Animal Assisted Intervention With Dogs for Children With ADHD: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Animal Assisted Intervention With Dogs for Children With ADHD (NCT05102344), a randomized na study. The primary outcome is ADHD-Rating Scale (ADHD-RS) at 8 Weeks.

2. Clinical Question

The comparison is between two treatment packages: social skills training with therapy dogs and social skills training without them. It therefore addresses the contrast between those packages, not the effect of training versus no treatment. The registry describes the study as a pilot and identifies physiological markers of HPA axis and ANS activity as additional interests. The listed primary measure is a symptom-rating outcome, while the physiological measures are secondary outcomes. The registry record does not report a separate primary question about whether a marker predicts or modifies treatment response in a formal analysis.

3. Trial Design

The registry describes a randomized, single-masked, parallel-group pilot study sponsored by the University of California, Irvine. It is marked completed, with enrollment of 39. The record lists the study start as 2021-09-17 and primary completion as 2023-08-30. The specific person or people masked are not reported in the registry record.

Both groups received active behavioral social skills training. Participants assigned to Animal Assisted Intervention received that training accompanied by live therapy dogs; participants assigned to Psychosocial Treatment as Usual received the training alone. This active-comparator design focuses the contrast on the addition of the therapy-dog component within a social-skills intervention. The registry does not report enough detail to describe session schedules, treatment fidelity, or the procedures used to maintain masking.

The primary outcome is the ADHD-Rating Scale (ADHD-RS) at 8 weeks. The registry describes it as a parent and teacher rating measure of inattention, hyperactivity, and impulsivity, while the primary result is specified as a mean and standard deviation. The record also lists physiological outcomes, including diurnal and acute salivary cortisol measures and salivary alpha-amylase measures. The brief study description says the pilot aims to replicate earlier work and examine whether candidate physiological markers differ between groups or moderate response.

The registry record does not report the original sample-size justification, the planned statistical analysis, or the identity of the masked party. It also does not report a formal analysis population. Those omissions limit how far the posted group summaries can be interpreted as a complete account of the trial's planned analysis.

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 ADHD-Rating Scale (ADHD-RS) at 8 Weeks, measured over At 8 weeks.

The primary endpoint is the mean ADHD-RS score at 8 weeks. The scale is described as a parent and teacher rating of symptoms of inattention, hyperactivity, and impulsivity, with a stated range from 0.00 to 54.00. Lower scores indicate less impairment. The reported primary results are means and standard deviations for each treatment group.

A symptom-rating scale gives a structured way to quantify behavioral features relevant to ADHD and to compare group averages at a specified follow-up. Using a continuous score retains information about differences in score values rather than reducing participants to broad categories. The reported endpoint is a group mean, however, and does not show the range of individual responses or how many participants experienced a change considered important to them.

The parent-rated outcome is relevant to the intervention's stated aim of addressing ADHD symptoms, but it is not a direct physiological measure. The study's separate salivary outcomes concern candidate biological markers, so they answer related but distinct questions. The registry record does not report a threshold for a clinically meaningful ADHD-RS change, a responder definition, or a specified primary analysis beyond the endpoint description. The 8-week score should therefore be read as a comparison of group averages on the stated scale, not as a count of children who did or did not benefit.

7. Results Posted in the Registry

• Animal Assisted Intervention: mean 23.90 versus 29.00 on control; difference -5.10 (95% CI -10.62 to 0.42), standardized effect d = -0.58; z-test p = 0.070.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Diurnal Salivary Cortisol Levels at 8 Weeks

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Animal Assisted Intervention: mean -0.10 versus -0.14 on control; difference 0.03 (95% CI -0.02 to 0.09), standardized effect d = 0.37; z-test p = 0.248.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Animal Assisted Intervention and the control. The interval gives the range of effects that remain compatible with the data.

Diurnal Salivary Cortisol Levels at 16 Weeks

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Animal Assisted Intervention: mean -0.14 versus -0.12 on control; difference -0.01 (95% CI -0.09 to 0.06), standardized effect d = -0.10; z-test p = 0.774.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Animal Assisted Intervention and the control. The interval gives the range of effects that remain compatible with the data.

Acute Salivary Cortisol Level (In-session Week 1)

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Animal Assisted Intervention: mean 0.14 versus 0.14 on control; difference 0.00 (95% CI -0.09 to 0.09), standardized effect d = 0.02; z-test p = 0.949.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Animal Assisted Intervention and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes broaden the study beyond the primary symptom-rating result. They include diurnal and acute salivary cortisol measures and salivary alpha-amylase measures, reflecting the study's interest in candidate physiological markers. The registry lists 13 secondary outcomes, but the posted comparisons include a subset of these outcomes. This distinction matters: a result for one listed measure cannot stand in for the full set of physiological questions.

Across the posted cortisol comparisons, the estimated differences do not form a consistent direction across measurement occasions, and the reported confidence intervals include zero. This overall pattern does not provide a clear, precise signal that separates the groups on the reported cortisol measures. It is also not a direct confirmation or refutation of the primary ADHD-RS result, because symptom ratings and salivary markers measure different aspects of the study.

The study description raises the possibility that physiological markers may differ between groups or moderate response. Establishing moderation requires a formal analysis of whether the treatment contrast varies with marker values; a simple difference in average marker level does not answer that question. Such an analysis is not reported in the registry record. Nor does the record report a formal relationship between changes in markers and changes in ADHD-RS scores.

Secondary outcomes generally carry less weight than the primary endpoint when many outcomes are examined. In general, repeated testing across outcomes and time points creates more opportunities for apparently noteworthy findings to arise by chance. Without a reported multiplicity plan, unadjusted secondary comparisons should be treated as exploratory rather than as independent confirmatory evidence. The registry record does not report a multiplicity adjustment or a hierarchy for secondary hypotheses.

The secondary results can help describe the range of questions the pilot addresses and inform future research planning. They do not establish that a marker explains a treatment response, and they should not be used to strengthen the primary conclusion beyond what its own estimate and uncertainty support.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Diurnal Salivary Cortisol Levels at 8 Weeks
• Diurnal Salivary Cortisol Levels at 16 Weeks
• Acute Salivary Cortisol Level (In-session Week 1)
• Acute Salivary Cortisol Level (In-session Week 4)
• Acute Salivary Cortisol Level (In-session Week 8)
• Alpha-Amylase From Saliva at 8 Weeks
• Alpha-Amylase From Saliva at 16 Weeks
• Acute Salivary Alpha-Amylase Level (In-session Week 1)

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is continuous: each participant's ADHD-RS is represented by a numerical score, and the reported group summaries are means with standard deviations. A mean describes the group's average score. A standard deviation describes the spread of scores around that mean. These quantities answer different questions: the mean describes the central level, while the standard deviation describes between-participant variability.

What does the mean difference represent?

The comparison is expressed as the Animal Assisted Intervention mean minus the Psychosocial Treatment as Usual mean. The reported estimate is -5.1 units. The negative sign indicates that the average score was lower in the Animal Assisted Intervention group, consistent with the scale description that lower scores indicate less impairment. This is an unadjusted comparison of group summaries. It does not account for any covariates or other features of the participants beyond what is reflected in the posted summary statistics.

A mean difference keeps the result in the scale's original units, which can aid interpretation. Its meaning still depends on understanding the scale and knowing whether a change of that size is important to patients, families, or clinicians. A threshold for meaningful change is not reported in the registry record. The mean difference also does not describe how many participants had higher or lower scores, or the distribution of individual changes.

How should the confidence interval be read?

A confidence interval expresses the uncertainty around an estimated contrast under the statistical procedure used. In general, a narrower interval indicates greater precision, while a wider interval indicates less precision. For the primary comparison, the interval includes zero, the value corresponding to no mean difference between groups. Its lower bound is -10.62, and its upper bound is above zero. Thus the interval does not isolate a difference in one direction; it is compatible with no difference and with effects on either side of zero within the stated range.

The registry record provides an unadjusted p-value of 0.07. In general, a p-value describes how compatible the observed data are with a specified null model under the assumptions of the analysis. It is not the probability that the null hypothesis is true, nor a measure of the size or importance of the difference. The record does not report a prespecified statistical analysis plan or a multiplicity procedure, so the p-value should not be treated as a complete account of the inferential plan.

Why do the group sizes and variability matter?

The reported group sizes for the primary endpoint are 19.0 and 20.0, with standard deviations of 9.1 and 8.44. In general, uncertainty in a difference between means depends on both the amount of information in each group and the variability of the outcome. More variability makes group means less precise for a given sample size, while more observations can improve precision. These considerations help explain why the observed mean difference is accompanied by an interval rather than a single certain value.

The reported comparison includes a pooled standard deviation of 8.767 as a summary used in the recalculated comparison and standardized effect information. A standardized effect expresses the difference relative to the outcome's variability, which can help compare measurements on different scales. It does not replace the original-unit result, and it does not establish clinical importance. The displayed standardized effect is not necessary to interpret the primary mean difference.

What does over-dispersion mean in general?

Over-dispersion is a general concern for outcomes whose variability is greater than a model assumes. If the analysis underestimates variability, standard errors may be too small and confidence intervals too narrow. This is more directly relevant to count outcomes or models with a specified mean-variance relationship than to interpreting a simple continuous mean and standard deviation. The registry record does not report an over-dispersion assessment or a model that would allow such an assessment for the primary endpoint.

The reported primary comparison is based on continuous group summaries, and the sample-size planning illustration uses a normal approximation. That planning assumption does not establish that the trial's original analysis used the same method. The original statistical plan, including any model choice, assumptions, handling of baseline scores, or adjustment for clustering, is not reported in the registry record.

What is and is not recalculated?

The displayed mean-difference comparison is an unadjusted recalculation from posted group summary statistics. It should not be mistaken for a sponsor-reported adjusted model. The registry record contains no reported analyses in its analysis listing. The recalculated comparison offers a transparent way to relate the two means and their uncertainty, but it cannot recover participant-level information, account for unreported covariates, or verify how outcomes were handled for participants without a measurement.

For the primary result, the key statistical reading is therefore the combination of the group means, the unadjusted difference, and its interval. The direction of the point estimate is clear, but the interval's inclusion of zero and the absence of a reported analysis plan mean that the result should be read with restraint. Statistical significance, clinical importance, and causal interpretation are separate questions; the posted summaries do not settle all three.

11. Confidence Intervals and Precision

The primary mean difference is -5.1 ADHD-RS units, with a reported confidence interval whose lower bound is -10.62 and whose upper bound is above zero. Because the interval crosses zero, the data do not pin down a single direction for the group difference at the level represented by that interval. It includes a range of possibilities from a lower average score with Animal Assisted Intervention to a small difference in the opposite direction. The interval's width signals limited precision rather than a precise estimate of the size of the contrast.

The interval should be considered alongside the group means and standard deviations. The means are 29.0 and 23.9, and the standard deviations are 9.1 and 8.44. These summaries show the observed group averages and the within-group spread, but they do not remove uncertainty about the underlying contrast. With a pilot enrollment of 39, the estimate is based on a limited amount of information relative to the planning illustrations for detecting effects of similar scale.

The unadjusted p-value is 0.07. It is not a substitute for the confidence interval: the interval communicates a range of values compatible with the data under the method, while the p-value condenses evidence relative to a null model. Neither should be interpreted as a verdict about clinical importance. The registry record does not identify a threshold for a meaningful change in ADHD-RS score, and it does not report an adjusted model or analysis plan that would clarify whether the interval reflects the intended primary analysis.

The precision also has limits beyond sampling uncertainty. The registry record does not report how missing outcome data were handled, the analysis population, or whether any model adjustments were planned. Those details can affect the interpretation of a group comparison. The interval is therefore useful as a measure of uncertainty around the posted unadjusted estimate, but it should not be read as a complete expression of every source of uncertainty in the trial.

12. 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 illustrations express the required number of participants per arm, not a total across both arms or a total number of events. They are derived from the observed primary effect for illustration, rather than from the trial's original design calculation. The stated assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, a normal approximation, and an effect to detect equal to a stated fraction of the observed effect. The trial's own original sample-size assumptions are not reported in the registry record.

For planning at 100% of the observed effect, the illustration gives 47 participants per arm for 80% power and 63 participants per arm for 90% power. At 75% of the observed effect, it gives 83 participants per arm for 80% power and 111 participants per arm for 90% power. At 50% of the observed effect, it gives 186 participants per arm for 80% power and 249 participants per arm for 90% power.

In plain language, the 80% power column describes a planning scenario designed to have an 80% chance of detecting the specified effect if that effect is truly present and the assumptions hold. The 90% column uses a higher target chance of detection for the same effect size and assumptions. The illustrations are planning quantities, not observed power in the completed trial.

The rows show why smaller effects require more participants: a smaller difference is harder to distinguish from random variation, so more information is needed to detect it under a fixed planning framework. These numbers depend on the assumed effect being detected; they do not guarantee that a future study will achieve a particular result. The displayed curve should be read in the same general way: it relates the assumed effect size to the planning sample size, rather than describing outcomes observed in this trial.

13. 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 = -5.100; pooled standard deviation σ = 8.767.
2. n = 2 × (1.96 + 0.842)² × 8.767² / -5.100² = 46.4, rounded up to 47 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 <- -5.1                      # observed difference in means
sigma <- 8.76728932807411                     # 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(5102344)
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 = 47 (80% power), 63 (90% power)
 75% of observed effect: n per arm = 83 (80% power), 111 (90% power)
 50% of observed effect: n per arm = 186 (80% power), 249 (90% power)
power.t.test: 47.4 
Simulated power at n = 47 per arm: 0.794 (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.

14. Multiplicity, Missing Data and Analysis Populations

The registry record lists 23 outcome measures and 13 posted secondary outcomes. It does not report a multiplicity strategy, such as a hierarchy of hypotheses or an adjustment for examining multiple endpoints. When many outcomes or time points are assessed, the chance of at least one seemingly unusual result can increase. This is a general statistical concern, not evidence that any particular reported result is false. Without a stated plan, secondary p-values and comparisons should be interpreted cautiously.

The analysis listing reports zero analyses. This does not mean that no calculations can be made from posted group summaries; the unadjusted comparisons are recalculated from those summaries. It means that the registry record does not provide reported analysis entries describing a sponsor-conducted inferential plan or results. The planned model, any covariate adjustment, and the intended treatment of multiple outcomes are not reported in the registry record.

Handling of missing data is also not reported in the registry record. The number of participants with posted measurements varies across outcomes, but the record does not explain why the numbers differ, whether data were missing, or how any missing values were addressed. It would be inappropriate to infer a reason from the counts alone. The record also does not report whether analyses followed intention-to-treat, per-protocol, or another analysis population definition.

These omissions limit interpretation because missingness, exclusions, and analytic choices can influence estimates. The published group summaries remain descriptive of the observations recorded for each outcome, but they cannot establish how all randomized participants were represented in each analysis. The record does not report an interim-analysis plan, stopping rules, or sensitivity analyses, so these aspects of the statistical approach cannot be assessed from the registry information.

A more complete account would specify the prespecified primary analysis, analysis populations, missing-data procedures, and multiplicity approach. In their absence, the primary unadjusted result can be described on its own terms, while secondary findings should remain exploratory and uncertainty about analysis choices should be kept in view.

15. 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 reports zero serious adverse events among the 20 participants at risk in Animal Assisted Intervention and zero among the 19 participants at risk in Psychosocial Treatment as Usual. It also reports zero other adverse events in each group and zero deaths in each group. These are the recorded figures for the groups in the safety results.

Zero reported events means that no events of the listed categories were recorded in these results; it does not prove that no adverse experiences occurred or that risk is absent. The registry record does not provide additional detail about how events were defined, collected, or attributed to treatment, and it lists no serious adverse event terms. Therefore, the figures should be read as a limited safety summary rather than a complete characterization of safety.

Safety counts are distinct from the symptom and physiological outcomes. The absence of recorded events in this pilot does not provide a precise estimate of uncommon harms, especially given the limited number of participants. The record does not report a broader safety analysis or follow-up beyond the stated trial information, so the reported zeros should not be generalized beyond the observed registry entries.

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

The posted primary data show a lower mean ADHD-RS score at 8 weeks in the group receiving social skills training accompanied by therapy dogs than in the group receiving social skills training alone. The unadjusted mean difference is -5.1 units. Since lower scores indicate less impairment, the point estimate favors a lower average score in the Animal Assisted Intervention group. The confidence interval includes zero, however, and the unadjusted p-value is 0.07. The estimate is therefore uncertain and does not establish a clear difference between the group averages.

This result does not show that every participant's score was lower, nor does it report the proportion of participants with meaningful improvement. The scale's stated range is 0.00 to 54.00, but the registry record does not report a threshold for meaningful change. Without such a threshold or participant-level outcomes, the clinical importance of the average difference cannot be determined from the posted summaries alone.

The treatment contrast also has a specific scope. It compares social skills training with live therapy dogs against social skills training without that component. It does not compare the full intervention with no care, and it cannot isolate the dogs' contribution from other features that may accompany their inclusion. The record does not provide sufficient treatment-delivery detail to assess those components separately.

The physiological outcomes address a different question from the primary symptom rating. The posted secondary comparisons do not establish that cortisol or other candidate markers explain treatment response, and no formal moderation analysis is reported in the registry record. The pilot can describe observed estimates and help frame further study, but its results should not be treated as definitive evidence about efficacy, mechanism, or effects in populations beyond those represented in the trial.

Finally, the registry record does not report the original statistical plan, missing-data handling, analysis populations, or a multiplicity strategy. These limitations do not erase the posted summaries; they define how cautiously those summaries should be interpreted. The most defensible reading is a point estimate in one direction accompanied by substantial uncertainty and incomplete information about the planned analysis.

17. Why This Trial Matters Statistically

This trial is statistically informative because it places an active behavioral treatment in both groups. The comparison is not between treatment and no treatment; it is between social skills training accompanied by therapy dogs and social skills training alone. That design makes the target contrast more specific, while also meaning that the result speaks to the added therapy-dog package rather than to social skills training itself.

The study also brings a clinical symptom rating together with candidate physiological measures. Those outcome types can illuminate different parts of a research question, but they should not be conflated. A difference in a salivary marker would not automatically explain a difference in symptoms, and marker moderation requires an explicit analysis of how marker values relate to the treatment contrast. That analysis is not reported in the registry record.

As a pilot, the study illustrates the importance of treating estimates as uncertain rather than relying on a point estimate alone. The primary comparison's confidence interval includes zero, and the planning illustrations show that detecting smaller effects requires more participants under the stated assumptions. These planning quantities can help frame future studies, but they do not reveal what the trial's original design assumptions were.

The registry record also highlights why transparent reporting matters. Information about the analysis plan, missing data, analysis populations, and multiplicity would help readers judge how the posted comparisons fit the intended statistical approach. With those elements not reported in the registry record, interpretation can remain clear about the observed group summaries while avoiding claims that go beyond them.

18. 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.

This is a pilot study with enrollment of 39, and the primary estimate is accompanied by a confidence interval that includes zero. The limited amount of information makes the size and direction of the underlying group difference uncertain. The planning illustrations reinforce that detecting smaller effects would require more participants per arm under their assumptions, but they are not a substitute for the original design calculation, which is not reported in the registry record.

The study compares a combined package of social skills training and therapy dogs with social skills training alone. The contrast cannot separate the contribution of the dogs from other differences that may come with the added component. The registry record does not provide enough detail about intervention delivery, adherence, or implementation to assess those possibilities.

The primary outcome is a parent-rated ADHD-RS score at 8 weeks. The record does not report a clinically meaningful change threshold, a responder analysis, or participant-level trajectories. Consequently, the group mean difference cannot show how many participants experienced a notable change or whether the average difference matters to families.

Important analytic details are also absent. Missing-data handling, analysis populations, the prespecified statistical model, multiplicity control, interim analyses, and the original sample-size justification are not reported in the registry record. The masking target is not specified. The posted summary comparisons are unadjusted recalculations, not a replacement for those missing methodological details.

The physiological outcomes are candidate markers, and the registry record does not report formal analyses establishing that they moderate response. Some listed secondary outcomes do not have posted comparisons in the summarized results. These limits leave the pilot best suited to describe its recorded estimates and motivate further investigation, rather than to provide a complete account of treatment effects or mechanisms.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Animal Assisted Intervention With Dogs for Children With ADHD — NCT05102344.
• Registry record last updated 2025-09-12; status last verified 2025-08.
• Results first posted 2025-09-12.
• 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.

22. Record Summary

The registry record describes a completed, randomized, single-masked, parallel-group pilot sponsored by the University of California, Irvine, with enrollment of 39. It compares behavioral social skills training accompanied by live therapy dogs with Psychosocial Treatment as Usual, which uses social skills training alone.

The primary outcome is mean ADHD-RS score at 8 weeks, with lower scores indicating less impairment. The posted group means are 29.0 for the comparator and 23.9 for Animal Assisted Intervention. The unadjusted mean difference is -5.1 units; its confidence interval includes zero, and the unadjusted p-value is 0.07.

The registry also lists physiological secondary outcomes, including salivary cortisol and alpha-amylase measures. The record does not report the original statistical plan, missing-data procedures, analysis populations, or multiplicity handling. Its safety results record zero serious adverse events, zero other adverse events, and zero deaths in each group.