Agile Development of a Digital Exposure Treatment for Youth With Chronic Musculoskeletal Pain: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Agile Development of a Digital Exposure Treatment for Youth With Chronic Musculoskeletal Pain (NCT05079984), a non-randomized na study. The primary outcome is Assessment of Acceptability of Treatment Content - Likert Scale (Aim 1).

2. Clinical Question

The project’s broader stated purpose was to develop the digital treatment and evaluate feasibility and preliminary effectiveness. Its summary describes two stages: user-centered prototype development and a subsequent intervention study. Those aims address different questions. Feedback about prototypes can inform whether content is acceptable to participants, while a single-arm intervention study can describe feasibility and patterns of outcomes during treatment. Without a control comparison, changes over time cannot be attributed to the intervention with the same basis as a randomized between-group comparison.

The project summary says Aim 2 included a baseline period followed by the digital intervention, with self-report outcomes again collected after treatment. It also describes repeated measurement as part of a single-case experimental design. The registry record does not report the resulting acceptability scores or the results of the other outcome measures. Consequently, the central question that can be identified is what acceptability measure was planned, not whether the posted findings indicate a particular level of acceptability.

3. Trial Design

The registry classifies this study as nonrandomized, unmasked, and parallel, with an enrollment of 108. The listed phase is NA. Its status is completed; the recorded study start is 2022-05-02 and the primary completion date is 2025-05-13. These administrative details describe the registered study, but do not establish that every planned measure or analysis was completed or reported.

The project summary distinguishes two aims. Aim 1 involved short iterations of user-centered development and alpha testing. Adolescents with chronic pain were to engage with prototypes and provide feedback, with one session lasting 2 hours. The summary gives N = 15 for the small Aim 1 sample. Aim 2 is described as a single-arm feasibility trial of the digital graded exposure intervention. The intervention period is described as 6-weeks, following a baseline period ranging from 7-25 days. Self-report measures were planned at a three-month post-discharge contact, identified as week 22 of enrollment.

The summary characterizes the overall approach as a sequential replicated and randomized single-case experimental design, while the registry’s allocation classification is nonrandomized and its Aim 2 description says single-arm. These statements do not establish a conventional randomized comparison between intervention and control groups. The record does not explain how participants were assigned to measurement schedules, what was randomized within the single-case design, or how the sequential replications were conducted.

The primary outcome title concerns acceptability of treatment content in Aim 1, with a one-day timeframe. However, the population description attached to that outcome refers to participants who received the intervention, which is associated with Aim 2. The record does not clarify whether the outcome was collected in both aims, which participants contributed to the primary analysis, or how this wording should be reconciled. No statistical analysis plan or sample-size justification is 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.

Aim 1

Aim 2(10-week Intervention+3-month FUP)

Analysis population for the primary outcome, as defined in the registry: Population for Aim 2 includes participants who received the intervention.

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 Assessment of Acceptability of Treatment Content - Likert Scale (Aim 1), measured over One day.

The primary outcome is participant-rated acceptability of treatment content, measured with a Likert-scale questionnaire. The registry describes a scale ranging from 0-4, with higher scores indicating that treatment content is more acceptable. The measure is described as being administered to youth with chronic pain and their parents. Its stated timeframe is one day, and the outcome type is a mean with standard deviation.

Acceptability is relevant to development because it records participants’ judgments about the treatment content. In general, a mean can describe the average response across the participants included in an analysis, while a standard deviation describes how spread out individual responses are around that average. Those summaries answer different questions: an average does not show whether participants’ responses were similar or varied substantially.

The endpoint title places the measure in Aim 1, whereas its population description says participants who received the intervention in Aim 2. The registry record does not explain this inconsistency or identify the analysis population more precisely. It also does not report the observed mean, standard deviation, number of participants contributing responses, or a confidence interval. The scale definition therefore clarifies what the measure is intended to capture, but the posted registry information does not establish the observed level of acceptability or its precision.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical interpretation begins by distinguishing the study’s design from its outcome summaries. The registry classifies allocation as nonrandomized and masking as none. Aim 2 is described as a single-arm feasibility trial, while the project summary refers to a sequential replicated and randomized single-case experimental design. These descriptions do not amount to a documented randomized comparison between a treatment group and a control group. The registry record does not explain the apparent difference in terminology or report how treatment timing or sequence was assigned.

What does the primary measure summarize?

The primary outcome is a continuous measure: a participant-rated acceptability score on a 0-4 Likert scale. Its summary parameter is the mean, with standard deviation as the measure of dispersion. In general, the mean gives a central summary of the recorded scores. The standard deviation describes how much individual scores vary around that mean. Reporting both can make clear whether an average reflects responses clustered together or responses spread more widely.

The scale has an upper and lower bound, so its values are constrained rather than unbounded. A mean is still a concise summary, but it can obscure the distribution of individual responses, especially if many responses lie near a boundary or if responses form distinct clusters. The registry record does not report the observed distribution, mean, or standard deviation, so these features cannot be evaluated for this study. It also does not state whether responses from youth and parents were summarized separately or combined.

What would an uncertainty interval add?

In general, a confidence interval describes the statistical uncertainty around an estimate under a specified analysis. It is not a guarantee that the true value falls within the interval, and its interpretation depends on the sampling and analysis assumptions. For a mean, an interval would help readers judge how precisely the average acceptability score was estimated. The registry record does not report a confidence interval for the primary outcome. It also does not give the analysis sample size or standard error needed to assess precision from the registry entry alone.

How does the design shape interpretation?

The project summary describes repeated measurement around a baseline period and an intervention period. In general, repeated observations can help describe within-person patterns and whether changes coincide with a treatment phase. Single-case experimental designs use those individual patterns and replication across cases to investigate whether an outcome is associated with a change in phase. The strength of such an interpretation depends on design details, measurement frequency, stability of baseline patterns, timing, and analysis choices. Those details are not reported in the registry record.

A single-arm design also differs from a parallel-group randomized comparison. In general, a control group can help address changes that might occur over time for reasons other than the intervention. Without a documented control comparison, outcome patterns should be interpreted as observations within the studied design, not as a direct estimate of a treatment-versus-control contrast. The registry’s parallel model classification does not itself establish that Aim 2 had a control arm, because Aim 2 is described as single-arm and the listed allocation is nonrandomized.

What is known about the analysis plan?

The registry record lists 12 outcome measures and 9 analyses, but it does not report the specific statistical tests, models, covariates, or decision rules used. It does not state whether the primary analysis was adjusted, whether repeated observations were modeled, or how dependence among measurements from the same participant was handled. No interim-analysis plan, sample-size justification, or detailed prespecified statistical plan is reported in the registry record. These omissions prevent a detailed assessment of how analysis choices relate to the design.

In general, repeated measurements from one person are correlated: nearby observations may share features and should not automatically be treated as independent. A suitable analysis accounts for that dependence. If there is extra variation beyond what a basic model assumes, over-dispersion can make standard errors too small when ignored; accounting for it can improve uncertainty estimates. The registry does not identify a model or report whether over-dispersion was assessed, so these are general considerations rather than claims about the analysis performed in this study.

How should planning calculations be read?

Any sample-size illustrations based on the observed effect are planning exercises, not observed trial outcomes or observed power. The stated assumptions for such illustrations are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. The registry describes the study as nonrandomized and Aim 2 as single-arm, so a two-arm illustration should not be mistaken for the registered design. The record does not give a sample-size justification for the original study. For time-to-event illustrations, the stated quantity is total events; for other illustrations, it is participants per arm.

No recalculated effect estimate or planning value can be interpreted as a sponsor analysis unless it is explicitly identified as such. If a recalculated value conflicts with the sponsor’s own analysis, the sponsor’s analysis takes precedence. The registry record does not report an observed primary effect or a sponsor analysis of that effect, so neither can be evaluated from the outcome information recorded. These distinctions keep design assumptions, descriptive summaries, inferential results, and planning scenarios separate.

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("User Centered Development-Youth", "User Centered Development-Caregivers")
n   <- c(15, 17)
m   <- c(3.6, 3.8)
sp  <- c(0.69, 0.23)
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  User Centered Development-Youth  15  3.600  0.690  3.218  3.982
CARM  User Centered Development-Caregivers  17  3.800  0.230  3.682  3.918

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 12 outcome measures and 9 analyses. It does not report how those analyses map to individual outcomes, which outcome was used in each analysis, or whether the analysis set was prespecified. The primary outcome is identified by title, but its population wording points to a different aim. This makes the intended analysis population unclear. The registry record does not report a multiplicity strategy, such as a hierarchy of outcomes or an adjustment to account for multiple statistical tests.

In general, when many outcomes or comparisons are tested, the chance of at least one apparently notable result can rise if the tests are treated as independent opportunities for a finding. A prespecified primary outcome and transparent reporting of all planned analyses help readers distinguish confirmatory questions from exploratory ones. The absence of a reported multiplicity approach does not establish that no approach was used; it means the approach is not reported in the registry record.

Missing-data methods are also not reported in the registry record. There is no description of how incomplete questionnaires, missed follow-up assessments, or withdrawal from the intervention were handled. The entry does not report the number of participants contributing to each outcome or analysis, nor whether any analysis used all enrolled participants, only participants with available outcome data, or another population. The population wording for the primary outcome adds uncertainty about whose responses were intended to contribute.

In general, missingness can affect an estimate if people with unobserved outcomes differ from those whose outcomes are recorded. The impact depends on why data are missing and on the analysis method. Without participant flow, outcome-specific denominators, and a stated missing-data approach, readers cannot assess the extent or potential influence of missing observations in this study.

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 5% reporting threshold.

The registry lists safety information separately for youth and caregiver groups in user-centered development and in the graded exposure intervention. For each listed group, the serious adverse event count is zero, the other adverse event count is zero, and the death count is zero. The at-risk counts recorded are 15 for user-centered development youth, 17 for user-centered development caregivers, and 38 for each graded exposure intervention group. These are the registry’s group-specific entries; they should not be added to infer an overall participant count.

These entries describe what was recorded in the registry, not a comparison of safety between treatments. Aim 2 is described as single-arm, and no control group is specified. The record does not provide event definitions, collection procedures, exposure time, severity details beyond the serious-versus-other categories, or attribution judgments. It also does not list serious adverse event terms.

Zero recorded events does not establish that an intervention is risk-free or that no event could have occurred outside the registry’s reporting framework. It indicates only that the recorded counts for these categories are zero in the listed groups. The safety entries should be interpreted independently of the efficacy or acceptability questions: they do not provide an outcome estimate for the treatment’s effect.

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

The registry record describes a project to develop and assess a digital graded exposure treatment for youth with chronic musculoskeletal pain. It identifies acceptability of treatment content as the primary outcome and describes a user-centered development aim followed by a single-arm feasibility aim. It also records the planned timing and types of several self-report measures. These details explain the study’s focus, but they are not substitutes for outcome results.

The record does not report the primary acceptability mean, its standard deviation, or a confidence interval. It also does not report numerical results for the listed secondary outcomes. Therefore, the registry information alone cannot establish how acceptable participants found the treatment, whether feasibility criteria were met, or what changes were observed in the measures. The study’s completed status does not fill in those missing results.

Even if outcome changes were reported elsewhere, a single-arm design would need to be interpreted in light of its lack of a stated comparison group. In general, change from baseline can describe the observed course in participants, but cannot by itself establish what would have happened over the same period without the intervention. The project summary’s single-case design description could support a different form of within-person evaluation, but the record does not include enough methodological detail or results to judge it.

The listed safety counts are zero for serious adverse events, other adverse events, and deaths in each group. Those counts are descriptive registry entries, not proof of absence of risk, and they do not establish an intervention effect. The available information therefore supports a careful account of the study’s design and reporting, but not a conclusion about effectiveness or a medical recommendation.

14. Why This Trial Matters Statistically

This study is statistically notable because it combines an intervention-development aim with a later feasibility aim, while the registry record uses design descriptions that are not fully reconciled. The summary refers to a sequential replicated and randomized single-case experimental design, the allocation classification is nonrandomized, and Aim 2 is described as single-arm. These distinctions matter: different design structures support different kinds of inference, and the name attached to a design does not replace its operational details.

The primary endpoint also illustrates why precise outcome definitions and analysis populations matter. Acceptability is a reasonable construct to measure during development, but the registry’s primary outcome title refers to Aim 1 while its population text refers to participants who received the Aim 2 intervention. If the intended population is uncertain, readers cannot confidently determine which participant responses the primary estimate was meant to represent.

The project summary describes individual-level repeated assessment, an approach that can focus attention on patterns within participants rather than only group averages. In general, such designs depend on measurement timing, baseline behavior, replication, and analysis of within-person dependence. The registry record does not provide enough detail to assess those features. Its record therefore highlights the importance of reporting the design’s structure and analysis plan alongside its outcome estimates.

Finally, this registry entry distinguishes planned evaluation from reported evidence. It identifies outcomes and records safety counts, but does not report the primary endpoint’s numerical result or the methods used to analyze the outcomes. Clear reporting of estimates, uncertainty, analysis populations, and missing-data handling would be necessary for readers to judge what the study found and how precisely it found it.

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.

The registry record does not report the primary acceptability result, including the mean and standard deviation identified in the outcome description. It also does not report confidence intervals, outcome-specific analysis counts, or numerical results for the secondary outcomes. This limits interpretation to the study’s registered aims and design descriptions rather than the magnitude or precision of any observed findings.

Several features of the record leave the analysis population unclear. The primary outcome title identifies Aim 1, but its population wording refers to participants who received the intervention, associated with Aim 2. The project summary describes an Aim 1 sample and an Aim 2 intervention cohort, but the registry does not clarify which population contributed to the primary endpoint. The enrollment entry does not resolve this question or give outcome-specific denominators.

The design descriptions also require caution. The registry classifies the study as nonrandomized and Aim 2 as single-arm, while the summary uses the phrase randomized single-case experimental design. The registry does not explain what was randomized or provide enough detail about the sequence, repeated measurements, or analysis of individual trajectories to reconcile these statements. No control comparison is specified for Aim 2.

The registry record does not report detailed statistical methods, a sample-size justification, handling of missing observations, or a multiplicity approach. It also does not give further information about adverse-event definitions or collection. These gaps do not establish that such procedures were absent, but mean they are not reported in the registry record. The safety counts and completed status should not be treated as substitutes for outcome results or full methods reporting.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Agile Development of a Digital Exposure Treatment for Youth With Chronic Musculoskeletal Pain — NCT05079984.
• Registry record last updated 2026-07-22; status last verified 2026-06.
• Results first posted 2026-07-22.
• 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

NCT05079984 is a completed, nonrandomized study of the development of a digital graded exposure treatment for youth with chronic musculoskeletal pain. Its registry entry describes user-centered prototype development and a single-arm feasibility study, with enrollment recorded as 108. The study start is listed as 2022-05-02 and primary completion as 2025-05-13.

The primary outcome is participant-rated acceptability on a 0-4 Likert scale, summarized as a mean and standard deviation. The record does not report the primary result, and its outcome title and population wording refer to different aims. It lists 12 outcome measures and 9 analyses but does not report detailed analysis methods, missing-data procedures, or a multiplicity approach. The safety entries record zero serious adverse events, zero other adverse events, and zero deaths in each listed group. The registry information describes the study, but does not establish its outcome findings.