A Pilot and Feasibility Study of Mobile-Based Asthma Action Plans: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Pilot and Feasibility Study of Mobile-Based Asthma Action Plans (NCT01514760), a na na study. The primary outcome is Mobile Asthma Action Plan (AAP) Usage.

2. Clinical Question

The registry describes a feasibility rationale: investigators hypothesized that an interactive mobile plan could reinforce long-term management guidance and provide acute-management instructions to adolescents with asthma. That is the study’s stated aim, not a conclusion established by the primary endpoint. The primary utilization measure can indicate whether the app was used, but it cannot alone establish whether participants learned self-management concepts, whether asthma control changed, or whether the app performed better than another approach. The listed secondary outcomes include participant utilization, adolescent asthma self-efficacy, and Asthma Control Test™ scores. Their results are not reported in the registry record.

3. Trial Design

The registry identifies this as a completed pilot and feasibility study of a mobile-based Asthma Action Plan. The design is single-group, with allocation recorded as NA and masking recorded as NONE. Enrollment was 22. The registry lists asthma as the condition and names Arkansas Children’s Hospital Research Institute as the sponsor. The study start is recorded as 2012-06, and primary completion as 2012-10. Phase is recorded as NA.

All participants were assigned the named mobile-based plan; the record does not describe a separate control arm. The application was described as including an ambulatory peak-flow and symptom diary, an individualized plan for routine care and acute symptoms, and educational components. These are descriptions of intended application features, not evidence that every feature was used or that it changed participants’ outcomes.

The stated focus on adolescents appears in the brief study description and rationale. Detailed eligibility criteria and participant demographics are not reported in the registry record. It is therefore not possible to characterize the enrolled participants beyond the reported condition and enrollment, or to determine from the record how closely the actual sample matched the intended adolescent target group.

A single-group feasibility design can describe whether an intervention was used and can help characterize practical aspects of its implementation. It does not provide a concurrent comparison that would support a causal estimate of what would have happened to similar participants without the application or with another intervention. The registry record does not report additional design details such as the recruitment procedure, the planned schedule of assessments, or procedures for handling departures from the intended app use.

The record lists one primary outcome and three secondary outcomes. The primary endpoint concerns days per week of use over eight weeks. Although the status is COMPLETED, a completed status does not itself establish that every participant contributed data to every outcome or that outcome results were posted. Those details 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

Reasons for not completing this period:

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 Mobile Asthma Action Plan (AAP) Usage, measured over Eight weeks.

The primary endpoint is the median number of days per week that the Asthma Action Plan was used to record routine symptoms or peak-flow measurements. The stated range is 0-7 days per week, and the timeframe is eight weeks. The registry specifies the median and full range as the intended summary.

Use is relevant to a feasibility study because an application intended to support self-management must be used to deliver its diary, treatment-plan, and educational functions. A median describes the middle of the observed values after they are ordered; it is less influenced by unusually high or low values than an arithmetic mean. The full range describes the lowest and highest observed values, although it does not show how participants’ values are distributed between those endpoints.

This endpoint measures utilization, not the quality of entries, adherence to a treatment plan, self-efficacy, asthma control, or a clinical event. Even frequent use would not by itself show that the app improved any of those outcomes. Conversely, the measure alone cannot explain why an individual used the app more or less often. The registry record does not report the observed median or full range, so the extent of use cannot be described from the posted result information.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary endpoint is a descriptive measure: the median days per week of app use for recording symptoms or peak-flow measurements, with a full range. No observed endpoint values or inferential statistics are reported in the registry record. The explanations below describe what the stated methods and summaries mean in general; they do not supply missing trial results.

What does a median describe?

In general, a median is the central observation after values are ordered from low to high. It gives a measure of a typical value that is relatively resistant to extreme observations. For a usage outcome, it can convey the central level of use without requiring the values to be symmetrically distributed. However, the median alone does not reveal how many participants had values near it, whether values clustered in groups, or whether a small number of participants had very different patterns. The registry specifies that the primary endpoint would be summarized by a median, but does not report that median.

The full range gives the smallest and largest observed values. It can show the span of usage, but it is sensitive to observations at the extremes and does not convey the pattern of values between them. The endpoint’s defined scale runs from 0-7 days per week. That range describes the possible weekly frequency in the measure; it should not be mistaken for the observed range among participants. The actual observed full range is not reported in the registry record.

What does the timeframe mean?

The primary outcome timeframe is eight weeks. The endpoint description concerns weekly use during that period, but the registry record does not explain the detailed aggregation procedure, such as how weekly records were combined for each participant or how incomplete weeks were handled. Without that information and the result values, readers cannot reconstruct the analysis or assess whether all participants had comparable observation time.

What can a single-group analysis establish?

In general, descriptive summaries from a single group can characterize the outcomes observed among those participants. They do not provide the counterfactual comparison needed to estimate how those same participants would have fared under another approach. A difference from an earlier measurement, if one were reported, would still not by itself distinguish an intervention effect from changes over time, other care, or other influences. The registry record does not report a comparator or a primary-outcome estimate.

Statistical uncertainty is often described using a confidence interval. In general, a confidence interval gives a range of values compatible with the data and the assumptions of the analysis; greater width indicates less precision. It does not give the probability that a particular treatment effect is true. No confidence interval for the primary endpoint is reported in the registry record. The record also does not report a test statistic or p-value for that endpoint, so inferential evidence cannot be evaluated from those measures.

How should planning calculations be read?

Sample-size calculations are planning illustrations, not results about participants and not observed power. The planning assumptions associated with this record describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of an observed effect. These assumptions describe a hypothetical planning exercise; they do not change the actual registry design, which is single-group and has no like-for-like control comparison. A planning calculation based on a two-arm allocation does not mean that the trial enrolled two arms.

The assumptions also distinguish calculations for time-to-event outcomes, where the total number of events is used, from other calculations, where participants per arm are used. Those are general planning conventions. The primary outcome recorded for this study is a median frequency of app use in days per week, not an event-time outcome. A time-to-event method should not be presumed to describe that endpoint. The record does not report a sponsor hazard ratio for this primary measure, and the posted information does not permit a trial-specific effect-based planning calculation to be checked.

In general, over-dispersion matters when count-like observations vary more than a simple model assumes. Ignoring extra variability can make uncertainty appear too small. That concept may be relevant to some repeated-use data, but the registry record does not report a model for the primary endpoint or a finding of over-dispersion. It would be inappropriate to claim that such a model was used or needed in this analysis.

Why is the analysis population important?

An analysis population states which participants contribute to a particular outcome or estimate. For a utilization endpoint, possible differences between enrollment and the number with complete usage records could affect the interpretation of a median and range. The registry reports enrollment of 22 but does not report the denominator analyzed for the primary endpoint, the analysis-population definition, or whether the analysis included all enrolled participants. These details are not reported in the registry record.

Likewise, the registry record does not describe a statistical model, covariate adjustment, data transformation, or a method for deriving a confidence interval. The primary outcome can therefore be explained at the level of its stated summary—median and full range—but not as a fully documented inferential analysis. No adjusted or recalculated estimate is available in the posted results information.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists one primary measure, Mobile Asthma Action Plan usage, and three secondary outcomes: the number of participants who utilized the plan, asthma self-efficacy for adolescent children, and Asthma Control Test™ scores. It reports four outcome measures in total. Results for the secondary outcomes are not reported in the registry record.

When multiple outcomes are examined, the chance of observing an apparently notable result can increase if each is tested separately. In general, a statistical analysis plan may specify which outcomes are primary, how secondary outcomes will be interpreted, and whether any adjustment for multiple testing will be used. The registry record does not report a multiplicity adjustment or a detailed testing hierarchy beyond identifying the primary and secondary outcomes. It is therefore not possible to determine how multiple outcomes were handled in the analysis.

The record reports enrollment of 22, but it does not report the number of participants with usable data for each outcome, the amount or pattern of missing data, or a method for handling missing observations. Missing-data procedures are not reported in the registry record. Without outcome-specific denominators, readers cannot tell whether the posted summaries, if available elsewhere, would represent all enrolled participants or only those with recorded measurements.

The analysis population is also not reported in the registry record. There is no stated definition of which participants were included in the primary or secondary analyses, nor a description of whether participants were analyzed according to any prespecified population. The record does not report an interim-analysis plan, a stopping rule, or the detailed statistical analysis plan. Their absence from the registry record should not be interpreted as proof that no such procedures existed; their details are not reported there.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry lists 22 participants at risk for serious adverse events and reports 0 affected. It also lists 22 participants at risk for other adverse events and reports 0 affected. These figures describe the adverse-event reporting fields in the registry record. They do not provide detail about event definitions, collection procedures, follow-up completeness, or whether all participants contributed safety information over the same period.

The deaths field is recorded as null. A null entry is not the same as a reported count of zero; the number of deaths is not reported in the registry record. The record lists no top serious adverse-event terms.

In general, an absence of reported affected participants in a registry field should be read as a statement about the posted data, not as proof that no event could have occurred. The registry record does not provide additional information about safety monitoring or event adjudication, so those aspects cannot be assessed from these figures. These counts also do not establish whether the application caused or prevented an event.

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

The record establishes that a completed single-group pilot and feasibility study enrolled 22 participants with asthma to use a mobile-based Asthma Action Plan. The app was described as offering a diary for symptoms and peak flow, an individualized routine and acute-symptom treatment plan, and educational content. The primary endpoint was defined as median days per week of use over eight weeks, with a stated possible weekly range of 0-7.

Those design details explain what the study set out to examine. They do not establish how much participants used the application, because the primary outcome value and observed range are not reported in the registry record. Nor do they establish whether participants’ self-efficacy or asthma control changed: the listed secondary outcomes have no reported results in the record.

The study’s single-group design also limits what can be concluded about causes. Without a comparison group, observed use or other within-group outcomes cannot show what would have happened under an alternative approach. The registry’s stated hypothesis that an interactive mobile plan could be feasible and reinforce management guidance is a rationale, not a finding confirmed by the outcome information posted in the record.

The enrollment figure is not a substitute for an outcome analysis. The number contributing data to the primary endpoint, missing-data procedures, and analysis-population definition are not reported in the registry record. No confidence interval or other measure of uncertainty is reported for the primary measure, so its precision cannot be judged. The adverse-event fields report 0 affected among 22 at risk for serious events and 0 affected among 22 at risk for other events; the deaths field is null, rather than a reported zero.

Accordingly, the registry information permits a description of the study’s purpose, intervention, design, and intended endpoint. It does not permit a quantitative assessment of app use, a causal estimate of benefit, or a conclusion about clinical outcomes. Those distinctions are particularly important for a pilot and feasibility study, where a utilization measure can inform practical questions but is not itself evidence of clinical effectiveness.

13. Why This Trial Matters Statistically

This study is statistically useful as an example of the difference between a feasibility question and an effectiveness comparison. The registry’s primary outcome focuses on how often a mobile asthma plan was used, which is relevant to whether an app-based approach was engaged with. That question is distinct from whether the app changes asthma control or self-management, and distinct again from whether it performs better than an alternative.

The endpoint also illustrates why outcome definitions and results must be kept separate. The registry precisely describes a median weekly-use measure, its possible range, and its timeframe. Yet the observed median and range are not reported in the registry record. A well-defined measure is necessary for interpretation, but it cannot stand in for the data collected on that measure.

The single-group structure is another important statistical feature. It can describe a group’s experience, but it does not provide a concurrent counterfactual. This matters when readers are tempted to interpret engagement or changes in secondary outcomes as effects of the app. Without a comparison group and reported outcome estimates, attribution and comparative precision cannot be assessed.

The record also demonstrates why analysis details matter for even a small feasibility study. Outcome-specific denominators, missing-data handling, and the analysis population help readers understand who contributed information and how representative the reported summaries may be. These details are not reported in the registry record. Likewise, identifying several outcomes makes transparency about multiplicity relevant, but no adjustment or detailed hierarchy is reported beyond the primary and secondary labels.

Finally, planning calculations should not be confused with observed evidence. The planning assumptions describe hypothetical two-arm calculations, while the registered design is single-group. Keeping those planning assumptions distinct from the actual design prevents a sample-size illustration from being mistaken for observed power or a comparative result. The available record supports careful description of the study question and its limitations, rather than a numerical efficacy conclusion.

14. 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 main limitation for interpreting results is that the primary outcome’s observed median and full range are not reported in the registry record. The endpoint is defined as weekly use over eight weeks, but no estimate or confidence interval is posted. The amount and precision of use therefore cannot be assessed from the record.

The single-group design provides no like-for-like control comparison. Even if within-group outcome values were available, they could not by themselves establish that the app caused a change. The record does not report random allocation or a comparator arm; allocation is recorded as NA and the model is single-group.

The study aimed particularly at adolescents, but detailed eligibility criteria, age information, and participant characteristics are not reported in the registry record. Enrollment is reported as 22, but the number included in each outcome analysis is not. Missing-data handling and the analysis-population definition are also not reported, which limits assessment of completeness and representativeness.

The registry describes the app’s intended features, but does not report implementation details such as actual exposure to each feature or how use records were aggregated into the endpoint. Results for the listed self-efficacy and Asthma Control Test™ outcomes are not reported. The record also does not report a statistical analysis plan or multiplicity procedure. These limitations are specific to interpreting this registry entry and should not be taken as evidence that the study did not collect additional information.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: A Pilot and Feasibility Study of Mobile-Based Asthma Action Plans — NCT01514760.
• Registry record last updated 2017-10-11; status last verified 2017-09.
• Results first posted 2016-02-18.
• 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.

18. Record Summary

NCT01514760 is a completed, single-group pilot and feasibility study of a Mobile-based Asthma Action Plan for asthma self-management, with adolescents as the stated target. Enrollment was 22; the study start is recorded as 2012-06 and primary completion as 2012-10. The sponsor is Arkansas Children’s Hospital Research Institute.

The primary outcome was median days per week of app use to record routine symptoms or peak-flow measurements during an eight-week timeframe, with a full range and a stated scale of 0-7 days per week. The registry record does not report the observed primary outcome value. It lists three secondary outcomes concerning utilization, self-efficacy, and Asthma Control Test™ scores, but their results are not reported in the registry record.

The record reports 0 affected among 22 at risk for serious adverse events and 0 affected among 22 at risk for other adverse events. The deaths field is null. The single-group design does not provide a control comparison, and analysis populations, missing-data methods, and detailed statistical procedures are not reported in the registry record.