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 Balance Recovery Training for Fall Prevention in Retirement Communities (NCT02551666), a randomized na study. The primary outcome is Maximum Torso Angle at 0.8 Mph.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02551666 |
| Phase | NA |
| Condition | Accidental Falls, Aged, Exercise Movement Techniques |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Single |
| Enrollment | 35 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Texas A&M University |
| Results posted | Yes |
2. Clinical Question
The trial asked whether treadmill-based reactive balance training and Tai Chi were associated with different balance-test performance among residents of senior housing. Its stated hypotheses distinguished between reactive balance and clinical balance or mobility: the investigators expected the balance recovery training group to perform better on reactive balance tests, and the Tai Chi group to perform better on clinical balance and mobility tests. These were hypotheses, not findings.
Population
Residents of five senior housing facilities. The study enrolled 35 people. The primary outcome population was participants who completed at least 9 of 12 sessions.
Intervention
Treadmill-based balance recovery training on a modified treadmill, for approximately 30 minutes per session, three sessions per week for four weeks.
Comparator
Tai Chi exercise using the Yang Short form, with 30-minute sessions three times per week for four weeks.
Primary question
How did maximum torso angle during a simulated trip differ between the training groups at 1 week, 1 month, 3 months, and 6 months after the four-week intervention?
The primary measure was recorded in degrees, with larger angles described as worse performance. The record lists additional balance and mobility outcomes, but does not give numerical estimates for the primary outcome or describe a single result covering its several follow-up times. The comparison therefore cannot be reduced to a stated group difference from the information in the registry record.
3. Trial Design
This was a randomized, parallel-group trial with single masking. The registry record does not identify who was masked, so the masking description alone does not establish whether participants, assessors, or other personnel were unaware of treatment assignment. The study is marked completed, and its phase is listed as not applicable.
The registry record lists 35 enrolled residents from five senior housing facilities. One group received treadmill-based balance recovery training and the other Tai Chi. Both programs were scheduled three times per week for four weeks, with sessions lasting approximately 30 minutes. The balance recovery program used a modified treadmill; the Tai Chi program used the Yang Short form.
Balance testing took place at baseline and again 1 week, 1 month, 3 months, and 6 months after training. The battery included six standard clinical balance and mobility tests and a reactive balance test. The primary outcome was maximum torso angle at 0.8 Mph during a simulated trip. The primary outcome population was restricted to participants who completed at least 9 of 12 sessions, rather than being described as everyone enrolled.
The registry record does not report the method used to generate or conceal the random allocation, whether treatment adherence differed between groups, or the number assessed at every follow-up. It also does not identify the person or group responsible for outcome assessment. These details matter when judging how randomization and masking may have protected the comparison from bias, but they cannot be inferred from the labels randomized and single masked.
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: 151 prospective subjects were assessed for eligibility. 74 failed the medical screening 28 ended up declining to participate after learning more about the study 14 were withdrawn for other reasons not related to the study 35 participants remained and were allocated to one of the two treatment groups.
Overall Study
| Stage | Tai Chi Exercise | Balance Recovery Training |
|---|---|---|
| STARTED | 16 | 19 |
| COMPLETED | 15 | 16 |
| NOT COMPLETED | 1 | 3 |
Reasons for not completing this period:
| Reason | Tai Chi Exercise | Balance Recovery Training |
|---|---|---|
| Withdrawal by Subject | 1 | 3 |
Analysis population for the primary outcome, as defined in the registry: participants who completed at least 9 of 12 sessions
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 | Tai Chi Exercise Intervention | Balance Recovery Training | Total |
|---|---|---|---|---|
| Participants analysed | 16 | 19 | 35 | |
| Age, Continuous | years | 82.6 (SD 4.5) | 80.9 (SD 6.2) | 81.7 (SD 5.4) |
| Sex: Female, Male: Female | Participants | 11 | 13 | 24 |
| Sex: Female, Male: Male | Participants | 5 | 6 | 11 |
| Race and Ethnicity Not Collected | Participants | — | — | 0 |
| Region of Enrollment: United States | participants | 16 | 19 | 35 |
| Body mass index (kg/m^2) | kg/(m^2) | 30.8 (SD 4.5) | 28.6 (SD 5.3) | 29.6 (SD 5.0) |
| Number of participants reporting falls with injury in the past year | participants | 5 | 1 | 6 |
| Number of participants reporting 2 or more falls in the past year | participants | 5 | 2 | 7 |
6. Primary Endpoint
The registry lists the primary outcome as Maximum Torso Angle at 0.8 Mph, measured over 1 week, 1 month, 3 months, and 6 months after completing four weeks of exercise intervention.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | degrees |
| Endpoint classification | Continuous Endpoint |
Maximum torso angle at 0.8 Mph is the primary endpoint. It measures the largest torso angle, in degrees, during a simulated trip. The registry record states that larger angles indicate worse performance. The measure was scheduled at 1 week, 1 month, 3 months, and 6 months after the four-week exercise intervention, so it was intended to describe performance at more than one post-training time.
A simulated trip provides a way to assess reactive balance: the response to an unexpected disturbance, rather than only the ability to hold a steady posture or complete a planned movement. The study rationale focused on balance recovery after perturbations such as tripping and slipping. In general, a measure tied to a simulated disturbance may address a different aspect of balance than clinical tests of mobility or static balance. That distinction is relevant because the trial proposed different expectations for reactive balance and for clinical balance and mobility outcomes.
The primary outcome is described as a mean with standard deviation. In general, a mean gives the average measurement in a group, while a standard deviation describes how spread out individual measurements are around that average. Neither one alone indicates the uncertainty in a difference between groups. The registry record does not report numeric group means, standard deviations, group differences, or confidence intervals for this endpoint. Its numerical results and the analysis used to compare the repeated follow-up measurements are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The record establishes the question, interventions, measurement schedule, and direction in which the primary measure is interpreted. It does not provide numerical primary-outcome findings. Maximum torso angle is defined in degrees, and a larger angle is described as worse performance, but there are no group means, standard deviations, estimated differences, or confidence intervals to quantify how the groups compared at any follow-up.
The study's hypotheses should not be read as results. The stated expectation was that balance recovery training would perform better on reactive balance tests, while Tai Chi would perform better on clinical balance and mobility tests. The record does not establish whether either expectation was supported. It also does not provide numerical findings for the listed secondary measures, including reactive balance rating, step length, timed-up-and-go, unipedal stance time, maximum step length, activities-specific balance confidence, performance-oriented mobility assessment, and Berg balance testing.
There are multiple planned post-training observations for the primary endpoint. A comparison at one follow-up would answer a different question from an overall comparison across the follow-up period, and the pattern over time could also matter. Because the registry record does not report the endpoint estimates or its analysis, it is not possible to describe the size, direction, or precision of the group contrast at any listed time. The information also does not establish whether the groups differed at baseline or whether any later contrast was adjusted for baseline values.
Precision cannot be judged without an estimate and its uncertainty. In general, a confidence interval describes a range of values compatible with the data and the statistical model; a narrow interval indicates greater precision than a wide one. No confidence interval for the primary comparison is reported in the registry record, so neither the plausible range of effects nor the degree of uncertainty can be characterized numerically.
The primary population consisted of participants who completed at least 9 of 12 sessions. That definition makes attendance relevant to interpreting the primary outcome population. The registry record does not say how many participants met the criterion, how missing measurements were handled, or whether results were also analyzed according to randomized assignment regardless of attendance. Consequently, the extent to which the primary analysis represents all randomized participants is not reported.
These limits are about what can be concluded from the registry record, not evidence that no analyses were conducted. The record lists zero analyses in its results information, and numerical outcome findings are not available there. No claim about which training performed better, whether a difference was statistically distinguishable from no difference, or whether any difference was clinically important can be made from the posted information.
9. Statistical Methods Explained
The registry record identifies a continuous primary measure summarized as a mean and standard deviation. It does not report a statistical analysis plan or numerical results for that measure. The explanations below describe general statistical ideas relevant to this design; they do not describe analyses confirmed to have been used in this trial.
What do a mean and standard deviation describe?
In general, the mean is the arithmetic average of observations in a group. The standard deviation describes the variation among individual observations around that average. For maximum torso angle, these summaries would describe the distribution of measured angles within each group at a particular assessment. They do not, by themselves, show how precisely the group means or a difference between groups have been estimated. Precision of an estimated contrast is usually communicated with an uncertainty measure such as a confidence interval.
Why does the repeated follow-up schedule matter?
The primary endpoint was scheduled at 1 week, 1 month, 3 months, and 6 months after training. In general, repeated measurements on the same participant are related: observations from one person tend to share features that observations from different people do not. An analysis that treats every measurement as independent can therefore misstate uncertainty. Repeated-measures methods can account for within-person correlation, but the registry record does not report whether such a method was used, how correlations were modeled, or whether each follow-up was analyzed separately.
Different analysis choices answer different questions. A separate contrast at each visit describes the groups at that visit. A model of change over time can assess whether trajectories differ across visits. A single average contrast across visits answers yet another question and may conceal a pattern in which the group contrast changes over time. The registry record does not identify which estimand or approach was used. No particular model should be attributed to the investigators based only on the visit schedule.
What do randomization and masking contribute?
In general, random allocation aims to make treatment groups comparable at the start with respect to both measured and unmeasured characteristics, though chance differences can remain, especially in a small study. Randomization can support a causal comparison when the analysis and follow-up preserve the randomized groups and relevant assumptions are reasonable. The record identifies the trial as randomized, but does not report the sequence-generation or allocation-concealment procedures. Single masking is reported, but the masked party is not identified. The degree to which expectations could have influenced test administration or measurement therefore cannot be determined from the record.
How should planning illustrations be read?
General sample-size planning asks how many participants would be needed to detect a specified effect with chosen statistical assumptions. The planning illustrations associated with this trial are described as using the observed effect, a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the target effect set as a stated fraction of the observed effect. These are planning illustrations, not a report of the trial's original design justification and not observed power. The registry record does not report the original sample-size justification. A planning calculation based on an observed effect also depends on that estimate; it cannot substitute for the uncertainty interval around the trial's result.
In general, a two-sided significance threshold considers departures in either direction, while a confidence interval conveys a range of estimates compatible with the data under a model. A p-value, if reported, would describe how unusual data at least as extreme as those observed would be under a specified null model; it would not measure the probability that a treatment is effective. The record does not report a p-value or a confidence interval for the primary endpoint. It also does not report whether comparisons were adjusted for baseline values, which covariates were included, or what assumptions were checked.
Why can over-dispersion matter?
General note: over-dispersion arises when observed variability is greater than a statistical model expects. It is especially relevant to count outcomes, where a simple model may assume a particular relationship between a mean and variance. More variability than expected can make standard errors too small if the model does not account for it. The primary endpoint in this trial is a continuous angle measurement, not a count, and the registry record does not report an over-dispersion issue or model. This concept should not be taken as a description of the trial's analysis.
Finally, statistical significance and practical importance are distinct. A small estimated difference can be precisely measured, while a larger estimate can remain uncertain. In general, interpretation requires the effect estimate, its uncertainty, and a relevant context for judging the size of the difference. The registry record gives the direction of the angle scale but does not provide an effect estimate or a threshold for an important difference.
10. Multiplicity, Missing Data and Analysis Populations
The primary endpoint has four stated post-training assessment times, and the trial also lists multiple balance and mobility outcomes. Looking at many outcomes or time points creates a multiplicity issue: in general, the chance of at least one apparently unusual result can increase when many statistical tests are performed. Approaches such as adjusting the significance threshold or specifying a primary contrast in advance can address different aspects of multiplicity. The registry record does not report whether an adjustment was planned or used, which comparisons were designated as confirmatory, or how the several primary-endpoint time points were handled statistically.
The record lists 11 outcome measures and zero analyses in its results information. It does not provide numerical findings for the primary or secondary outcomes. The statistical plan, interim analyses, and any prespecified hierarchy among outcomes are not reported in the registry record. It is therefore not possible to determine whether the posted outcome list represents all planned analyses or how selective reporting was addressed.
The primary outcome population is described as participants who completed at least 9 of 12 sessions. This attendance-based definition differs from an analysis of all participants according to randomized assignment. The registry record does not report how many participants qualified, how many were measured at each visit, the amount or reasons for missing data, or how missing measurements were treated. It also does not state whether an intention-to-treat analysis or another analysis population was used. Missingness can affect interpretation if participants with missing measurements differ systematically from those observed; whether that occurred cannot be assessed from the 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 |
|---|---|---|---|
| Tai Chi Exercise | 0 | 16 | 0.0% |
| Balance Recovery Training | 0 | 19 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Tai Chi Exercise | 0 of 16 |
| Balance Recovery Training | 0 of 19 |
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 |
|---|---|
| Tai Chi Exercise | 0 of 16 |
| Balance Recovery Training | 0 of 19 |
The serious adverse event figures record zero serious events among 16 participants at risk in the Tai Chi Exercise group and zero among 19 participants at risk in the Balance Recovery Training group. The record also gives zero other adverse events and zero deaths in each group. No serious-event terms are listed.
These figures describe events recorded during the trial, not proof that the interventions carry no risk. In general, observing no events in a study does not rule out uncommon events, and event counts depend on the number followed and the period over which they were observed. The registry record does not state the adverse-event observation window, provide additional detail about how events were collected, or report participant-level follow-up duration for safety. The at-risk counts used for these figures are not necessarily evidence that every participant completed every assessment or had the same length of follow-up.
The figures should be read as a report of no recorded serious events, other adverse events, or deaths in the listed groups, rather than as a comparative estimate of safety. No inferential comparison or confidence interval for adverse events is reported in the registry record. These counts alone cannot establish that the groups had equivalent safety profiles.
12. What the Result Does, and Does Not, Mean
The registry record describes a randomized comparison of two exercise programs and specifies a primary measure intended to assess reactive balance after a simulated trip. It provides the direction of the measure's scale: larger maximum torso angles indicate worse performance. It also gives the intended follow-up schedule and defines the primary outcome population by session attendance. These details clarify the study question, but they do not supply the numerical results needed to answer it.
The record does not report the primary outcome means, between-group estimates, confidence intervals, or p-values. It therefore does not show whether maximum torso angle differed between groups, how large any difference was, or how precisely it was estimated. The investigators' hypotheses are not outcome evidence, and the absence of numerical results in the registry record should not be interpreted as a null finding.
The record lists several clinical balance and mobility outcomes in addition to reactive balance measures. Without their numerical results, it is not possible to determine whether the different outcome domains followed the distinct patterns anticipated in the study hypotheses. Nor can results at one visit be substituted for results at the other scheduled visits, since each time point addresses a different part of the follow-up course.
In general, statistical evidence and clinical importance are related but not interchangeable. A result may be statistically precise without being large enough to matter in practice, while an uncertain estimate may still include effects that would be meaningful. Interpretation would require effect estimates and uncertainty, along with an appropriate basis for judging importance. The registry record does not state a threshold for an important change in torso angle.
The safety entries indicate zero recorded adverse events in the listed categories, but these counts do not demonstrate the absence of risk. Overall, the record supplies design and measurement information but not a numerical basis for concluding that one program outperformed the other or that the programs were equivalent.
13. Why This Trial Matters Statistically
This trial is statistically interesting because it separates reactive balance from clinical balance and mobility rather than treating all balance tests as interchangeable. Its stated hypotheses anticipated that the two training approaches might have different patterns across those domains. That makes outcome selection and interpretation important: a result on a simulated-trip measure would address a different question from a result on a mobility test.
The randomized parallel-group design provides a framework for comparing the programs. The measurement schedule also raises a common analytic issue: repeated observations from the same participant are related, and the chosen method needs to reflect the timing and dependence of those observations. With assessments scheduled at 1 week, 1 month, 3 months, and 6 months after training, an effect might be described at each time or through an overall pattern. The registry record does not report which statistical question was ultimately analyzed.
Another important issue is the difference between the enrolled group and the primary outcome population. The primary endpoint is specified for participants who completed at least 9 of 12 sessions. That attendance criterion makes it important to know how many participants were analyzed and whether those excluded or missing differed from those included. Those details are not reported in the registry record.
The record also illustrates why registering outcomes and hypotheses is not a substitute for posting estimates and uncertainty. Knowing the planned endpoint helps define the question, but without group summaries and a between-group estimate, readers cannot assess direction, magnitude, precision, or consistency over time. The same applies to the multiple listed secondary outcomes. The registry record's structural details are useful for understanding the intended comparison, while the missing numerical results limit statistical interpretation.
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 interpreting the trial from the registry record is the absence of numerical outcome results. The primary measure and its interpretation are described, but group summaries, effect estimates, confidence intervals, and p-values are not reported. The secondary outcomes are listed without numerical results. Consequently, the direction and size of any between-group differences cannot be assessed.
The primary endpoint was scheduled at several follow-up times, but no analysis approach is described for handling repeated observations or making comparisons across visits. The record does not report whether the visits were analyzed separately or jointly, whether a primary time point was prioritized, or whether multiplicity was addressed. These omissions prevent assessment of the statistical framework for interpreting results.
The primary outcome population requires completion of at least 9 of 12 sessions. The number meeting that criterion is not reported in the registry record, nor are the numbers assessed at each time point, reasons for missing measurements, or methods for handling missing data. The record also does not say whether participants were analyzed according to randomized assignment irrespective of adherence. These details are important for understanding the population represented by the primary comparison.
Although the trial is described as randomized and single masked, the allocation procedure and the identity of the masked party are not reported. The record does not describe assessor training, measurement reliability, or whether outcome assessors knew group assignments. It also does not report the original sample-size justification or a statistical analysis plan. The planning illustrations are not a substitute for those trial-specific details. These are limitations of the information in the registry record and do not establish that the trial investigators did not conduct the relevant procedures or analyses.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Balance Recovery Training for Fall Prevention in Retirement Communities — NCT02551666.
- Registry record last updated 2020-07-14; status last verified 2020-06.
- Results first posted 2020-07-14.
- 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
NCT02551666 is a completed, randomized, single-masked, parallel-group trial sponsored by Texas A&M University. The record lists enrollment of 35 residents from five senior housing facilities. It compared treadmill-based balance recovery training with Tai Chi, delivered three times per week for four weeks in sessions lasting approximately 30 minutes.
The primary outcome was maximum torso angle at 0.8 Mph during a simulated trip, measured at 1 week, 1 month, 3 months, and 6 months after training. Larger angles indicate worse performance. The primary outcome population was participants who completed at least 9 of 12 sessions. The registry record lists additional balance and mobility outcomes but does not report numerical findings for the primary endpoint or those secondary outcomes. Serious adverse events, other adverse events, and deaths are recorded as zero in both groups.