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 Measurement of Body Fat in Infants (NCT03490227), a registered phase not stated study. The primary outcome is Whole Body Fat Mass.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03490227 |
| Phase | Phase not stated |
| Condition | Brown Adipose Tissue, Body Composition |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 10 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Pennington Biomedical Research Center |
| Results posted | Yes |
2. Clinical Question
Population
Infants were the intended population. The registry record lists an enrollment of 10 and describes a study in which up to 10 infants would complete the study. It does not report further eligibility details or a demographic description of participants.
Intervention
This was a measurement study, not a treatment intervention. The stated aim was to establish techniques for measuring whole body adiposity with dual energy x-ray absorptiometry and brown adipose tissue with magnetic resonance imaging.
Comparator
No randomized comparator is described. Allocation is not stated, and the registry record flags that the arms are not a like-for-like control comparison. The record therefore does not support interpreting the study as a comparison of treatment groups.
Primary question
The primary outcome was whole body fat mass, expressed as percentage of fat mass and measured using dual energy x-ray absorptiometry. The registry record specifies a timeframe of 1 day. It does not report the measured mean, its standard deviation, or a numerical result from which to assess the measurement outcome.
The scientific focus is measurement: whether whole body fat mass and brown adipose tissue can be characterized with the stated imaging approaches in infants. The listed secondary outcomes concern average brown adipose tissue fat signal fraction at the first and second visit, and the reliability of average brown adipose tissue volume measurement between those visits. Those outcomes indicate interest in measurements across visits as well as the primary whole body fat measure.
The record does not describe a treatment assignment, a usual-care group, or a randomized contrast. It should therefore be read as a study of measurement methods, not as an efficacy trial. The registry record does not report detailed eligibility criteria, participant characteristics, or numerical outcome findings.
3. Trial Design
The registry record identifies this study as completed and lists an enrollment of 10. Its brief summary says that up to 10 infants would complete the study. The sponsor was Pennington Biomedical Research Center. The recorded start date is 2018-04-30, and the primary completion date is 2019-12-02.
The stated aim was to establish a technique for measuring whole body adiposity and brown adipose tissue in infant subjects. Dual energy x-ray absorptiometry was specified for whole body fat mass, while magnetic resonance imaging was specified for brown adipose tissue. The primary outcome was whole body fat mass, reported as a mean with standard deviation and expressed as percentage of fat mass. Its recorded timeframe was 1 day.
The secondary outcomes listed in the registry concern average fat signal fraction of brown adipose tissue at the first visit, average fat signal fraction at the second visit, and reliability of average brown adipose tissue volume measurement between the first and second visit. The record lists 6 outcome measures, but does not provide numerical results for the primary outcome in the registry record for interpretation.
The registry record does not state allocation, and the study is not described as a randomized comparison. Its own comparison note warns that the arms are not a like-for-like control comparison. Any division into arms should not be treated as a randomized control structure or as evidence of a treatment effect. The record does not report a protocol description, sample-size justification, or detailed analysis plan. It also does not describe the recruitment process, eligibility criteria, or participant characteristics. The record marks the study completed, but completion status by itself does not establish whether every planned measurement was obtained or analyzed.
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
| Stage | All Participants |
|---|---|
| STARTED | 10 |
| COMPLETED | 10 |
| NOT COMPLETED | 0 |
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 | All Participants |
|---|---|---|
| Participants analysed | 10 | |
| Age, Continuous | days | 22.6 (SD 1.31) |
| Sex: Female, Male: Female | Participants | 3 |
| Sex: Female, Male: Male | Participants | 7 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 8 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 2 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 1 |
| Race (NIH/OMB): White | Participants | 9 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Gestational Age at Birth | weeks | 39.129 (SD 1.296) |
6. Primary Endpoint
The registry lists the primary outcome as Whole Body Fat Mass, measured over 1 day.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | percentage of fat mass |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is whole body fat mass, expressed as percentage of fat mass. The registry record specifies that it is measured in infant subjects using dual energy x-ray absorptiometry, with a timeframe of 1 day. The endpoint is listed as a continuous measure summarized by a mean and standard deviation. A mean describes the central value of measured fat mass in the analyzed observations; a standard deviation describes how spread out those measurements are around the mean.
In general, quantifying body composition can provide a measurement target for evaluating a method intended to characterize adiposity. That makes the endpoint relevant to the study’s stated measurement aim. However, the record does not report the observed mean or standard deviation, so the magnitude and variability of whole body fat mass in the enrolled infants cannot be assessed from the recorded details. Nor does the record provide a reference measurement or a numerical comparison that would establish agreement or accuracy.
The primary endpoint should not be read as a clinical outcome or as a treatment benefit. It is a body-composition measurement. The registry’s description states what was intended to be measured and how, but the numerical result is not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a completed study with an enrollment of 10 and a measurement-focused aim. It specifies whole body fat mass as the primary outcome and identifies dual energy x-ray absorptiometry as the measurement method. Brown adipose tissue is addressed through magnetic resonance imaging, with listed secondary outcomes involving fat signal fraction at two visits and reliability of volume measurement between visits.
These details define the intended measurement questions, but they do not provide the findings needed to answer them. The numerical mean and standard deviation for the primary endpoint are not reported in the registry record. Numerical findings for the listed secondary outcomes are also not present in the registry record. Consequently, the size and distribution of the measured whole body fat mass, the observed fat signal fractions, and the repeat-visit reliability cannot be characterized from the registry record.
The record lists 6 outcome measures and 0 analyses. The absence of analyses means there is no reported analysis result to interpret in the registry entries. It does not, by itself, establish why analyses are absent, whether measurements were unavailable, or whether results were analyzed outside the record. Those explanations are not reported in the registry record.
The comparison note is important for interpretation: allocation is not stated, and arms are not a like-for-like control comparison. Thus, an apparent difference between any arms would not automatically be interpretable as a randomized treatment contrast. The stated purpose is to establish a measurement technique, not to estimate a treatment effect. The registry record does not report a randomized allocation process, a comparator definition, or an adjusted analysis that would support a causal comparison.
In general, a mean and standard deviation give complementary descriptions of a continuous outcome: one locates the average and the other describes dispersion. Neither is available as a numerical result for this primary endpoint. In general, an assessment of measurement reliability requires reported repeated measurements and a defined reliability statistic. Although reliability between the first and second visit is named as a secondary outcome, the reliability estimate and its precision are not reported in the registry record.
The adverse-event record lists 0 serious adverse events among 10 participants at risk and 1 other adverse event among 10 participants at risk, with 0 deaths. Those counts are descriptive safety reporting, not evidence about whether the measurement methods are accurate or reliable. The record does not supply event terms for the other adverse event.
Overall, the registry record establishes the study’s intended population, measurement approaches, outcomes, and completion status. It does not establish the observed performance of the measurement techniques, because numerical outcome estimates are not reported in the registry record. Any stronger conclusion about measurement accuracy, repeatability, or clinical usefulness would go beyond the reported findings.
9. Statistical Methods Explained
The methods information in the registry record is limited. It identifies a continuous primary measure, names a mean and standard deviation as its summary, and describes the imaging method and timeframe. It does not report a full statistical analysis plan, a sample-size justification, or numerical outcome estimates. The explanations below are general statistical context, not claims about analyses performed in this study.
What does a mean describe?
For a continuous measure, the mean is the arithmetic average of the observed values included in an analysis. It offers a concise description of the group’s central measurement. In this study, the named measure is whole body fat mass as a percentage of fat mass. The registry record does not report the numerical mean, so the central value cannot be read from the recorded result information.
A mean can be informative while concealing variation among individuals. It does not show whether values cluster closely around the average, whether they are widely spread, or whether a small number of unusual values influence the average. Those questions require additional descriptive information and, where relevant, inspection of the distribution. The registry entries identify standard deviation as the planned dispersion summary, but do not give its value.
What does standard deviation add?
In general, standard deviation describes the spread of observations around their mean, using the same measurement scale as the data. A smaller standard deviation indicates measurements closer to the mean, while a larger one indicates greater spread. This is a description of observed variability; it is not, by itself, a measure of precision of the mean or a statement about the accuracy of an imaging method. No numerical standard deviation for whole body fat mass is reported in the registry record.
How should a confidence interval be understood?
In general, a confidence interval conveys uncertainty around an estimated quantity under the assumptions of the method used to calculate it. Its width reflects both the amount and variability of information and the chosen interval procedure. A confidence interval is not a guarantee that the true value lies within a particular interval, nor does it replace consideration of study design and measurement quality. The registry record does not report a confidence interval for the primary endpoint or for the secondary outcomes.
What does reliability mean for repeated measures?
In general, reliability concerns the consistency of measurements when the same underlying characteristic is assessed repeatedly under relevant conditions. A reliability analysis may use different statistics depending on the measurement scale, the study design, and whether the question concerns consistency, agreement, or both. Those choices matter: a result for rank ordering is not necessarily equivalent to a result for absolute agreement. The registry names reliability of average brown adipose tissue volume measurement between the first and second visit, but does not specify the reliability statistic or report its estimate. It is therefore not possible to determine which aspect of repeatability was assessed or how consistent the measurements were.
The listed fat signal fraction outcomes at the first and second visit are distinct from the reliability outcome. A value at each visit would describe the measurements at those visits; a reliability analysis would assess how measurements correspond across visits. One cannot infer a reliability result just from the fact that two visits are named. The record does not provide the visit-specific numerical values or a statistical comparison.
Why does over-dispersion matter in general?
Over-dispersion arises when the variability in data is greater than a statistical model assumes. If a model underestimates variability, its uncertainty estimates can be too small and its inferential conclusions can be overly confident. The relevance of this issue depends on the outcome type and model. The primary endpoint is described as a continuous measure, and no model-based analysis is reported. The registry record does not say that over-dispersion was assessed or that a model requiring such an assessment was used.
What can planning illustrations tell a reader?
In general, sample-size calculations are planning tools. They describe the sample size that would be needed under stated assumptions about the effect to detect, variability, significance level, allocation, and analysis approach. They are not a measure of the probability that a completed study found a real effect, and they are not an observed result. The planning assumptions recorded for the sample-size illustrations specify a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. The record also distinguishes participants per arm for non-time-to-event outcomes from total events for time-to-event outcomes.
Those planning assumptions do not establish that this measurement study used equal randomized arms. The registry does not state allocation and explicitly cautions that the arms are not a like-for-like control comparison. The assumptions also do not substitute for a reported observed effect. No numerical effect estimate for the primary outcome is reported in the registry record, and no study-specific sample-size justification is reported. A planning illustration should therefore not be described as observed power or as evidence that the measurement approach succeeded.
More generally, statistical summaries must be interpreted alongside the design and the data actually reported. A mean, its dispersion, an interval estimate, and a reliability statistic answer different questions. The registry record names some intended summaries and outcomes, but the missing numerical estimates and the absence of reported analyses prevent direct evaluation of those questions.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists 6 outcome measures, including the primary whole body fat mass measure and secondary measures concerning brown adipose tissue. It lists 0 analyses. The outcome list alone does not show which outcomes were successfully measured, which were analyzed, or how results were selected for reporting. Numerical outcome findings are not reported in the registry record.
Multiplicity refers, in general, to the interpretive issue created when multiple statistical hypotheses or outcomes are examined. When many tests are conducted, the chance of at least one apparently unusual result can increase unless the analysis plan addresses that issue. The registry record does not report a multiplicity adjustment, a hierarchy among the secondary outcomes beyond their labeling, or a prespecified strategy for interpreting multiple comparisons. It is not possible to say whether any adjustment was performed.
Missing-data handling is also not reported in the registry record. The enrollment and completion status do not establish how many observations were available for each endpoint, whether any measurements were missing, or how missing values were handled. The record does not describe imputation, exclusion, or sensitivity analyses. It would be inappropriate to infer that all enrolled participants contributed to each outcome merely from the enrollment figure.
The analysis populations are not reported in the registry record. No description is given of an intention-to-treat population, a per-protocol population, or an outcome-specific analysis set. Because allocation is not stated and the arms are not a like-for-like control comparison, the usual interpretation of randomized-trial analysis populations should not be imposed on this study. These omissions limit assessment of the scope and robustness of any analysis, in addition to the absence of numerical results.
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 |
|---|---|---|---|
| All Participants | 0 | 10 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| All Participants | 0 of 10 |
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 |
|---|---|
| All Participants | 1 of 10 |
Most frequent non-serious adverse event terms
| Event term | Organ system | All Participants |
|---|---|---|
| Flatulence | Gastrointestinal disorders | 1 of 10 |
The safety record lists all participants as the group at risk. It records 0 serious adverse events among 10 participants at risk, 1 other adverse event among 10 participants at risk, and 0 deaths. The record does not provide a term for the other adverse event, its severity, timing, relationship to study procedures, or outcome.
These figures are descriptive counts in the registry record. The absence of a recorded serious adverse event does not establish that no event of any kind occurred, and the other-event count does not explain the nature or cause of that event. The registry record does not report additional detail that would support a fuller safety assessment.
The study’s aim was measurement rather than treatment comparison. These adverse-event counts should not be treated as a comparative estimate of risk, particularly because allocation is not stated and the arms are not a like-for-like control comparison. They also do not answer whether the imaging measurements were accurate or reliable.
12. What the Result Does, and Does Not, Mean
The record supports a description of what the study set out to measure: whole body fat mass in infants using dual energy x-ray absorptiometry, along with brown adipose tissue measures using magnetic resonance imaging. It also shows that the study is marked completed and that the registry lists an enrollment of 10. Its secondary outcomes include fat signal fraction at the first and second visit and reliability of brown adipose tissue volume measurement across those visits.
It does not provide numerical findings for the primary outcome. The mean and standard deviation are specified as the planned summaries, but their values are not reported in the registry record. The record also does not report numerical secondary-outcome findings or analyses. As a result, it is not possible to quantify the observed body-fat measurement, describe its variability, or evaluate the reported repeat-visit reliability from these registry entries.
The study should not be interpreted as demonstrating a treatment effect. No randomized comparison is described, allocation is not stated, and the registry warns that arms are not a like-for-like control comparison. The stated purpose is to establish a measurement technique, so conclusions about treatment benefit or harm are outside the information recorded.
In general, a completed status indicates the registry’s stated trial status; it does not mean that results are available in the registry record or that every planned analysis is reported. Likewise, a named secondary outcome indicates an outcome of interest, not a positive finding. The record does not establish the reasons that numerical results or analyses are absent.
The safety counts provide limited descriptive information: 0 serious adverse events and 0 deaths were recorded, alongside 1 other adverse event. Without event details, these figures cannot explain the nature of the event or support a broader conclusion about safety. Overall, the registry record documents the measurement questions and selected design details, but does not report the outcome evidence needed to judge measurement performance.
13. Why This Trial Matters Statistically
Measurement studies address a foundational statistical question: whether a characteristic can be quantified in a defined population with a method that produces interpretable measurements. Clinical research depends on measurement quality because later descriptions, comparisons, or models can only be as informative as the variables they use. The registry record’s focus on whole body fat mass and brown adipose tissue in infants makes the measurement aim explicit.
The listed outcomes distinguish several related but different questions. Whole body fat mass is a continuous measurement summarized by a mean and standard deviation. Fat signal fraction is named at two visits, while reliability of brown adipose tissue volume measurement is a separate outcome. In general, describing a value, comparing values across visits, and assessing reliability are not interchangeable statistical tasks. Each requires the appropriate estimate and uncertainty information.
This record also illustrates why completed status and outcome descriptions are not enough to evaluate study findings. The primary result, secondary numerical results, and analyses are not reported in the registry record. Without those estimates, readers cannot assess the amount of measurement variation, the consistency across visits, or the precision of any result. Transparent reporting of estimates and analysis details is essential for interpreting a measurement study.
Design context matters as well. Allocation is not stated, and the registry says that arms are not a like-for-like control comparison. That caution prevents an unsupported treatment-style reading of any arm differences. The statistical value of the record is therefore primarily in documenting the intended measurement aims and outcomes, while also making clear that the posted information does not resolve the measurement-performance questions.
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 important limitation for interpreting this record is the absence of numerical outcome findings. The primary outcome is defined, but its mean and standard deviation are not reported in the registry record. Numerical results for the secondary outcomes are also not reported, and the record lists 0 analyses. Therefore, the measurement performance cannot be evaluated from the recorded results.
The registry record provides limited design detail. Allocation is not stated, and the record explicitly notes that the arms are not a like-for-like control comparison. It does not report how participants were selected, detailed eligibility criteria, participant characteristics, or a comparator structure. These omissions limit understanding of the study population and prevent a valid treatment-comparison interpretation.
The record does not identify the reliability statistic used for the repeated brown adipose tissue volume measure, nor does it report uncertainty around any estimate. It also does not describe missing-data handling, analysis populations, or a multiplicity strategy. The absence of this information does not establish that particular procedures were or were not used; those details are not reported in the registry record.
Although enrollment is listed as 10 and the study is marked completed, the record does not state how many observations contributed to each outcome. Completion status alone does not establish endpoint completeness. The adverse-event information is also limited: 1 other adverse event is recorded without a term or further description.
Finally, planning assumptions are not a substitute for the study’s own design justification or observed results. The registry record does not report a sample-size justification, and the planning assumptions do not establish that arms were randomized or comparable. These limitations restrict both statistical interpretation and assessment of how broadly the measurement findings might apply.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Measurement of Body Fat in Infants — NCT03490227.
- Registry record last updated 2021-12-07; status last verified 2021-12.
- Results first posted 2021-10-12.
- 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
NCT03490227, titled “Measurement of Body Fat in Infants,” is marked completed. The registry lists an enrollment of 10, identifies Pennington Biomedical Research Center as sponsor, and records a start date of 2018-04-30 and primary completion date of 2019-12-02.
The primary outcome is whole body fat mass, expressed as percentage of fat mass, measured using dual energy x-ray absorptiometry and summarized as a mean with standard deviation. Its timeframe is 1 day. The study’s stated aim also concerns brown adipose tissue measurement using magnetic resonance imaging. Listed secondary outcomes include fat signal fraction at the first and second visit and reliability of volume measurement between those visits.
The registry lists 6 outcome measures and 0 analyses. Numerical primary and secondary outcome results are not reported in the registry record. Allocation is not stated, and the record cautions that arms are not a like-for-like control comparison. Safety reporting lists 0 serious adverse events, 1 other adverse event, and 0 deaths.