Translating an Efficacious Illness Management Intervention for Youth With Asthma: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Translating an Efficacious Illness Management Intervention for Youth With Asthma (NCT03317977), a randomized na study. The primary outcome is Number of Emergency Department Visits.

2. Clinical Question

3. Trial Design

This was a randomized, single-masked, parallel-group study comparing two behavioral interventions: Reach for Control and Michigan MATCH. The registry lists enrollment of 75 and the status as completed. The study began on 2018-02-01, and primary completion was recorded as 2023-08-08. Its phase is listed as not applicable.

The study is described as a hybrid implementation-effectiveness design. Its aim was to test Reach for Control in real-world public healthcare settings, with delivery integrated into hospital emergency departments and carried out by community health workers. The intervention description characterizes RFC as home-based family therapy addressing asthma management across individual, family, and community systems. The comparator, Michigan MATCH, is described as a state-endorsed program for poorly controlled asthma.

Random allocation means that assignment to the intervention groups was intended to be determined by chance, rather than chosen by participants or clinicians. In general, randomization can help balance both measured and unmeasured participant characteristics across groups, although it does not guarantee balance in a study of any particular size. The registry does not report the randomization sequence method or allocation concealment details.

The record lists single masking but does not specify who was masked. It also does not describe how masking was maintained or whether it was feasible for participants and intervention providers. Because the interventions are behavioral programs, the exact masking arrangements would be relevant to understanding which parts of study conduct could be masked; those details are not reported in the registry record.

The primary outcome was planned across multiple follow-up time points. The registry describes change from baseline at 6 months, 12 months, and 18 months, but the primary outcome results are not reported in a form that supports one comparison. The registry also names the Family Asthma Management System Scale and Asthma Symptom Frequency as secondary outcomes, without reporting their results in the 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

Analysis population for the primary outcome, as defined in the registry: All randomized participants were analyzed with the exception of study removals

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 Number of Emergency Department Visits, measured over Change from Baseline at 6 months, 12 months, and 18 months.

The primary endpoint is the number of emergency department visits, expressed as a count of ED visits in the prior six months. The registry says that visit information would be obtained from electronic medical records. It frames the endpoint as change from baseline, assessed at 6 months, 12 months, and 18 months.

Counts of visits describe how often an event occurred during a defined period. They differ from continuous measurements, such as a scale score, because a count can be concentrated at zero or a small number of events and may have a skewed distribution. The registry specifies the mean as the parameter and standard deviation as the dispersion measure. Those summaries can describe the average count and the variability among participants, but they do not by themselves reveal the full shape of the count distribution.

ED visits were selected as an outcome relevant to asthma-related care use in the study’s stated aims, which also mention admissions, symptoms, asthma management, and lung functioning. The endpoint’s electronic-record source is distinct from self-report and may provide a record of healthcare use within the systems captured by those records. The registry does not describe which records or settings were available, how events were validated, or how visits outside those systems were handled.

Although the outcome definition and assessment times are described, the registry record does not report the group-specific changes, a between-group estimate, its confidence interval, or a test result. Consequently, the endpoint’s observed comparative pattern and its statistical precision are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Randomization, outcome definition, and analysis reporting answer different statistical questions. Randomization describes how participants were assigned. The endpoint definition describes what was measured and when. The analysis reporting shows how the data were compared and how uncertain the estimates are. The registry describes the first two in broad terms, but its primary outcome results do not include the estimates needed to evaluate the randomized contrast.

What does a randomized parallel-group design do?

In general, randomization assigns participants to groups by chance. Its statistical purpose is to reduce systematic differences between groups at assignment, so that a later outcome contrast can be interpreted as a comparison of assigned strategies, subject to the study’s conduct and analysis. Randomization does not ensure that every baseline characteristic will be identical between groups, especially in a study with limited enrollment. The registry identifies the study as randomized and parallel, but does not report the sequence-generation method, allocation concealment, or baseline balance details.

A parallel-group design follows participants in their assigned group rather than having each participant receive both interventions in sequence. Here, the groups were Reach for Control and Michigan MATCH. The registry calls the study single-masked, but does not identify who was masked. This missing detail limits assessment of how knowledge of assignment might have influenced intervention delivery, outcome reporting, or other study processes.

How should a count endpoint be understood?

In general, a count outcome records the number of occurrences over a defined interval. Counts can have many zeros, a long right tail, or variability that is larger than the mean. These features matter because a simple mean comparison may not capture all aspects of the distribution. The registry specifies the mean and standard deviation for the ED-visit endpoint, but does not report whether the observed count distribution was examined or whether any model accounted for its shape.

Over-dispersion is a general statistical issue in count data: it occurs when the variability exceeds what a simple count model would expect. If present and not addressed, uncertainty estimates from an unsuitable model can be too small or otherwise poorly calibrated. The registry record does not report whether over-dispersion was assessed, what model was used, or whether model assumptions were checked. No particular modeling approach can therefore be attributed to this study based on the record.

What do change from baseline and follow-up times imply?

The endpoint is described as change from baseline at 6 months, 12 months, and 18 months. In general, a change score compares a follow-up measurement with the baseline measurement for the same participant. A between-group comparison of change then asks whether those within-participant changes differ by randomized group. Another possible approach is to model follow-up measurements while accounting for baseline values. The registry does not identify which approach was used, so neither should be assumed.

Repeated assessments from the same participant are generally correlated: a participant’s measurements across follow-up times are not independent observations. An analysis that considers several time points may need to account for this dependence. The record does not report whether the time points were analyzed together or separately, how within-participant correlation was handled, or which time point, if any, was designated as the primary comparison for inference.

How should estimates and uncertainty be read?

In general, an effect estimate describes the size and direction of a comparison, while a confidence interval describes a range of values compatible with the data and the assumptions of the analysis. A narrower interval indicates greater precision than a wider interval, but interpretation also depends on the endpoint and the scientific question. A p-value addresses compatibility with a specified null hypothesis under a statistical model; it does not measure the probability that an intervention is effective.

The registry does not report an effect estimate, confidence interval, or p-value for the primary ED-visit comparison. Thus, neither magnitude nor precision can be assessed. A non-reported result is not equivalent to a finding of no difference. It also cannot be used to infer whether an estimate was statistically significant or clinically important.

What does the planning illustration describe?

The record describes planning illustrations based on the observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. The illustration is explicitly not the trial’s own design calculation. It describes an effect to detect as a stated fraction of the observed effect, with participant counts intended per arm for non-time-to-event settings. The record does not provide the numerical illustration results in the information available for interpretation.

As a general concept, a planning calculation estimates the sample size associated with chosen assumptions about an effect, variability, significance level, power, and allocation. It is not a measure of the trial’s observed power. Observed power is not a substitute for the actual effect estimate and its uncertainty. Because these illustrations are based on an observed effect and are labeled as planning illustrations rather than the trial’s original design, they should not be read as evidence that the study was designed with those assumptions.

The registry does not report the original sample-size justification or its assumptions. It also does not report interim analyses or the detailed statistical analysis plan. Those omissions prevent reconstruction of the intended inferential framework from the registry record alone.

10. Multiplicity, Missing Data and Analysis Populations

The primary endpoint is described at 6 months, 12 months, and 18 months. Considering several assessments can create a multiplicity issue: in general, when multiple comparisons are tested, the chance of at least one apparently unusual result can increase if no adjustment or prespecified hierarchy is used. The registry record does not report whether the assessments were treated as separate tests, whether a single time point was prioritized, or whether any multiplicity adjustment was planned or applied.

The record lists the Family Asthma Management System Scale and Asthma Symptom Frequency as secondary outcomes. It does not report a multiplicity strategy covering the primary assessments and secondary outcomes. The existence of multiple outcomes does not show that any particular adjustment was necessary or used; the analysis plan is not reported in the registry record.

For the primary outcome population, the record says all randomized participants were analyzed except study removals. It does not state the number removed, reasons for removal, group-specific outcome availability, or missing-data methods. There is no report of imputation, sensitivity analyses, or assumptions about why data might be missing. Therefore, the extent and handling of missing endpoint data cannot be assessed.

In general, analyses that exclude participants with missing measurements can be biased if missingness is related to outcomes or group assignment. Imputation and other methods also depend on assumptions and should be described alongside sensitivity analyses. These are general considerations, not claims about the analysis used in this study. The registry does not provide enough detail to determine how missingness or multiplicity affected the reported analyses.

11. 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.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: hospitalization (13.2%), new family problem (2.6%), new health problem (2.6%).

The registry reports serious adverse event counts for both groups. In Reach for Control, 36 participants were at risk and 4 were reported as affected by serious adverse events; 36 were at risk for other adverse events and 18 were affected. In Michigan MATCH, 38 participants were at risk and 7 were reported as affected by serious adverse events; 38 were at risk for other adverse events and 20 were affected. The recorded death count was 0 in each group.

These counts describe the registry’s adverse-event summaries. The number at risk is the group denominator reported for that event category, and the affected count is the number of participants recorded as affected. The figures do not indicate how many events each affected participant experienced, and they do not establish that an event was caused by either intervention.

The registry identifies Hospitalization as a serious event term at 13.2%, and New Family Problem and New Health Problem at 2.6% each. These are the listed top serious-event terms; the record does not provide additional context for their occurrence or attribution. Counts and percentages should be read as descriptive safety information rather than as a substitute for a formal comparative safety analysis. The registry record does not report such an analysis or uncertainty estimates for these event comparisons.

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

The record describes a randomized comparison of Reach for Control with Michigan MATCH among youth with poorly controlled asthma, with the primary endpoint defined as ED visits in the prior six months. It also gives the outcome assessment schedule, the electronic-record source for ED visits, the stated analysis population, and adverse-event counts. These details help identify what the study intended to compare and what information the registry records.

The primary outcome information does not include group-specific results or a between-group estimate. As a result, the registry record does not show whether the ED-visit pattern differed between the randomized groups, how large any difference was, or how precise an estimate might be. No conclusion about a primary outcome effect should be inferred from the trial’s completion status or from the fact that an analysis was listed.

In general, statistical significance and effect size are distinct. A p-value, if reported, would address compatibility with a null hypothesis under specified assumptions; it would not by itself show the magnitude or practical importance of a contrast. A confidence interval would help describe precision, but no primary endpoint interval is reported. Neither should be reconstructed from the information in the registry record.

The absence of outcome estimates is also not evidence that the interventions produced the same result. It means that the comparative primary outcome findings are not reported in the registry record. The secondary outcomes named in the record likewise have no reported numerical results in the information, so they cannot be used to fill that gap.

The serious and other adverse-event counts are descriptive. They provide information about recorded events and affected participants, but do not establish causation or demonstrate a statistically reliable difference between groups. No causal attribution or formal comparative safety estimate is reported.

Accordingly, the record supports a description of study design, endpoint definition, analysis-population wording, and safety counts. It does not support a numerical judgment about comparative effectiveness, precision, or the direction of the primary outcome. Those distinctions keep the interpretation aligned with what is actually documented.

13. Why This Trial Matters Statistically

This trial is statistically notable because it evaluates a behavioral intervention in a real-world public healthcare context and compares it with an established state-endorsed program. Its hybrid implementation-effectiveness framing connects questions about an intervention’s outcomes with questions about delivery in practical settings. For statistical interpretation, the connection makes clear why the population, intervention delivery, comparator, outcome source, and follow-up schedule all matter.

The use of electronic medical records for ED visits gives the primary endpoint a defined source, while the count-based measure raises questions about distribution, repeated observations, and completeness of captured healthcare use. In general, objective records can reduce reliance on participant recall for recorded visits, but interpretation still depends on which records were accessible and how events were identified. The registry does not describe those operational details.

The multiple follow-up assessments also make analysis choices important. A reader would need to know how within-participant dependence was handled, how comparisons across time were prioritized, and whether multiplicity was addressed. The registry record does not report those details. Their absence limits the ability to evaluate the statistical analysis, even though the endpoint and assessment schedule are stated.

Finally, the record illustrates an important distinction between a completed randomized study and a fully interpretable result record. Design information and safety counts can be available without the primary effect estimate and its uncertainty. Without those quantities, readers cannot assess the magnitude or precision of the primary comparison. The study’s clinical and implementation aims remain clear, but the registry does not report enough primary outcome results to support a statistical conclusion about the comparison.

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 most important limitation for statistical interpretation is that the registry record does not report the comparative primary outcome results. Group-specific values, changes from baseline, between-group estimates, confidence intervals, and p-values are not reported. This prevents assessment of effect direction, size, and precision.

The primary outcome is described at multiple follow-up times, but the record does not state which comparison was intended to anchor the main inference or whether the time points were analyzed jointly. It also does not report the model, handling of repeated measurements, assessment of count-data assumptions, or any treatment of over-dispersion. These details are necessary to evaluate whether the uncertainty estimates match the data structure.

The analysis population is described as all randomized participants except study removals, but the number and reasons for removals are not reported. Outcome availability at each assessment, missing-data methods, and sensitivity analyses are also not reported. This leaves uncertainty about attrition and the assumptions underlying the analysis population.

The registry lists secondary outcomes but does not report their results or a multiplicity strategy. It does not specify who was masked, the randomization procedure, or the allocation concealment method. The original sample-size justification and interim analysis information are not reported in the registry record. The stated sample-size illustrations are planning illustrations rather than the trial’s own design calculation.

For the ED-visit endpoint, electronic medical records are identified as the source, but the record does not describe record coverage, event validation, or how visits outside the captured systems were handled. Safety counts are available, but the record does not provide causal attribution or a formal comparative safety analysis. These limitations concern what can be evaluated from the registry record; they do not establish that unreported methods were or were not used.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Translating an Efficacious Illness Management Intervention for Youth With Asthma — NCT03317977.
• Registry record last updated 2024-04-04; status last verified 2024-04.
• Results first posted 2024-04-04.
• 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

NCT03317977 is a completed, randomized, single-masked, parallel-group study comparing Reach for Control with Michigan MATCH for youth with poorly controlled asthma. Enrollment was 75. The study is described as a hybrid implementation-effectiveness design in real-world public healthcare settings, with RFC intended for delivery by community health workers and integration into hospital emergency departments.

The primary endpoint was the number of ED visits in the prior six months, assessed as change from baseline at 6 months, 12 months, and 18 months using electronic medical records. The registry describes the analysis population as all randomized participants except study removals. It names the Family Asthma Management System Scale and Asthma Symptom Frequency as secondary outcomes.

The registry reports group-level adverse-event counts and selected serious-event terms. It does not report comparative primary endpoint estimates, their precision, or the detailed statistical analysis methods. Therefore, the record supports a description of the trial’s design and outcome definitions, but not a numerical interpretation of the primary randomized comparison.