Temperature Control in Central Fever in the Neuro-ICU: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Temperature Control in Central Fever in the Neuro-ICU (NCT00751634), a na phase 4 study. The primary outcome is Core Temperature as Measured With an Approved Device (Urinary Catheter) in Place for Usual Clinical Care.

2. Clinical Question

In general, a single-group study can describe what was observed after an intervention, but it cannot by itself separate an intervention-associated change from other explanations. For example, temperature may change over time for reasons unrelated to the device. Without a concurrent comparator, the record cannot show how temperature would have changed under another approach. The registry lists secondary outcomes concerning time to a core temperature below 100.4F, severe shivering, hypotension and arrhythmia. Results for those outcomes are not reported in the registry record.

3. Trial Design

The registry describes a completed phase 4 study titled “Temperature Control in Central Fever in the Neuro-ICU.” The recorded enrollment is 20. The study start is recorded as 2009-01, and primary completion as 2011-01. These are registry dates at month-level precision; more detailed dates are not reported in the registry record.

The design is single-group, with allocation recorded as NA and masking recorded as none. The registry identifies one intervention: the Gaymar Rapr-Round external cooling blanket. Its arm description states that the device was applied per approved use. No randomized control arm or alternative treatment group is described. Consequently, any results from this design would be descriptions of participants’ outcomes in the treatment group, not estimates from a randomized comparison.

The primary outcome was core temperature, expressed in degrees F and summarized as a mean with standard deviation. The stated assessment times were baseline and one, two and six hours after application. The device was to remain in place throughout the study period unless severe shivering led to termination per protocol. The registry also lists four secondary outcomes: time from device application to core temperature below 100.4F, severe shivering, hypotension and arrhythmia. The registry lists five outcome measures overall, but results for these measures are not reported in the registry record.

The study status is completed. Completion indicates the recorded study status; it does not by itself establish that results were posted or that the outcome analyses were completed as planned. The registry reports zero analyses. The protocol details, eligibility criteria, sample-size justification, interim analyses and statistical analysis plan are not reported in the registry record. These omissions limit what can be concluded about how the study was conducted and how its outcome data were handled.

4. Participant Flow and Accounting

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

Overall Study

5. Baseline Characteristics

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

6. Primary Endpoint

The registry lists the primary outcome as Core Temperature as Measured With an Approved Device (Urinary Catheter) in Place for Usual Clinical Care, measured over baseline, one, two and six hours after application..

The primary endpoint was core temperature, measured in degrees F using an approved urinary catheter that was already in place for usual clinical care. The registry describes the outcome as a mean and standard deviation, with measurements at baseline and one, two and six hours after the cooling device was applied. It also states that the blanket remained in place throughout the study period unless severe shivering led to termination per protocol.

Core temperature is a direct measure of the temperature-control question posed by this study. Repeated measurement can describe the temperature pattern over time after device application. In general, a mean indicates the average measurement in a group, while a standard deviation describes the spread of individual measurements around that average. Neither statistic alone shows how much uncertainty surrounds an estimated mean; that requires additional information, such as a confidence interval or other inferential analysis.

The registry record does not report the temperature values, standard deviations, numbers measured at each time, or an analysis comparing measurements across time. It therefore does not establish the observed temperature pattern or its precision. A time course after application would also remain an observation in a single-group design: without a control condition, it cannot isolate the effect of the cooling blanket from other influences on temperature.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the primary endpoint as a continuous measure summarized by a mean and standard deviation. It does not report the result values or the statistical analyses. The explanations below describe general statistical concepts that help interpret this type of outcome; they do not assert that any particular method was used in this study.

What does a mean describe?

For a continuous outcome such as temperature, the mean is the arithmetic average of the observed measurements in the group being described. It gives a central summary, but it does not show the range or shape of the measurements. A few unusually high or low values can influence a mean. The standard deviation describes how dispersed measurements are around the mean. A small standard deviation indicates that observations are closer to the mean, while a larger one indicates greater spread. The standard deviation is not the same as the uncertainty in the estimated mean.

To interpret a mean as an estimate of a population value, readers generally need an uncertainty measure, such as a confidence interval. A confidence interval expresses a range of values compatible with the data and the statistical assumptions used to construct it. Its width reflects precision: a narrower interval indicates greater precision under those assumptions, and a wider interval indicates less. The registry record does not report confidence intervals for the temperature endpoint, so the precision of any mean cannot be assessed from this record.

What does measuring at several times add?

Measurements at baseline and after device application can describe a trajectory rather than a single endpoint. In general, repeated measurements on the same participant are related: each person’s later temperature may be more similar to their own earlier temperature than to another participant’s measurement. An analysis that treats such measurements as independent may fail to account for that relationship. Methods for repeated measures can model the within-person relationship, but the appropriate method depends on the study design, data structure and assumptions.

The registry identifies measurement times but does not report a repeated-measures method or any other analysis method. It also does not report whether all participants contributed measurements at every time. Thus, it is not possible to determine how the data were analyzed, what observations entered a particular estimate, or whether a model accounted for within-person correlation.

Why does the single-group design matter?

In general, a change between baseline and follow-up is a within-group contrast. It can describe the observed difference over time if the relevant results are reported. It does not isolate a causal intervention effect, because no concurrent control group is available to show what would have happened over the same period without the intervention. Other changes over time, including usual care or changes in the clinical condition, could contribute to a before-and-after pattern. The registry labels this study single-group and does not report a randomized comparison.

Statistical adjustment cannot fully recreate a missing control condition. A model can describe or account for measured features, but it cannot rule out all alternative explanations for a change when there is no suitable comparison group. The registry record does not report covariate adjustment or an analysis plan, so no claim about such methods is warranted.

How should threshold and event outcomes be understood?

The registry lists a time-to-event outcome defined as time from device application to core temperature below 100.4F. In general, time-to-event analyses describe how long it takes for a specified event to occur while accounting for participants whose event time may not be observed during follow-up. Such analyses can depend on how follow-up ends and how events that do not occur are handled. Neither the time summaries nor the analysis approach for this outcome is reported in the registry record.

The other listed secondary outcomes are counts of participants with severe shivering, hypotension and arrhythmia. For event outcomes, a count alone does not convey precision or establish whether an event was caused by the intervention. The interpretation also depends on the number assessed, event definitions, follow-up period and method of ascertainment. The registry names the outcomes but does not report their results or further details about their definitions.

What do the planning assumptions mean?

The registry describes a planning illustration based on the observed effect, not the trial’s own design. Its stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms and a normal approximation; the effect to detect is described as a stated fraction of the observed effect. These are assumptions for hypothetical sample-size planning, not evidence that this single-group study had two arms or used those methods for its own analysis.

Sample-size planning asks how many participants per arm would be required under specified assumptions to detect a chosen effect with a chosen power. The result depends on the effect size, variability, significance level, allocation and analysis assumptions. A planning calculation is not an observed study outcome. It is also not observed power, which should not be used to imply that a completed study had a particular likelihood of detecting an effect after the fact. The observed primary effect and its variability are not reported in the registry record, limiting interpretation of any planning illustration based on them.

10. Multiplicity, Missing Data and Analysis Populations

The primary endpoint includes temperature measurements at baseline and one, two and six hours after device application. Assessing multiple times can raise questions about which comparison is primary and how conclusions account for the number of comparisons. In general, testing several outcomes or time points can increase the chance of a false-positive finding if each is assessed separately without an appropriate strategy. A prespecified analysis plan can clarify which comparisons are primary and how multiplicity is handled.

The registry record does not report a statistical analysis plan, a multiplicity adjustment, or the results of tests at any measurement time. It is therefore not possible to determine whether the investigators planned one overall analysis of the temperature trajectory, separate time-specific comparisons, or another approach. No claim about adjustment or control of false-positive risk can be made.

Missing data are also important for repeated measurements. In general, participants may have an unavailable measurement at one or more times, and the number observed can differ across assessments. The analysis method and assumptions about why measurements are missing can affect interpretation. The registry record does not report the number of temperature measurements available at each time, reasons for missing measurements, or a method for handling them.

The record does not specify an analysis population, such as whether analyses included everyone enrolled or only participants with particular available measurements. It lists 20 participants as enrolled, but the relationship between enrollment and the population used for each outcome analysis is not reported. The registry also lists zero analyses, and the primary and secondary outcome results are not reported. These gaps prevent assessment of analysis denominators, protocol deviations, outcome completeness and the robustness of the findings.

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 5% reporting threshold.

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: shivering (20.0%).

The adverse-event record lists a treatment group with 20 participants at risk for serious adverse events and 4 affected. For other adverse events, it lists 20 at risk and 0 affected. The leading serious adverse-event term is Shivering, recorded as 20.0%. These entries should be read as descriptive registry information, not as a comparison with another group.

Serious adverse events and other adverse events are separate registry categories. The figures do not state that every adverse event was serious, and the listed serious-event term does not establish that the cooling device caused the event. The record does not provide additional detail about event timing, severity beyond the serious classification, recurrence, attribution or the criteria used to classify events.

These figures also do not replace the separately listed secondary outcomes for severe shivering, hypotension and arrhythmia. The registry names those outcomes but does not report their results. A safety reading should therefore distinguish the adverse-event entries from those unreported outcome measures and avoid treating an absent result as evidence that no event occurred.

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

The registry establishes that a completed, single-group study evaluated an external cooling blanket in the context of central fever in neurologically ill patients. It specifies core temperature as the primary endpoint, measured at baseline and one, two and six hours after application, and names several secondary outcomes. It also records adverse-event information for the treatment group.

What the record does not establish is the observed temperature response. The primary endpoint values and analyses are not reported in the registry record. As a result, the direction and size of any change, the variability between participants and the precision of an estimate cannot be determined from the posted information. Results for the named secondary outcomes are also not reported.

Even if within-group temperature measurements were available, a single-group design would not provide a randomized control comparison. A pattern after application could be described, but it could not by itself demonstrate that the device caused the pattern. Other influences over time would remain possible explanations. The registry record does not describe a comparator that could address this issue.

The safety entries provide limited descriptive information: 4 participants were recorded as affected by a serious adverse event, and 0 were recorded as affected by other adverse events, with 20 at risk in each category. Shivering is listed as a serious adverse-event term at 20.0%. These entries do not establish causation, capture every possible safety outcome, or supply a comparison with an untreated group.

Accordingly, the registry record is informative about study design, endpoint definitions and selected safety entries, but it does not supply the clinical outcome results needed to judge the observed temperature pattern or its statistical precision. It should not be interpreted as evidence that the intervention did or did not change temperature or as a comparison of the intervention with another treatment.

13. Why This Trial Matters Statistically

This study illustrates an important distinction between a clearly named clinical question and an answer supported by posted results. The registry defines a direct physiological endpoint, core temperature, and gives its measurement schedule. It also identifies safety outcomes relevant to a cooling intervention. These design details help readers understand what the study set out to observe, even though the registry does not report the outcome results.

Statistically, the single-group design is central to interpretation. Before-and-after measurements can be useful for describing what happened in the observed group, but they do not provide the counterfactual comparison needed to attribute a change to the device. This distinction applies even when an outcome is measured objectively. A precise measurement does not, on its own, remove confounding from time or other aspects of care.

The record also demonstrates why reporting estimates and uncertainty matters. Means and standard deviations are identified as the intended summaries, but no values or confidence intervals are posted. Without those, readers cannot assess the scale of the observed temperatures, the variability, or the precision of a possible change. Naming an endpoint and a method of summarization is not equivalent to reporting a result.

Finally, planning calculations and outcome analyses answer different questions. A sample-size illustration based on an observed effect is a planning exercise under stated assumptions; it is not an analysis of the clinical outcomes and is not observed power. Because the observed effect is not reported, such planning information cannot substitute for the missing endpoint results. The record is therefore a useful example of how design information, outcome reporting and causal interpretation must be considered separately.

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 most immediate limitation is that the registry record does not report the primary temperature results or analyses. It also omits results for the listed secondary outcomes. Without those data, the observed outcome pattern, variability and precision cannot be assessed.

The study is identified as single-group, with allocation recorded as NA and masking as none. There is no like-for-like control comparison in the record. Consequently, the design cannot distinguish a change associated in time with device application from changes attributable to other factors. The record does not report details that would allow readers to assess additional sources of bias or the consistency of outcome measurement.

The registry provides little information about eligibility criteria, participant characteristics, the analysis population or outcome completeness. It does not report the number of measurements available at each assessment, missing-data handling, protocol deviations, or the statistical analysis plan. Those details are relevant to evaluating whether the reported measurements would represent the intended population and how analytic choices might affect estimates.

The safety entries are also limited. They report selected counts and a leading serious-event term, but do not provide event narratives, timing, attribution, recurrence or fuller definitions. The separately listed secondary safety outcomes have no posted results. These omissions limit assessment of the scope and interpretation of safety reporting.

The registry records enrollment as 20 and the study status as completed, but completion alone does not resolve the absence of outcome analyses. The protocol’s sample-size justification and interim-analysis approach are not reported in the registry record. These limits should be kept distinct: some concern the single-group design, while others arise because results and analytic details are not posted.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Temperature Control in Central Fever in the Neuro-ICU — NCT00751634.
• Registry record last updated 2013-05-06; status last verified 2013-04.
• Results first posted 2012-04-09.
• 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 record describes a completed phase 4, single-group study of the Gaymar Rapr-Round external cooling blanket for central fever in neurologically ill patients. Enrollment is recorded as 20; the study start is 2009-01 and primary completion is 2011-01. Allocation is listed as NA and masking as none.

The primary endpoint is mean core temperature in degrees F, measured at baseline and one, two and six hours after device application, with standard deviation as the stated measure of dispersion. The registry lists secondary outcomes concerning time to core temperature below 100.4F, severe shivering, hypotension and arrhythmia. Their results, along with the primary temperature results and analyses, are not reported in the registry record.

The adverse-event record lists 4 affected by a serious adverse event and 0 affected by other adverse events, with 20 at risk in each category; Shivering is listed as a serious-event term at 20.0%. These descriptive entries do not constitute a control comparison. The record lists zero analyses, and its statistical plan and missing-data procedures are not reported.