Managing AsThma AnD Obesity Related Symptoms (MATADORS) Feasibility Study: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Managing AsThma AnD Obesity Related Symptoms (MATADORS) Feasibility Study (NCT05742646), a randomized na study. The primary outcome is Number of Participants Completing 4-week Study Period.

2. Clinical Question

3. Trial Design

MATADORS was a randomized, parallel-group behavioral feasibility study listed as completed. The registry record lists the phase as NA. It enrolled 24 participants and compared the MATADORS App Basic Information arm with the MATADORS App to Include Basic Information and Expanded Educational Features arm. The record lists no masking. The intervention was described as a 4-week pilot intended to test an mHealth approach to supporting self-management among youth with asthma and obesity.

The basic app was described as supporting real-time symptom monitoring through ecological momentary assessment and medication-adherence entry, with basic text-message reminders to complete symptom questions and enter medication taken. Participants were also provided activity trackers, although the description in the registry record is incomplete. The expanded arm had access to the basic app as well as educational and resource material on asthma, obesity, medications, symptom management, and lifestyle modifications, presented through images, text, and video.

The primary outcome was the count of participants completing the 4-week study period. Its posted arm counts were 10 for basic information and 11 for expanded educational features. The record also contains secondary outcomes covering interviews, fatigue, self-efficacy, asthma control, physical activity, medication adherence, and study retention or withdrawal. The listed assessment timeframe for the dyadic interview outcome is 8 weeks, whereas the primary endpoint concerns the 4-week study period. The registry record does not explain the relationship between those timeframes.

The record describes the study's purpose as testing feasibility and informing refinement of the app and intervention approach for future larger-scale research. It does not report a sample-size justification, detailed randomization procedures, or a statistical analysis plan.

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.

Before assignment: Participants randomized to control or experimental arms were youth only. Parents reported symptom at baseline and weeks 4 and 8 but were not exposed or involved in other study procedures. Only enrolled youth participated in EMA reports, activity tracking, medication reporting, and engaged with the app. Enrollment numbers represent dyads, although parents weren't not exposed to the intervention regardless of randomization.

Overall Study

Analysis population for the primary outcome, as defined in the registry: The number of participants analyzed is less than the number enrolled due to loss of follow-up.

5. Baseline Characteristics

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

Population: Baseline data were not collected for caregivers/parents.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants Completing 4-week Study Period, measured over 4-week study period.

The primary endpoint is the number of participants completing the 4-week study period. It is a count of completion, intended to describe retention and feasibility rather than change in symptoms, asthma control, or another clinical measure. The registry record explicitly describes the endpoint as participant retention and feasibility in completing the study period.

For a feasibility study, completion can help show whether participants remain engaged through the planned period of study activities. It is relevant to deciding whether an intervention and its procedures merit refinement for future research. It should not be interpreted as a measure of clinical effectiveness: completion alone does not indicate whether asthma symptoms, medication adherence, or health outcomes changed.

The posted completion counts were 10 for the basic-information arm and 11 for the expanded-feature arm. The registry record also states that the number analyzed was less than the number enrolled because of loss to follow-up. It does not report additional detail about how completion was defined, the circumstances of loss to follow-up, or how missing endpoint information was handled. Those omissions limit interpretation of the count as a complete account of engagement across all enrolled participants.

7. Results Posted in the Registry

• MATADORS App to Include Basic Information and Expanded Educational Features: 100.0% (11/11) versus 100.0% (10/10) on control; risk difference 0.0 percentage points (95% CI 0.0 to 0.0), risk ratio 1.00 (1.00–1.00); unadjusted two-proportion z-test p = n/a.

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.

End of Study Dyadic Interviews

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • MATADORS App to Include Basic Information and Expanded Educational Features: 91.7% (11/12) versus 58.3% (7/12) on control; risk difference 33.3 percentage points (95% CI 1.4 to 65.3), risk ratio 1.57 (0.95–2.61); unadjusted two-proportion z-test p = 0.059.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between MATADORS App to Include Basic Information and Expanded Educational Features and the control. The interval gives the range of effects that remain compatible with the data.

Short Assessment of Health Literacy-English

• 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:
  • MATADORS App to Include Basic Information and Expanded Educational Features: mean 14.80 versus 14.20 on control; difference 0.60 (95% CI -1.27 to 2.47), standardized effect d = 0.26; z-test p = 0.529.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between MATADORS App to Include Basic Information and Expanded Educational Features and the control. The interval gives the range of effects that remain compatible with the data.

The registry lists a broad range of secondary topics, including study withdrawals, loss to follow-up, dyadic interviews, fatigue, self-efficacy, asthma control, physical activity patterns, and medication adherence. It also includes a baseline health-literacy score. These topics extend beyond the primary completion count: some concern feasibility, while others concern symptoms, behavior, or participant characteristics.

The posted secondary summaries therefore serve a different role from the primary result. The primary endpoint addresses completion of the 4-week study period. The interview count concerns participation at a listed 8-week timeframe, and the health-literacy summary describes a baseline score. Neither should be treated as a direct explanation of the primary completion result. The registry record does not describe how the different assessment timeframes relate to one another.

The record lists 15 secondary outcomes, but only some have numerical summaries in the posted results, and no reported analyses are listed. Results for other listed outcomes are not reported in the registry record. The absence of an analysis record means it is not possible to tell which secondary comparisons were planned, whether particular outcomes were prioritized, or how missing observations were handled across outcomes.

Unadjusted secondary results carry less weight than a prespecified primary analysis because examining multiple outcomes increases the opportunity for chance findings. Without a reported multiplicity strategy, p-values should be regarded as exploratory rather than as a collection of confirmatory tests. Secondary outcomes can help identify measures worth refining for future research, but they cannot replace a clear primary analysis or independently establish intervention effects.

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

• Loss to Follow-up
• Study Withdrawals
• End of Study Dyadic Interviews
• Change in Fatigue
• Change in Self-Efficacy
• Change in Asthma Control
• Physical Activity Patterns
• Medication Adherence

9. Statistical Interpretation

10. Statistical Methods Explained

What does the primary count represent?

A count endpoint records how many participants meet a stated condition. Here, the condition is completion of the 4-week study period. It is a direct way to describe retention in a feasibility study, but it does not capture the reasons for completion or non-completion. Nor does a completion count measure the magnitude of a clinical change.

The registry gives arm-level completion counts and a risk-difference comparison. A risk difference expresses the contrast between the proportions experiencing the outcome in the arms. For the primary result, the posted risk difference is 0.0 and its confidence limits are also 0.0. This is the registry's reported comparison. It should not be expanded into a conclusion about outcomes that were not measured by this endpoint.

How should the secondary comparisons be read?

The dyadic interview outcome is also a count-based comparison. Its posted contrast is a risk difference of 0.333, with a confidence interval from 0.013 to 0.653 and an unadjusted p-value of 0.059. The baseline health-literacy outcome is continuous: each arm has a mean and standard deviation, and the comparison is expressed as a mean difference. Its posted estimate is 0.6, with a confidence interval from -1.268 to 2.468 and an unadjusted p-value of 0.529.

For a continuous outcome, a mean difference describes the contrast between group averages in the scale's units. A standard deviation describes variation among individual scores around the group mean; it is not the uncertainty around the mean difference. A confidence interval for the difference represents uncertainty in the estimated contrast under the method used. The registry record does not report the detailed statistical procedures for these comparisons, so the displayed estimates should not be attributed to a specific adjustment or model.

What does an unadjusted p-value convey?

A p-value measures how compatible the observed data are with a specified null hypothesis under the assumptions of the test. It is not the probability that the null hypothesis is true, and it does not measure clinical importance. An unadjusted p-value is calculated without accounting for the fact that multiple outcomes or comparisons may have been considered. When many outcomes are examined, some results may appear notable by chance alone. The registry record does not report a multiplicity adjustment or a plan defining which secondary comparison, if any, should be treated as confirmatory.

The registry lists no reported analyses for the posted secondary summaries. That absence makes it difficult to determine whether these contrasts were planned in advance, which statistical tests were used, or how assumptions were checked. The comparison estimates remain useful as descriptive summaries, but their inferential status is uncertain.

What are the planning illustrations?

Planning illustrations are not observed power. They show hypothetical participants per arm for 80% power and 90% power, using the stated fraction of the observed effect. The record says these illustrations assume a two-sided significance level of 0.05, equal allocation between the arms, and a normal approximation. For the interview comparison, planning for 100% of the observed effect gives 26 participants per arm for 80% power and 34 for 90% power; planning for 75% gives 51 and 68, and planning for 50% gives 125 and 167. For the health-literacy comparison, planning for 100% of the observed effect gives 238 and 319 participants per arm; planning for 75% gives 423 and 566, and planning for 50% gives 951 and 1,273.

These figures are illustrations derived from the observed effects, not the trial's own design justification and not evidence of the power achieved. A small study can produce an unstable observed effect, and planning directly from that estimate can yield misleading future targets. The registry record does not report a prespecified sample-size rationale or any statistical plan explaining how these illustrations should inform later studies.

Why does over-dispersion matter in general?

In general, over-dispersion occurs when count outcomes vary more than a statistical model expects. Ignoring it can make uncertainty appear smaller than it is. The primary endpoint is posted as a participant count, but the registry does not report a model for the count, a dispersion estimate, or an over-dispersion assessment. It would therefore be inappropriate to assume that such a model was used or needed. The same principle applies more broadly: statistical methods should match the outcome and its distribution, and the registry record does not provide enough detail to assess all modeling choices.

11. Confidence Intervals and Precision

Precision concerns how narrowly an estimate is determined by the data and analysis method. A confidence interval describes a range of values compatible with the data under the assumptions of the interval procedure. It does not guarantee that the true value lies in the reported range, and it does not include uncertainty from unmeasured bias, missing data, or an incorrect analysis method.

For the primary completion comparison, the posted risk difference is 0.0 and its confidence limits are 0.0 and 0.0. That reported interval gives no visible range around the estimate, but the registry does not report the calculation method or explain how the interval was produced. It should not be read as proof of exact equivalence between app versions, particularly for outcomes other than completion.

The secondary interview comparison has a risk-difference interval from 0.013 to 0.653 around an estimate of 0.333. The interval spans a wide range of possible contrast magnitudes. Its p-value is 0.059, and the registry does not report the test or interval methods needed to explain why these summaries have different implications. The health-literacy mean-difference interval, from -1.268 to 2.468, includes values on either side of 0.6 and is compatible with a range of contrasts. Neither interval alone identifies a clinically important effect.

In a feasibility study with limited outcome counts, estimates can be imprecise and sensitive to individual observations. The posted intervals quantify only the uncertainty represented by their statistical procedures. The missing-data approach and detailed analysis methods are not reported in the registry record, so additional sources of uncertainty cannot be assessed from these summaries.

12. Multiplicity, Missing Data and Analysis Populations

The registry record lists a primary endpoint and a range of secondary outcomes, but it does not report a multiplicity strategy. No method for adjusting secondary comparisons, prioritizing outcome families, or controlling the overall chance of false-positive findings is reported. The secondary comparison p-values are unadjusted. In general, interpreting many unadjusted tests as if each were the only test can overstate evidence, because chance findings become more likely as the number of examinations grows. This concern supports treating the secondary comparisons as exploratory.

Missing-data reporting is limited. The primary endpoint description states that the number analyzed is less than the number enrolled because of loss to follow-up. The registry record does not report the reasons for loss, the timing of missingness, whether missingness differed between arms, or the method used to handle unavailable outcomes. It also does not report whether an intention-to-treat population, a per-protocol population, or another analysis population was prespecified. These omissions limit assessment of potential bias in the completion result and the secondary summaries.

The record lists no reported analyses for the secondary outcomes and does not provide a detailed analysis plan. Interim analyses, stopping rules, covariate adjustment, or approaches to repeated measurements are not reported in the registry record. Their absence from the record should not be interpreted as proof that they were or were not conducted; the posted information does not establish this.

In general, a transparent analysis plan would identify the primary comparison, define analysis populations, specify missing-data handling, and explain how multiple outcomes are interpreted. Such details help readers distinguish planned inference from exploratory examination. Because these details are not reported, the numerical summaries are best read as descriptive evidence from a feasibility study rather than as a fully documented confirmatory analysis.

13. 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 safety summaries list 12 participants at risk in each arm. In both arms, the record reports 0 serious adverse events, 0 other adverse events, and 0 deaths. These are the posted counts for the groups and safety categories recorded in the registry.

A zero count means no event was recorded in that category in the reported data; it does not demonstrate that an event is impossible or establish a precise estimate of safety. The registry record does not provide event narratives, follow-up detail, or a description of how adverse events were collected. It also does not list serious adverse event terms. These figures should therefore be read as a limited safety account for this feasibility study, not as a broad assessment of risk.

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

The primary result describes completion of the study period in the two app arms. It does not test whether the expanded educational features improve asthma control, reduce fatigue, change medication adherence, or produce another clinical benefit. Completion is relevant to feasibility, but it is not itself a health outcome.

The posted primary comparison has a risk difference of 0.0 with confidence limits of 0.0 and 0.0. This is a result for the recorded completion endpoint in this study. It does not establish that the apps are equivalent, that their effects are identical in other populations, or that differences could not emerge in a larger study. The registry does not report a design for testing equivalence or noninferiority.

The secondary summaries are also not definitive evidence of clinical effectiveness. They include an interview participation measure and a baseline health-literacy score, while the registry lists further outcomes for which results are not reported in the registry record. The available summaries are not accompanied by a reported analysis plan, and the secondary p-values are unadjusted. They can describe observations and inform measurement choices, but they do not resolve whether the intervention changes clinical outcomes.

The registry's stated purpose was to test a 4-week pilot and facilitate refinement of the app and intervention approach for future larger-scale research. That purpose matters when interpreting small feasibility results: they can identify practical questions for future study, while remaining insufficient for broad efficacy claims. The record does not report a sample-size justification or establish how a future trial should be designed.

Accordingly, the result is best understood as a record of completion and selected secondary observations from a randomized app comparison among youth with asthma and obesity. It does not support medical advice or a conclusion that either version should be preferred for care. Further evidence would be needed to evaluate clinical outcomes and the durability of any effects.

15. Why This Trial Matters Statistically

This study matters statistically because it illustrates the distinction between feasibility outcomes and clinical outcomes. Completion of a study period is useful for understanding whether research procedures and an intervention can be sustained, but it does not quantify improvement in asthma or obesity. Keeping that distinction clear prevents a retention result from being mistaken for evidence of clinical efficacy.

The randomized parallel design provides a direct comparison between a basic-information app and an expanded educational version. Yet interpretation depends on more than random allocation: readers also need clear definitions of the analysis population, missing-data procedures, outcome timing, and statistical methods. The registry record leaves several of these details unreported, which limits the strength of inference from the posted estimates.

The record also shows why secondary outcomes require cautious interpretation. A broad set of topics may be valuable for an intervention-development study, but unadjusted findings across multiple outcomes can be unstable. Without a reported multiplicity plan and prespecified analysis details, secondary comparisons are most useful as exploratory information rather than as independent confirmation.

Finally, planning illustrations based on observed effects are not evidence of achieved power and are not the trial's original sample-size rationale. They depend on assumptions and the observed effect, which may be uncertain in a feasibility study. Treating these illustrations as conditional planning aids, rather than as proof that the study could or could not detect an effect, supports more transparent design of future research.

16. 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 most important limitations specific to this trial concern the scope and completeness of the posted record. Enrollment was 24, while the primary endpoint description says that the number analyzed was smaller because of loss to follow-up. The record does not report the reasons for loss, missingness by arm, or the approach used for missing outcomes. As a result, the completion counts cannot be fully assessed against the enrolled population.

The primary endpoint is a feasibility count, so it cannot answer whether the app content affected asthma control, obesity-related outcomes, or other clinical measures. The registry lists several such secondary topics, but results for many are not reported in the registry record. The reported secondary summaries do not provide a substitute for a complete analysis of those outcomes.

The registry does not report detailed randomization procedures, a statistical analysis plan, a sample-size justification, or analysis-population definitions. It also does not report how the listed 8-week dyadic interview timeframe relates to the 4-week primary period. These gaps make it difficult to assess prespecification, potential bias, and the intended interpretation of secondary comparisons.

The intervention descriptions are incomplete in the registry record, including a truncated description of activity trackers and the expanded arm. The population is described as youth with asthma and obesity, but detailed participant characteristics are not reported in the posted results. These limitations restrict replication and assessment of how broadly the findings might apply. The small feasibility scope and limited statistical reporting mean that the posted estimates should be treated as preliminary descriptive evidence.

17. Related Tutorials

18. Related Statistical Calculators

19. Sources

• ClinicalTrials.gov: Managing AsThma AnD Obesity Related Symptoms (MATADORS) Feasibility Study — NCT05742646.
• Registry record last updated 2025-07-23; status last verified 2025-07.
• Results first posted 2025-07-23.
• 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.

20. Record Summary

The completed MATADORS Feasibility Study was a randomized, parallel-group behavioral study with no masking, comparing a basic-information app with an expanded educational app for youth with asthma and obesity. Enrollment was 24, and the primary endpoint counted completion of the 4-week study period. The posted counts were 10 in the basic-information arm and 11 in the expanded-feature arm; the registry notes loss to follow-up and an analyzed number below enrollment.

The registry lists secondary outcomes concerning feasibility, interviews, fatigue, self-efficacy, asthma control, physical activity, and medication adherence. Some secondary summaries are posted, but no reported analyses are listed. Safety summaries report 0 serious adverse events, 0 other adverse events, and 0 deaths in each arm's recorded group. The record does not report a detailed statistical analysis plan, missing-data method, multiplicity approach, or sample-size justification. The study was intended to inform refinement of the intervention for future research, rather than establish clinical effectiveness.