This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for CB3 Pilot (Communication Bridge: A Person-centered Internet-based Intervention for Individuals With Primary Progressive Aphasia) (NCT05697380), a na na study. The primary outcome is Change in Communication Confidence (CCRSA).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT05697380 |
| Phase | NA |
| Condition | Aphasia, Primary Progressive Aphasia, Dementia |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 8 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Chicago |
| Results posted | Yes |
2. Clinical Question
Population
Adults with mild primary progressive aphasia (PPA) and their actively engaged, co-enrolled communication partners. The intervention description treats both members of the dyad as recipients. The registry record lists enrollment as 8. The primary communication-confidence outcome was not collected for care partners.
Intervention
Communication Bridge™, a behavioral, internet-based and personalized intervention. The study description includes speech therapy, evaluations, sessions with a licensed social worker or related clinician, and access to a web application for home practice. Participants were to receive an iPad equipped for study activities.
Comparator
No concurrent comparison group is described. The registry record identifies a single-group model, with allocation listed as NA and masking as none. This design does not provide a randomized, like-for-like control comparison.
Primary question
How did communication confidence, measured with the Communication Confidence Rating Scale in Aphasia (CCRSA), change across assessment time points through study completion? The registry describes five assessment time points over an average of 1 year. Numerical outcome results are not reported in the registry record.
The study focused on communication confidence among people with PPA receiving the multi-component intervention alongside their communication partners. Its stated purpose was to evaluate evidence-based treatments and help identify communication and quality-of-life interventions for people with PPA and their care partners. That purpose is not itself evidence of benefit: the registry record does not provide outcome estimates with which to assess change.
The design is best understood as a pilot evaluation of participants followed over time, not as a trial comparing intervention with usual care or another treatment. Without a concurrent control group, any observed within-person or group change would not, by itself, establish that the intervention caused the change. The registry record does not report the numerical changes, their uncertainty, or an inferential analysis.
3. Trial Design
Communication Bridge (NCT05697380) is listed as a completed, single-group behavioral intervention study sponsored by the University of Chicago. The registry gives a start date of 2021-06-01 and a primary completion date of 2023-07-12. Enrollment is recorded as 8. The phase is listed as NA; allocation is also listed as NA, and masking is listed as none.
The study description concerns adults with PPA and actively engaged communication partners. Each participant was to be involved for 12 months. The intervention description identifies Communication Bridge™ as a participation-focused, dyadic intervention in which both the person with PPA and their co-enrolled communication partner are recipients. Study activities included evaluations, speech therapy sessions with a speech and language therapist, and sessions with a licensed social worker or related clinician. The description also says participants would have access to a personalized web application for practicing home exercises and would receive an iPad equipped with study applications and features.
The registry describes five assessment time points through study completion, over an average of 1 year. It does not describe a control arm or randomized allocation. Consequently, the design can describe participant outcomes over time, but does not directly compare those outcomes with what would have occurred under a different intervention or without the intervention.
The registry record does not report a protocol, a detailed schedule for each assessment, eligibility criteria beyond the summary description, or a statistical analysis plan. It also does not report why the study used this enrollment or how enrollment was chosen. The record is marked completed, but completion status alone does not establish that results were analyzed or 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
| Stage | Experimental: Communication Bridge™ (PPA Participants) | Experimental: Communication Bridge™ (Care Partners) |
|---|---|---|
| STARTED | 4 | 4 |
| COMPLETED | 4 | 4 |
| NOT COMPLETED | 0 | 0 |
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.
| Characteristic | Unit | Experimental: Communication Bridge™ (PPA Participants) | Experimental: Communication Bridge™ (Care-Partners) | Total |
|---|---|---|---|---|
| Participants analysed | 4 | 4 | 8 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 | 0 | 0 |
| Age, Categorical: >=65 years | Participants | 4 | 4 | 8 |
| Sex: Female, Male: Female | Participants | 2 | 2 | 4 |
| Sex: Female, Male: Male | Participants | 2 | 2 | 4 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 | 0 | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 4 | 4 | 8 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): White | Participants | 4 | 4 | 8 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Highest Degree Earned: Did not complete high school | Participants | 0 | 0 | 0 |
| Highest Degree Earned: High School/GED | Participants | 0 | 1 | 1 |
| Highest Degree Earned: Some College | Participants | 0 | 2 | 2 |
| Highest Degree Earned: Bachelor's Degree | Participants | 3 | 0 | 3 |
| Highest Degree Earned: Master's Degree | Participants | 1 | 1 | 2 |
| Highest Degree Earned: Advanced Graduate/Phd | Participants | 0 | 0 | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Change in Communication Confidence (CCRSA), measured over Time Frame: 5 assessment time points through study completion, an average of 1 year, including change over time.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | score on a scale |
| Endpoint classification | Continuous Endpoint |
The primary outcome is change in communication confidence, assessed with the Communication Confidence Rating Scale in Aphasia (CCRSA). The measure is described as a 0-100 numeric rating scale: 0 represents “not confident” and 100 represents “very confident.” Higher scores indicate greater confidence. The registry describes the outcome as a mean with standard deviation and specifies five assessment time points through study completion, over an average of 1 year.
Communication confidence is relevant to the study’s focus on communication in daily life for people with PPA. A rating scale can capture a participant’s own assessment rather than relying only on an external measure of performance. Repeated assessments can describe how those ratings vary over the study period. In general, a mean describes the central level of scores for a group, while a standard deviation describes how dispersed scores are around that mean. Neither statistic, alone, establishes why scores changed.
The registry explicitly notes that the primary outcome was not collected for care partners. The listed endpoint therefore concerns PPA participants, not a combined score for the dyad. The registry record does not report the mean scores, standard deviations, changes between assessments, uncertainty intervals, or an analysis of change. It is therefore not possible to quantify the direction or precision of the outcome from the posted record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies communication confidence as the primary outcome and describes repeated assessment over the study period. However, it does not report numerical scores or a statistical analysis of those scores. There is no posted estimate of mean change, no reported standard deviation by assessment, and no confidence interval or test result for the primary outcome. The record therefore does not establish the size, direction, or precision of change in communication confidence.
The study is a single-group pilot rather than a randomized comparison. If outcomes had changed over time, that pattern could have been described for participants in the study. A before-and-after pattern alone, however, cannot separate an intervention effect from other possible explanations, such as the natural course of PPA, changes in care or circumstances, repeated measurement, or selective availability of follow-up data. These are general interpretive considerations for uncontrolled longitudinal studies, not findings about what occurred in this trial.
The registry summary explains the intervention and the intended population, but it does not report the primary endpoint results. The study is marked completed, and its primary completion date is 2023-07-12. Completion status and a completion date do not substitute for outcome data or an analysis. The registry record also lists no statistical analyses. Accordingly, the available record supports a description of the study’s question and design, but not a numerical conclusion about participant outcomes.
Care partners were included in the intervention, but the primary communication-confidence outcome was not collected for them. Any interpretation of the primary endpoint must therefore be limited to the PPA participants for whom it was intended. The record separately lists safety counts for PPA participants and care partners; those counts do not supply evidence about communication-confidence change.
The planned duration was 12 months, and the outcome description refers to five assessment time points over an average of 1 year. Repeated measurement can help describe trajectories, but the registry record does not report the observed assessment schedule, the number of participants contributing data at each time point, or how incomplete observations were handled. Without those details and numerical results, neither the trajectory nor its uncertainty can be evaluated.
In general, an estimate and its uncertainty are both important: an estimate describes the observed pattern, while an interval can indicate how compatible the data are with a range of values under the analysis assumptions. No such numerical estimate or interval is reported for this outcome. No conclusion about efficacy, lack of efficacy, or the clinical importance of a change follows from the absence of posted results.
9. Statistical Methods Explained
The registry describes a continuous primary outcome summarized as a mean and standard deviation, measured repeatedly over time. The explanations below are general statistical context; they are not a description of an analysis reported for this study. The registry record does not report numerical outcome results or a detailed statistical plan.
What does a mean describe?
For a continuous measure such as the CCRSA score, the mean is the arithmetic average of the observed scores in the group being summarized. It provides a compact description of the group’s score level at an assessment. A mean can be useful for comparing the group’s average score across assessment times, but it does not show whether individual participants followed the same pattern. The same group average can arise from different individual trajectories.
The standard deviation describes spread among observed scores around the mean. A smaller spread indicates that scores are more closely clustered around the group average; a larger spread indicates more variation. It is not the same as the uncertainty in the estimated mean. In general, uncertainty also depends on how many observations contribute and on the analysis structure. The registry identifies standard deviation as the dispersion measure but does not report any values.
Why do repeated assessments matter?
Scores from the same participant over time are generally related: a person’s score at one assessment may be more similar to that person’s other scores than to scores from another participant. General statistical methods for longitudinal data account for this within-person dependence when estimating changes and their uncertainty. Treating all repeated scores as though they came from unrelated people can misstate the precision of an estimate.
The registry specifies five assessment time points through study completion, with the timeframe described as an average of 1 year. It does not say which longitudinal model, if any, was used; how assessments were spaced; whether change was modeled as a straight-line trend or as separate time-specific contrasts; or how individual variation was handled. Those details are not reported in the registry record.
What would an uncertainty interval add?
In general, a confidence interval expresses the precision of an estimated quantity under a statistical model and its assumptions. A narrow interval indicates greater precision than a wide interval, while the interval’s location communicates which values are compatible with the data and method. An interval is not a guarantee that the true value lies within it, and it does not address biases that arise from design limitations or missing data. No confidence interval for the primary outcome is reported in the registry record.
A significance test, when used, assesses compatibility between observed data and a specified null hypothesis under assumptions. A p-value does not measure the size or practical importance of an effect and does not prove that an intervention caused an outcome. The registry record does not report a primary-outcome test or p-value. The significance level of 0.05 mentioned in the planning assumptions should not be read as the level used for an outcome analysis; the record presents it as an assumption for a planning illustration.
What do the sample-size planning assumptions mean?
The planning description states that its illustrations use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a stated fraction of an observed effect. These are assumptions for a planning illustration, not a description of the single-group trial’s design. They do not show that the study itself had two randomized arms, and the registry record does not report the trial’s own sample-size justification or design calculation.
Such planning illustrations are conditional: the estimated number of participants depends on the effect chosen for detection and the calculation assumptions. A planning number is not an observed result and is not “observed power.” Because no numerical planning outputs or primary-outcome effect estimate appear in the registry record, no such values can be interpreted for this study. The record also does not report an interim analysis plan or whether any interim analyses occurred.
Why can over-dispersion matter?
In general, over-dispersion means that observed variability is greater than a statistical model assumes. If a method assumes less variability than the data actually contain, uncertainty can be understated and tests can be too optimistic. This concept is most directly relevant to outcomes modeled as counts or rates; the primary endpoint is described as a continuous rating score. The registry record does not report a model or a dispersion assessment, so there is no basis to say whether over-dispersion was examined or relevant to the reported analysis.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists one outcome measure, with change in CCRSA communication confidence identified as the primary outcome. It does not report a multiplicity plan, such as whether any additional outcomes or time-specific comparisons were treated as confirmatory, how multiple tests were handled, or whether any hierarchy of hypotheses was specified. The absence of a reported plan means the control of false-positive findings across analyses cannot be assessed from the registry record.
Missing-data methods are also not reported in the registry record. The outcome description gives five assessment time points through study completion, but does not state how many observations were available at each time, why any observations might be missing, or how missing scores were handled. General approaches can range from analyses using only available observations to model-based methods that make assumptions about unobserved data. Each approach has assumptions, and incomplete follow-up can affect both estimated change and its precision. No particular approach can be attributed to this study from the record.
The registry does not describe the analysis population, such as whether analyses were intended to include all enrolled participants, participants who completed a specified set of assessments, or another group. It also does not report a participant flow or a primary-outcome analysis. The enrollment entry is 8, but that figure alone does not show how many contributed endpoint data or how many contributed at each time point.
The primary outcome was not collected for care partners, as stated in the outcome description. This is a distinction in the measure’s target population, not evidence that care-partner scores were missing from an analysis of the same endpoint. Separate care-partner safety figures are reported, but they do not establish the completeness of outcome assessments. Analysis populations, missing-data handling, and multiplicity methods are not reported in the registry record.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Experimental: Communication Bridge™ (PPA Participants) | 1 | 4 | 25.0% |
| Experimental: Communication Bridge™ (Care Partners) | 0 | 4 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Experimental: Communication Bridge™ (PPA Participants) | 0 of 4 |
| Experimental: Communication Bridge™ (Care Partners) | 0 of 4 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Experimental: Communication Bridge™ (PPA Participants) | 1 of 4 |
| Experimental: Communication Bridge™ (Care Partners) | 2 of 4 |
Most frequent serious adverse event terms
| Event term | Organ system | Experimental: Communication Bridge™ (PPA Participants) | Experimental: Communication Bridge™ (Care Partners) |
|---|---|---|---|
| Medical Event | Surgical and medical procedures | 1 of 4 | 0 of 4 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Experimental: Communication Bridge™ (PPA Participants) | Experimental: Communication Bridge™ (Care Partners) |
|---|---|---|---|
| Other psychosocial events | Psychiatric disorders | 0 of 4 | 2 of 4 |
| medical event (non serious) | Musculoskeletal and connective tissue disorders | 1 of 4 | 0 of 4 |
Serious events with the highest arm-level rate: medical event (25.0%).
The registry lists serious and other adverse-event counts separately for PPA participants and care partners. For PPA participants, the serious adverse-event figures are 1 affected among 4 at risk; for care partners, they are 0 affected among 4 at risk. The listed deaths are 0 in each group. For other adverse events, the registry lists 1 affected among 4 PPA participants at risk and 2 affected among 4 care partners at risk.
The record also identifies “Medical Event” as the top serious-event term and displays 25.0%. That entry should be read as the reported term and percentage, not as a complete description of event severity, causation, or relationship to the intervention. The registry record does not provide further details about the event, its timing, outcome, or attribution.
These figures are descriptive counts, not a comparison of treatment-related risk against a control group. The study has no concurrent control group, and the record does not report a method for assessing whether events were caused by the intervention. The counts also do not establish that no unlisted events occurred beyond what the registry reports. They should not be interpreted as an estimate of comparative safety or as evidence about communication-confidence outcomes.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a completed, single-group pilot was designed to assess communication confidence over time among people with PPA receiving Communication Bridge™. It describes the CCRSA, its 0-100 scale, the direction of scoring, and five assessment time points through study completion. It also reports enrollment as 8 and gives separate adverse-event counts for PPA participants and care partners.
It does not report the primary outcome scores, change estimates, standard deviations, confidence intervals, p-values, or statistical analyses. As a result, the posted record does not show whether communication confidence increased, decreased, or remained similar over time, nor how precisely any change was estimated. The study’s completed status does not fill this gap.
Even if a change estimate were available, this single-group design would not by itself establish that the intervention caused the change. Without a concurrent comparison group, changes over time could reflect factors other than intervention exposure. That is a general limitation of uncontrolled studies, not a claim about the cause of any unreported outcome in this trial.
The primary endpoint applies to PPA participants; it was not collected for care partners. The registry’s safety figures describe reported events in both groups, but they are not a controlled safety comparison and do not answer whether the primary endpoint changed. Taken together, the available record describes the research question, intervention, and design, but leaves the central quantitative outcome unanswered. No conclusion that the intervention is effective or ineffective is supported by the posted results.
13. Why This Trial Matters Statistically
This pilot addresses a measurement question that matters in studies of communication: how to describe participants’ confidence over time using a patient-reported rating scale. The CCRSA is described with clear endpoints, from “not confident” at 0 to “very confident” at 100, and the registry identifies the direction of scoring. These details clarify what the measure is intended to capture, even though the numerical scores are not reported.
The dyadic intervention model is also relevant to interpretation. The person with PPA and their communication partner are both described as intervention recipients, while the primary communication-confidence outcome was collected only for PPA participants. Keeping the target of each outcome clear prevents a care-partner measure or a safety count from being mistaken for the primary endpoint.
Statistically, the single-group, repeated-assessment structure illustrates the distinction between describing change and attributing a cause. Repeated measurements can provide a picture of participants’ scores over time, but within-person patterns do not provide the same evidence as a comparison against a concurrent control group. The registry record does not report an outcome analysis that would quantify even the observed trajectory.
The record also highlights why reporting plans and results matters. Details about missing observations, analysis populations, uncertainty, and multiplicity determine how readers should interpret a longitudinal estimate. Those methods are not reported in the registry record. Consequently, the study is informative as a description of a pilot question and design, but its posted record does not permit a statistical assessment of the primary outcome’s magnitude or precision.
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 principal limitation for statistical interpretation is the absence of numerical primary-outcome results. The registry record describes the CCRSA and planned repeated assessments but gives no scores, changes, variability estimates, uncertainty intervals, or inferential results. The magnitude and direction of change therefore cannot be assessed from the posted record.
The single-group design has no concurrent control comparison. This limits causal interpretation even when within-group outcome data are available, because temporal changes cannot be separated from other influences using a randomized comparison. The registry also lists masking as none. It does not report additional procedures that might affect measurement or analysis.
Enrollment is recorded as 8, but the record does not show how many participants contributed primary-outcome data, whether all five time points were completed, or how missing observations were handled. It does not report an analysis population, multiplicity procedures, or a detailed statistical plan. The endpoint was not collected for care partners, so the primary outcome cannot describe change for the full dyad.
The registry’s intervention description is available, but the arm description ends before completing its account of the framework on which the intervention was modeled. Further intervention detail and implementation information are not reported in the registry record. The record also does not report a sample-size justification, interim-analysis plan, or numerical analysis results. These limitations constrain both reproducibility and interpretation of the pilot’s intended outcome.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: CB3 Pilot (Communication Bridge: A Person-centered Internet-based Intervention for Individuals With Primary Progressive Aphasia) — NCT05697380.
- Registry record last updated 2024-10-16; status last verified 2024-09.
- Results first posted 2024-10-16.
- 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.
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18. Record Summary
NCT05697380 is a completed, single-group behavioral pilot of Communication Bridge™ sponsored by the University of Chicago. The registry lists enrollment as 8 and describes involvement over 12 months for adults with PPA and their actively engaged communication partners. The study start date is 2021-06-01, and the primary completion date is 2023-07-12.
The primary outcome is change in CCRSA communication confidence among PPA participants, assessed at five time points over an average of 1 year. The measure ranges from 0 to 100, with higher scores indicating greater confidence; it was not collected for care partners. The registry record does not report numerical primary-outcome results, statistical analyses, missing-data methods, or an analysis population. It lists separate adverse-event counts for PPA participants and care partners, but no concurrent control group is described.