Translating a Dementia Caregiver Intervention Into a Mobile Application: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Translating a Dementia Caregiver Intervention Into a Mobile Application (NCT04330482), a randomized na study. The primary outcome is Randomization.

2. Clinical Question

The registry describes a randomized, parallel-group study with single masking. It does not state who was masked. The central statistical question is therefore whether the trial’s randomization-related outcome differed between the CARE-Well App and Internet Links groups, and how precisely that result can be interpreted from the posted information. The registry’s stated project goal also included assessing study procedures and outcome measures, but the record does not post results for those feasibility domains.

3. Trial Design

This completed study, NCT04330482, is titled “Translating a Dementia Caregiver Intervention Into a Mobile Application.” Rhode Island Hospital is listed as the sponsor. The registry reports a randomized, parallel-group design with single masking; it does not identify the masked party. The phase is listed as NA. The registry reports an enrollment of 40, a start date of 2020-01-13, and a primary completion date of 2022-05-30.

The two behavioral interventions were CARE-Well App and Internet Links. Each arm description specifies a tablet and an instruction to use the assigned resource at least 4 times weekly for 3 months. The descriptions establish what participants were instructed to use, but the registry record does not report actual adherence, frequency of use, or how adherence was measured. The assignment of participants to each group is described as randomized; details of sequence generation and allocation concealment are not reported in the registry record.

The primary outcome timeframe was 3 months. Its focus was participants who declined participation because of randomization. The registry also names secondary outcomes concerning depression, caregiver burden, memory and behavior problems, and desire to institutionalize. These are distinct from the primary feasibility outcome, and the registry record does not post their results. Although the project summary describes a feasibility aim that included intervention acceptability, study procedures, and outcome measures, the posted primary result alone cannot establish the findings for every aspect of that aim.

The registry record does not report a sample-size justification, a detailed statistical analysis plan, an interim-analysis plan, or the identities of participants included in each analysis. It also does not report a protocol-level explanation of the masking procedures. Those omissions limit reconstruction of the intended analysis beyond the design and outcome descriptions that are posted.

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

Reasons for not completing this period:

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 Randomization, measured over 3 months.

The primary endpoint is described as the percentage of participants who decline participation because of randomization, with a timeframe of 3 months. It measures a decision related to being assigned through randomization. It is not a measure of caregiver symptoms, app use, or clinical improvement. The posted results list zero participants with this outcome in the Internet Links arm and zero in the CARE-Well App arm; each arm’s reported denominator is 20.

This kind of endpoint can be relevant in a feasibility study because willingness to accept random assignment may affect whether a larger randomized study can recruit and retain participants. That is a general rationale for measuring randomization-related refusal, not a reported conclusion about this trial’s broader feasibility. The registry summary identifies feasibility and acceptability as project goals, but the record does not provide a detailed rationale for choosing this particular primary endpoint or describe how the outcome was ascertained.

The registry’s other named outcomes include the Center for Epidemiologic Studies Depression Scale, Zarit Burden Interview, Revised Memory and Behavior Problem Checklist, and Desire to Institutionalize Scale. These outcomes concern different aspects of caregiver experience and are not substitutes for the primary endpoint. Their results are not reported in the registry record, so the posted randomization outcome cannot answer questions about change on those measures.

7. Results Posted in the Registry

• CARE-Well App: 0.0% (0/20) versus 0.0% (0/20) on control; risk difference 0.0 percentage points (95% CI 0.0 to 0.0); unadjusted two-proportion z-test p = n/a.

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a randomized, parallel-group study. In a randomized design, assignment is intended to make the groups comparable on average, while a parallel-group design assigns participants to one group rather than having each participant receive both conditions. These are general features of the design; the registry record does not report the sequence-generation method, allocation concealment procedures, or a detailed statistical plan. Single masking is listed, but the masked party is not reported in the registry record.

What does the primary comparison represent?

The primary outcome is a binary event: a participant either declined participation because of randomization or did not have that recorded event. For a binary outcome, a group risk is generally the proportion of participants with the event among the group used in the analysis. The record gives a count of zero events for each arm and reports 20 participants in each arm for this outcome. The posted risk difference is 0.0. As a general interpretation, a risk difference compares the event risks directly; zero means the estimated risks are the same on that scale.

The posted results also give an interval from 0.0 to 0.0 for the risk difference. A confidence interval is a range produced by a statistical procedure to represent uncertainty about an estimated quantity. Its interpretation depends on the procedure and assumptions used. The registry record does not state how this interval was calculated. When no events are observed in either group, different methods can characterize uncertainty differently. The posted interval should therefore be read as a reported result, while recognizing that the record does not give enough methodological detail to evaluate its construction.

What does randomization contribute?

Random assignment can reduce systematic differences between groups at the point of assignment, in expectation. It does not guarantee that all relevant characteristics are balanced in a small study, and it does not address problems arising after assignment, such as missing measurements or differences in adherence. The registry does not report baseline characteristics, adherence results, or analysis populations for the posted primary outcome. Consequently, the record does not permit a full assessment of these features.

The two groups were assigned different resources, but both were instructed to use their assigned resource at least 4 times weekly for 3 months. In general, results by assigned group answer a different question from results based on actual use. The registry record does not state whether the primary comparison followed an intention-to-treat approach, whether any participants were excluded, or how deviations from the instructions were handled. No such analytic choice should be assumed.

How should the feasibility outcome be understood?

A randomization-related refusal is a process outcome rather than a clinical endpoint. In general, feasibility outcomes can help characterize whether a study procedure is acceptable and workable. Here, the measure concerns declining participation because of randomization, not all reasons for nonparticipation and not ongoing engagement with the assigned resource. The zero counts do not establish that the overall study procedures were feasible, because the registry does not post results for recruitment, retention, adherence, or completeness of outcome collection.

The registry summary says the project was intended to assess acceptability and feasibility of the intervention, study procedures, and outcome measures. That broad goal is not equivalent to a single primary endpoint. The record lists 12 outcome measures and names four secondary scales, but does not provide results for those scales. It lists no analyses. The rationale for the outcome set, prespecified contrasts, handling of repeated measurements, and any adjustment for baseline values are not reported in the registry record.

What can be learned from the planning illustrations?

The described sample-size planning illustrations use the observed effect, two-sided significance level 0.05, equal allocation, and a normal approximation; the target effect is a stated fraction of the observed effect. These are planning calculations, not observed power. A planning illustration asks how a future study might be sized under specified assumptions. It does not alter the evidence from the completed trial, and it is not proof that the study had a particular probability of detecting an effect.

When a planning calculation is based on an observed effect, its usefulness depends on the stability and relevance of that estimate. In general, estimates from small feasibility studies may be imprecise, and planning around an observed estimate can carry that uncertainty forward. The registry record does not report the trial’s own sample-size justification or design assumptions, and the planning assumptions described should not be mistaken for the original protocol’s rationale. The record also does not give the numerical planning results in the registry record for this analysis, so no required sample size can be stated.

Finally, there are no reported inferential details for the primary comparison beyond its estimate and interval, and no analyses are listed. The test used, treatment of missing data, choice of analysis population, and any adjustment strategy are not reported in the registry record. A careful statistical reading separates the posted descriptive counts and comparison from methods that remain undocumented.

10. Confidence Intervals and Precision

The reported primary outcome has zero events in each arm, with 20 participants reported in each arm. The risk difference is 0.0, and the posted interval runs from 0.0 to 0.0. These values describe the result as recorded, but the interval’s identical endpoints should not be taken to mean that all relevant uncertainty has been resolved. The registry record does not state the interval method or provide enough information to assess how uncertainty was handled when both event counts were zero.

A confidence interval is a statistical range whose interpretation depends on a model and method. In general, it communicates the precision of an estimate under those assumptions; it does not guarantee that the true value lies within the particular reported limits. The width of an interval is often used to discuss precision, but a reported interval with no width can be especially difficult to evaluate without knowing its construction. For this result, methodological details are not reported in the registry record.

The outcome is also limited in scope. Its precision concerns only the risk difference for declining participation because of randomization. It does not quantify uncertainty about app acceptability, adherence, caregiver burden, depression, memory and behavior problems, or desire to institutionalize. Results for the named secondary outcomes are not reported in the registry record. The trial’s stated enrollment and arm denominators describe the posted record, but do not by themselves provide precision for outcomes that are unreported.

The planning illustrations described in the registry are not confidence intervals and are not observed power. They are planning calculations tied to specified assumptions and the observed effect. Their numerical outputs are not reported in the registry record details, so they cannot be used to make a quantitative claim about future-study precision.

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 12 outcome measures and names four secondary outcomes: the Center for Epidemiologic Studies Depression Scale, Zarit Burden Interview, Revised Memory and Behavior Problem Checklist, and Desire to Institutionalize Scale. The record does not report results for these named secondary outcomes. It lists no analyses. The specific relationship between the named outcomes and the full set of outcome measures is not described in the registry record.

When a study examines multiple outcomes or multiple comparisons, the chance of at least one apparently notable result can increase. This is a general statistical issue, not a claim that any particular adjustment was needed or used in this trial. The registry record does not report a multiplicity strategy, a hierarchy of outcomes, or a prespecified analysis plan. It is therefore not possible to determine from the posted information whether or how multiple testing was addressed.

Missing-data handling is also not reported in the registry record. The posted primary outcome gives arm denominators and zero event counts, but the record does not describe whether any participants had missing outcome status, how missingness was defined, or whether sensitivity analyses were planned. It does not report analysis populations or explain whether results were based on all randomized participants or another group. These details matter because exclusions and missing outcome measurements can affect interpretation even when the observed event count is clear.

The registry summary says the project aimed to assess feasibility of procedures and outcome measures, but the posted record does not report recruitment flow, retention, adherence, completion of measures, or detailed analysis decisions. Those absences limit assessment of both the broader feasibility aims and the risk of selective reporting. They do not establish that missing data or multiplicity problems occurred; they mean that the relevant handling and results 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 adverse-event record lists zero serious adverse events and zero other adverse events in the Internet Links arm, with 20 participants at risk for each category. It reports the same counts and at-risk numbers for the CARE-Well App arm. Deaths are listed as zero in both arms. No serious adverse-event terms are listed.

These figures describe the events recorded in the registry for the stated groups. They do not establish that no events of any kind occurred outside the categories or reporting period captured in the record, and they do not show that the interventions are risk-free. The registry record does not provide event definitions, collection procedures, severity criteria, attribution rules, or additional detail about the observation period for adverse events. The primary outcome’s 3-month timeframe should not automatically be treated as the adverse-event timeframe, which is not specified in the registry record.

Because the reported event counts are zero in both arms, the posted data do not show a between-group difference in recorded adverse-event counts. With no reported event terms and no further safety detail, the record offers limited information for comparing the types or patterns of events. These safety counts should be kept separate from the primary feasibility endpoint, which concerns declining participation because of randomization.

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

The result supports a narrow descriptive statement: the registry reports zero participants who declined participation because of randomization in each arm, among the 20 participants reported for each arm’s primary outcome. The posted risk difference is 0.0, with an interval from 0.0 to 0.0. This is the evidence available for the primary endpoint.

It does not establish that CARE-Well App improves caregiver health, reduces burden, changes depression, or affects any other clinical outcome. The primary endpoint does not measure those outcomes. Although the registry names secondary measures covering depression, burden, memory and behavior problems, and desire to institutionalize, their results are not reported in the registry record. It also does not establish that participants used the assigned resource as instructed, because usage and adherence results are not posted.

The trial’s summary frames the work as a development and feasibility project. The primary finding is relevant to one aspect of accepting randomization, but it is not a comprehensive measure of feasibility or acceptability. The record does not provide results for study procedures, outcome-measure completion, recruitment, or retention. Thus, the finding should not be extended to claims about the feasibility of every part of the study or about likely participation in a different trial.

Nor does the result demonstrate that the two resources are equivalent. A zero estimated difference is not, by itself, a formal equivalence finding. The registry record does not report an equivalence margin, a detailed analysis plan, or the method used for the posted interval. The safest interpretation is limited to the observed counts and comparison for this specific endpoint, with the methodological and outcome-reporting gaps kept in view.

The adverse-event record separately reports zero serious events, zero other events, and zero deaths in both arms. Those counts describe what is posted and should not be generalized beyond the record’s reporting scope. Taken together, the posted information documents a completed randomized feasibility trial and a null descriptive contrast on its randomization-related primary outcome, while leaving clinical-effect and broader feasibility questions unanswered.

14. Why This Trial Matters Statistically

This trial is statistically notable as a feasibility study rather than as a definitive test of a clinical outcome. Its primary endpoint focuses on whether participants declined participation because of randomization. Such a measure is relevant to the practical acceptability of random assignment, which can affect the conduct of future studies. The posted outcome is therefore informative about a specific study process, even though it does not measure caregiver health or benefit from the app.

The comparison also illustrates why an endpoint must be interpreted according to what it actually measures. A result showing zero randomization-related refusals in each arm cannot stand in for results on depression, caregiver burden, or other named outcomes. The registry identifies those outcomes but does not report their findings. Keeping process outcomes separate from clinical outcomes avoids overstating what a feasibility study can establish.

Statistically, the identical zero event counts produce a posted risk difference of 0.0 and an interval from 0.0 to 0.0. That concise result still requires context: the interval method is not reported, and a zero-width interval should not be mistaken for proof that uncertainty is absent. This is a useful reminder that numerical outputs need their analytic methods and data context to support strong interpretation.

The registry’s planning assumptions also distinguish study planning from evidence observed in the trial. Planning illustrations based on an observed effect are not observed power, and they do not replace a prespecified sample-size justification. The registry record does not report the original sample-size rationale. For researchers considering feasibility evidence, the important statistical lesson is to identify which outcomes were measured and posted, how their uncertainty was calculated, and which design and analysis details remain undocumented.

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 main trial-specific limitation is the narrow primary endpoint: declining participation because of randomization. It does not directly capture app acceptability, adherence, intervention engagement, or change in caregiver outcomes. Although the project summary describes broader feasibility goals, results for those other domains are not reported in the registry record. The named secondary outcomes also lack posted results, limiting assessment of the caregiver measures.

The primary result consists of zero events in each arm and a risk difference of 0.0 with an interval from 0.0 to 0.0. The registry record does not report the interval method, test, or detailed analysis plan, so the precision and inferential interpretation cannot be fully assessed. It also does not report missing-data handling, analysis populations, or whether all randomized participants contributed to the reported outcome.

The record lists a randomized parallel-group design and single masking but does not identify who was masked or describe sequence generation and allocation concealment. Actual use of the app or internet links is not reported, despite instructions to use the assigned resource at least 4 times weekly for 3 months. Baseline characteristics and study-flow information are also not reported in the registry record for this analysis.

The registry reports 12 outcome measures, names four secondary outcomes, and lists no analyses. It does not report how outcomes were prioritized or whether multiplicity was addressed. Safety counts are all zero in both arms, but event definitions and collection details are not reported. These gaps do not show that specific problems occurred; they constrain what can be concluded from the posted record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Translating a Dementia Caregiver Intervention Into a Mobile Application — NCT04330482.
• Registry record last updated 2023-09-28; status last verified 2023-09.
• Results first posted 2023-09-28.
• 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

NCT04330482 is a completed, randomized, parallel-group feasibility trial sponsored by Rhode Island Hospital. It compared a tablet pre-loaded with CARE-Well App against a tablet pre-loaded with internet links relating to dementia caregiving. Participants in both arms were instructed to use their assigned resource at least 4 times weekly for 3 months. The registry reports an enrollment of 40 and lists single masking, without identifying who was masked.

The primary outcome was the percentage of participants who declined participation because of randomization over 3 months. The posted counts are zero in both arms, with 20 participants reported in each arm; the risk difference is 0.0 and the interval is 0.0 to 0.0. Serious adverse events, other adverse events, and deaths are listed as zero in both arms.

The registry names secondary caregiver outcomes but does not report their results. It lists 12 outcome measures and no analyses. Details of the statistical plan, missing-data handling, analysis populations, interval method, and sample-size justification are not reported in the registry record.