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 Modulating Brain Activity to Improve Goal-directed Physical Activity in Older Adults (NCT04278560), a randomized na study. The primary outcome is Change of Daily Step Counts From Baseline.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04278560 |
| Phase | NA |
| Condition | Aging |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Triple |
| Enrollment | 34 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Hebrew SeniorLife |
| Results posted | Yes |
2. Clinical Question
Population
Relatively sedentary older adults without overt illness or disease. The registry lists aging as the condition and records an enrollment of 34.
Intervention
A personalized, goal-based behavioral intervention to promote physical activity, combined with transcranial direct current stimulation (tDCS) targeting the left dorsolateral prefrontal cortex. The stimulation schedule is described as 10 once-daily, 20-minute sessions during the first two weeks of the behavioral intervention.
Comparator
The same behavioral intervention combined with sham stimulation. The counseling approach is described as personalized and goal-based, with a two-month duration.
Primary question
Does adding tDCS to behavioral counseling change average daily step counts from the two-week baseline across the specified follow-up periods? The registry defines change from baseline for weeks 3-4, weeks 5-6, weeks 7-8, and weeks 9-10. Outcome estimates for these periods are not reported in the registry record.
The study rationale connects goal-directed physical activity with motivation, mood, and executive function, and identifies brain networks that include the left dorsolateral prefrontal cortex. The investigators describe the trial as a pilot study of feasibility and effects. That rationale explains why stimulation and counseling were studied together; it is not evidence that the intervention changed activity or the factors motivating activity.
The comparison is designed to distinguish the added contribution of active stimulation from the behavioral program and the experience of receiving stimulation. Because both groups receive counseling and a stimulation procedure, the intended contrast is active tDCS versus sham stimulation in that shared context. The registry record does not report outcome results with which to estimate that contrast.
3. Trial Design
The registry describes a randomized, parallel-group trial with triple masking and an enrollment of 34. Its status is listed as completed. The recorded study start date is 2020-02-12, and the primary completion date is 2022-11-03. The registry record does not explain which people or roles were masked, how randomization was generated or concealed, or whether masking was assessed.
Both groups receive a two-month personalized, goal-based counseling approach intended to promote physical activity. During the first two weeks of that intervention, one group receives tDCS and the other receives sham stimulation. The tDCS schedule is described as 10 once-daily sessions lasting 20 minutes. The summary identifies the left dorsolateral prefrontal cortex as the stimulation target. The intervention description for the active stimulation arm is truncated in the registry record, so other technical details are not reported there.
The primary outcome is change from a two-week baseline in averaged daily step counts. Follow-up is divided into weeks 3-4, weeks 5-6, weeks 7-8, and weeks 9-10. The outcome is described as a mean, with standard error as the dispersion measure. Secondary outcomes include motivation, mobility, cognitive tests, depressive symptoms, and completion rates for brain stimulation and behavior sessions.
The registry identifies the study as a pilot randomized controlled trial. It does not report the rationale for the enrollment target, a protocol for stopping or modifying the study, or details of the randomization procedure. The registry record also does not report whether the outcome assessments were conducted by masked assessors or how adherence to the counseling and stimulation procedures was handled in the analysis.
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: Two participants signed the informed consent at the in-person screening but withdrew prior to the baseline assessment and were never randomized.
Overall Study
| Stage | Behavioral Intervention Plus tDCS | Behavioral Intervention Plus Sham Stimulation |
|---|---|---|
| STARTED | 16 | 16 |
| COMPLETED | 15 | 13 |
| NOT COMPLETED | 1 | 3 |
Reasons for not completing this period:
| Reason | Behavioral Intervention Plus tDCS | Behavioral Intervention Plus Sham Stimulation |
|---|---|---|
| Adverse Event | 1 | 2 |
| Withdrawal by Subject | 0 | 1 |
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 | Behavioral Intervention Plus tDCS | Behavioral Intervention Plus Sham Stimulation | Total |
|---|---|---|---|---|
| Participants analysed | 16 | 16 | 32 | |
| Age, Continuous | years | 76.1 (SD 7.8) | 81.2 (SD 6.0) | 78.6 (SD 7.3) |
| Sex: Female, Male: Female | Participants | 15 | 14 | 29 |
| Sex: Female, Male: Male | Participants | 1 | 2 | 3 |
| 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 | 15 | 15 | 30 |
| Race (NIH/OMB): More than one race | Participants | 0 | 1 | 1 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 1 | 0 | 1 |
6. Primary Endpoint
The registry lists the primary outcome as Change of Daily Step Counts From Baseline, measured over Week 3-4, Week 5-6, Week 7-8, and Week 9-10..
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Error |
| Unit | Steps per day |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is absolute change in averaged daily step counts from the two-week baseline, expressed in steps per day. Baseline is defined as the first two weeks, and the registry specifies four follow-up periods: weeks 3-4, weeks 5-6, weeks 7-8, and weeks 9-10. The endpoint therefore tracks activity over time rather than reducing the follow-up to one post-intervention measurement. The registry describes the summary as a mean and its dispersion as a standard error.
Step counts provide a behavioral measure aligned with the study aim of increasing goal-directed physical activity. Unlike a questionnaire about motivation or perceived activity, the endpoint is based on recorded daily steps. The registry record does not identify the device used to measure steps, rules for valid wear or missing days, or how daily observations were averaged within each period. Those measurement details are not reported in the registry record.
Change from baseline expresses follow-up activity relative to each participant’s baseline level. In general, a comparison of changes between randomized groups can describe whether the groups followed different activity patterns after treatment began. A mean describes the group’s average change, while a standard error describes the precision of that estimated mean. The registry’s primary outcome has several time periods, and no single primary contrast across those periods is identified in the record. Outcome estimates and uncertainty intervals are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies the outcome and follow-up schedule but does not report the primary results. There are no posted group means, changes from baseline, between-group contrasts, confidence intervals, or p-values for daily step counts in the record. As a result, the magnitude and precision of any difference between active stimulation and sham stimulation cannot be assessed from the registry record. The record does not establish whether the groups’ activity patterns differed.
The primary endpoint is measured at several follow-up periods. A result at one period would describe activity during that interval; it would not by itself establish a consistent pattern across all periods. Conversely, an estimate near zero at one period would not determine what happened at another period. Since period-specific estimates are not reported in the registry record, no time course can be characterized.
The outcome is a mean change in steps per day. In general, a mean is useful for describing the average change in a group, but it can conceal variation between individuals. Standard errors convey uncertainty in estimated means, not the range of individual responses. Confidence intervals, if reported, would help show the precision of an estimate and the values compatible with the data under the analysis assumptions. Such intervals are not reported in the registry record.
The registry lists adverse-event counts for both groups, including serious events, other events, and deaths. These counts describe events recorded in the trial; they do not determine whether an event was caused by stimulation, counseling, or another factor. The record does not provide event-level descriptions, timing, severity grading beyond the serious-versus-other classification, or an attribution assessment. The serious-event terms listed in the record should therefore be read as reported terms, not as evidence of a treatment relationship.
Secondary outcomes cover motivation, mobility, cognitive performance, depressive symptoms, and intervention completion. Their inclusion indicates a broader set of questions than the primary step-count outcome alone. Their results are not reported in the registry record, so they cannot clarify whether changes in these domains accompanied changes in activity.
The trial is identified as a pilot, and the registry does not report a sample-size justification or a prespecified statistical analysis plan. The enrollment should not be treated as evidence that the study was designed to estimate a particular effect with a stated precision. Without outcome estimates and uncertainty measures, the record supports a description of the study question and its recorded safety counts, but not a quantitative conclusion about the primary comparison.
9. Statistical Methods Explained
The registry describes a randomized parallel-group design. Randomization is intended, in general, to make treatment groups comparable at the point of assignment by distributing measured and unmeasured characteristics without systematic selection. It does not guarantee that groups will be identical, especially in a pilot study. The record does not describe the sequence-generation method, allocation concealment, or whether randomization was stratified. Those methods are not reported in the registry record.
Triple masking indicates that the registry classifies the study as masked at three levels, but the record does not identify the roles involved. Masking can reduce the chance that knowledge of assignment influences behavior, assessment, or interpretation. Its practical success can depend on whether active and sham procedures feel or appear different. The registry record does not report whether participants or staff guessed assignments, or whether masking was evaluated.
The primary outcome is continuous: averaged daily step-count change from baseline. The registry specifies the mean as the summary measure and standard error as the dispersion measure. In general, the mean is the arithmetic average of observed values. A standard error describes the sampling uncertainty of an estimated mean; it is not a description of the spread of individual observations. A standard deviation, by contrast, describes variation among observations. The registry does not provide the underlying step-count distributions or standard deviations.
The outcome is assessed over several periods, each compared with the two-week baseline. Repeated measurements can describe whether group differences vary over follow-up, but they also require a clear analysis strategy. In general, an analysis may account for correlation between measurements from the same participant, because observations on one person are not necessarily independent. The registry does not state whether it used a repeated-measures model, analyzed each period separately, adjusted for baseline values, or applied another approach. The statistical model is not reported in the registry record.
A treatment contrast should be distinguished from the change within either group. In general, a between-group comparison of change addresses whether the average change differs between assignments. A within-group change alone does not isolate the contribution of the assigned intervention, since time, counseling, measurement, and other influences may affect both groups. The registry record does not post a between-group estimate or enough results to reconstruct one.
Standard errors and confidence intervals answer related but different presentation needs. In general, a standard error quantifies uncertainty in an estimate under the model, while a confidence interval gives a range of estimates compatible with the data and method at a stated confidence level. A narrow interval indicates greater precision than a wide interval, but neither measure alone establishes clinical importance. The registry record lists standard error as the dispersion measure for the primary endpoint but does not report endpoint estimates or confidence intervals.
The record describes a planning illustration based on an observed effect, a two-sided significance level of 0.05, equal allocation, and a normal approximation. It describes the effect to detect as a stated fraction of the observed effect. These are planning assumptions, not observed trial findings. Numerical planning scenarios are not reported in the registry record. The record also does not describe the original sample-size justification, so the planning illustration should not be interpreted as the trial’s own design calculation or as observed power.
Power is a design concept: in general, it is the probability that a specified analysis will reject a null hypothesis under a particular assumed effect and model. It depends on assumptions about the effect, variability, significance threshold, and design. A calculation made after observing a study result does not establish that the study had adequate power or that a non-significant result demonstrates no effect. No primary test result is reported in the registry record, and no claim about observed power can be made.
Multiplicity arises when several outcomes, time points, or analyses are examined. In general, testing many hypotheses can increase the chance of at least one apparently unusual result under a collection of null hypotheses. Approaches such as prespecifying a primary contrast or adjusting inference can address that issue, but the appropriate method depends on the analysis plan and aims. The registry identifies several primary-outcome time periods and multiple secondary outcomes but does not report a multiplicity strategy, a hierarchy among tests, or adjusted results.
For count outcomes and event counts, the recorded numbers have a different interpretation from the continuous step-count endpoint. Serious and other adverse events are reported by group, alongside numbers at risk. These descriptive counts do not by themselves provide a causal comparison, especially without information about event definitions, follow-up completeness, and attribution. No inferential analysis of adverse events is reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The primary outcome is defined across weeks 3-4, weeks 5-6, weeks 7-8, and weeks 9-10. The registry record does not identify one period as the sole primary comparison, specify an overall test across periods, or describe how repeated time-point testing was handled. It also lists secondary outcomes for motivation, Timed Up-and-Go, Trail Making Test A and B, Montreal Cognitive Assessment total score, the 15-item Geriatric Depression Scale, and completion rates for brain stimulation and behavior sessions. A multiplicity procedure or testing hierarchy is not reported in the registry record.
The record does not describe missing-data rules for daily step measurements, the minimum amount of usable monitoring needed to calculate an average, or how missing visits or incomplete measures were handled. It does not report whether the analysis used imputation, a likelihood-based method, complete observations only, or another approach. The reasons for missing data and their distribution across groups are also not reported in the registry record.
Analysis populations are not defined in the record. In particular, it does not state whether the primary analysis followed randomized assignment regardless of adherence, included only participants who completed the intervention, or used another population. The record does not explain how participants who discontinued stimulation or counseling were treated in the analysis.
These omissions affect interpretation because analysis choices can influence estimates and their uncertainty. They do not show that any particular method was or was not used; they mean the method cannot be established from the registry record. Results by period, multiplicity-adjusted inference, missing-data handling, and analysis-population definitions 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 |
|---|---|---|---|
| Behavioral Intervention Plus tDCS | 1 | 16 | 6.2% |
| Behavioral Intervention Plus Sham Stimulation | 2 | 16 | 12.5% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Behavioral Intervention Plus tDCS | 0 of 16 |
| Behavioral Intervention Plus Sham Stimulation | 0 of 16 |
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 |
|---|---|
| Behavioral Intervention Plus tDCS | 11 of 16 |
| Behavioral Intervention Plus Sham Stimulation | 10 of 16 |
Most frequent serious adverse event terms
| Event term | Organ system | Behavioral Intervention Plus tDCS | Behavioral Intervention Plus Sham Stimulation |
|---|---|---|---|
| Thrombosis | Vascular disorders | 1 of 16 | 0 of 16 |
| Peripheral T-cell lymphoma unspecified | Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 0 of 16 | 1 of 16 |
| Pneumonia | Respiratory, thoracic and mediastinal disorders | 0 of 16 | 1 of 16 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Behavioral Intervention Plus tDCS | Behavioral Intervention Plus Sham Stimulation |
|---|---|---|---|
| Fall | Injury, poisoning and procedural complications | 1 of 16 | 5 of 16 |
| Coronavirus infection | Infections and infestations | 0 of 16 | 3 of 16 |
| Dizziness | Nervous system disorders | 1 of 16 | 1 of 16 |
| Pruritus | Skin and subcutaneous tissue disorders | 0 of 16 | 2 of 16 |
| Back pain | Musculoskeletal and connective tissue disorders | 1 of 16 | 1 of 16 |
| Mole excision | Surgical and medical procedures | 2 of 16 | 0 of 16 |
| Pain of skin | Skin and subcutaneous tissue disorders | 1 of 16 | 0 of 16 |
| Pain in extremity | Musculoskeletal and connective tissue disorders | 0 of 16 | 1 of 16 |
| Arthritis | Musculoskeletal and connective tissue disorders | 0 of 16 | 1 of 16 |
| Pneumonia | Infections and infestations | 0 of 16 | 1 of 16 |
Serious events with the highest arm-level rate: thrombosis (6.2%), peripheral t-cell lymphoma unspecified (6.2%), pneumonia (6.2%).
The registry reports serious adverse events for the behavioral intervention plus tDCS group as 1 affected among 16 at risk, and for the behavioral intervention plus sham stimulation group as 2 affected among 16 at risk. It reports other adverse events as 11 among 16 at risk in the tDCS group and 10 among 16 at risk in the sham group. Deaths are recorded as 0 in each group. These are descriptive registry counts.
The serious-event terms listed are thrombosis, peripheral T-cell lymphoma unspecified, and pneumonia, each with a reported percentage of 6.2%. The registry record does not link these terms to a specific arm, describe the event narratives, or state whether investigators considered them related to study procedures. It also does not explain the definitions used for serious and other adverse events or provide event timing.
Counts alone do not show whether events were caused by an intervention. They also do not characterize the full clinical context, duration, or recurrence of events. The recorded numbers should be interpreted as adverse-event reporting for this trial, rather than as a causal estimate or a complete assessment of safety.
12. What the Result Does, and Does Not, Mean
The trial addresses a specific statistical question: whether adding tDCS to a shared behavioral program is associated with a different pattern of daily step-count change than adding sham stimulation to that program. The registry provides the intervention descriptions and the schedule for measuring the primary endpoint. It does not report the primary outcome estimates, so the direction, magnitude, and precision of the comparison are not available.
The absence of posted primary estimates is not evidence that the interventions produced the same activity levels, nor is it evidence that one group had greater activity. Without group results and an uncertainty measure, the trial’s primary question cannot be answered quantitatively from the registry record. The same limitation applies to the listed secondary outcomes, for which results are not reported in the registry record.
The trial’s pilot designation describes its stated role, but the record does not report a formal feasibility threshold or a sample-size justification. The listed enrollment should therefore not be treated as proof that the study could detect a particular difference. The planning illustration described in the record is a framework for hypothetical sample-size scenarios, not a replacement for reported outcomes or a measure of observed power.
The safety counts offer a record of adverse events by group, but they do not establish cause. The event terms and counts lack the contextual details needed to assess attribution or the full pattern of event experience. They should be interpreted separately from the unreported primary efficacy estimates.
Overall, the registry record establishes what was planned and which adverse-event counts were recorded, while leaving the main comparative outcome unresolved. A sound interpretation would require the group-specific step-count changes, between-group estimates, uncertainty intervals, analytic methods, and information about missing observations. Those results and methods are not reported in the registry record.
13. Why This Trial Matters Statistically
This trial raises a useful design question for behavioral and device interventions: when both groups receive an activity-focused counseling program, can a randomized comparison isolate the added contribution of active stimulation relative to sham? Keeping counseling common to both groups makes the contrast relevant to the incremental role of stimulation, provided the analysis preserves that randomized comparison. The registry describes the design but does not report the outcome estimates needed to evaluate the contrast.
The repeated step-count periods also matter statistically. Activity may change over time, and a series of follow-up windows can distinguish a short-lived difference from a pattern that persists. At the same time, multiple time points create choices about the primary comparison, correlation among observations, and multiplicity. The registry specifies the periods but does not report how those issues were addressed in the analysis.
The trial also illustrates why outcome definitions and analysis details are important for objectively measured behavior. Step counts are concrete, but the interpretation of their averages depends on how observations were collected, which days were considered valid, and how missing measurements were handled. These details are not reported in the registry record.
Finally, a pilot study can address feasibility as well as effects, but those aims require distinct reporting. The registry lists completion-rate outcomes for stimulation and behavior sessions, yet does not report their results or define a feasibility criterion. Without those results and the primary endpoint estimates, the record allows a clear description of the statistical questions but not a determination of what the trial found.
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 interpreting this trial is that primary outcome results are not reported in the registry record. The mean changes, between-group contrasts, standard errors, confidence intervals, and p-values for the specified follow-up periods are absent. Consequently, neither the estimated treatment contrast nor its precision can be described.
The registry defines several follow-up periods but does not identify a single period or overall contrast as the primary inferential target. It does not describe the statistical model, baseline adjustment, handling of within-person correlation, or multiplicity strategy. The primary outcome is a daily step average, but the device, valid-measurement rules, and averaging procedures are not reported.
There is also no account of missing outcome data, adherence-related exclusions, analysis populations, or the handling of participants who may have discontinued an intervention. The registry does not report how randomization was implemented or which roles were included in triple masking. These gaps limit assessment of potential bias and the reproducibility of the analysis.
The intervention description for the active stimulation group is incomplete in the registry record. The record also does not report results for the listed secondary outcomes or completion-rate measures, and it does not provide a sample-size justification. Adverse-event counts are available, but event narratives, attribution, and timing are not reported. These limitations leave the main comparative outcome and important aspects of implementation and safety context unresolved.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Modulating Brain Activity to Improve Goal-directed Physical Activity in Older Adults — NCT04278560.
- Registry record last updated 2024-05-16; status last verified 2024-05.
- Results first posted 2024-01-03.
- 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
The registry lists NCT04278560 as a completed randomized, triple-masked, parallel pilot trial with an enrollment of 34. It compares a two-month personalized, goal-based physical-activity intervention combined with tDCS against the same behavioral intervention combined with sham stimulation. The primary outcome is change in mean daily step counts from a two-week baseline across weeks 3-4, weeks 5-6, weeks 7-8, and weeks 9-10.
Primary and secondary outcome results are not reported in the registry record. The record lists serious and other adverse-event counts by group and records no deaths in either group. It does not report the analysis plan, missing-data methods, analysis populations, or multiplicity strategy. The principal comparative activity results therefore cannot be assessed from the registry record.