Heated Vest for Persons With Spinal Cord Injury: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Heated Vest for Persons With Spinal Cord Injury (NCT03662308), a randomized na study. The primary outcome is Change in Core Body Temperature (Tcore).

2. Clinical Question

The clinical rationale in the registry is that people with higher-level spinal cord injury may be vulnerable to changes in core temperature in cool environments. The registered study therefore examined temperature response during a controlled thermal challenge, rather than reporting a test of everyday use, longer-term comfort, or performance of daily activities. Thermal comfort is listed as a secondary outcome, but the primary result is core body temperature change. The registry’s rationale explains why temperature is of interest; it does not establish that any observed change translates into a change in symptoms, function, or quality of life.

3. Trial Design

The study is registered as randomized, unmasked, and crossover. It is titled “Heated Vest for Persons With Spinal Cord Injury,” and its official title describes developing a feedback-controlled heated vest for thermoregulatory dysfunction in persons with spinal cord injury. The registry lists enrollment of 17 and status as completed. The study start date is 2020-02-25, and the primary completion date is 2022-10-31. Its phase is listed as NA.

The primary temperature comparison involved the heated-vest efficacy condition and the non-heated-vest control condition in persons with tetraplegia. The record describes the same subjects with tetraplegia taking part in both conditions. The reported primary outcome groups each have n = 9. Because this is a crossover design, conditions are repeated within participants; group counts should not be interpreted as independent sets of people or added to infer how many distinct participants took part.

A separate arm is titled Heated Vest Safety & Comfort for able-bodied subjects. Its primary-outcome group has n = 0, and the registry explicitly states that core body temperature measurement was not performed in able-bodied participants. That arm therefore does not contribute to the reported primary temperature comparison. Safety information is listed separately for the able-bodied condition and the two tetraplegia conditions.

The intervention descriptions specify a seated thermal challenge in a pre-cooled chamber, with participants wearing a standard cotton T-shirt and shorts. The challenge period is described as lasting up to two hours in the arm descriptions, while the primary outcome timeframe refers to a two-hour thermal challenge. Randomization is recorded, but the method of sequence generation, allocation concealment, condition order, washout interval, and handling of possible period effects are not reported in the registry record. Masking is listed as none.

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.

First Intervention

Second Intervention (Tetraplegia ONLY)

Analysis population for the primary outcome, as defined in the registry: Tcore measurement was not performed in able-bodied participants.

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 Change in Core Body Temperature (Tcore), measured over Visits 2 & 3 (subjects with tetraplegia only): Continuously throughout baseline & Thermal Challenge (2 hrs) periods. The change in Tcore from baseline to the end of Thermal Challenge will be determined..

The primary endpoint is change in core body temperature, measured in degrees Celsius. The registry defines the change as the difference from baseline to the end of the thermal challenge. Core temperature was to be monitored continuously during baseline and challenge periods with heated and non-heated vests. The registry describes use of a rectal probe and multichannel thermometer, with the probe placed 10 cm beyond the anal sphincter.

Temperature is used as a direct physiological measure relevant to the study’s stated concern about thermoregulation in persons with tetraplegia. The endpoint captures the direction and magnitude of the recorded temperature change during the controlled challenge. It does not, by itself, measure comfort, cognitive performance, quality of life, or the ability to complete self-care activities. Thermal comfort is listed as a secondary outcome, but the temperature result should not be treated as a substitute for that separate outcome.

The registry reports the endpoint as a mean with standard deviation. The heated-vest condition has a mean change of -0.22 and standard deviation of 0.34; the non-heated condition has a mean change of -0.46 and standard deviation of 0.24. Both posted means are below zero, indicating a decrease from baseline as represented by the reported change values. The registry does not provide confidence intervals for these group means. Interpreting how precisely the population means are estimated therefore requires caution.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry reports two kinds of numerical information for the primary outcome: descriptive summaries by vest condition and an inferential comparison attributed to the sponsor. Keeping those distinct is important. A mean and standard deviation describe the values within a condition, while a model-based comparison estimates a contrast according to the analysis method. In a crossover trial, measurements from the same person under different conditions are related, so methods that account for within-person pairing are generally relevant. The registry identifies ANOVA as the sponsor’s method but does not describe the model terms or how the crossover structure was represented.

What does the mean describe?

The primary measure is continuous: core body temperature change in degrees Celsius. A mean is the arithmetic average of the recorded changes for a condition. The posted means, -0.22 for the heated-vest condition and -0.46 for the non-heated condition, summarize the direction and central value of the observed changes. These condition summaries are not themselves an estimate of uncertainty around the contrast. They also do not show each participant’s paired changes, which would be needed to understand the distribution of within-person responses.

The standard deviation describes the spread of observations around a condition mean. The posted standard deviations are 0.34 and 0.24, respectively. A standard deviation is not a confidence interval and does not directly express how precisely the mean or treatment contrast has been estimated. In crossover data, the relationship between a participant’s measurements under the two conditions also affects the precision of a paired comparison. That relationship is not reported in the registry record.

How should the ANOVA result be read?

ANOVA is a general family of methods for comparing means. The registry states that the sponsor used ANOVA and labels the parameter “Mean Difference (Final Values).” It reports .6 and p <0.05. The registry does not report the model specification, degrees of freedom, test statistic, confidence interval, or the handling of repeated observations. Without those details, readers cannot fully assess whether the analysis accounts for the crossover design, or how the reported estimate relates to the change-score summaries.

In general, a confidence interval gives a range of values compatible with the data and the model under a specified confidence procedure. It helps convey precision as well as the direction of an estimated contrast. No confidence interval is reported for the sponsor comparison in this record. A p-value provides a measure of compatibility between the data and a null hypothesis under model assumptions; it does not describe effect size or precision by itself. Here, the reported p-value is a threshold, p <0.05, rather than an exact value.

Why does the crossover structure matter?

In a crossover design, each participant may contribute observations under more than one condition. This can allow comparisons within the same person, but it also means that analysis should consider the dependence between repeated observations. Random allocation is recorded, and the record says the same subjects with tetraplegia were involved in the heated and non-heated vest conditions. However, the condition sequence, any washout, potential carryover, period effects, and the specific paired or repeated-measures analysis are not reported in the registry record. These omissions limit independent appraisal of the statistical method.

General statistical practice also distinguishes the randomized condition assignment from the analysis population actually included in an outcome model. The record gives n = 9 for each primary condition, but it does not describe exclusions, missing temperature measurements, or whether every participant with data contributed to the sponsor’s analysis. The number enrolled is 17, but the registry does not explain the relationship between enrollment and the outcome-analysis counts. No participant-level data are included in the record summarized by these registry entries.

What can recalculation add?

A recalculated comparison from summary statistics would be an unadjusted calculation and could not reproduce a sponsor model that accounts for crossover pairing or other analysis features. For this continuous endpoint, a two-arm recalculation is marked as not estimable because required values are missing or not estimable. Therefore, there is no independent recalculated effect estimate or p-value to compare with the sponsor’s analysis. The sponsor result remains the only reported inferential comparison in this record. The registry does not report a confidence interval that could clarify its precision.

Sample-size calculations based on an observed effect, when present, are planning illustrations rather than evidence about the adequacy of the completed trial or its observed power. The stated planning framework uses a two-sided significance level of 0.05, equal allocation, and a normal approximation, with effects defined as fractions of the observed effect. No numerical planning results are included in the registry record. Such illustrations would not replace a prespecified sample-size justification, which is not reported in the registry record.

Why might variability affect interpretation?

In general, over-dispersion means that observed variation is greater than a model assumes. When that occurs, standard errors may be too small if the model does not account for the extra variability, making confidence intervals too narrow and p-values too optimistic. No over-dispersion assessment is reported for this continuous endpoint, and the registry does not give enough detail to determine whether it is relevant to the sponsor’s ANOVA. The broader principle is that conclusions depend not only on the numerical result but also on whether the model represents the design and variability appropriately.

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("Heated Vest Efficacy (Persons With Tetraplegia)", "Non-Heated Vest Control Condition (Persons With Te")
n   <- c(9, 9)
m   <- c(-0.22, -0.46)
sp  <- c(0.34, 0.24)
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  Heated Vest Efficacy (Persons With Tetraplegia)  9  -0.220  0.340  -0.481  0.041
CARM  Non-Heated Vest Control Condition (Persons With Te  9  -0.460  0.240  -0.644  -0.276

11. Analyses Reported by the Sponsor

The sponsor’s reported analysis is an ANOVA comparing “Mean Difference (Final Values).” The registry lists the estimate as .6 and the p-value as <0.05. No confidence interval, test statistic, or detailed model description is reported. The ANOVA result is therefore the only posted inferential comparison for the primary endpoint.

A simple unadjusted recalculation is not available for this continuous two-condition comparison: the registry marks the necessary values as missing or not estimable. There is consequently no recalculated estimate or p-value to set alongside the sponsor’s result. The discrepancy flag is false, so the record does not identify a conflict between a sponsor result and a recalculation. This does not supply additional validation of the sponsor’s model; it means that a recalculated comparison is not available from the posted summary statistics.

The condition means concern change from baseline, whereas the sponsor’s parameter is labeled as a mean difference in final values. The record does not explain the coding of the reported .6 or how it relates to the change summaries. The sponsor’s significance result can be reported as stated, but its magnitude, precision, and interpretation in the crossover model cannot be independently reconstructed from the registry information.

12. Multiplicity, Missing Data and Analysis Populations

The registry lists seven outcome measures and one posted secondary outcome, change in thermal comfort. It does not report how many statistical tests were performed across all outcomes, whether a primary analysis was selected in advance for each outcome, or whether adjustments were made for multiple comparisons. Multiplicity handling is therefore not reported in the registry record. If multiple outcomes or analyses were tested, the chance of at least one apparently notable result can be affected; the record does not provide enough information to evaluate that issue.

Missing-data methods are also not reported. The primary outcome group counts are n = 9 in each vest condition, but the record does not state whether temperature data were missing, whether participants were excluded, or whether any imputation or other missing-data procedure was used. It does not describe the number of complete paired records used in the ANOVA. The posted counts alone cannot answer these questions.

The registry does not identify the analysis population by a named principle such as intention-to-treat or per-protocol, nor does it explain which participants were included in the sponsor’s model. Enrollment is listed as 17, while the primary outcome summaries show n = 9 for each condition. Since the trial is a crossover, condition-specific counts should not be added to infer the number of distinct participants. The record does not reconcile enrollment with the analysis counts.

Other details that matter for interpreting a crossover analysis are not reported, including the order of conditions, period effects, carryover, and handling of repeated measurements. The study is marked randomized and unmasked, but the registry record does not describe the randomization procedure or whether the outcome analysis followed a prespecified statistical plan. These reporting gaps do not prove that methods were absent; they mean that their use cannot be assessed from the registry record.

13. 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 zero serious adverse events and zero other adverse events in each of the three reported safety groups. For the able-bodied heated-vest safety and comfort group, the record lists 8 at risk, 0 serious events, and 0 other events. For the heated-vest efficacy group with tetraplegia, it lists 9 at risk, 0 serious events, and 0 other events. For the non-heated control condition with tetraplegia, it also lists 9 at risk, 0 serious events, and 0 other events. Deaths are listed as 0 for each group.

These entries describe what the registry reports for adverse events; they should not be read as proof that no risk exists. The record does not include event terms, and no serious-event terms are listed. It also does not explain whether adverse-event monitoring or reporting differed between conditions. Because the design is crossover, the condition-specific groups should not be interpreted as independent participant cohorts or added to infer distinct people. The safety figures are descriptive registry counts, not a precise estimate of the frequency of uncommon harms.

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

The registry reports decreases in core body temperature from baseline during the thermal challenge in both vest conditions: a mean change of -0.22 with the heated vest and -0.46 with the non-heated vest. The sponsor reports an ANOVA comparison of final values with estimate .6 and p <0.05. These are the principal numerical findings available for the primary outcome in this record.

The figures do not by themselves establish how large or clinically meaningful the contrast is. The sponsor comparison has no reported confidence interval, and the model details are not described. A p-value below 0.05 does not show the probability that the result is due to chance, nor does it measure the likelihood that the intervention has a particular effect. The condition means are descriptive summaries and do not substitute for a paired analysis of individual responses.

The result is specific to core temperature measured during a controlled thermal challenge in persons with tetraplegia. It is not a direct measure of daily comfort, self-care, cognitive performance, or quality of life. Although thermal comfort is listed as a secondary outcome, the numerical result for that outcome is not reported in the registry record for this analysis. Nor does this endpoint establish what happens with longer use or in other environments.

The study’s registered rationale identifies a potential vulnerability to cool conditions in people with higher-level spinal cord injury. That rationale provides context for the outcome, but the observed temperature summaries cannot be extended to all people with spinal cord injury or to everyday experiences without additional evidence. The primary temperature measurement was not performed in able-bodied participants, and the able-bodied arm therefore does not provide a primary endpoint comparison.

Overall, the record supports a narrow description of measured temperature changes and a statistically significant sponsor-reported comparison. Uncertainty about the estimate, crossover analysis, missing data, and the connection between temperature and patient-important outcomes remains. The result should be read as a trial-specific statistical finding, not as medical advice or a definitive statement about broader benefits or risks.

15. Why This Trial Matters Statistically

This trial is statistically notable because it uses a crossover comparison: the same subjects with tetraplegia took part in the heated and non-heated vest conditions. Such designs can make within-person contrasts informative, since each participant contributes observations under both conditions. At the same time, repeated measurements require appropriate analysis of their dependence. The registry identifies ANOVA but does not give enough detail to determine how the sponsor modeled that design.

The distinction between condition-level summaries and an inferential contrast is important. The posted means and standard deviations describe the distribution of temperature changes within each condition. The sponsor’s ANOVA is labeled as a comparison of final values, and its estimate and p-value are reported without a confidence interval. These pieces of information answer different statistical questions and should not be collapsed into one conclusion.

The record also illustrates how limited reporting can constrain independent checking. A two-condition recalculation is not estimable from the available summary information, and the sponsor analysis cannot be reproduced from the stated details. In particular, the paired observations, model specification, analysis population, and missing-data approach are not reported. The significance threshold alone cannot resolve these gaps.

Finally, the endpoint is physiological and measured under a controlled challenge. Its statistical interpretation needs to remain distinct from claims about comfort or daily function. The registry lists thermal comfort as a secondary outcome, but a numerical result is not included. The study therefore highlights both the value of a clearly defined measurement and the need for transparent reporting of model assumptions, uncertainty, and outcomes that matter to participants.

16. 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 primary outcome summaries are available for n = 9 in each vest condition, but the registry does not report confidence intervals for the group means or the sponsor’s comparison. The sponsor gives an ANOVA estimate of .6 and p <0.05 without the model specification, test statistic, or degrees of freedom. The reported contrast is labeled as a difference in final values, while the arm summaries are changes from baseline. The record does not explain their relationship or the sign convention for the estimate.

The crossover structure raises questions that cannot be answered from the record: condition sequence, washout, carryover, period effects, and the treatment of repeated measurements are not described. Missing-data methods, exclusions, and the sponsor analysis population are also not reported. A recalculated continuous two-condition comparison is marked as not estimable, so the sponsor result cannot be independently checked using a simple summary-statistic recalculation.

The primary endpoint was collected during a controlled thermal challenge and only in the tetraplegia population. Temperature measurement was not performed in able-bodied participants. This limits what the primary result can say about other populations, usual environments, or outcomes beyond temperature change. Although thermal comfort is listed as a secondary outcome, its numerical result is not included in the registry record for this analysis.

The record lists enrollment of 17 and outcome groups of n = 9 for each vest condition but does not explain the relationship between enrollment and these analysis counts. Multiplicity handling and any sample-size justification are not reported in the registry record. The adverse-event entries list zero events, but the record provides no event terms and cannot establish the absence of risk beyond what was recorded.

17. Related Tutorials

18. Related Statistical Calculators

19. Sources

• ClinicalTrials.gov: Heated Vest for Persons With Spinal Cord Injury — NCT03662308.
• Registry record last updated 2024-05-06; status last verified 2024-05.
• Results first posted 2024-02-01.
• 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.

20. Record Summary

NCT03662308 is a completed, randomized, unmasked crossover study titled “Heated Vest for Persons With Spinal Cord Injury.” The registry lists enrollment of 17, a study start date of 2020-02-25, and a primary completion date of 2022-10-31. The primary outcome was change in core body temperature during a thermal challenge in persons with tetraplegia.

The heated-vest condition had mean change -0.22 and standard deviation 0.34 among n = 9; the non-heated condition had mean change -0.46 and standard deviation 0.24 among n = 9. The sponsor reports an ANOVA comparison of final values, estimate .6, p <0.05, with no confidence interval. A simple recalculated comparison is not estimable from the available summary information. The record does not report enough model or analysis details to assess the precision and crossover handling fully.