Activity, Adiposity, and Appetite in Adolescents 2 Intervention: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Activity, Adiposity, and Appetite in Adolescents 2 Intervention (NCT05443347), a randomized na study. The primary outcome is Appetite- Subjective.

2. Clinical Question

3. Trial Design

The registry record identifies this as a randomized, double-masked, parallel-group trial. Participants were assigned to structured exercise or newsletter control. A parallel design compares groups assigned to different interventions over the same study period; randomization is intended to support a fair comparison by reducing systematic differences in assignment. The record does not explain how the random sequence was generated or concealed.

The study is marked completed. Its recorded start date is 2022-09-14, and its primary completion date is 2024-11-25. Registry enrollment is 31. The brief summary describes a planned enrollment of N=44, so the planned figure and recorded enrollment differ. The posted primary-outcome arm sizes are 14.0 for structured exercise and 11.0 for newsletter control. The safety populations are reported separately. The record does not explain the differences among these participant counts, nor does it describe participant flow or analysis-population rules.

The intervention description gives examples of supervised aerobic activity, including treadmill walking and stationary cycling, and states an intended expenditure of 400 kcals/session, approximately 45-60 min/session, on three days/week. The newsletter description says newsletters were sent biweekly and included parenting tips, praise statements, activities, and recipes. Both interventions are classified as behavioral. The planned duration is three months, while the primary outcome timeframe is recorded as 3 months.

The study phase is listed as NA. The sponsor is Children's Mercy Hospital Kansas City. Additional details about masking procedures, the people who were masked, adherence, exercise supervision, and deviations from the planned interventions are not reported in the registry record. Consequently, the design label and intervention descriptions establish the broad comparison, but do not describe all procedures needed to evaluate implementation.

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 Appetite- Subjective, measured over 3 months.

The primary outcome is titled Appetite- Subjective and measures hunger using self-rated visual analogue scales following a fixed-calorie meal. Participants rated hunger on a scale from 0, “I am not hungry at all,” to 100, “I have never been more hungry.” The reported endpoint is the area under the curve (AUC) for hunger, with units of score*minute, at 3 months.

AUC represents the area formed by the response across the measurement period. In general, it can summarize both the level and duration of a response rather than relying on a single rating. The registry description says the area was calculated using the trapezoid approach. Measurement time points and the complete timing protocol are not reported in the registry record, so the exact temporal detail behind the AUC cannot be assessed from the record.

The outcome is reported as a least-squares mean with standard error. In general, a least-squares mean is a model-based group estimate; the specific model and any adjustment variables are not reported in the registry record. The posted values therefore identify the outcome and reported summary statistic, but do not establish which covariates, if any, contributed to the estimates.

7. Results Posted in the Registry

• Structured Exercise: mean 6,282 versus 8,738 on control; difference -2,456 (95% CI -5,572 to 659.58), standardized effect d = -0.62; z-test p = 0.122.

8. Statistical Interpretation

9. Statistical Methods Explained

What does a randomized parallel-group design compare?

In general, randomization assigns participants to study groups by chance. Its purpose is to reduce the risk that the groups differ systematically because of how assignments were made. A parallel-group design follows the assigned groups and compares their outcomes. This trial is recorded as randomized and parallel, but the sequence-generation and allocation-concealment procedures are not reported in the registry record. The record also does not explain how double masking was implemented or which people remained unaware of assignment.

Randomization does not guarantee that every observed difference is caused by the intervention. In a small study, chance differences between groups can remain, and loss to follow-up or differences in adherence can affect the comparison. The registry record does not provide participant flow, adherence results, or detailed intervention fidelity, so those aspects cannot be evaluated from the posted outcome summary.

What do the group estimates represent?

The outcome is summarized using least-squares means and standard errors. In general, a least-squares mean is a model-based estimate of a group mean. A standard error describes the precision of an estimated mean: smaller standard errors generally indicate more precise estimates, while larger ones indicate more uncertainty. A standard error is not the same as a standard deviation, which describes variability among individual observations.

The registry does not report the model formula, covariates, assumptions, or missing-data method. The least-squares label should not be taken as evidence of a specific adjustment set. The posted arm estimates and contrast can be described, but the model-based details behind them remain unknown from the registry record.

How should the group contrast be read?

The mean difference is reported as -2456.0 score*minute for structured exercise relative to newsletter control. The sign indicates the direction of the reported contrast, with a negative value corresponding to a lower estimated hunger AUC in the exercise group. The estimate is expressed in the endpoint's units, making it a difference on the recorded scale rather than a standardized effect.

The comparison also reports a confidence interval and an unadjusted p-value. These are related but distinct summaries. A confidence interval conveys a range of values compatible with the data and the interval's statistical assumptions. A p-value summarizes compatibility with a specified null hypothesis under the test assumptions. Neither statistic communicates clinical importance by itself, and neither removes uncertainty about unreported analysis choices.

The outcome comparison is described as unadjusted in the posted statistical summary. The record does not describe whether the least-squares means themselves involve adjustment, nor does it give details that reconcile the estimate label with the comparison method. No discrepancy is recorded for the comparison. Interpretation should therefore track the quantities and labels as posted and avoid inferring additional model specifications.

What does AUC add to a subjective rating?

In general, a visual analogue scale records a participant's subjective rating at a measurement time. An AUC combines ratings across time, accounting for both the height of the response and how it changes during the observation period. The registry says the AUC was calculated with the trapezoid approach, which approximates the area between measured points by connecting them with straight lines. The outcome's score*minute unit reflects a score accumulated over time.

The registry record does not give the specific rating schedule, number of assessments, or exact duration used for the AUC. Those details matter for reproducing the measure and judging whether the observation period captures the response of interest. The described scale anchors clarify the direction of hunger ratings, but do not supply information about measurement reliability or the smallest meaningful difference.

What does the p-value say, and what does it not say?

The unadjusted p-value is 0.122. In general, a p-value assesses how unusual data at least as incompatible with a null hypothesis would be if that null hypothesis and the test assumptions were correct. It is not a measure of the probability that the result happened by chance, nor does it determine whether an effect matters. Its interpretation also depends on the analysis plan, including how many outcomes or comparisons were considered. That plan is not reported in the registry record.

The posted estimate and confidence interval are useful alongside the p-value because they communicate the direction, scale, and uncertainty of the contrast. Here, the confidence interval crosses zero, and the point estimate is not precise enough to determine a single direction or magnitude with confidence. That statistical uncertainty is distinct from questions of design quality, outcome relevance, and generalizability.

How do planning illustrations differ from trial results?

The sample-size illustrations use the observed effect as a planning reference and consider smaller fractions of that effect. They are not an analysis of the probability that this completed trial detected an effect. In general, power is a design-stage probability calculated under specified assumptions for a study of a particular size and target effect. A planning calculation does not establish that the trial had a particular observed power, and it does not modify the uncertainty in the posted estimate.

The record lists a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation for these illustrations. It does not report the original design assumptions for the trial or a sample-size justification. Thus, the planning calculations can be read as hypothetical design illustrations based on the observed result, not as confirmation of the trial's intended design or analytic plan.

10. Confidence Intervals and Precision

The 95% confidence interval for the reported mean difference is -5572 to 659.6 score*minute. A confidence interval is a range of estimates compatible with the observed data and the method's assumptions. In repeated use of the same procedure under its assumptions, intervals constructed this way would cover the true value at the stated rate. The interval is not a probability statement about the fixed true difference in this particular trial.

The interval includes zero and spans negative and positive values. This means the posted estimate does not precisely distinguish a lower AUC in the exercise group from no difference or a higher AUC. The point estimate, -2456.0 score*minute, is only one value within a substantially broader range of plausible contrasts. The interval's breadth signals limited precision for this comparison.

The arm-level standard errors are 1075.0 for structured exercise and 1171.0 for newsletter control. They describe uncertainty in the estimated arm means, not the range of individual hunger AUC values. No confidence intervals for the arm means are listed. The record reports 14.0 participants for the exercise outcome estimate and 11.0 for the control estimate, but does not explain why those counts differ from registry enrollment or the safety populations.

Precision depends on factors such as the amount of information available, variability in measurements, and the analysis method. The registry record does not provide the underlying participant-level data, missing-data details, or full model specification, limiting further assessment. Statistical precision should also be distinguished from practical importance: the record does not report a threshold for a meaningful change in hunger AUC.

11. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning display gives the number of participants per arm, not total events. It considers planning for 100% of the observed effect, 75% of the observed effect, and 50% of the observed effect. For each assumed effect, it gives separate participant counts for 80% power and 90% power. The 80% column is the number of participants per arm in the illustration for an 80% chance of detecting the specified effect under its assumptions; the 90% column has the corresponding target of 90%.

The planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The assumed effect is the stated fraction of the observed effect. The original trial's own sample-size justification and design assumptions are not reported in the registry record. These figures are planning illustrations, not observed power.

Smaller target effects require more participants per arm in the displayed scenarios. That pattern reflects a general design principle: when the difference a study aims to detect is smaller, more information is usually needed to distinguish it from random variation under the same assumptions. The illustrations use the observed effect as their starting point, so they should not be treated as independent evidence about the true effect or as a guarantee that a future study would achieve the stated power.

The curve should be read in the same planning context as the participant counts. Its assumptions define the scenario being illustrated; it does not show the probability that this completed trial found an effect. A planning curve cannot resolve missing information about the original protocol, such as the effect size originally targeted, anticipated variability, or allowance for participant loss. Those details are not reported in the registry record.

12. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -2456.000; pooled standard deviation σ = 3962.653.
2. n = 2 × (1.96 + 0.842)² × 3962.653² / -2456.000² = 40.9, rounded up to 41 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- -2456                      # observed difference in means
sigma <- 3962.65315161446                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(5443347)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 41 (80% power), 55 (90% power)
 75% of observed effect: n per arm = 73 (80% power), 98 (90% power)
 50% of observed effect: n per arm = 164 (80% power), 219 (90% power)
power.t.test: 41.8 
Simulated power at n = 41 per arm: 0.793 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

13. Multiplicity, Missing Data and Analysis Populations

The registry record lists three outcome measures, identifies Appetite- Subjective as the primary outcome, and reports no posted secondary outcomes. It does not describe how the primary outcome was selected from the outcome set, whether additional outcomes or time points were planned, or whether there were multiple comparisons within the primary analysis. The analysis plan is not reported in the registry record.

Multiplicity arises when several statistical tests are conducted. In general, the more tests considered, the greater the chance that at least one result appears unusual by chance if no true effects are present. Statistical plans may address this through prespecified primary outcomes, adjustment procedures, or a hierarchy of tests. The registry record does not report a multiplicity strategy. The posted p-value is explicitly unadjusted, so it should not be interpreted as accounting for an unreported family of tests.

Missing-data handling is also not reported in the registry record. The primary outcome summaries list 14.0 participants in structured exercise and 11.0 in newsletter control; registry enrollment is 31, and the safety groups list 19 and 12 participants at risk. The record does not describe whether these populations differ because of unavailable measurements, eligibility criteria, exclusions, or another reason. It also does not report how incomplete AUC measurements were handled.

Analysis-population definitions are not reported in the registry record. In particular, it is not clear whether the posted outcome comparison includes all randomized participants, only participants with measured outcomes, or another defined group. The record does not specify an intention-to-treat analysis, per-protocol analysis, or other population. Without participant flow and explicit population definitions, the extent to which the outcome summaries preserve the randomized comparison cannot be assessed.

These omissions do not establish that the study failed to use a prespecified plan or a particular missing-data method; they mean those details are unavailable in the registry record. The posted comparison can be interpreted as reported, while its sensitivity to missing outcomes, the full testing strategy, and the analysis population remain uncertain.

14. 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.

Most frequent non-serious adverse event terms

The serious adverse event figures list 0 affected participants in the structured-exercise group among 19 at risk and 0 in the newsletter-control group among 12 at risk. Deaths are recorded as 0 in each group. The registry record lists no serious adverse event terms.

For other, non-serious adverse events, the record lists 0 affected participants among 19 at risk in structured exercise and 2 among 12 at risk in newsletter control. These are the registry's reported counts, not an assessment of whether events were caused by an intervention. The record does not give event descriptions, severity details, timing, or attribution, and it does not explain the difference between the safety populations and the primary-outcome populations.

Counts from a study of this size are descriptive and do not rule out uncommon events. They also do not support a comparative safety conclusion without fuller information on ascertainment, follow-up, and event classification. The safety figures should be read as the adverse-event information posted in the registry record, not as a complete account of all possible harms.

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

The result describes a comparison of subjective hunger AUC after a fixed-calorie meal at 3 months. The reported mean difference was -2456.0 score*minute for structured exercise relative to newsletter control, with a 95% confidence interval from -5572 to 659.6 and an unadjusted p-value of 0.122. The point estimate is in the direction of lower AUC in the exercise group, but the interval includes zero and a range of values on both sides.

This is not a definitive estimate of the effect of exercise on appetite in adolescents generally. The registry record does not provide detailed eligibility criteria, the complete analysis plan, the missing-data approach, participant flow, or the model specification. The outcome arm sizes are limited, and the posted confidence interval shows substantial uncertainty in the contrast. Generalization beyond the participants and circumstances represented by these results is therefore not established by the registry record.

The primary endpoint is a self-rated hunger measure summarized over time. It is not a direct measure of energy balance, metabolism, insulin sensitivity, body weight, or overall health. Although those topics appear in the study conditions and objective, outcome results for them are not posted in the registry record. Nor does the result show whether any observed difference was mediated by physical activity or another mechanism.

The study's registry status is completed, but completion does not resolve the uncertainty in the estimate. The statistical result should be understood as an imprecise comparison of the reported groups on the specified outcome, rather than as proof of a particular effect or no effect. The record does not report a threshold for a meaningful difference, so statistical estimates cannot be translated into a claim about practical importance.

The adverse-event counts are also limited to the figures recorded: no serious adverse events or deaths are listed, and other adverse events are reported in the control group. These data do not establish comparative safety. Taken together, the record supports a cautious account of the measured outcome and its uncertainty, not a medical recommendation or a broad conclusion about treatment benefit.

16. Why This Trial Matters Statistically

This trial is statistically relevant because it places a subjective, time-varying appetite measure in a randomized comparison of structured exercise and newsletter control. Using hunger AUC can summarize ratings across a post-meal observation period rather than relying on one rating. The registry describes the scale anchors and trapezoid calculation, making the broad construction of the endpoint understandable, even though the measurement schedule is not reported.

The result also illustrates why an estimate should be read with its interval. The mean difference is -2456.0 score*minute, but the 95% confidence interval extends from -5572 to 659.6. The interval includes zero and is broad relative to the point estimate, so the comparison remains uncertain. A single point estimate or p-value would not communicate that uncertainty as clearly.

Several design and reporting details matter for interpreting this comparison. The registry lists enrollment of 31, while the primary outcome arm sizes and safety populations are reported separately. The record does not reconcile those counts or describe participant flow and missing data. It also does not report the model specification, analysis populations, or a multiplicity strategy. These details are important because they affect how confidently readers can connect the posted result to the randomized assignment and prespecified question.

The sample-size illustrations offer a separate statistical lesson: planning for smaller target effects generally requires more participants under otherwise similar assumptions. Those illustrations are based on the observed effect and are not evidence of the original design rationale or of observed power. Keeping planning calculations distinct from the trial's result helps prevent a hypothetical design exercise from being mistaken for an evaluation of the completed study.

Overall, the record offers a focused example of how outcome definition, effect direction, uncertainty, and incomplete analysis details shape interpretation. Its value is in clarifying what was measured and what the posted comparison can support, while making the remaining uncertainty visible.

17. 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.

Several trial-specific limitations restrict interpretation. The primary outcome result is reported for 14.0 participants in structured exercise and 11.0 in newsletter control, while registry enrollment is 31 and the safety populations are 19 and 12. The registry record does not explain these differences or provide a participant flow diagram or account. It is therefore unclear how the outcome and safety groups relate to the randomized population.

The registry does not report detailed eligibility criteria, demographic characteristics, adherence, intervention fidelity, or the handling of participants who did not complete the intervention. It describes the planned exercise program and newsletter control but does not establish how closely those interventions were delivered as described. The control description is incomplete, so its full content cannot be evaluated.

The analysis details are limited. The model behind the least-squares means, covariates, analysis population, assumptions, and missing-data method are not reported in the registry record. The record does not describe multiplicity procedures, despite listing three outcome measures, and no secondary outcome results are posted. The original sample-size justification is also not reported; the displayed planning illustrations use the observed effect and should not be treated as a reconstruction of the original design.

The outcome is subjective, and the record does not give the visual-analogue rating schedule, the AUC observation duration, or evidence about measurement reliability. It also does not report a threshold for a practically meaningful difference. The confidence interval for the group contrast is wide and includes zero, leaving considerable uncertainty about the size and direction of the underlying difference.

Finally, the record's focus is a specific appetite outcome at 3 months. Results for the broader metabolic and energy-balance objectives are not posted. The available result should not be extended to those unreported outcomes or to populations and settings not described by the registry.

18. Related Tutorials

19. Related Statistical Calculators

20. Sources

• ClinicalTrials.gov: Activity, Adiposity, and Appetite in Adolescents 2 Intervention — NCT05443347.
• Registry record last updated 2026-02-12; status last verified 2026-02.
• Results first posted 2026-02-12.
• 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.

21. Record Summary

NCT05443347 is recorded as a completed, randomized, double-masked, parallel-group study sponsored by Children's Mercy Hospital Kansas City. The registry enrollment is 31. The brief summary describes a planned three-month comparison in sedentary adolescents with overweight or obesity, assigning participants to structured exercise or newsletter control.

The primary outcome is subjective hunger AUC after a fixed-calorie meal at 3 months, measured in score*minute. The posted arm estimates are 6282.0 for structured exercise and 8738.0 for newsletter control. The reported mean difference is -2456.0, with a 95% confidence interval of -5572 to 659.6 and an unadjusted p-value of 0.122.

The registry record does not report the full analysis plan, participant flow, missing-data handling, analysis populations, or results for secondary outcomes. Its posted comparison should be read as an uncertain estimate for the specified endpoint, with these reporting limits in mind.