Translational Investigation of Growth and Everyday Routines in Kids: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Translational Investigation of Growth and Everyday Routines in Kids (NCT02784509), a registered phase not stated study. The primary outcome is Objective 1 Primary Outcome: Change in Minutes of Sedentary Behavior, Light Physical Activity, and Moderate-to-vigorous Physical Activity.

2. Clinical Question

The study, titled Translational Investigation of Growth and Everyday Routines in Kids (TIGER Kids), also aimed to examine whether race modifies associations between severe obesity and physical activity, sedentary behavior, or cardiometabolic risk factors. A further aim was to investigate whether total, regional, and depot-specific fat accumulation contributes to changes in those measures during childhood and adolescence.

The primary outcome is a change in minutes measured using accelerometers at baseline and Year 2. The registry also lists secondary analyses concerning change in daily moderate-to-vigorous physical activity minutes, change in days per week of physical activity, and the relationship between fat mass accumulation and change in physical activity. These are stated aims, not reported findings: results for these questions are not reported in the registry record.

3. Trial Design

NCT02784509 is a study of childhood obesity sponsored by Pennington Biomedical Research Center. The registry record gives a start date of 2016-06, a primary completion date of 2020-09, a status of completed, and enrollment of 342. Its title is Translational Investigation of Growth and Everyday Routines in Kids, also identified as TIGER Kids.

The study examines activity, sedentary behavior, and cardiometabolic risk during childhood and adolescence. Its stated objectives include assessing the effect of severe obesity on those measures, examining whether associations are modified by race, and investigating the contribution of total, regional, and depot-specific fat accumulation. These are observational questions about relationships and change; the record does not describe assigned treatment groups. It explicitly notes that this is not a randomized comparison and that allocation is not stated.

The primary outcome is described as change from baseline to Year 2 in minutes of sedentary behavior, light physical activity, and moderate-to-vigorous physical activity. The registry describes accelerometer measurement and a lifestyle survey. It does not report a detailed statistical analysis plan, covariate adjustment strategy, or the specific model used to compare measurements over time.

The registry lists 8 outcome measures, but reports 0 analyses. It therefore does not give primary outcome estimates, uncertainty intervals, or inferential test results. The record also does not report a sample-size justification, interim analyses, or a prespecified multiplicity procedure. Although the study is marked completed, completion status alone does not supply the missing outcome results or clarify how each stated objective was 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

Analysis population for the primary outcome, as defined in the registry: 284/342 children had complete accelerometry data and were therefore included in analysis.

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 Objective 1 Primary Outcome: Change in Minutes of Sedentary Behavior, Light Physical Activity, and Moderate-to-vigorous Physical Activity, measured over Baseline and Year 2.

The primary endpoint concerns change in minutes spent in sedentary behavior, light physical activity, and moderate-to-vigorous physical activity between baseline and Year 2. The measure is continuous: time is recorded in minutes, and the registry identifies the intended summary as a mean with standard deviation. The endpoint is measured using a triaxial Actigraph GT3X+ accelerometer.

In general, accelerometers provide an objective way to record movement over a period of wear, rather than relying only on a participant’s recollection. The registry says participants were encouraged to wear the device 24-hours per day for at least 7-days, including 2 weekend days, with an initial familiarization day and the morning of the final day. Participants were also asked to complete a lifestyle survey about diet and physical activity habits. These details describe the planned measurement approach; actual wear adherence and the resulting activity estimates are not reported in the registry record.

Measuring change can describe whether activity-time estimates differ across the two stated visits. It does not, by itself, establish that obesity caused any difference. The registry gives no mean values, standard deviations, or estimates of change for the primary endpoint, so the size and precision of any observed change cannot be assessed from the reported record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The endpoint is continuous, and the registry describes it using a mean and standard deviation. In general, a mean represents the arithmetic average of measured values. A standard deviation describes how dispersed individual values are around that mean. Together, these summaries can convey both the central level of activity time and the variability among participants, but they do not show the full distribution or explain why participants differ.

What does change between visits mean?

The primary outcome is framed as a change from baseline to Year 2. In general, a change measure compares observations made at different times for the same participant or population. A group-level mean change can summarize the average movement in an outcome, while individual changes may vary substantially. The registry does not report the calculated changes, the method used to estimate them, or whether the analysis accounted for the paired nature of repeated measurements.

The endpoint comprises minutes in three activity categories: sedentary behavior, light physical activity, and moderate-to-vigorous physical activity. The registry names a triaxial accelerometer as the measurement instrument and describes the requested wear schedule. Accelerometer-based estimates depend on device wear and the rules used to convert recorded movement into categories. The registry does not report wear-time compliance, data-processing thresholds, or the classification rules used for these categories. The lifestyle survey was also intended to collect information including diet and physical activity habits, but the registry does not report how survey information was analyzed.

How should uncertainty be understood?

In general, an estimate is more informative when accompanied by a measure of uncertainty. A confidence interval communicates the range of values reasonably compatible with the estimate under the chosen model. Its interpretation depends on the analysis assumptions and design. No primary outcome estimate or confidence interval is reported in the registry record, so precision cannot be evaluated. The record also reports no p-values or other inferential test results.

The registry lists 8 outcome measures and 0 analyses. It identifies secondary analysis questions about change in daily moderate-to-vigorous physical activity minutes, change in days per week of physical activity, and the relationship between fat mass accumulation and change in physical activity. The record does not specify the statistical models, how repeated observations were handled, or whether analyses adjusted for other variables. It is not possible to determine from the record how the stated objectives were translated into estimates.

What do planning illustrations represent?

In general, sample-size planning asks how many participants would be needed to detect a specified effect under stated assumptions. The registry’s planning assumptions describe 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 planning assumptions, not evidence that the study used that design or that a particular effect was detected. This study is not a randomized comparison, and the record does not state an allocation scheme. The registry does not report a sample-size justification for the study itself.

Sample-size illustrations are not observed power. They do not establish how likely the actual analysis was to detect an effect, nor do they replace a reported estimate and its uncertainty. No numerical planning estimates or observed effect values are reported in the registry record. In general, over-dispersion matters when data vary more than a statistical model assumes: standard errors and resulting uncertainty estimates may then be understated if the model does not accommodate that extra variability. The registry does not report whether over-dispersion was relevant or how it was assessed.

Finally, statistical methods should be interpreted in light of the study design and the available results. The record identifies measurement times and outcomes, but does not report a full analysis plan. It does not specify model choice, handling of covariates, treatment of missing observations, or correction for multiple outcomes. Those details are needed to evaluate how robustly the analyses answer the stated questions; they should not be inferred from the outcome descriptions alone.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 8 outcome measures, including a primary outcome and secondary questions concerning physical activity and fat mass accumulation. When several outcomes or analyses are considered, general statistical practice recognizes a possibility of increased false-positive findings if each is tested independently without accounting for multiplicity. The record does not report a multiplicity strategy, such as a prespecified hierarchy or adjustment procedure. It also reports 0 analyses, so there are no reported findings with which to assess how multiple testing was handled.

The primary accelerometry analysis included 284/342 children with complete accelerometry data. This is the stated analysis population for that outcome. The record does not report why data were incomplete, whether incomplete measurements differed by participant characteristics, or how missing values were handled beyond describing the complete-data group included in analysis. It does not report whether missingness methods were used for other outcomes.

In general, missing data can affect an estimate when the observed participants differ systematically from those without measurements. The extent and direction of any such effect depend on the reasons data are missing and on the analysis approach. The registry does not provide enough detail to evaluate those possibilities or to establish whether the complete accelerometry group represents all enrolled children. It also does not describe the analysis populations for the other listed outcomes.

11. 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 registry lists a TIGER Kids Sample group with 342 participants at risk for serious adverse events and 0 serious adverse events. It also lists 342 at risk for other adverse events and 0 other adverse events, with 0 deaths. No top serious adverse event terms are listed.

These figures are the event counts recorded for the study population; they are not a comparison between randomized treatment groups. The study is not described as a randomized comparison, and no assigned arms are stated. The registry record does not report details about adverse-event collection, definitions, reporting windows, or completeness of ascertainment. A zero count in the record therefore means no events are listed in these fields; it does not establish that every possible event was assessed or that no event could occur outside the recorded period.

Because no intervention comparison is described, these safety figures should not be interpreted as evidence about comparative risk between treatments. They are registry-reported counts for the listed sample and do not establish safety for other populations or settings.

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

The registry record establishes that TIGER Kids was designed to investigate activity, sedentary behavior, and cardiometabolic risk in relation to severe obesity during childhood and adolescence. It also describes interest in race as a possible modifier of associations and in the contribution of fat accumulation. The primary outcome was defined around accelerometer-measured minutes at baseline and Year 2.

Those design details do not answer whether activity changed, whether obesity or fat accumulation was associated with a particular outcome, or whether associations differed by race. The registry reports 0 analyses and does not provide numerical estimates, uncertainty intervals, or test results for the primary or secondary questions. The completed status indicates the study’s registry status, not that its results are available in the record.

In general, an observational association does not by itself demonstrate causation. Participants are not described as randomly allocated, and the record does not report how potential confounding was addressed. Even if an association estimate were available, interpretation would depend on its precision, measurement quality, analysis methods, and the plausibility of alternative explanations. Those result details are not reported in the registry record.

The accelerometry analysis is reported for 284/342 children with complete data. That defines the reported primary analysis population, but it does not establish how representative that group was of all enrolled children. The record also does not provide the actual activity estimates or describe missing-data methods. Consequently, the available information supports a description of the study’s purpose, endpoint, and measurement approach, but not a conclusion about the direction or size of any result.

13. Why This Trial Matters Statistically

This study is statistically relevant because its questions involve repeated measurement and several related outcomes. Activity and sedentary behavior are represented as time measured by accelerometer at baseline and Year 2, while the stated objectives also address cardiometabolic risk, race-related effect modification, and fat accumulation. Those aims raise distinct analytical questions: estimating change over time, describing associations, and assessing whether associations vary across groups.

In general, these questions require clear definitions of the outcome, analysis population, and statistical model. Repeated measurements from the same participant are not independent observations, and an analysis should account for that structure when appropriate. Examining several outcomes and possible modifiers also makes a prespecified analysis strategy important for interpreting evidence and uncertainty. The registry record does not report those methods or any corresponding analyses, so it cannot show how these statistical challenges were addressed.

The record does provide useful information about the intended primary measure and the number of participants with complete accelerometry data. It describes the use of an accelerometer and the requested wear schedule, allowing readers to understand the measurement concept. But without estimates, uncertainty intervals, and methodological details, the stated objectives cannot be translated into conclusions about the data.

The statistical value of the record is therefore primarily descriptive: it documents the intended questions, endpoint, and analysis population while leaving results and key analysis details unreported. Distinguishing aims from findings is essential, especially for an observational study in which associations should not automatically be read as causal effects.

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 main limitation for interpreting this record is the absence of reported outcome analyses. Although the study is marked completed and lists 8 outcome measures, it reports 0 analyses. The primary outcome has no reported mean, standard deviation, estimate of change, confidence interval, or test result. Findings for the stated secondary questions are also not reported in the registry record.

The registry reports that 284/342 children had complete accelerometry data and were included in analysis. It does not describe reasons for incomplete data, compare included participants with those lacking complete measurements, or report a missing-data method. This limits assessment of how the analyzed accelerometry group relates to the enrolled sample.

The study is not a randomized comparison, and allocation is not stated. The record does not report a covariate adjustment strategy or other details needed to assess confounding in associations involving obesity, race, fat accumulation, and activity or cardiometabolic risk. The stated aims therefore cannot be interpreted as causal findings.

Measurement details are described, including device type and intended wear schedule, but actual adherence, data processing, and activity-category definitions are not reported in the registry record. The statistical model, multiplicity approach, and sample-size justification for the study are also not reported. These omissions prevent a full assessment of measurement quality, precision, and analytical robustness.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Translational Investigation of Growth and Everyday Routines in Kids — NCT02784509.
• Registry record last updated 2024-12-24; status last verified 2024-11.
• Results first posted 2024-12-24.
• 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

NCT02784509, TIGER Kids, is a completed study sponsored by Pennington Biomedical Research Center. The registry lists enrollment of 342, with a start date of 2016-06 and primary completion in 2020-09. Its aims concern severe obesity, physical activity, sedentary behavior, cardiometabolic risk, race, and fat accumulation during childhood and adolescence.

The primary outcome is change in accelerometer-measured minutes of sedentary behavior, light physical activity, and moderate-to-vigorous physical activity from baseline to Year 2. The record reports that 284/342 children had complete accelerometry data and were included in analysis. It lists 8 outcome measures but reports 0 analyses, so outcome estimates and inferential results are not reported in the registry record.

The safety fields list 0 serious adverse events, 0 other adverse events, and 0 deaths among a group of 342 participants at risk. The record does not describe a randomized comparison or report detailed statistical methods.