identified as caregivers’ self-efficacy. It does not report a statistical analysis plan, a hierarchy among all outcomes, a multiplicity procedure, or whether interim analyses were conducted. These details matter because choices about which outcomes and time points to emphasize can affect the interpretation of p-values. The absence of those details means that the posted unadjusted p-value should not be treated as evidence that all relevant sources of statistical uncertainty have been addressed.

General statistical interpretation also depends on the structure and distribution of the data. For a continuous score, a mean-based comparison is often useful when the group averages are meaningful and the analysis model is appropriate. The registry record does not report diagnostics, distributional assumptions, the specific test, or whether robust or alternative methods were considered. It is therefore not possible to assess those methodological details from the posted record.

The planning illustrations use the observed effect as their reference and state assumptions of a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. They vary the effect to detect as a stated fraction of the observed effect. In general, planning calculations show how sample-size requirements depend on the effect targeted and the chosen statistical assumptions. They are not a reconstruction of the trial’s original design, because the original sample-size justification and design assumptions are not reported in the registry record.

Over-dispersion is a general concern when the observed variability is greater than a model assumes: standard errors may then be understated and intervals too narrow if the model does not account for the extra variation. The outcome is summarized with means and standard deviations, but the registry record does not report a model-based variance assessment or indicate that over-dispersion was evaluated. This general issue should not be mistaken for a documented problem in this trial.

11. Confidence Intervals and Precision

The primary mean difference is reported as 23.0 units on a scale, with interval limits of 10.21 and 35.79. In general, a confidence interval expresses a range of values that are compatible with the data under the statistical method used, while reflecting sampling uncertainty. Its width conveys precision: a narrower interval indicates more concentrated uncertainty than a wider interval, all else equal. The confidence level and interval-construction method are not reported in the registry record, so the interval should be interpreted using its posted limits without assigning an unreported confidence level.

Both limits of the primary interval are positive. Thus, the reported interval does not include zero, the value corresponding to no mean difference, and the estimate’s direction is consistently positive across the interval. The interval still includes a range of possible effect sizes; it does not mean the true difference is known exactly. Nor does it establish whether any value within that range would be important to caregivers, because a minimally important difference is not reported in the registry record.

The standard deviations of 34.0 in control and 26.0 in intervention describe score variation among participants, rather than uncertainty around the mean difference. The arm-specific standard errors are 5.068 and 4.111. In general, standard errors quantify sampling variability of an estimate and contribute to the precision of statistical inference. These values do not by themselves identify the analysis method or establish how missing measurements were handled.

The outcome counts are 45 in control and 40 in intervention. The registry does not explain why those counts differ from total enrollment or whether outcome availability varied by group or participant characteristics. If measurements are missing, the resulting estimate’s precision and potential bias depend partly on why they are missing and on the analysis approach. Missing-data handling and sensitivity analyses are not reported in the registry record.

The p-value is <0.001, but it does not replace the interval as a description of effect-size uncertainty. It addresses compatibility with a null model under the unadjusted analysis, whereas the interval shows a range of estimates on the scale used. Together, the estimate, interval, arm-level summaries, and unadjusted p-value describe the posted comparison more fully than a threshold-based interpretation alone.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size figures are planning illustrations, not observed trial results. For this continuous outcome, the figures are participants per arm, rather than total events. The planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect targeted is the stated fraction of the observed effect. These calculations are separate from the trial’s original design assumptions, which are not reported in the registry record.

The 80% power column describes the number of participants per arm estimated to give an 80% chance of detecting the specified effect if the planning assumptions and effect are correct. The 90% power column describes the corresponding number per arm for a 90% chance of detection. In general, power is a property of a study design under a specified effect and statistical model; it is not a guarantee that a particular result will be statistically significant.

The rows vary the target from 100% of the observed effect to 75% and 50% of the observed effect. A smaller target effect is harder to distinguish from random variation, so the planning figures require more participants per arm. The figures therefore illustrate the dependence of sample size on the effect being targeted, rather than predicting what a future study will find. They do not indicate the number of participants actually enrolled in this trial’s original plan, and this is not observed power.

The sample-size curve should be read as a visual counterpart to these planning assumptions: it relates the targeted effect to the required number of participants per arm. It does not add evidence about the treatment comparison or replace the reported outcome data. The original sample-size justification, the trial’s design power target, and the assumptions used by investigators before enrollment are not reported in the registry record.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = 23.000; pooled standard deviation σ = 30.503.
2. n = 2 × (1.96 + 0.842)² × 30.503² / 23.000² = 27.6, rounded up to 28 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- 23                      # observed difference in means
sigma <- 30.5034068806306                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(2667951)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 28 (80% power), 37 (90% power)
 75% of observed effect: n per arm = 50 (80% power), 66 (90% power)
 50% of observed effect: n per arm = 111 (80% power), 148 (90% power)
power.t.test: 28.6 
Simulated power at n = 28 per arm: 0.789 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when several outcomes, time points, subgroups, or statistical comparisons are evaluated. In general, each additional test creates another opportunity for a result to appear statistically notable by chance under a collection of null effects. This does not make every secondary finding false, but it means that unadjusted p-values need to be considered in the context of the full testing plan.

The registry identifies caregivers’ self-efficacy as the primary outcome and lists caregivers’ quality of life and depressive symptoms as secondary outcomes. It also reports six outcome measures. The statistical analysis plan, testing hierarchy, choice of time points for inference, and any adjustment for multiple comparisons are not reported in the registry record. No interim-analysis information is reported. Consequently, it is not possible to determine from the record whether the posted p-values were selected from a larger set of analyses or how the investigators intended to control multiplicity.

The record’s reported-analyses listing is empty. This does not erase the arm-level summary results and comparisons that are posted, but it leaves the formal analysis procedures undocumented. The specific test, any covariate adjustment, the use of baseline values, and the definition of the analysis population are not reported in the registry record. The available information also does not identify whether participants were analyzed according to their randomized group.

Outcome counts are reported for the primary and depressive-symptom summaries, but the participant flow and reasons for the counts are not reported. The handling of missing data, withdrawals, protocol deviations, and incomplete follow-up is not reported in the registry record. There are no reported sensitivity analyses to show how conclusions might change under different assumptions about unavailable outcomes. A numerical result for quality of life is also not reported in the registry record.

These omissions constrain assessment of robustness. They do not establish that bias or selective analysis occurred; they mean that the registry record does not contain enough detail to evaluate those possibilities. In particular, the unadjusted secondary result should be interpreted cautiously because the overall multiplicity strategy and complete analysis record are unavailable.

15. Safety Results

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

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 serious adverse events for 66 participants at risk in the control group and 63 at risk in the intervention group. Zero serious adverse events affected participants in either group. For other adverse events, the reported at-risk counts are also 66 in control and 63 in intervention, with zero affected participants in either group.

These figures describe what was recorded in the registry under the reported adverse-event categories. They should not be read as proof that no adverse events occurred outside the categories, time period, or reporting process represented by the record. The registry does not provide serious-event terms, and the deaths fields are not reported. The nature of event monitoring, the adverse-event collection period, and the definition of the categories are not reported in the registry record.

The adverse-event at-risk counts differ from the arm-specific counts reported for the outcome summaries. The reason for that difference is not reported in the registry record. The zero counts are therefore best read alongside the stated at-risk denominators and the limited detail about ascertainment, rather than as a complete account of all possible harms.

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

The primary result describes higher average caregiver self-efficacy scores in the intervention group than in the control group at 18 months. The estimate and its interval give a sense of the direction and precision of that group-level contrast. The result concerns caregivers’ reported confidence in managing agitation, which is the construct measured by the scale.

It does not directly show that people with dementia experienced fewer behavioral problems, that caregivers’ actual management skills improved, or that the care model changed clinical outcomes. It also does not establish a change in caregiver quality of life or cost effectiveness. The numerical quality-of-life and cost results are not reported in the registry record. Depressive symptoms are a separate secondary outcome and should not be treated as interchangeable with self-efficacy.

In general, a randomized comparison can support causal interpretation when randomization is implemented appropriately and the analysis preserves the comparison created by assignment. The registry record does not describe random-sequence generation, allocation concealment, analysis populations, baseline adjustment, or missing-data procedures. Those limitations prevent a full evaluation of how well the posted estimate represents the randomized comparison and how sensitive it may be to unavailable outcomes.

Statistical evidence and practical importance are also different questions. The primary p-value is small under the unadjusted comparison, and the interval is on the positive side of zero. Neither fact identifies a threshold of benefit that caregivers would consider meaningful. The registry does not report a minimally important difference for the scale, so practical significance cannot be determined from the posted statistics alone.

The record supports a focused interpretation: a difference in average reported self-efficacy was observed between the groups at the stated follow-up, in the direction of higher scores for the intervention group. It does not establish how long any difference persisted, whether the findings apply to other settings or populations, or whether the intervention’s benefits outweigh its costs or burdens. Those questions require information beyond the reported outcome summaries.

17. Why This Trial Matters Statistically

This trial illustrates how an outcome can be statistically clear while still requiring careful definition. The primary measure concerns a caregiver’s confidence, not the frequency of agitation itself. Statistical interpretation depends on keeping the measured construct distinct from broader claims about patient symptoms, caregiver functioning, or service use.

It also illustrates why an effect estimate and its interval are more informative than a p-value alone. The posted mean difference is expressed in the scale’s units, and the interval indicates the range of estimates compatible with the reported comparison under its method. The p-value addresses compatibility with a null model; it does not determine practical importance or explain the underlying effect.

The distinction between enrollment and outcome counts matters when interpreting a trial record. The registry reports enrollment of 129, while the primary outcome summaries use arm-specific counts of 45 and 40. Without participant flow and missing-data details, readers cannot determine why the counts differ or assess the impact of unavailable outcomes. This is a statistical limitation, not merely a reporting detail.

Finally, the record demonstrates the value of a complete analysis plan. The lack of reported methods for multiplicity, analysis populations, missing data, and the original sample-size rationale leaves important questions unanswered. Planning illustrations based on observed effects can show how assumptions influence future sample-size requirements, but they do not recover the original design rationale. Clear reporting of these elements is essential for judging precision, robustness, and the scope of conclusions.

18. 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.

Important trial-specific details are absent from the registry record. Eligibility criteria and a fuller description of the enrolled caregivers and people with dementia are not reported, limiting assessment of how closely the study population resembles other care settings. The setting is described as Taiwan, but the record does not provide further information about recruitment sites, community services, or implementation context.

The intervention included several components: behavioral-problem guidance, referrals, telephone consultation, monthly follow-ups, and progress evaluation. The record does not describe the content or intensity of each component, intervention adherence, caregiver participation, or the extent to which the program was delivered as intended. It is therefore not possible to identify which elements may be associated with the observed group contrast.

The masking label is single, but the identity of the masked party and masking procedures are not reported. Because the primary outcome is self-reported confidence, the absence of detail about masking and assessment procedures limits evaluation of possible expectation or reporting effects. The record also does not report baseline primary scores, adjustment methods, or the randomization and allocation-concealment procedures.

The primary and depressive-symptom outcomes have arm-specific counts below the overall enrollment, and the reason is not reported. Participant flow, missing-data methods, and sensitivity analyses are not reported in the registry record. The statistical analysis plan, multiplicity procedure, and original sample-size justification are also not reported. A numerical result for quality of life and cost results are not reported.

These limitations do not show that the trial’s findings are invalid. They restrict what can be concluded from the registry record about implementation, completeness of follow-up, analysis choices, and the applicability of the results beyond the studied context.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: A Home-based Training Program for Elderly Patients With Dementia — NCT02667951.
• Registry record last updated 2023-08-30; status last verified 2023-08.
• Results first posted 2020-09-24.
• 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.

22. Record Summary

The registry describes a completed randomized, single-masked, parallel-group trial of a home-based caregiver-training program compared with routine care for elderly people with dementia in Taiwan. Enrollment was 129. The primary outcome was caregiver self-efficacy for managing agitation at 18 months, measured on the Agitation Management Self-efficacy Scale.

The posted primary comparison reports a higher mean score in the intervention group, with a mean difference of 23.0 units on a scale and an unadjusted p-value of <0.001. Caregivers’ depressive symptoms are also reported as a secondary outcome; a numerical result for quality of life is not reported in the registry record. Interpretation is limited by unreported analysis methods, missing-data handling, participant flow, multiplicity procedures, and the original sample-size rationale.