Enhancing BodyWorks: A Canine Health Literacy Module: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Enhancing BodyWorks: A Canine Health Literacy Module (NCT04516252), a randomized na study. The primary outcome is Change in Mean Physical Activity Associated With the BodyWorks + Canine Health Literacy Intervention for Parents and Adolescents.

2. Clinical Question

The study asks whether adding a canine health-literacy component to a family lifestyle program is associated with a different pattern of physical activity among participating adolescents and parents. Its primary endpoint is expressed separately for parents and adolescents, rather than as a single combined result. The endpoint description refers to tracker measurements at the beginning and end of the intervention period, using qualifying days with more than 100 steps.

The registry identifies the study as randomized and parallel. The published record describes a total enrollment of 202, but that figure is not the number contributing valid data to the primary endpoint. For that endpoint, the record lists 12 parents and 16 adolescents in the intervention group, and 11 parents and 16 adolescents in the control group. These are described as participants with at least 7 days of valid tracker data. The registry does not report the primary outcome values or a numerical comparison between groups, so the direction and precision of any difference cannot be assessed from the record.

3. Trial Design

This completed study, NCT04516252, is titled Enhancing BodyWorks: A Canine Health Literacy Module. It was sponsored by Children's Hospital Los Angeles and is listed as a randomized, single-masked, parallel-group behavioral study. The registry lists the phase as not applicable. The study start date is 2021-02-27, and the primary completion date is 2025-01-13.

The study population is described as adolescents with overweight or obesity who own dogs, together with their parents. The intervention was designed to enhance the Department of Health and Human Services BodyWorks program with a canine health-literacy module concerning canine physical activity, nutrition, and behavior. The intervention description also names ecological momentary assessment and physical-activity trackers. The control description includes trackers for children, parents, and dogs, and surveys for children, without the canine curriculum being described as part of the control.

Both groups therefore had several study activities in common. The registry distinguishes the groups principally by the canine curriculum included in the intervention description. It does not report the exact allocation procedure, how masking was implemented, or which participants or staff were masked. It also does not report whether allocation was stratified or whether other design restrictions were used.

The registry lists enrollment as 202. That enrollment figure should not be confused with the endpoint-specific participant counts: the primary outcome description lists participants with at least 7 days of valid tracker data separately for parents and adolescents in each group. The record does not explain all reasons for the difference between enrollment and those endpoint counts. The study status is completed, but the registry record does not provide a numerical primary-outcome result or an analysis entry. Completion status alone does not show what the estimated intervention effect was.

4. Participant Flow and Accounting

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

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Total parents, adolescents. I group: (12 parents, 16 adolescents); C group: (n= 11 parents, 16 adolescents). Below, the groups are parents and adolescents showed separately. These are participants with \>= 7 days of valid data (\>100 steps per day).

5. Baseline Characteristics

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

Population: Total parents, adolescents. I group: (46 parents, 51 adolescents); C group: (n= 50 parents, 55 adolescents)

6. Primary Endpoint

The registry lists the primary outcome as Change in Mean Physical Activity Associated With the BodyWorks + Canine Health Literacy Intervention for Parents and Adolescents, measured over Baseline to 7 weeks.

The primary endpoint concerns mean physical activity, measured in steps per day, for parents and adolescents. The stated timeframe is baseline to 7 weeks. The registry describes using physical-activity trackers and determining a mean based on the average of the first 7 days and the last 7 days of the intervention, with valid data defined as more than 100 steps. The endpoint population is further described as participants with at least 7 days of valid data.

Steps per day provide a quantitative measure of movement captured by a wearable tracker. A continuous measure can retain variation across participants and can be summarized by a mean and standard deviation, as specified in the registry. Reporting parents and adolescents separately preserves the distinction between these groups, whose activity patterns and roles in the intervention may differ.

Baseline-to-endpoint change is intended to describe how the measured activity changed during the study period. A comparison between the randomized groups can help distinguish change associated with the enhanced program from change observed in the control group, subject to the study's analysis and data quality. The registry record does not give the actual mean values, changes, group contrast, uncertainty interval, or statistical test for this endpoint. Consequently, the endpoint definition is available, but its observed result and precision are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry characterizes the primary measure as the mean of a continuous outcome, with standard deviation as its dispersion measure. General statistical explanation: a mean describes the central level of a quantitative measure, while a standard deviation describes how spread out individual measurements are around that mean. They answer different questions; the standard deviation is not itself an estimate of how precisely a group mean or between-group contrast has been estimated.

What does the endpoint summarize?

The measured quantity is steps per day from physical-activity trackers. The description specifies a baseline-to-7-week timeframe and refers to an average of the first 7 days and the last 7 days of the intervention. It also defines valid data using a threshold of more than 100 steps and describes the endpoint population as participants with at least 7 days of valid data. These details define the intended measurement and eligibility for the reported endpoint, but the registry does not state the actual group means or changes.

General statistical explanation: repeated daily measurements can vary because of ordinary day-to-day behavior, device use, or measurement conditions. Averaging observations can produce a summary that is less dominated by a single unusual day, but it also means that the result depends on how valid days are defined and how incomplete records are handled. The registry gives a validity threshold and a minimum number of valid days, but it does not report additional rules for selecting days or calculating each participant's summary.

How would a randomized comparison be interpreted?

Random assignment is intended to make groups comparable on average at the start of a study, although it does not guarantee that every characteristic will be balanced. A comparison of change between the groups can help estimate the difference associated with assignment to the enhanced program, provided that the analysis and data collection support that interpretation. The record does not state whether the primary analysis compared change scores, adjusted for baseline, or used another approach. Such details are not reported in the registry record.

General statistical explanation: an estimate is more informative when accompanied by an uncertainty interval. A confidence interval describes a range of values compatible with the data under the statistical model and its assumptions. It communicates precision as well as the direction and size of an estimated effect. A p-value addresses compatibility with a specified null hypothesis under an analysis model; it does not measure the size or importance of an effect. The registry record does not report a confidence interval or p-value for the primary outcome, so neither the effect's precision nor a test result can be assessed.

Why can over-dispersion matter?

General statistical explanation: over-dispersion occurs when observed variability is greater than a model assumes. If a model understates variability, uncertainty estimates can be too narrow and statistical tests can be misleading. The relevance of over-dispersion depends on the type of outcome and model. The primary measure is a continuous steps-per-day outcome, and the registry describes the mean and standard deviation, but it does not report a fitted model or a check for over-dispersion. It would therefore be inappropriate to claim that this issue was present or addressed in the analysis.

What role do sample-size illustrations play?

General statistical explanation: sample-size planning asks how many participants might be needed to detect an effect under stated assumptions. A planning illustration based on an observed effect is not the same as a trial's original design calculation, and it is not observed power. The record describes assumptions for planning illustrations, including a two-sided significance level of 0.05, equal allocation, a normal approximation, and effects defined as fractions of an observed effect. It does not report specific resulting sample-size values in the information available for this explanation, nor does it state that these assumptions were used to plan the trial.

The record also does not report the original sample-size justification, any interim analyses, or the statistical analysis plan. Those omissions prevent assessment of whether the final analysis followed a prespecified approach or how planning related to the endpoint-specific data. Statistical interpretation should therefore remain limited to the outcome definition and design information that the registry does report.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 8 outcome measures, but gives 0 analysis entries. It does not describe a multiplicity procedure, such as a prespecified hierarchy of outcomes or an adjustment for testing multiple hypotheses. Without those details, the registry record does not establish how the investigators handled the possibility of false-positive findings across multiple outcomes or analyses. This is a documentation gap in the record, not evidence that no such procedure was used in other study materials.

The primary endpoint description defines valid tracker data as more than 100 steps and states that endpoint participants had at least 7 days of valid data. It lists endpoint-specific participants separately for parents and adolescents in the intervention and control groups. The registry does not explain how participants without enough valid days were handled, whether missing days were imputed, or what assumptions were used about missing observations. It also does not report the amount or pattern of missing tracker data beyond the endpoint counts.

The analysis populations are not fully described. The record does not say whether the primary analysis followed an intention-to-treat principle, included only participants with valid outcome data, or used another defined population. The listed valid-data counts identify participants described for the endpoint, but do not by themselves establish the analysis set or explain exclusions.

Details of statistical handling for missing data and multiplicity are not reported in the registry record. These details matter because different choices can affect estimates and uncertainty, particularly when outcome availability differs between groups or when many outcomes are examined. The posted information is insufficient to assess those possibilities.

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 5% reporting threshold.

The registry reports no serious adverse events, other adverse events, or deaths in each of the listed parent and adolescent intervention and control groups. It also lists the number at risk separately for those four groups: 46 parents in intervention, 50 parents in control, 51 adolescents in intervention, and 55 adolescents in control. These are safety figures in the registry record and should be read within their listed group categories.

Zero reported events means that the record lists no events in those categories; it does not prove that the intervention has no risks or that no events occurred outside the registry's reporting definitions or observation period. The registry record does not describe the safety follow-up window, the method of event collection, or how an event was judged related to an intervention. The listed figures also do not provide information about event severity beyond the serious-versus-other categories or about outcomes not captured in those categories.

These safety counts do not substitute for the primary physical-activity outcome. They address reported adverse events and deaths, while the primary endpoint concerns steps per day. No causal safety conclusion should be drawn from zero event counts alone, particularly without further information about collection and follow-up procedures.

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

This registry record establishes the study's question and intended comparison: a canine health-literacy module added to BodyWorks versus the described control condition, with physical activity measured for parents and adolescents. It defines the primary endpoint as steps per day over baseline to 7 weeks and specifies the validity threshold used for tracker data. It also reports that the study is completed and lists endpoint-specific participants with valid data.

What the record does not establish is the observed result. There are no reported group means, changes, between-group estimates, confidence intervals, or p-values for the primary endpoint. Without those statistics, it is not possible to describe the direction or size of any difference, judge how precise an estimate was, or determine whether the groups showed similar patterns. A completed study status is not a result, and the study's public-health rationale is not evidence of an effect.

The record also does not establish how the analysis handled missing observations, whether the primary analysis followed an intention-to-treat principle, or how multiple outcomes were considered. These are important qualifications for interpreting any study result, but their absence from the registry record should not be mistaken for proof that investigators did not address them elsewhere.

Accordingly, the registry supports a description of the design, population, endpoint, and reported safety counts, but not a conclusion about the intervention's effect on physical activity. It does not establish that the canine curriculum changed activity or that it had no effect. A numerical estimate with an uncertainty measure and a clear account of the analysis would be needed to evaluate the primary comparison. The available information is descriptive of the planned and registered study, rather than a complete statistical report of its primary result.

13. Why This Trial Matters Statistically

This study is statistically interesting because it evaluates a behavioral program with a family and human-animal context, while measuring activity separately for parents and adolescents. That structure highlights a practical issue in trial analysis: one intervention can involve multiple participants within a family, but the registry does not specify whether or how any within-family dependence was handled. It would be inappropriate to assume a particular modeling method from the design description alone.

The endpoint also relies on repeated tracker observations rather than a single self-reported activity measure. The registry defines a threshold for valid daily data and a minimum number of valid days. Those rules make measurement quality part of the analysis question: an estimate represents the participants and observations meeting the endpoint's stated validity conditions. The record does not describe additional missing-data methods or how the resulting analysis population relates to randomized enrollment.

Another statistical point is the distinction between an endpoint definition and a result. The registry is sufficiently detailed to identify the primary measure, timeframe, and comparison, but it does not post numerical results or an analysis entry. Consequently, readers can understand what was intended to be estimated without being able to assess its magnitude or uncertainty. This distinction is essential when interpreting completed trials in a registry.

The study also lists multiple outcomes, while the record does not provide a multiplicity strategy or a statistical analysis plan. This leaves open how outcomes were prioritized and how inference was intended to be controlled. These gaps do not invalidate the design, but they limit independent statistical appraisal based on the registry alone. The case illustrates why complete reporting of estimates, uncertainty, missing-data handling, and analysis populations is important for interpreting behavioral trial results.

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 primary limitation for interpreting this trial from the registry is the absence of numerical primary-outcome results. The outcome definition is available, but group values, changes, a between-group estimate, and measures of uncertainty are not reported in the registry record. The listed 0 analysis entries likewise mean that the registry does not contain an analysis entry for the comparison; they do not show whether results were analyzed or reported elsewhere.

The primary endpoint depends on valid tracker data, defined as more than 100 steps, and the description refers to participants with at least 7 days of valid data. The registry does not give the missing-data rules, the number or pattern of invalid days, or the reasons participants may not have contributed valid endpoint data. It also does not fully define the primary analysis population. The endpoint counts should therefore be interpreted as the participants described for valid data, not as a complete account of outcome availability or exclusions.

The record does not explain the randomization procedure, the implementation of single masking, or the statistical model used for the outcome. It does not report whether results were adjusted for baseline activity, how repeated observations were summarized for each participant, or whether any family-level dependence was considered. These methods are not reported in the registry record.

The registry identifies 8 outcome measures but does not state a multiplicity strategy. It also does not provide the original sample-size justification, interim-analysis details, or a statistical analysis plan. Safety follow-up procedures and the observation period for adverse events are also not described. These reporting limits constrain assessment of precision, robustness, and generalizability from the registry alone; they do not establish that the omitted procedures or analyses were absent from the study.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Enhancing BodyWorks: A Canine Health Literacy Module — NCT04516252.
• Registry record last updated 2026-07-01; status last verified 2026-06.
• Results first posted 2026-07-01.
• 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.

18. Record Summary

NCT04516252 is a completed randomized, single-masked, parallel-group behavioral study sponsored by Children's Hospital Los Angeles. It evaluated a canine health-literacy module intended to enhance BodyWorks for adolescents with overweight or obesity and their parents. The registry lists enrollment as 202 and describes physical-activity trackers and child ecological momentary assessment in both groups, with the canine curriculum included in the intervention description.

The primary outcome was mean physical activity in steps per day from baseline to 7 weeks, measured using tracker data. The record lists endpoint participants with at least 7 days of valid data separately for parents and adolescents. It does not report numerical primary-outcome results, an analysis entry, confidence intervals, or p-values. The record lists no serious adverse events, other adverse events, or deaths in the four safety groups. Missing-data methods, analysis populations, and multiplicity handling are not reported in the registry record.