Transitional Rehabilitation in CABG Patients: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Transitional Rehabilitation in CABG Patients (NCT03892460), a randomized na study. The primary outcome is Short Physical Performance Battery.

2. Clinical Question

3. Trial Design

The registry record describes a randomized, parallel-group trial with no masking. Participants were assigned to a treatment arm described as neuromuscular electrical stimulation or to a no treatment control. The study is listed as completed, with enrollment of 54. Its listed conditions are coronary artery disease and coronary artery bypass graft surgery. The sponsor is the University of Vermont.

The study summary describes a goal of understanding whether an at-home exercise program begun soon after CABG surgery and continued for 4 weeks after hospital discharge can preserve or improve physical function. The listed treatment intervention is neuromuscular electrical stimulation. The record does not report further details about the schedule, device settings, adherence, or other elements of intervention delivery. It also does not describe what care participants in the control arm received beyond identifying that arm as no treatment control.

The primary outcome is the Short Physical Performance Battery, with a timeframe of 4 weeks. Secondary outcomes listed in the record include 6 Minute Walk Distance and several Medical Outcomes Short Form 36 domains: Physical Function, Role Physical, Bodily Pain, General Health, Vitality, Social Function, and Role Emotional. The registry lists 11 outcome measures, but the primary outcome record is not reduced to one comparison and no analyses are listed. Therefore, the design and planned measurement domains can be described, but the registry record does not support a conclusion about the size or direction of an intervention effect.

The record does not report the allocation sequence method, concealment procedures, participant flow, or the timing of assessments beyond the primary outcome timeframe. These details should not be inferred from the randomized, parallel-group designation.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Short Physical Performance Battery, measured over 4 weeks.

The Short Physical Performance Battery is the designated primary endpoint, measured at 4 weeks. It combines three physical-performance tasks: balance, gait speed, and ability to stand from a chair. Each domain ranges from 0-4 units, and the total score ranges from 0 to 12. A higher score indicates better physical function.

As a general statistical concept, a composite measure can capture performance across more than one related task in a single score. That can make an outcome useful when the scientific question concerns overall physical function rather than only one activity. The component tasks also give the score clinical context: balance, walking speed, and standing from a chair represent different aspects of physical performance. The score does not, by itself, show which component accounts for a difference between groups.

The registry record specifies the endpoint as a mean with standard error as its dispersion measure. A mean describes the average score in a group; a standard error describes the precision of that estimated average, rather than the spread of individual participants’ scores. No group means, standard errors, or arm-to-arm estimate for this endpoint are reported in the registry record. The record also does not explain whether the primary comparison was intended to use change from baseline or scores at 4 weeks alone.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record identifies a randomized, parallel-group design with no masking. In general, randomization is intended to make assigned groups comparable, on average, with respect to factors known and unknown at the time of assignment. It does not guarantee that every characteristic will be balanced in a particular trial. A parallel-group design compares groups assigned to different approaches over the study period, rather than having each participant receive every approach. The record does not report how the allocation sequence was generated or concealed, so those procedures cannot be assessed.

What does a mean summarize?

The primary endpoint is specified as a mean on the Short Physical Performance Battery. A mean is the arithmetic average of the measured scores in a group. In a comparative trial, the central effect estimate would ordinarily express a contrast between the groups, such as a difference in mean scores or a difference in mean change. This is general explanation, not a statement of which contrast was used in this study. The registry record does not report the primary comparison or any numerical group means.

What does the standard error describe?

The record names standard error as the dispersion measure for the primary outcome. In general, the standard error reflects the sampling uncertainty of an estimated mean: it indicates how much the estimate would tend to vary across repeated samples under the statistical model. It is not a description of the range of individual scores. A standard deviation, by contrast, describes variation among individual observations. The record does not provide a standard error value, and does not report a standard deviation for the primary endpoint.

For a comparison, uncertainty is most directly conveyed by the interval around the effect estimate. A confidence interval gives a set of values that are compatible with the observed data and the method’s assumptions. If an interval is wide, the estimate is less precise; if it is narrow, it is more precise. The interval’s location also matters for judging the direction and possible size of the effect. No interval or test statistic is reported for the primary outcome in the registry record.

Why does the outcome structure matter?

The record’s note that the primary outcome has several categories or time points and was not reduced to one comparison means it does not present one result for a straightforward interpretation. When an outcome is recorded across time points or categories, the analysis needs to define which contrast answers the research question. For example, an analysis might focus on a follow-up value, a change from baseline, or a pattern over time. These are general possibilities, not claims about the analysis used in this trial. The registry record does not identify which comparison was prespecified or provide a result for one.

The record lists 11 outcome measures and zero analyses. Listing an outcome measure identifies what was to be assessed, but does not show the statistical model, the analysis population, the handling of missing observations, or the estimated effects. Those details are not reported in the registry record. The listed secondary outcomes span walking distance and domains of the Medical Outcomes Short Form 36; their names do not establish that results were analyzed or posted.

How should planning calculations be understood?

General sample-size calculations estimate how many participants may be needed to detect a defined effect under specified assumptions. The planning assumptions described for this record use a two-sided significance level of 0.05, equal allocation between arms, a normal approximation, and effects defined as fractions of the observed effect. These are planning illustrations based on an observed effect, not the trial’s own design justification. The record does not report a sample-size justification, and no values for planning scenarios are reported.

Such calculations are not observed power. Observed power is not a substitute for examining an effect estimate and its uncertainty after the data have been collected. Planning illustrations can show how assumptions about the effect to detect influence a future study’s required enrollment, but they do not prove that the current study was adequately powered or that a result is reliable. The registry record does not report a formal statistical plan or explain the origin of the assumed effect used for planning.

These general concepts help distinguish design information from results. In this record, design features and outcome definitions are available, but a primary estimate, uncertainty interval, test result, analysis model, and analysis population are not reported in the registry record. Statistical interpretation therefore remains limited to describing the study framework and noting which information is absent.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists 11 outcome measures, including the Short Physical Performance Battery and secondary measures of walking distance and health-related physical function and other domains. When a study evaluates multiple outcomes, time points, or contrasts, multiplicity can arise: the more statistical tests considered, the greater the chance that at least one result may appear notable by chance alone. This is a general statistical concern, not a claim that any particular adjustment was required or used in this trial.

The registry record reports zero analyses and does not specify a multiplicity strategy, such as a hierarchy of outcomes or an adjustment to testing thresholds. It also does not identify a single primary comparison, noting that the primary outcome has several categories or time points and was not reduced to one comparison. Therefore, the record does not support assessment of how the primary question was separated from secondary analyses or how any multiplicity was handled.

Missing-data methods and analysis populations are also not reported in the registry record. It does not state how missing outcome measurements were handled, whether all randomized participants were included in an analysis, or whether any other analysis population was used. These details affect how results should be interpreted because exclusions and missing observations can change the data represented by an estimate. No assumptions about those procedures should be made from the randomization label or the reported enrollment.

The absence of these details is distinct from evidence that a particular method was or was not used. It means the registry record does not report the information needed to evaluate multiplicity control, missing-data handling, or the population underlying an efficacy analysis.

11. 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 1% reporting threshold.

Most frequent non-serious adverse event terms

The registry record reports adverse-event counts by arm. In the treatment arm, 30 were listed as at risk for serious adverse events; 0 were affected. The record lists 30 at risk for other adverse events, with 1 affected. In the control arm, 24 were listed as at risk for serious adverse events; 0 were affected. It lists 24 at risk for other adverse events, with 0 affected. Deaths are reported as 0 in both arms.

These are counts, not comparative estimates adjusted for follow-up time or other factors. The registry record does not describe event definitions, the period over which events were collected, or the method used to attribute an event to an arm. It lists no serious-event terms. The single other adverse event in the treatment arm is not further described in the record.

Zero reported serious events and deaths in these entries do not establish that no events could occur or that the intervention has a particular safety profile. The figures should be read as the event counts recorded for this trial, with the available detail and follow-up context limited by what the registry record reports.

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

The registry record establishes that a randomized, parallel-group study compared a neuromuscular electrical stimulation treatment arm with a no treatment control in patients undergoing CABG surgery. It identifies physical function at 4 weeks as the primary outcome and describes the Short Physical Performance Battery, including its tasks and score direction. This information clarifies what the study set out to measure.

It does not establish what the comparison found. No primary outcome values, arm-to-arm estimate, confidence interval, or test result are reported, and the outcome entry is not reduced to one comparison. As a result, the registry record cannot show whether scores differed, which direction any difference took, or how precise an estimate would be. The absence of a posted result should not be interpreted as evidence of no effect.

The outcome scale also has limits as an interpretation tool. A total score combines balance, gait speed, and the ability to stand from a chair. A difference in the total score would not, by itself, identify which task contributed to it. The record does not report component-level results or explain what size of change would be clinically important.

The adverse-event entries describe counts recorded by arm, but they do not provide full event descriptions, definitions, or a detailed account of safety follow-up. They should not be used as a substitute for a complete safety analysis. Similarly, the trial’s randomized designation describes its design; it does not, without results and analysis details, answer the efficacy question.

The most defensible reading is therefore limited: the registry describes a study intended to assess post-CABG physical function and identifies its primary measure and comparison groups, but the posted record does not provide the primary comparative result. It neither supports a conclusion that the intervention improved function nor a conclusion that it did not.

13. Why This Trial Matters Statistically

This trial is statistically relevant because it frames a practical clinical research question around a defined functional outcome after CABG surgery. The Short Physical Performance Battery combines balance, gait speed, and standing from a chair, and its higher scores indicate better physical function. These details let readers understand the construct the study intended to measure and the direction in which scores are interpreted.

The randomized, parallel-group design is also important to statistical interpretation. In general, random assignment supports comparison between groups by reducing systematic differences in expectations at the point of assignment. But design labels alone are not enough to evaluate a result. Readers also need the actual outcome estimates, uncertainty, and analysis methods. Those are not reported for the primary outcome in the registry record.

The record highlights a common distinction between a study’s outcome framework and its evidence. It lists 11 outcome measures, yet reports zero analyses and does not reduce the primary outcome to one comparison. Without a defined contrast, an estimate, and its uncertainty, the primary research question remains unanswered by the posted results. The record also does not report multiplicity, missing-data, or analysis-population procedures, which limits appraisal of any analysis that might exist outside the registry entry.

Finally, the safety counts illustrate why event counts require context. Counts by arm are useful descriptive information, but they do not by themselves characterize event timing, definitions, or comparative risk. The record’s limited adverse-event detail and absence of a primary outcome result make careful separation of what is documented from what remains unknown particularly important.

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 trial-specific limitation of the registry record is that it does not report a primary outcome result. Although the Short Physical Performance Battery is specified at 4 weeks, there are no group means, standard errors, arm-to-arm estimate, confidence interval, or test result. The primary outcome entry is not reduced to one comparison, preventing a direct reading of the intended primary contrast from the record.

The record describes enrollment of 54 but does not provide participant characteristics, eligibility criteria, baseline outcome values, participant flow, or adherence information. The arm descriptions identify neuromuscular electrical stimulation and no treatment control, but details of intervention delivery and control-arm care are not reported in the registry record. Thus, the record alone does not show how closely the intervention description maps to the study summary’s at-home program framing.

Although 11 outcome measures are listed, the registry reports zero analyses. It does not identify a statistical model, analysis population, missing-data approach, or multiplicity strategy. The allocation sequence and concealment methods are also not reported. These omissions do not prove that such procedures were absent; they mean that they cannot be evaluated from the registry entry.

The safety information is limited to group counts. The record does not provide event descriptions for the other adverse event, event definitions, follow-up duration for safety, or detailed serious-event reporting. The registry also does not report a sample-size justification or the statistical plan. The sample-size assumptions described for planning are illustrations, not evidence about the trial’s original design rationale or observed statistical power.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Transitional Rehabilitation in CABG Patients — NCT03892460.
• Registry record last updated 2021-08-03; status last verified 2021-07.
• Results first posted 2021-08-03.
• 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.

18. Record Summary

NCT03892460, titled “Transitional Rehabilitation in CABG Patients,” is listed as a completed, randomized, unmasked, parallel-group study sponsored by the University of Vermont. Enrollment is reported as 54. The listed intervention is neuromuscular electrical stimulation, compared with a no treatment control.

The primary outcome is the Short Physical Performance Battery at 4 weeks, described as a mean score with standard error. The scale combines balance, gait speed, and chair-standing tasks; higher scores indicate better physical function. Secondary outcomes include 6 Minute Walk Distance and domains of the Medical Outcomes Short Form 36.

The registry record lists 11 outcome measures and zero analyses. It does not provide a single primary comparison or numerical primary outcome result. Adverse-event entries report no serious adverse events and no deaths in either arm, with one other adverse event in the treatment arm and none in the control arm. Further event details and the analysis methods are not reported in the registry record.