Outcomes of Compliance With Brace Wear in Clubfoot: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Outcomes of Compliance With Brace Wear in Clubfoot (NCT01481324), a registered phase not stated study. The primary outcome is Wear Rate Percentage (Number of Hours Per Day Brace Was Worn Out of the Recommended 24 Hours).

2. Clinical Question

In statistical terms, the primary question is descriptive and comparative: what wear rate was recorded by the sensor, what wear rate was reported by parents, and how did those measurements relate? The planned measurement period was 3 months, with assessments at month 1, month 2, and month 3. No numerical outcome values, comparison estimates, or analyses of the relationship with future surgery are reported in the registry record. Therefore, the stated hypotheses identify the questions the study sought to examine, not findings that can be concluded from its posted results.

3. Trial Design

The registry describes a completed study titled “Outcomes of Compliance With Brace Wear in Clubfoot,” with the official title “Measurement of Compliance in Clubfoot Bracing Via a Novel Pressure Sensor.” Shriners Hospitals for Children is listed as the sponsor. The recorded start was 2009-10, primary completion was 2012-10, and enrollment was 67. Clubfoot is the listed condition.

The study record describes three arms. In the functioning pressure sensor group, a functioning sensor was placed on the foot abduction orthosis; participants were blinded as to whether the sensor was functioning. In the non-functioning pressure sensor group, a non-functioning sensor described as a placebo was placed on the orthosis, with the same stated blinding. Participants in the no sensor group did not have a pressure sensor placed on the orthosis. These descriptions establish the planned group arrangements, but not how participants were assigned. Allocation is not stated, and the registry cautions that the arms are not a like-for-like control comparison. The study should therefore not be interpreted as a randomized comparison on the basis of this record.

The primary outcome is wear rate percentage: the number of hours per day in the brace, expressed relative to the recommended 24 hours. Sensor measurements and parent reports were to be documented at month 1, month 2, and month 3. The record identifies the primary endpoint as a mean with full-range dispersion and gives a timeframe of 3 months.

The registry lists one outcome measure and no analyses. It does not report an analysis plan, statistical tests, outcome estimates, confidence intervals, or group-level wear rates. Nor does it report eligibility criteria in detail, the sequence or method of allocation, or the intended handling of repeated measurements. The completed status indicates the study record is marked complete; it does not by itself establish that the outcome results were posted.

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: Number analyzed in each group

6. Primary Endpoint

The registry lists the primary outcome as Wear Rate Percentage (Number of Hours Per Day Brace Was Worn Out of the Recommended 24 Hours), measured over 3 months.

The primary endpoint is the percentage of recommended brace time worn. It expresses daily brace wear in relation to the recommended 24 hours, using either hours measured by the pressure sensor or hours reported in a parent diary. Sensor measurements and parent reports were to be documented at month 1, month 2, and month 3, with a stated timeframe of 3 months.

This endpoint is relevant to the study question because the registry summary describes uncertainty about whether family logs reflect actual brace use. A pressure sensor offers a way to record wear independently of a parent’s report, while collecting both types of information allows the study to examine how they compare. The endpoint therefore addresses measurement of adherence, rather than a direct measure of correction or another clinical outcome.

The outcome is specified as a mean, with full range as the dispersion measure. In general, a mean summarizes the average value in a group, while the full range describes the span from the lowest to the highest observed value. Those summaries answer different questions: the mean describes a group’s central level, whereas the range shows how widely individual observations extend. Neither is reported numerically in the registry record.

The outcome description also leaves key details unreported, including how the measurements at the different timepoints were combined into the primary endpoint, whether the mean was calculated separately for each measurement method or group, and how incomplete sensor or diary observations were handled. No wear-rate estimates are posted, so the endpoint definition can be described but its observed magnitude and precision cannot be assessed.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a percentage derived from hours of brace wear relative to the recommended 24 hours. The record says that hours would be measured by a pressure sensor or reported in a parent diary. It also specifies a mean and full range, but does not report the numerical summaries or explain exactly how the measurements from the different timepoints were combined.

What does a mean describe?

In general, a mean is the arithmetic average of the observations included in a group. It gives a concise summary of the group’s central level, but does not show whether observations cluster near that average or are spread out. A mean can also be influenced by unusually high or low observations. The registry record does not provide the underlying wear measurements, so the mean cannot be checked against the distribution or recalculated from posted data.

Why report the full range?

In general, the full range gives the minimum and maximum observed values. It can communicate the breadth of the measurements, but it does not show how values are distributed between those endpoints. A wide range may reflect substantial variation, but the range alone cannot establish whether most participants had similar or very different wear rates. Here, the record names full range as the dispersion measure without posting its values.

How should repeated measurements be understood?

The outcome description specifies measurement at month 1, month 2, and month 3. In general, measurements from the same participant over time are related rather than independent: a participant’s earlier wear can be associated with later wear. An analysis that treats repeated observations as unrelated may misstate uncertainty. Methods for repeated measures can account for within-participant dependence, but the registry record does not state whether such a method was planned or used. It also does not say whether the primary result was based on a particular timepoint, an average across timepoints, or another summary.

Why distinguish the sensor from parent reports?

The study aims to compare objective sensor measurement with parent-reported brace wear. In general, two methods can differ because they measure or record behavior differently. A useful comparison may examine the average difference, the agreement between individual measurements, or both; those approaches answer distinct questions. A correlation alone, for example, can describe whether values tend to move together without demonstrating that the methods give similar values. The registry record does not specify the planned comparison method or report results for any such analysis.

What do the study arms permit?

The record distinguishes a functioning sensor group, a non-functioning sensor group, and a no sensor group. Participants in the two sensor groups were described as blinded to sensor function. In general, masking can reduce the chance that awareness of an assigned condition affects behavior or reporting. The record does not state whether assignment was randomized, and it explicitly cautions that the arms are not a like-for-like control comparison. This makes it important not to interpret arm differences as causal effects without further design and analysis information.

What is missing from the statistical account?

The registry lists no analyses. It does not report a statistical model, an estimate, an uncertainty interval, a p-value, or a plan for handling repeated observations. It also does not state how missing sensor readings or diary entries were treated, whether any adjustment variables were used, or which analysis population was intended. These omissions prevent an assessment of whether the statistical approach matched the measurement structure and the study questions.

The record includes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. Such calculations are planning illustrations, not observed power and not evidence that the study had a particular chance of detecting a result. The registry’s own sample-size justification and design assumptions are not reported. The illustration also does not resolve the study’s allocation limitations or substitute for the missing outcome estimates.

10. Multiplicity, Missing Data and Analysis Populations

The registry describes a primary wear-rate outcome measured with a sensor and by parent report across month 1, month 2, and month 3. It also states broader study aims involving actual compliance, comparisons of actual and assumed wear time, and the relationship between wear and clinical outcomes. However, the record does not report a statistical analysis plan specifying which comparisons were primary, how multiple timepoints or measurement methods were handled, or whether any adjustment for multiple testing was planned.

Multiplicity matters in general when several outcomes, timepoints, groups, or comparisons are examined. Each additional analysis can create another opportunity to observe an apparently notable result by chance. A prespecified hierarchy or multiplicity adjustment can help define how evidence should be interpreted, but the registry record does not state whether either approach was used. No analysis results are posted for evaluating the issue directly.

Missing-data methods are also not reported. The record does not state how the analysis would handle absent sensor readings, incomplete parent diaries, withdrawal, or unavailable later outcomes. Nor does it report the number of participants contributing data to each measure or timepoint. Without those details, the completeness and potential selection of the analyzed observations cannot be assessed.

Analysis populations are not described. The registry record does not state whether results would include all enrolled participants, only those with usable sensor data, or another defined group. Enrollment of 67 should not be assumed to equal the number analyzed for every endpoint. The record’s completed status does not resolve these reporting gaps, and no statistical analyses are listed.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

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 summary lists group-specific numbers at risk and numbers affected for serious and other adverse events. For the functioning pressure sensor group, the record lists 21 at risk and 0 affected for serious events, and 21 at risk and 0 affected for other events. For the non-functioning pressure sensor group, it lists 24 at risk and 0 affected for both categories. For the no sensor group, it lists 22 at risk and 0 affected for both categories.

These entries mean that no affected participants are recorded in the listed serious or other adverse-event summaries. They do not establish that no event occurred outside the recorded categories or observation period, and the registry does not report deaths; the death entries are not available as numeric counts. The record also does not provide event definitions, follow-up completeness, or detail about how events were collected. The listed numbers at risk should not be assumed to represent the primary-outcome analysis population. These safety figures describe the registry entries and do not establish a comparative safety effect.

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

The registry record is useful for understanding the study’s measurement approach: pressure sensors were intended to record brace wear, parent reports were collected for comparison, and the primary endpoint expressed wear relative to the recommended 24 hours. The stated follow-up for the endpoint was 3 months, with measurements at month 1, month 2, and month 3. These details define the question, but they are not evidence of the observed wear rate.

The posted results do not report numerical wear-rate outcomes, comparisons between sensor and parent reports, or analyses of future surgery. Consequently, the record cannot support a conclusion about whether actual wear was lower than self-reported wear, how large any difference might have been, or whether compliance was associated with later surgery. The absence of posted estimates should not be mistaken for a finding of no difference or no association.

The study arms also require caution in interpretation. The registry does not state allocation and notes that the groups are not a like-for-like control comparison. A difference between groups, if reported elsewhere, would need to be interpreted in light of how participants entered each group and whether the groups differed before measurement. The record does not provide the information needed to evaluate those questions.

In general, a study result is most informative when its estimate, uncertainty, analysis population, and methods are available together. Those details allow readers to distinguish an imprecise estimate from a precisely estimated effect and to assess whether missing observations or analytic choices could influence the conclusion. They are not reported for the primary outcome in this registry record.

The study therefore has a clearly described measurement objective and a completed status, but the registry entry does not provide the outcome evidence needed to judge its hypotheses. This interpretation is limited to the registry record and should not be extended to unreported results or to clinical decisions.

13. Why This Trial Matters Statistically

This study addresses a statistical measurement problem: a reported behavior and an objectively recorded behavior may not represent the same quantity. When clinical research relies on self-report, measurement error can affect estimates of adherence and associations with later outcomes. Comparing parent diaries with pressure-sensor measurements is therefore relevant not only to clubfoot bracing but also to how behavioral outcomes are measured in clinical studies.

The repeated measurement structure is another important feature. Wear was to be documented at month 1, month 2, and month 3. Repeated observations can show whether measurements change over time, but they are usually related within each participant. The analysis needs to account for that dependence if it uses multiple observations together. The registry record does not report how this issue was handled, making the missing analysis details consequential rather than merely administrative.

The study also illustrates why a control group’s design and allocation matter. A functioning sensor, a non-functioning sensor, and no sensor create distinct measurement conditions, but the registry does not state the allocation method and warns that the arms are not like-for-like controls. Describing group labels alone cannot establish comparability or support a causal interpretation.

Finally, the entry shows the distinction between a well-defined research question and a result that can be evaluated. It states the primary outcome and the hypotheses, yet does not report primary outcome estimates or statistical analyses. For readers assessing evidence, transparent reporting of the measurement results, uncertainty, missing data, and analysis population is essential to determine what the study can establish.

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.

Several trial-specific limitations are apparent from the registry record. First, allocation is not stated, and the record explicitly cautions that the arms are not a like-for-like control comparison. The group descriptions alone do not show whether participants were comparable at entry, or whether any observed group differences would reflect sensor status rather than other differences.

Second, the primary endpoint combines information from sensor measurements and parent reports, but the record does not explain how those sources were used to form the primary result. It describes measurements at month 1, month 2, and month 3 without stating whether each timepoint was analyzed separately or combined. The endpoint description therefore does not fully define the analysis target.

Third, the registry does not report primary-outcome values, statistical analyses, confidence intervals, or p-values. It also does not report the number with usable measurements at each timepoint, the handling of missing sensor or diary data, or the analysis population. These gaps preclude assessment of precision, completeness, and possible bias from unavailable observations.

Fourth, the stated hypothesis includes an association with future surgeries, but no surgery outcomes or analysis are reported. The record therefore does not permit assessment of that clinical-outcome question. Detailed eligibility criteria, participant characteristics, and the study’s own sample-size justification are also not reported in the registry record.

These limitations concern what can be learned from the registry entry; they do not establish that the underlying study did not collect or analyze the relevant information.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Outcomes of Compliance With Brace Wear in Clubfoot — NCT01481324.
• Registry record last updated 2014-11-24; status last verified 2014-11.
• Results first posted 2014-11-24.
• 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

The registry lists NCT01481324 as a completed study of brace-wear measurement in clubfoot, sponsored by Shriners Hospitals for Children. Enrollment was 67; the recorded start was 2009-10 and primary completion was 2012-10.

The study describes a functioning pressure sensor group, a non-functioning pressure sensor group, and a no sensor group. The primary outcome is wear rate percentage relative to the recommended 24 hours, measured by sensor and parent report at month 1, month 2, and month 3. The outcome is specified as a mean with full-range dispersion.

The registry record does not report numeric primary-outcome results or statistical analyses. Allocation is not stated, and the record cautions that the arms are not like-for-like controls. The adverse-event summaries list 0 affected participants for serious and other events in each group; deaths are not reported as numeric counts.