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 Translational Control of Anabolic Resistance in Aging Muscle (NCT03839628), a na na study. The primary outcome is Lean Mass.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03839628 |
| Phase | NA |
| Condition | Physical Inactivity |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 9 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Utah |
| Results posted | Yes |
2. Clinical Question
Population
Older individuals aged 60-85y. The registry record lists Physical Inactivity as the condition and records enrollment of 9 participants.
Intervention
Participants reduced their physical activity levels for 2-weeks by approximately 75% of their baseline level of physical activity.
Comparator
There is no separate control group or randomized comparison in the registry record. Each participant's baseline measurement is the reference point for the before-and-after assessment.
Primary question
How did lean mass change between baseline and 2-weeks during a period of reduced physical activity? The registry record names change in lean mass as the primary outcome, measured in grams, but does not report the observed change.
The study is described as an investigation of the relation between short-term physical inactivity and muscle health and function. Its registry summary also describes assessments of body composition, muscle function, oral glucose tolerance, and metabolic measures before and after reduced activity. Each metabolic study included three muscle biopsies: one before and two after leucine ingestion.
The central statistical question is about within-participant change over time, rather than a difference between randomized treatment groups. Baseline measurements provide a point of comparison, but they do not by themselves show what would have happened over the same period without reduced activity. The record does not report a control condition, outcome estimates, or analyses that quantify the change.
3. Trial Design
NCT03839628 is an interventional, single-group study sponsored by the University of Utah. Its allocation is recorded as NA, its masking as NONE, and its model as SINGLE GROUP. These entries describe a study without a randomized, masked, parallel-group comparison in the registry record. The study is marked COMPLETED.
The record gives a start date of 2019-03-05 and a primary completion date of 2019-12-17. Enrollment is recorded as 9, while the study summary states an enrollment goal of 8. Participants were described as older individuals aged 60-85y. The intervention was reduced physical activity for 2-weeks, by approximately 75% of each participant's baseline activity level.
The summary describes a study occurring over the course of a month, with testing before and after the reduction in activity. It lists a screening event with baseline data collection, two body composition scans, muscle function testing, oral glucose tolerance tests, and metabolic studies before and after the 2-week inactivity period. Each metabolic study was to include three muscle biopsies, one before and two after leucine ingestion.
This structure supports a before-and-after description within the enrolled group. It does not provide a like-for-like control comparison. A change between baseline and follow-up can describe what happened during the observation period, but without a separate comparison group it cannot isolate reduced activity from other changes occurring over time. A more detailed protocol, including the operational definition of activity reduction and any adherence criteria, is not reported in the registry record.
The registry lists two outcome measures and zero analyses. The design and timing are described, but the posted results do not include outcome estimates or an analysis report. Sample-size assumptions appearing in the record are identified as planning illustrations rather than the study's own design assumptions; they do not change the recorded single-group design.
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 | Reduced Physical Activity |
|---|---|
| STARTED | 9 |
| COMPLETED | 8 |
| NOT COMPLETED | 1 |
Reasons for not completing this period:
| Reason | Reduced Physical Activity |
|---|---|
| Withdrawal by Subject | 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 | Reduced Physical Activity |
|---|---|---|
| Participants analysed | 8 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 2 |
| Age, Categorical: >=65 years | Participants | 6 |
| Sex: Female, Male: Female | Participants | 6 |
| Sex: Female, Male: Male | Participants | 2 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 8 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | participants | 8 |
| HbA1c | % of hemoglobin | 5.5 (SD 0.3) |
6. Primary Endpoint
The registry lists the primary outcome as Lean Mass, measured over baseline and 2-weeks.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Error |
| Unit | grams |
| Endpoint classification | Continuous Endpoint |
The primary outcome is change in lean mass, measured in grams, with the timeframe listed as baseline and 2-weeks. Lean mass is a body-composition measure intended to quantify the amount of mass classified as lean rather than fat. Repeating the measurement makes it possible to describe within-participant change over the period of reduced physical activity.
In general, a continuous outcome such as lean mass can be summarized by its mean, while standard error describes the precision of an estimated mean. The registry identifies the outcome parameter as a mean and its dispersion as standard error. These labels do not reveal the actual mean, variability, or change: none of those result values is reported in the registry record.
Using lean mass as an endpoint addresses one aspect of body composition. It does not, by itself, represent every dimension of muscle health or function. The registry summary also describes muscle-function and metabolic assessments, but the primary endpoint named in the record is change in lean mass. The record does not report measurement details such as the specific instrument, procedures for quality control, or how an individual participant's change was calculated.
Baseline-to-follow-up measurement can make each participant's initial value a reference for interpreting later measurements. In general, that approach can account for stable differences between participants when changes are analyzed appropriately. However, a before-and-after endpoint without a separate control group does not distinguish the intervention period from other time-related influences. The observed lean-mass result and its precision are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a completed single-group study of reduced physical activity in older individuals aged 60-85y. It specifies change in lean mass from baseline to 2-weeks as the primary outcome, measured in grams. The record does not report the observed lean-mass change, its standard error, a confidence interval, a test statistic, or a p-value. Consequently, the direction, magnitude, and statistical precision of the primary outcome cannot be characterized from the reported results.
The enrollment entry is 9, and the study summary states an enrollment goal of 8. Enrollment alone does not establish how many participants completed each measurement or contributed to an outcome analysis. The registry lists zero analyses, and analysis populations are not reported in the registry record. It is therefore not possible to determine whether all enrolled participants had baseline and follow-up measurements or how missing observations were handled.
The study's single-group before-and-after structure is important for interpretation. A change from baseline would describe the enrolled participants over the observation period. In general, however, without a concurrent comparison group, such a change cannot be separated from other influences that may vary over time. The registry record does not identify a randomized comparison, and its allocation is listed as NA. No causal conclusion about the effect of reduced activity follows from the design description alone.
The record also lists two outcome measures but does not report the analysis details for either. It is not possible to establish whether the primary outcome was analyzed according to a prespecified plan, whether other outcomes were treated as exploratory, or how multiple statistical tests were handled. An outcome count is not itself evidence that any particular analysis was conducted.
Sample-size assumptions in the record describe planning illustrations using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. They are explicitly illustrations based on an observed effect, not the study's own design. Those assumptions do not match the recorded single-group structure and should not be interpreted as evidence about the actual enrollment decision, observed power, or precision of this study's result. Numerical planning outputs and the observed effect are not reported in the registry record.
The appropriate reading is therefore descriptive and limited: the record documents a study plan and enrollment, but not the primary outcome findings or inferential analysis. The missing results prevent an assessment of whether lean mass changed, how much it changed, or how precisely that change was estimated.
9. Statistical Methods Explained
The record describes a single-group, continuous-outcome study with baseline and follow-up assessment. The primary outcome is change in lean mass, expressed in grams, and the stated summary parameter is the mean. No outcome estimate or analysis result is reported. The methods concepts below are general explanations; they do not describe unreported procedures from this study.
What does a mean describe?
In general, the mean combines participants' measured values into a single estimate of the group's average. For a change outcome, analysts may first calculate each participant's follow-up value relative to baseline and then summarize those changes. Another approach can compare group means at the different measurement times. These approaches do not necessarily produce the same estimate, particularly when participants have incomplete measurements. The registry record does not say which approach was used.
A mean can be easy to interpret, but it may not show the spread of individual responses. Participants can have different changes even when the group mean is near zero, or can have broadly similar changes around a nonzero mean. Participant-level results and a description of the distribution are not reported in the registry record.
What does standard error mean?
In general, the standard error describes the sampling precision of an estimated mean. It is not the same as the standard deviation, which describes variation among individual measurements. A smaller standard error generally indicates a more precise estimate under the assumptions of the analysis, but it does not imply that individual participants had little variation. Although the registry lists standard error as the dispersion measure for the primary outcome, it does not report a value.
In general, a confidence interval expresses a range of values compatible with an estimate under a statistical model and its assumptions. It conveys uncertainty more directly than a point estimate alone. No confidence interval for lean-mass change is reported in the registry record, so the precision of the outcome estimate cannot be assessed.
Why does the study structure matter?
In a within-participant design, each participant can serve as their own reference across measurement times. This can reduce the influence of stable differences between people when the analysis uses paired measurements. The statistical analysis must account for the relationship between each participant's baseline and follow-up observations; treating them as independent measurements would ignore that pairing. The registry record does not state how the analysis handled repeated measurements.
A before-and-after comparison does not, by itself, establish what would have occurred without the intervention. In general, changes over time can also reflect factors such as measurement variation, ordinary fluctuation, or events occurring during the same period. A concurrent control group can help distinguish changes associated with an intervention from changes that would occur over time, but the registry record describes a single group and no randomized comparison.
How should the planning assumptions be read?
The record's planning assumptions specify a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The record characterizes the calculations as planning illustrations based on an observed effect, not as the trial's design. Those are assumptions for sample-size illustrations, not evidence that participants were assigned to two arms. The study is recorded as single-group, and no control arm is described.
In general, a planning calculation estimates the sample size needed under assumed conditions, such as a target effect and a chosen significance level. The resulting sample size depends on those inputs and on the analysis model. An illustration based on an observed effect is not a measurement of how much power the completed study had. It is not observed power, and it cannot replace a confidence interval or an estimate of the actual outcome. The numerical planning outputs and the observed effect are not reported in the registry record.
Over-dispersion is a general concern when observed variability is greater than a statistical model assumes. If a model understates variability, uncertainty can be understated and inferential results can be misleading. Whether over-dispersion is relevant depends on the outcome and model; the record does not report a model fit or a dispersion assessment. Since the primary outcome is continuous and the analysis is not reported, no specific conclusion about over-dispersion can be made.
What can be inferred from the listed analyses?
The registry lists zero analyses. This does not provide estimates, tests, or evidence about the primary endpoint. In general, reporting an analysis would clarify the estimator, the handling of repeated measurements and incomplete data, the uncertainty measure, and any assumptions used. Those details are not reported in the registry record. Without them, the design can be described, but statistical findings cannot be reconstructed or evaluated.
10. Confidence Intervals for Each Arm
No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.
| Arm | Participants | Mean | Standard deviation | 95% CI for the mean |
|---|---|---|---|---|
| Reduced Physical Activity | 9 | 403.000 | 426.000 | 75.547 to 730.453 |
R code and output
arm <- c("Reduced Physical Activity")
n <- c(9)
m <- c(403)
sp <- c(142)
sd <- sp * sqrt(n) # standard errors converted to SDs
for (i in seq_along(n)) {
se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}
CARM Reduced Physical Activity 9 403.000 426.000 75.547 730.45311. Multiplicity, Missing Data and Analysis Populations
The registry record lists two outcome measures and zero analyses. It identifies change in lean mass as the primary outcome, but does not report results for that outcome or the other listed measure. The names and analysis details for the other outcome measure are not reported in the registry record.
Multiplicity arises in general when several outcomes, time points, subgroups, or statistical tests are examined. Conducting multiple tests can increase the chance of a statistically notable result occurring by chance if no adjustment or other prespecified strategy is used. A registry entry with two outcome measures does not establish that both were tested, how they were prioritized, or whether any adjustment was planned. Multiplicity handling is not reported in the registry record.
Missing-data information is also absent. The record does not report how many participants had each scheduled assessment, whether any measurements were missing, or how incomplete observations were addressed. Enrollment of 9 does not establish the number included in an outcome analysis. Analysis populations, such as all enrolled participants or participants with complete measurements, are not reported in the registry record.
Details about the statistical analysis plan, interim analyses, and prespecified rules for exclusions are not reported in the registry record. In general, those details help readers distinguish planned analyses from analyses chosen after examining the data. Their absence means that the reported record cannot establish how analytic decisions were made. No conclusions about multiplicity control, missingness, or analysis-population selection can be drawn from the listed outcome count alone.
12. 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 |
|---|---|---|---|
| Reduced Physical Activity | 0 | 9 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Reduced Physical Activity | 0 of 9 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Reduced Physical Activity | 0 of 9 |
The registry records 9 participants at risk in the Reduced Physical Activity group. It reports 0 serious adverse events, 0 other adverse events, and 0 deaths. These are the event counts recorded for the group; they do not provide detail on particular event types, severity beyond the serious/non-serious distinction, timing, or relationship to the study intervention. The registry lists no serious adverse event terms.
In general, an event count is best read alongside the number of participants monitored, the duration and completeness of follow-up, and the definitions used to classify events. The record provides the at-risk count but does not report detailed event-collection procedures or participant-level follow-up information. A recorded count of zero means no events of that category are recorded in this entry; it does not establish that the possibility of an event is absent.
The safety figures should be interpreted as registry reporting for this study, not as a comparison between treatment groups. There is only one recorded group, and no control group or comparative safety analysis is reported. The figures therefore describe the event counts in the enrolled group, without estimating a relative difference in risk.
13. What the Result Does, and Does Not, Mean
The registry record establishes that NCT03839628 was a completed interventional study of reduced physical activity in older individuals aged 60-85y. It documents enrollment of 9 and describes a reduction in activity for 2-weeks by approximately 75% of baseline activity. It names change in lean mass between baseline and 2-weeks as the primary outcome, with measurements expressed in grams.
Those details describe the study question and its structure, not the answer to the question. The registry record does not report the lean-mass change, its uncertainty, or any statistical test. It therefore does not show whether the group mean increased, decreased, or stayed similar. The magnitude and precision of any change cannot be assessed from the record.
Even if a before-and-after estimate were reported, a single-group design would describe change over time in the enrolled participants. In general, without a concurrent comparison group, the estimate would not separate changes associated with reduced activity from other influences during the same period. The record does not describe a randomized control comparison.
The record also does not establish how many participants contributed to each outcome analysis, how missing measurements were handled, or whether analyses followed a prespecified statistical plan. The listed count of two outcome measures and zero analyses does not substitute for numerical results. Sample-size illustrations based on an observed effect are planning calculations; they are not observed power and do not establish the outcome's statistical precision.
Accordingly, the available registry information supports a description of the study's population, intervention, timeframe, primary endpoint, and recorded adverse-event counts. It does not support a conclusion about the size or direction of lean-mass change, the certainty of an effect, or a causal interpretation of any change. These questions require outcome estimates and analysis details, which are not reported in the registry record.
14. Why This Trial Matters Statistically
This study illustrates a distinction that matters in biostatistics: a clearly described research question is not the same as a reported result. The registry identifies a population, a period of reduced activity, and a primary continuous endpoint. Those elements define what the study set out to observe, but without outcome estimates they do not establish what happened to lean mass.
The single-group before-and-after structure also highlights the difference between measuring change and estimating a causal effect. Repeated measurements can provide a direct description of change within participants. In general, a separate concurrent comparison helps address what might have happened over the same period in the absence of the intervention. The record does not describe such a comparison, so its design supports a narrower interpretation than a randomized trial with a control group.
Another statistical issue is the distinction between a planning calculation and evidence from the completed study. The registry's sample-size assumptions are explicitly presented as illustrations, using equal allocation between two arms even though the trial is recorded as single-group. Such calculations cannot be read as the trial's actual design or as proof of adequate precision. Nor can sample-size planning replace the estimate, uncertainty measure, and analysis details needed to interpret an observed result.
Finally, the record lists two outcome measures but no analyses. This makes it difficult to evaluate missing data, multiplicity, and the analysis population. Those are not minor reporting details: they inform how reliable and interpretable an estimate would be. The case shows why registry design information, outcome results, and statistical methods each serve different roles in understanding a clinical study.
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 for interpreting the posted record is the absence of numerical outcome results. Although change in lean mass is named as the primary outcome, its estimate, standard error, confidence interval, and statistical test are not reported in the registry record. The record therefore cannot establish the direction, size, or precision of the primary outcome.
The study is recorded as single-group, with allocation listed as NA and no control group described. This limits what a before-and-after change could establish: in general, a change over time is not equivalent to a comparison against what would have occurred without the intervention. No randomized comparison is available in the record.
Enrollment is recorded as 9, and the study summary gives an enrollment goal of 8, but the number of participants with complete measurements or included in analyses is not reported. The record lists zero analyses. It does not describe missing-data handling, participant exclusions, analytic populations, measurement quality procedures, or the specific statistical model.
The intervention is described as reducing activity by approximately 75% of baseline for 2-weeks, but details of how activity was measured, monitored, or maintained are not reported in the registry record. The summary describes several assessments, yet their numerical results and analysis details are not included. The record also does not report the statistical plan, multiplicity approach, or interim analyses.
The planning assumptions use a two-arm equal-allocation illustration, while the study is recorded as single-group. These assumptions are not a description of the trial's design and should not be used to infer the actual analysis or precision. Together, these reporting gaps limit interpretation to the study's stated design and recorded event counts.
16. Related Tutorials
17. Related Statistical Calculators
18. Sources
- ClinicalTrials.gov: Translational Control of Anabolic Resistance in Aging Muscle — NCT03839628.
- Registry record last updated 2022-06-22; status last verified 2022-06.
- Results first posted 2022-06-02.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
19. Record Summary
NCT03839628, titled “Translational Control of Anabolic Resistance in Aging Muscle,” is a completed interventional study sponsored by the University of Utah. The registry records a single-group model, no masking, enrollment of 9, and a study population of older individuals aged 60-85y.
Participants reduced physical activity for 2-weeks by approximately 75% of baseline activity. The primary outcome is change in lean mass, measured in grams, between baseline and 2-weeks. The study summary describes additional body-composition, muscle-function, glucose-tolerance, and metabolic assessments, including muscle biopsies before and after leucine ingestion.
The registry records 0 serious adverse events, 0 other adverse events, and 0 deaths among 9 participants at risk. It lists two outcome measures and zero analyses. Numerical outcome results, analysis populations, missing-data handling, and multiplicity methods are not reported in the registry record. The record supports description of the study design, but not interpretation of the size or precision of its primary outcome.