Balance Function in Patients Post Corona Virus Disease 2019 (COVID-19): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Balance Function in Patients Post Corona Virus Disease 2019 (COVID-19) (NCT04914364), a registered phase not stated study. The primary outcome is Motor Balance as Measured by Timed Up and Go (TUG).

2. Clinical Question

The study’s stated purpose is to describe balance deficits in patients after COVID-19. The assessment session also included questionnaires about balance and dizziness. The listed secondary outcomes concern sensory influence on balance, measured with the Modified Clinical Test of Sensory Interaction in Balance, and balance confidence, measured with the Activities Specific Balance Confidence Scale.

The question is descriptive rather than comparative: the record does not specify a randomized treatment assignment or a control condition. It therefore concerns the recorded balance measures in the study population, not a contrast between assigned interventions. The registry record does not report results for the primary or secondary outcomes, so the magnitude and precision of any observed balance findings cannot be characterized from that record.

3. Trial Design

This is a completed study sponsored by Duke University, with the registry title “Balance Function in Patients Post Corona Virus Disease 2019 (COVID-19)” and official title “Describing Balance Function in Patients Post-COVID-19.” The record lists enrollment of 28 and identifies Covid19 as the condition. The listed start date is 2021-07-23, the primary completion date is 2022-06-22, and the status is COMPLETED.

Participants were to have a primary or secondary diagnosis of COVID-19 during hospitalization, be off COVID-19 isolation, and be receiving care in an acute inpatient hospital. The arm description identifies patients who tested positive for COVID-19 and were designated “COVID recovered” in the electronic medical record while meeting inclusion criteria. Following consent, participants completed balance assessments and questionnaires about balance and dizziness in a single session. Vital signs were monitored during the session.

The intervention is categorized as “Balance assessments.” In this context, that label describes measurement activities, not a therapeutic intervention. No randomized comparison is described. Allocation is not stated, and the registry record cautions that the arms are not a like-for-like control comparison. The record does not report a comparator that would support a controlled treatment-effect interpretation.

The primary outcome is motor balance measured by TUG at baseline, with the result characterized as a mean and standard deviation in seconds. The record lists sensory influence on balance and balance confidence as secondary outcomes. It lists three outcome measures overall but does not report their observed values. It also lists zero analyses. The protocol details, including a fuller account of the statistical analysis plan and sample-size justification, are not reported in the registry record.

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

Reasons for not completing this period:

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.

Population: Participants who completed the study.

6. Primary Endpoint

The registry lists the primary outcome as Motor Balance as Measured by Timed Up and Go (TUG), measured over Baseline.

The primary endpoint is motor balance measured by the Timed Up and Go (TUG), recorded in seconds at baseline. The test is described as timing how long a patient takes to stand up, walk 10 feet, turn around, walk back, and sit down. It combines elements of mobility, motor balance, and walking ability in one timed task. The registry description also connects the measure with falls risk.

The description gives reference interpretations: less than 10 seconds is described as normal; less than 20 seconds as good mobility, the ability to walk outside alone, and not requiring a walking aid; and less than 30 seconds as walking and balance problems, inability to walk outside alone, and requiring a walking aid. These are the registry’s stated interpretive thresholds, not results for participants in this study.

Timing a standardized sequence provides a continuous measure that can be summarized as a mean and standard deviation, as specified in the record. In general, a timed functional task can help characterize performance in a way that is straightforward to record and compare across observations. That general rationale does not establish how well a measure predicts an individual’s outcomes or how it should guide care.

The registry record does not report the participants’ TUG mean, standard deviation, or other outcome results. Consequently, it does not establish where the study group’s measured performance fell relative to the stated thresholds, nor how variable the recorded times were.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What kind of outcome is TUG?

TUG is recorded as a continuous measurement in seconds. The registry specifies that the primary outcome is summarized as a mean with a standard deviation. In general, a mean gives a measure of the central value of a set of observations. A standard deviation describes how dispersed observations are around that mean. Together, these summaries can convey the typical recorded time and variability across participants, but they do not show the distribution’s full shape or identify every participant’s performance.

The registry record does not report either summary for TUG. It therefore does not allow readers to assess the study group’s mean time, the observed spread, or whether unusually long times influenced the mean. In general, continuous data can be skewed or contain outlying observations, in which case a mean and standard deviation may not fully convey the distribution. Whether that occurred in this study is not reported in the registry record.

What can the stated thresholds tell readers?

The TUG description gives thresholds of less than 10 seconds, less than 20 seconds, and less than 30 seconds, each accompanied by a functional interpretation. These are interpretive statements in the outcome definition. They are not trial findings, and the registry does not report how many participants fell within any threshold category. They also do not replace the missing group summary or describe the distribution of observed times.

In general, thresholds can make a continuous score easier to interpret, but converting a continuous result into categories can discard information about differences within each category. Thresholds also do not by themselves establish that a measure is valid for every population or setting. The registry record does not report an evaluation of the thresholds in this study population.

What can be inferred from the analysis record?

The registry lists zero analyses and does not report a statistical test, confidence interval, or p-value for the outcomes. No particular inferential procedure should be assumed. In general, a confidence interval expresses the uncertainty around an estimate under specified assumptions. A p-value, when used, relates the observed data to a statistical model and a null hypothesis. Neither quantity is an outcome result on its own, and neither is reported for the primary endpoint in the registry record.

The distinction between descriptive and inferential statistics matters. A descriptive summary would characterize the participants measured in this study. An inferential analysis might address how an estimate relates to a broader population, but requires an analysis method and assumptions. The record supplies neither reported outcome estimates nor a stated inferential analysis. No conclusion about statistical significance or precision can therefore be drawn from the registry entry.

How should planning illustrations be read?

The listed planning framework describes an illustration based on a stated fraction of an observed effect, a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It distinguishes participant counts per arm for ordinary outcomes from total event counts for time-to-event outcomes. These are planning assumptions, not evidence that the study used those assumptions in its own design. The registry record does not report a sample-size justification for this study.

Any sample-size illustration based on an observed effect is conditional on that effect and on the assumptions used for the calculation. It is not observed power and should not be interpreted as a measure of how likely the completed study was to detect an effect. The record does not provide a primary outcome effect estimate from which readers could assess such an illustration. No calculated participant counts are reported in the registry record.

In general, over-dispersion means that variability is greater than a statistical model assumes. If a model ignores over-dispersion, uncertainty may be understated and inferential conclusions may be unreliable. That is a general statistical consideration, not a reported feature or analysis of this study. The registry record does not describe a model or a check for over-dispersion.

Overall, the reported statistical information defines the primary measure and its intended summary, but not the resulting estimate or analysis. The record does not specify missing-data handling, analysis populations, adjustment variables, or an interim analysis plan. Those details are not reported in the registry record and should not be inferred from the outcome definitions or planning framework.

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.

R code and output

arm <- c("Patients Who Have Tested Positive for COVID-19")
n   <- c(25)
m   <- c(20.57)
sp  <- c(10.34)
sd  <- sp      # posted standard deviations
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  Patients Who Have Tested Positive for COVID-19  25  20.570  10.340  16.302  24.838

11. Multiplicity, Missing Data and Analysis Populations

The registry lists three outcome measures: the primary TUG measure and two secondary measures concerning sensory influence on balance and balance confidence. It lists zero analyses and does not report results for any of these measures. A multiplicity adjustment, testing hierarchy, or other plan for handling several outcomes is not reported in the registry record.

In general, multiplicity arises when multiple hypotheses or outcomes are tested. If each is tested separately, the chance of at least one apparently notable finding can differ from the chance associated with a single prespecified test. Statistical plans may address this through a hierarchy, adjusted significance levels, or other approaches. Those are general options; the registry record does not identify which, if any, applied to this study. Since no outcome analyses or p-values are listed, no multiplicity-adjusted interpretation can be made.

The registry does not state how missing outcome measurements were handled, whether all enrolled participants contributed data to each outcome, or which analysis population was used. These details are not reported in the registry record. Enrollment of 28 does not establish the number with a recorded TUG result or questionnaire result. Likewise, the completed status does not by itself demonstrate that every outcome was observed for every participant.

In general, missing measurements can affect descriptive summaries and comparisons, especially if missingness is related to participants’ characteristics or measured outcomes. The implications depend on how much information is missing, why it is missing, and the analysis approach. The registry record provides no such details, so the direction or size of any missing-data influence cannot be assessed.

12. 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 0% reporting threshold.

The adverse-event record lists 28 people at risk for serious adverse events and 0 affected. It also lists 28 people at risk for other adverse events and 0 affected, with 0 deaths. No serious adverse-event terms are listed. These entries describe the reported counts; they do not provide further details about how events were collected, defined, or attributed.

The study summary identifies shortness of breath, falling, and musculoskeletal soreness as the greatest risks of the assessment session, and says these risks are no greater than those experienced during a usual physical therapy visit. That description concerns anticipated risks. The adverse-event counts are separate registry entries and should not be treated as a detailed assessment of each anticipated risk.

In general, a zero count in a registry entry means no affected participants were recorded in that category in the posted data. It does not prove that an event is impossible, establish that every possible event was captured, or show that risk is absent in other settings. The record does not report additional safety details or event narratives. The counts should therefore be read as the safety information entered in the registry, not as a comprehensive estimate of risk.

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

The study record establishes that a completed descriptive study enrolled 28 participants and planned balance assessments and questionnaires in a single session. It identifies TUG time at baseline as the primary outcome and lists two secondary measures concerning sensory influence on balance and balance confidence. This information clarifies the study’s focus and the types of measurements collected or intended.

The record does not report the outcome values. It therefore does not show the group’s TUG mean or standard deviation, the results of the secondary measures, or how many participants had results for each outcome. It cannot establish whether the recorded measurements were above or below the functional thresholds in the TUG description. The absence of posted results is not evidence for any particular balance finding.

The study does not describe a randomized control comparison. The registry says allocation was not stated and cautions that the arms are not a like-for-like control comparison. The record consequently does not support a causal claim about the effect of an intervention, nor does it provide a basis for comparing recovery with a separate control group.

In general, a descriptive study can characterize measurements in the population it assesses, while the strength of broader conclusions depends on the study population, measurement procedures, completeness of observations, and analysis. Here, several relevant details—including outcome results, analysis populations, and missing-data handling—are not reported in the registry record. The eligibility description also confines the stated population to patients recovering from COVID-19 in acute inpatient care; the record alone does not establish how findings would apply to other settings or groups.

The safety entry reports zero affected participants in the listed serious and other adverse-event categories among 28 at risk, and zero deaths. Those are the registry’s reported counts, not proof of zero risk. In short, the record documents the question and measurement plan, but its posted results do not answer the quantitative balance question.

14. Why This Trial Matters Statistically

This trial is statistically useful to examine because it separates a clearly defined measurement plan from the evidence needed to interpret measured outcomes. The record identifies a continuous primary measure, its unit, its intended summary, and the setting and population under study. Those details help readers understand what the researchers intended to describe without mistaking the assessment session for a randomized treatment comparison.

The record also illustrates why a completed status is not a substitute for posted outcome data. Without a mean and standard deviation for TUG, readers cannot characterize the group’s recorded performance or its variability. Without secondary outcome results, those measures cannot add quantitative detail. A registry entry can therefore be informative about design while remaining insufficient to answer the central empirical question.

The distinction between a measurement threshold and an observed result is important. Thresholds may help explain the scale, but they do not reveal where participants’ results fell. Likewise, the listed enrollment does not tell readers how many measurements were available for analysis. Clear reporting of outcome summaries, participant counts contributing to each outcome, and analysis methods would be needed to interpret the data statistically.

The study also highlights the importance of design-appropriate claims. Since the record does not describe random allocation or a like-for-like control comparison, the question is descriptive. That framing prevents an unsupported causal interpretation. The registry’s caution about the arms is particularly relevant whenever a record lists groups without establishing that they are comparable.

Finally, the entry demonstrates the limits of sparse safety summaries. Counts of zero affected participants are useful to report, but their interpretation depends on event definitions, collection methods, and the extent of follow-up. Those details are not reported in the registry record. Taken together, the study is a useful example of how outcome definitions, design, analysis, and completeness of reporting all shape the conclusions readers can responsibly draw.

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 central limitation for statistical interpretation is that the registry record does not report outcome results. It gives no observed TUG mean or standard deviation and no results for the secondary outcomes. This prevents quantitative characterization of balance measurements and makes it impossible to assess their precision or distribution from the registry entry.

The record describes a population receiving acute inpatient care after COVID-19, with eligibility tied to hospitalization, recovery status, and being off isolation. That setting and population define the scope of the study description. The registry record does not report information that would establish whether the participants represent other post-COVID-19 populations or care settings.

No randomized comparison is described. Allocation is not stated, and the record cautions that the arms are not a like-for-like control comparison. The findings, if reported elsewhere, would therefore require interpretation consistent with a descriptive design rather than a controlled estimate of treatment effect. The registry entry does not report enough detail to characterize any group contrast.

Further limitations arise from missing reporting details. The number of participants contributing to each outcome, the handling of missing measurements, analysis populations, and the statistical analysis plan are not reported in the registry record. The entry lists zero analyses, so no inferential results can be evaluated. The record also does not report a sample-size justification specific to the study.

The TUG definition includes functional thresholds, but the registry does not report participant counts or summaries in relation to those thresholds. The safety record gives event counts without further collection or attribution details. These gaps constrain interpretation of both the balance outcomes and safety information. They should be understood as limits of what the registry record reports, rather than evidence that a particular result or event did or did not occur outside the posted entries.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Balance Function in Patients Post Corona Virus Disease 2019 (COVID-19) — NCT04914364.
• Registry record last updated 2024-09-19; status last verified 2024-09.
• Results first posted 2024-09-19.
• 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.

19. Record Summary

The registry record describes NCT04914364, “Balance Function in Patients Post Corona Virus Disease 2019 (COVID-19),” also titled “Describing Balance Function in Patients Post-COVID-19.” Duke University is listed as sponsor. The study is marked COMPLETED, with enrollment of 28, a start date of 2021-07-23, and a primary completion date of 2022-06-22.

Participants were described as patients recovering from COVID-19 in acute inpatient care. After consent, they were to complete balance assessments and questionnaires in a single session. The primary outcome is baseline TUG time in seconds, summarized as a mean and standard deviation. Secondary outcomes concern sensory influence on balance and balance confidence.

The registry record does not report outcome results or analyses. It lists 0 affected participants for serious adverse events, 0 affected for other adverse events, and 0 deaths, with 28 at risk in each adverse-event category. Allocation is not stated, and the registry cautions that the arms are not a like-for-like control comparison.