Youth Mayo Clinic Anxiety Coach Pilot Study: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Youth Mayo Clinic Anxiety Coach Pilot Study (NCT02205177), a randomized na study. The primary outcome is Mean Change From Baseline in Pediatric Anxiety Rating Scale (PARS) at Treatment Completion.

2. Clinical Question

3. Trial Design

This was a completed, randomized, single-masked, parallel-group pilot study, with a listed enrollment of 10 participants. The registry lists the study condition as anxiety and identifies the Mayo Clinic Anxiety Coach as a device intervention. The study was intended to assess feasibility and effectiveness of adding a smartphone app to traditional therapy for youth with anxiety disorders, particularly youth who may have limited access to mental health treatment in a traditional clinical setting.

Participants were assigned to face-to-face therapy with Anxiety Coach or minimal contact with Anxiety Coach. The planned face-to-face approach included 6 to 12 50-minute therapy sessions. The minimal-contact approach included an initial 50-minute face-to-face tutorial for the patient and primary caregiver, with therapist review of progress through a web-based portal and communication with the patient. The registry does not report additional details about how the two approaches were delivered beyond these descriptions, which are incomplete in the record.

The record identifies masking as single, but does not report who was masked or how masking was maintained. The method used to generate the random allocation sequence, conceal allocation, or assign participants is not reported in the registry record. The study phase is listed as NA. The recorded start date is 2016-01-15, primary completion is listed as 2017-03, and status is completed.

The arm-level primary outcome summaries include 8 participants in the face-to-face arm and 2 in the minimal-contact arm. These are the reported outcome sample sizes, and the record does not explain why they differ from each other or from the listed enrollment. Recruitment details, participant flow, withdrawals, and the numbers assessed at each study visit are not reported in the registry record.

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 Mean Change From Baseline in Pediatric Anxiety Rating Scale (PARS) at Treatment Completion, measured over Within 5 working days of Treatment Completion.

The primary endpoint was mean change from baseline in Pediatric Anxiety Rating Scale score at treatment completion, assessed within 5 working days of treatment completion. The scale is an interview-based assessment of anxiety symptom presence and severity in children and adolescents. Parent and youth input guides clinician ratings. It has 5 questions: four use a scale from none (1) to extreme (5), and the other has a rating of 1-5. The total score ranges from 0 - 25, with 25 representing the worst score.

Change from baseline is used to describe how the measure differs at follow-up from its starting value. A mean summarizes the average change among participants with reported measurements; the standard deviation describes the spread of individual values around that mean. Reporting change rather than a treatment-completion score alone can make the starting assessment relevant to interpretation, but the registry record does not report baseline means or individual-level changes.

The posted arm summaries are a mean change of 11 with a standard deviation of 3.1 among 8 participants in face-to-face therapy with Anxiety Coach, and a mean change of -1 with a standard deviation of 0.7 among 2 participants receiving minimal contact with Anxiety Coach. The record does not state the calculation convention for the sign of change. Since higher total PARS scores indicate worse symptoms, interpreting a positive or negative change requires knowing whether change was calculated as treatment completion minus baseline or in the reverse direction. That convention is not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous: it is a score summarized as a mean and standard deviation. For a continuous endpoint, an arm mean describes the central value of observed measurements, while the standard deviation describes how spread out those measurements are around the mean. These summaries do not show the full distribution, and they do not by themselves express the precision of the estimated mean or of a comparison between arms.

A comparison of two group means can be expressed as an estimated contrast, accompanied by an uncertainty measure such as a confidence interval and, in some analyses, a p-value. In general, the confidence interval reflects both the observed contrast and the amount of information available under the model. The registry record does not report a formal between-arm contrast, confidence interval, p-value, or analysis model for the primary endpoint. It lists 0 analyses.

The arm summaries are based on 8 participants in the face-to-face arm and 2 participants in the minimal-contact arm. Unequal group sizes can affect the precision of a comparison; the smaller group often contributes less information about its mean and variability. This is a general statistical principle. In this study, the very small reported count in the minimal-contact arm also means that its reported mean and standard deviation are summaries of only those participants, rather than stable estimates of the range of outcomes that might occur in a wider population. No further inference should be drawn from that general point without the underlying data and analysis.

Randomization is a design strategy intended to make assigned groups comparable on average, including on characteristics that are not measured. In a small pilot, chance imbalances can still occur. The registry record says allocation was randomized, but does not report the sequence-generation method, allocation concealment, stratification, or blocking. It also does not report who was masked, despite listing single masking. These omissions limit assessment of how the trial design was implemented.

Change scores compare a follow-up value with a baseline value. An analysis of change can be presented as an arm-specific mean change, as in the posted results, or as a direct comparison of mean changes. The registry record reports the arm-specific means and standard deviations, but not the sign convention, a direct comparison, baseline summaries, or a model that accounts for baseline values. As a general matter, the direction of a change score depends on which time point is subtracted from which; the PARS scale description alone does not resolve that convention.

Over-dispersion is a general concern in count outcomes when observed variation exceeds what a simple count model expects. It is not a method issue that can be evaluated from these primary endpoint summaries: PARS change is reported as a continuous outcome, and the registry record does not report a count-model analysis. More broadly, the record does not identify a statistical model, assumptions, covariates, or any adjustment approach for the primary outcome.

Sample-size calculations can be used during planning to estimate how many participants might be needed to detect a specified effect under assumptions about variability, allocation, significance level, and statistical approach. The registry record does not report the trial's own sample-size justification or design assumptions. Any planning illustration associated with the posted summaries is distinct from the study's actual design rationale, and it is not evidence that the study had a particular probability of detecting an effect. It should not be described as observed power.

Interim analyses and stopping rules can affect the interpretation of trial estimates if they are planned and used, but they are not reported in the registry record. The record also does not report whether analyses were prespecified, whether they followed the randomized assignment regardless of treatment received, or whether any adjusted or per-protocol analyses were conducted. With no posted analysis records, the stated means and standard deviations remain descriptive results rather than a complete account of an inferential analysis.

Multiplicity refers generally to the increased chance of finding an apparently notable result when many outcomes, comparisons, or analyses are examined. The registry lists 2 outcome measures and 1 secondary outcome, but does not report a multiplicity strategy or the statistical plan for handling multiple outcomes. Since no analysis records are listed, the registry does not establish which comparisons were performed or whether any adjustment was used. These are limits on interpretation, not evidence that a particular analysis was or was not performed outside the registry.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Face-to-Face w/ Anxiety Coach (FTF-AC)", "Minimal Contact w/ Anxiety Coach (MC-AC)")
n   <- c(8, 2)
m   <- c(11, -1)
sp  <- c(3.1, 0.7)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Face-to-Face w/ Anxiety Coach (FTF-AC)  8  11.000  3.100  8.408  13.592
CARM  Minimal Contact w/ Anxiety Coach (MC-AC)  2  -1.000  0.700  -7.289  5.289

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 2 outcome measures, including the primary PARS mean change and a secondary outcome described as the number of participants who completed the Subject Safety and Treatment Adherence Interview. It lists 0 analyses. The registry record does not report a multiplicity plan, a hierarchy for interpreting outcomes, or how repeated comparisons would be handled. Consequently, the listed outcomes do not establish which analyses were conducted or which results were intended to support a primary inference.

Missing-data handling is not reported in the registry record. The primary outcome summaries include 8 participants in the face-to-face arm and 2 in the minimal-contact arm, while total enrollment is listed as 10. The record does not provide participant flow, reasons for missing measurements, whether all enrolled participants posted endpoint data, or how any missing values were treated. It is therefore not possible to assess whether the posted outcome summaries reflect all randomized participants or a subset defined by availability of measurements.

The analysis population is also not reported. The registry does not state whether participants were analyzed according to randomized assignment, treatment received, or another rule. It does not describe exclusions, protocol deviations, or analysis-set definitions. These details matter because different inclusion rules can produce different summaries, especially in a small pilot. No conclusion about the effect of missing data or population selection can be drawn from the registry record alone.

12. 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 adverse-event counts separately for the two arms. In face-to-face therapy with Anxiety Coach, 8 participants were listed as at risk for serious adverse events and 0 were listed as affected; 8 were listed as at risk for other adverse events and 0 were listed as affected. In minimal contact with Anxiety Coach, 2 participants were listed as at risk for serious adverse events and 0 were listed as affected; 2 were listed as at risk for other adverse events and 0 were listed as affected. Deaths are listed as 0 in both arms, and no serious adverse-event terms are listed.

These figures are registry counts, not a comparison of risk between the arms. The record does not provide event-level descriptions, timing, exposure duration, or further details about adverse-event collection. A zero count in the posted record means no affected participants are listed for those categories; it should not be expanded into a claim about safety beyond the recorded data or interpreted as evidence that an event could not occur.

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

The posted results describe a small randomized pilot with a primary outcome focused on mean change in PARS score at treatment completion. The registry gives arm-level means, standard deviations, and outcome counts. It also records that the trial was completed and lists no posted analysis records. Those details allow a descriptive account of the reported endpoint summaries, but not a formal assessment of the precision or statistical significance of a between-arm difference.

The registry's scale description says that higher PARS totals indicate worse anxiety symptoms, but it does not state the direction used to calculate change. That missing detail prevents a confident interpretation of the positive and negative signs as improvement or worsening. The arm-level means should therefore be read as reported change summaries, not translated into a clinical direction based on an unstated convention.

The participant counts are small and uneven, with 8 in one outcome group and 2 in the other. This limits how much can be learned about variability and makes the descriptive summaries sensitive to the values of the few participants represented. The registry does not report confidence intervals or a direct comparison estimate, so the uncertainty around any contrast is not quantified.

The record does not establish whether the app-based approaches improve symptoms, whether one approach is better than the other, or whether results would generalize to youth outside the study. It also does not report a detailed sample-size justification, analysis plan, missing-data method, participant flow, or analysis population. These absences prevent broader claims beyond the posted descriptive results. The study's stated purpose was to test feasibility and effectiveness, but the reported fields do not provide a complete statistical evaluation of either question.

The safety counts are likewise limited to the adverse-event categories and counts listed in the registry. They do not supply detailed information about event monitoring or the duration over which participants were observed. Interpreting all these findings requires keeping the distinction between what the record counts and what it does not report.

14. Why This Trial Matters Statistically

This trial is statistically informative as an example of how a pilot study can provide descriptive outcome data without supplying the elements needed for a precise comparative conclusion. The registry identifies random allocation and a parallel-group design, and it records a continuous symptom score at treatment completion. It also shows a substantial imbalance in the number of outcome summaries across arms: 8 participants in face-to-face therapy with Anxiety Coach and 2 in minimal contact with Anxiety Coach.

That imbalance matters because a mean based on a small group gives limited information about the distribution of outcomes and the uncertainty of a comparison. The reported standard deviations add useful descriptive context, but cannot substitute for an inferential estimate or uncertainty interval. The registry lists no analyses, which makes it especially important not to interpret the arm means as a demonstrated treatment difference.

The study also illustrates why endpoint definitions must be complete. The PARS description explains the scale and its direction, while the change-score sign convention is not reported. Without knowing how change was calculated, readers cannot assign a reliable clinical direction to the signs of the two means. Likewise, absent baseline summaries make it impossible to inspect starting scores from the registry record.

Finally, the record lists a secondary interview-completion outcome and adverse-event counts, but does not report a full analysis plan, missing-data procedures, or participant flow. For researchers, these reporting gaps mark the boundary between descriptive registry information and a fully interpretable trial analysis. The pilot can be read as a record of study design and posted summaries, not as a stand-alone basis for a definitive comparative claim.

15. 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 reporting gaps limit interpretation. The registry lists 10 enrolled participants, while the primary outcome summaries include 8 participants in the face-to-face arm and 2 in minimal contact. It does not report a participant flow diagram or explain whether these counts represent every randomized participant, endpoint availability, or another analysis set. Reasons for missing outcome data and the approach to handling any missing values are not reported.

The registry does not state how change was calculated, even though the scale description establishes that higher PARS scores represent worse symptoms. This leaves the direction of the reported change values uncertain. It also does not provide baseline scores, treatment-completion scores, or a direct comparison estimate. No confidence interval, p-value, or model is reported, and the record lists 0 analyses.

Details of randomization and masking are limited. Allocation is listed as randomized and masking as single, but the sequence method, concealment procedure, and identity of the masked party are not reported. The arm descriptions are incomplete in the registry record, including the description of minimal contact. The record does not report adherence results, treatment fidelity, or the details needed to assess how consistently the approaches were delivered.

The registry does not report the study's sample-size justification, prespecified statistical plan, interim analyses, multiplicity handling, or analysis populations. It lists a secondary outcome but provides no result for it in the posted outcomes. The adverse-event counts lack event-level detail and further information about observation or collection. These limits do not establish that procedures or analyses were absent; they mean that those details are not reported in the registry record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Youth Mayo Clinic Anxiety Coach Pilot Study — NCT02205177.
• Registry record last updated 2019-08-05; status last verified 2019-08.
• Results first posted 2019-08-05.
• 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.

19. Record Summary

NCT02205177 is a completed, randomized, single-masked, parallel-group pilot study of the Mayo Clinic Anxiety Coach in youth with anxiety. It lists enrollment of 10 and compares face-to-face therapy using the app with a minimal-contact approach using the app. The primary outcome is mean change from baseline in PARS score at treatment completion, assessed within 5 working days of treatment completion.

The registry reports a mean change of 11 with standard deviation 3.1 among 8 participants in the face-to-face arm, and a mean change of -1 with standard deviation 0.7 among 2 participants in the minimal-contact arm. No formal analyses are listed. The record also lists one secondary outcome and reports zero affected participants in the posted serious and other adverse-event categories, with zero deaths in both arms.