iTransition Development: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for iTransition Development (NCT04383223), a non-randomized na study. The primary outcome is Linkage to Adult Care.

2. Clinical Question

The central statistical question is whether the study’s posted results establish how often participants reached adult care under the study’s definition, and how precisely that frequency or any group contrast is estimated. The registry record identifies the outcome and its timeframe, but does not report results for it. Consequently, the record does not establish the observed linkage frequency, the size or direction of a difference between groups, or the uncertainty around such a difference.

The broader study addresses a transition in care that the study summary describes as a point when youth living with HIV may be at risk of falling out of care. The design includes youth, providers, and transition champions, but the primary outcome applies only to groups with youth participants. Results for the provider and transition champion groups would not themselves answer the primary participant-level question.

3. Trial Design

The registry describes iTransition Development as a completed, non-randomized, parallel study of a behavioral intervention. Enrollment is listed as 78. The recorded study start is 2020-08-28, and primary completion is recorded as 2024-06-30. The phase is listed as NA. These registry fields describe the study’s status and structure; they do not establish that an outcome analysis was completed or posted.

The arms include a YLH Historical Control Group, a YLH iTransition Intervention Group, a Provider Group, and a Transition Champion Group. The historical control group is described as having screening and a single visit assessment. The youth intervention group is described as having screening, a baseline visit, follow-up visits at 6, 12 and 18 month, and interviews for selected YLH around 3 and 9 month. Provider and Transition Champion groups are also described as having baseline and follow-up visits at 6, 12 and 18 month. Their interview visits for selected participants are listed around 3, 9 and 15 month.

The comparison is not randomized, and masking is listed as none. The historical control structure differs from the prospective intervention-group visit schedule. These features matter when interpreting any apparent contrast: a difference between groups could reflect differences in who entered each group, when information was collected, or other factors, as well as any intervention-related change. The registry record does not report an adjusted analysis or methods for addressing such differences.

The study summary describes the intended support as a mobile app for patients and clinical providers navigating the transition from pediatric to adult care. The record identifies iTransition as behavioral but does not report the app’s detailed content, the implementation procedures, or the extent to which participants used it. The planned follow-up and interview schedules describe data-collection activities, not evidence that all participants completed them.

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: This outcome only applies to the groups with YLH (Youth Living With HIV) participants.

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 Linkage to Adult Care, measured over 18 month post-intervention.

The primary outcome is linkage to adult care, measured among youth living with HIV. The registry defines it dichotomously: a participant either had one completed adult clinic appointment or did not. The stated timeframe is 18 month post-intervention. The outcome is reported in participant-count terms rather than as a continuous measure such as a number of appointments per participant.

In general, a clearly defined binary outcome can make a clinical or service milestone straightforward to interpret: it distinguishes participants who reached the specified milestone from those who did not. Here, the milestone is a completed appointment in an adult clinic. It does not, by itself, describe the number of later appointments, continuity of care over time, or other aspects of engagement. The record lists care retention per each 6-month period and number of participants with viral suppression as secondary outcomes, but does not report their results.

The endpoint is relevant to the stated transition-to-adult-care aim because it captures whether a participant crossed a specific care-access threshold. Its scope is also limited by that definition. An appointment counts only if it is completed; the registry definition does not treat a scheduled appointment as sufficient. The record does not report additional operational details, such as how appointment completion was verified or how participants without an observed appointment were handled analytically.

No primary outcome counts, group estimates, confidence intervals, or analysis results are reported in the registry record. The outcome definition therefore identifies what would be measured, but the posted record does not show how many participants met the definition.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the primary measure as a dichotomous participant outcome. Each youth is classified according to whether at least one adult clinic appointment was completed within the stated follow-up timeframe. The measure is expressed as a count of participants. The registry record does not report an analysis of those counts, an effect estimate, or a statistical test.

What a binary outcome can show

In general, a binary outcome represents whether a defined event occurred for each participant. Analysts may describe the number who experienced the event and the number assessed, then estimate the event frequency. When comparing groups, they may report an absolute difference or another contrast, with uncertainty around the estimate. Those are general analytical possibilities, not results reported for this study. Without the group-specific outcome counts and denominators, the linkage frequency and any contrast cannot be recovered from the registry record.

The definition matters to interpretation. Here, the event is a completed adult clinic appointment, not simply referral, scheduling, or an intention to attend. The binary measure records whether the threshold was met, but does not capture how often a participant attended after the first appointment. A participant with one completed appointment and a participant with several completed appointments both meet the stated binary definition. This outcome can therefore represent an initial connection to adult care without describing subsequent retention.

Why uncertainty matters

In general, a point estimate is an estimate based on observed data, while a confidence interval communicates its statistical uncertainty under specified assumptions. A narrow interval indicates greater precision than a wide interval, but an interval does not account automatically for every source of bias. In a non-randomized study, uncertainty from sampling is distinct from possible confounding or differences in measurement. No point estimate or confidence interval for linkage is reported in the registry record, so neither magnitude nor precision can be evaluated.

A statistical test, in general, assesses how compatible the observed data are with a specified null hypothesis under the test’s assumptions. A p-value is not the probability that an intervention works, and it does not indicate the size or importance of an effect. No primary-outcome test or p-value is reported. With no posted outcome analysis, there is no test result to interpret, and statistical significance cannot be inferred from study completion or enrollment.

What the design implies for comparisons

The study is listed as non-randomized and parallel. In a randomized comparison, random assignment is intended to balance measured and unmeasured characteristics across groups on average. That protection is not posted by the design. In general, non-randomized group comparisons can be affected by selection into groups, differences in baseline characteristics, or differences in care and measurement. Adjustment methods may address measured differences, but their adequacy depends on the data and assumptions. An adjustment plan is not reported in the registry record.

The historical control group and intervention group also have different visit descriptions. The control group is listed with a single visit assessment, while the youth intervention group has scheduled follow-up visits. In general, differences in observation schedules can affect whether an outcome is detected or documented. The record does not describe procedures for harmonizing outcome ascertainment across these groups. The posted information is insufficient to determine whether ascertainment was equivalent.

Over-dispersion and model choice

As general statistical context, over-dispersion occurs when observed variation exceeds what a chosen model expects. It is often relevant to count outcomes when counts vary more than a simple model allows. The primary outcome is described as a participant count for a binary event, rather than a repeated count of appointments per person. Over-dispersion is therefore not a result reported for this endpoint, and the registry record does not identify a model or discuss its assumptions. A model should not be inferred from the outcome label alone.

For binary outcomes, analysts may choose methods based on whether the goal is to estimate event probabilities, compare groups, or adjust for covariates. In general, method choice also depends on the study design, the number and structure of observations, and how missing outcome data are handled. No such analysis details are reported for the primary outcome. The record also does not report whether repeated follow-up measurements were modeled jointly or summarized by visit.

Planning calculations are not trial results

In general, sample-size planning explores how many participants might be needed under specified assumptions about an effect, variability, allocation, and significance level. Such calculations are planning illustrations, not observed power and not evidence that a study detected an effect. The registry record does not report the trial’s sample-size justification or the assumptions used in its original design. It also does not report a primary analysis estimate that could be interpreted as an observed effect. A planning calculation should not be treated as a substitute for outcome data or an analysis result.

Overall, the available information establishes the outcome definition and broad design, but not the statistical analysis used to produce results. The registry record does not report model specifications, covariate adjustment, confidence intervals, hypothesis tests, or handling of repeated measures. These omissions prevent evaluation of whether a particular analysis was appropriate or whether its assumptions were checked.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("YLH Historical Control Group", "YLH iTransition Intervention Group")
n      <- c(21, 33)
events <- c(16, 22)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  YLH Historical Control Group  21  16  76.2  52.8  91.8  54.9  89.4  54.6  89.3
ARM  YLH iTransition Intervention Group  33  22  66.7  48.2  82.0  49.6  80.2  49.5  80.3

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome and two secondary outcomes: care retention per each 6-month period and number of participants with viral suppression. Considering several outcomes can raise multiplicity concerns. In general, when many hypotheses are tested, the chance of at least one apparently notable result can increase. Analysts may prespecify a primary outcome, adjust for multiple testing, or treat secondary findings as exploratory. The registry record does not report a multiplicity strategy or clarify how the secondary outcomes were to be interpreted relative to the primary outcome.

The registry record does not report the number of participants with observed primary outcome data, exclusions from analysis, or the analysis population. Overall enrollment of 78 does not establish the denominator for any endpoint. It is also not reported in the registry record whether all enrolled participants were intended to be included in each outcome analysis, whether analysis followed an intention-to-treat principle, or whether a different population was used.

Missing outcome data can affect estimates when participants with unobserved outcomes differ from those with observed outcomes. In general, analysts may describe the amount and reasons for missingness, use methods under stated assumptions, and assess how conclusions change under alternative assumptions. The registry record does not report missing-data counts, reasons, imputation methods, or sensitivity analyses. The scheduled follow-up visits do not establish that every participant attended or had outcome data collected.

Interviews were planned for selected participants in some groups, but the registry record does not describe how those participants were selected or how interview data were analyzed. Those activities should not be mistaken for a reported approach to handling missing primary-outcome data. Without a stated analysis population, outcome denominators, and missing-data methods, the completeness and representativeness of any eventual estimate cannot be assessed from the registry record.

12. Safety Results

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

Deaths

Other (non-serious) adverse events

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

The safety record lists serious adverse event counts and other adverse event counts for each group. For the YLH Historical Control Group, 21 participants are listed at risk, with 0 serious events affected, 0 other events affected, and 0 deaths. For the YLH iTransition Intervention Group, 33 are listed at risk, with 0 serious events affected, 0 other events affected, and 0 deaths. For the Provider Group, 17 are listed at risk, with 0 serious events affected, 0 other events affected, and 0 deaths. For the Transition Champion Group, 7 are listed at risk, with 0 serious events affected, 0 other events affected, and 0 deaths.

These figures describe the registry’s posted safety counts. They do not establish that no adverse events occurred outside the categories or reporting procedures represented in this record. A zero count means that zero affected participants are recorded in the corresponding field; it is not, by itself, proof that an intervention has no safety risks. The registry record does not list serious adverse event terms.

The at-risk counts are safety denominators and should not be used as denominators for linkage to adult care. The record does not report the primary outcome analysis population. Because the groups were not randomized, the safety figures also should not be read as a controlled comparison of risk. The posted counts provide limited descriptive information and do not replace a full account of event definitions, timing, severity, or ascertainment, which is not reported in the registry record.

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

The record establishes that iTransition Development was registered as a completed, non-randomized study with a primary outcome focused on a completed adult clinic appointment among youth living with HIV. It also documents a proposed mobile-app approach intended to support patients and clinical providers during transition from pediatric to adult care. These registry entries describe the study’s purpose and measurement framework.

The record does not establish the observed rate of linkage to adult care. It does not give the number of participants meeting the endpoint, a comparison between the youth intervention and historical control groups, or an estimate of uncertainty. Therefore, it does not show whether the groups differed, how large any difference was, or whether an observed difference could be distinguished from chance variation. No inference about the intervention’s effect on linkage can be made from the registry information alone.

Even if group outcome results were available, the non-randomized design would require caution. In general, differences between groups may reflect selection and other baseline or care differences, not only the intervention. The distinct visit schedules described for the historical control and intervention groups are another reason that a comparison would require attention to outcome measurement. The registry record does not report methods that address these issues.

The endpoint also has a specific scope. It records whether a participant had one completed adult clinic appointment within 18 month post-intervention. It does not, on its own, demonstrate sustained retention, repeated attendance, viral suppression, or other health outcomes. Those are separate matters, and the named secondary outcomes have no results reported in the registry record.

The safety fields list zero affected participants and zero deaths in each group, but these entries should be interpreted as registry counts rather than broad evidence about all possible harms. In short, the record describes a study and its planned measures, while leaving the statistical findings needed to judge outcome frequency, precision, and group differences not reported in the registry record.

14. Why This Trial Matters Statistically

This study is statistically notable because its primary outcome is a concrete care-transition milestone: whether a youth living with HIV completed an adult clinic appointment. That definition makes the intended event understandable, while also focusing the measure on an initial connection to adult care rather than the full course of later engagement. Distinguishing the endpoint’s scope from broader ideas such as ongoing retention is essential when interpreting any future result.

The design also illustrates why a control label does not guarantee a strong causal comparison. A historical control can offer context, but non-random allocation leaves open the possibility that groups differ for reasons unrelated to the intervention. Here, the registry describes a single assessment for the historical control and repeated scheduled follow-up for the youth intervention group. General statistical reasoning calls for attention to comparability, timing, and outcome ascertainment when interpreting contrasts across such groups.

Equally important is the distinction between a registered outcome and a reported result. A defined endpoint and a completed study status do not reveal the event count, estimate, or precision. In this record, no outcome analyses are listed, so the central question cannot be answered statistically from the posted information. That gap is not a null result: it is an absence of a reported analysis.

The study also includes provider and transition champion groups, recognizing that care transitions involve more than the youth participants alone. Their inclusion may be relevant to understanding the intervention’s intended setting, but the primary endpoint applies only to groups with youth participants. Keeping the outcome population distinct from the broader study enrollment is important for interpreting denominators and results.

Overall, the trial’s statistical importance lies in clarifying what would count as linkage and in showing why study design and reporting determine what can be concluded. The registry record supplies design context but not the outcome evidence required to estimate linkage or evaluate an intervention-related difference.

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.

A major limitation for interpretation is that the registry record does not report primary or secondary outcome results. Without event counts, analysis denominators, estimates, or uncertainty intervals, the study’s outcome findings cannot be evaluated. The record lists 0 analyses, so the completed status should not be taken to imply that statistical findings are posted.

The non-randomized allocation limits causal interpretation. The historical control and youth intervention groups may differ in participant characteristics or circumstances, and the record does not report an adjustment strategy. The historical control’s single assessment also differs from the intervention group’s baseline and scheduled follow-up visits. The registry record does not explain whether outcome ascertainment was made comparable across groups.

Overall enrollment is reported as 78, but group-specific denominators for primary-outcome analysis are not reported in the registry record. The safety counts cannot fill that gap. Participant characteristics, the completeness of follow-up, and reasons for missing data are also not reported. These omissions prevent assessment of how representative an outcome estimate would be, even if one were posted.

The endpoint is limited to having one completed adult clinic appointment by the specified timeframe. It does not capture continued attendance or the quality and duration of care. Although the record names care retention and viral suppression as secondary outcomes, it provides no results for them. The intervention is described broadly as behavioral and as a proposed mobile app, but its detailed content, implementation, and participant use are not reported in the registry record.

Finally, the registry record does not report the statistical plan, sample-size justification, multiplicity approach, missing-data methods, or analysis populations. These reporting gaps restrict evaluation of both the intended analysis and the strength of any conclusions that might eventually be drawn.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: iTransition Development — NCT04383223.
• Registry record last updated 2025-08-13; status last verified 2025-08.
• Results first posted 2025-08-13.
• 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

iTransition Development is listed as a completed, non-randomized, parallel behavioral study with enrollment of 78. The recorded study start is 2020-08-28, and primary completion is 2024-06-30. The study summary describes a proposed mobile app to support youth living with HIV and clinical providers during transition from pediatric to adult care.

The primary outcome is linkage to adult care, defined as whether a youth participant completed one adult clinic appointment by 18 month post-intervention. The registry also names care retention per each 6-month period and number of participants with viral suppression as secondary outcomes. The record lists 0 analyses and does not report results for these outcomes.

The non-randomized historical-control design and differing visit schedules limit straightforward group comparisons. Outcome denominators, statistical methods, missing-data procedures, and a sample-size justification are not reported in the registry record. Safety fields list zero serious events affected, zero other events affected, and zero deaths in each group; these are descriptive registry counts, not an outcome analysis.