Intensive Combination Approach to Rollback the Epidemic in Nigerian Adolescents: UH3 Phase: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Intensive Combination Approach to Rollback the Epidemic in Nigerian Adolescents: UH3 Phase (NCT04950153), a randomized na study. The primary outcome is Proportion of Participants With Viral Load Suppression, (Plasma HIV-1 RNA <200 Copies/ml).

2. Clinical Question

3. Trial Design

The study is registered as a randomized, stepped-wedge trial with a sequential model and no masking. It evaluates peer navigation and SMS text messaging in a multi-site Nigerian study of adolescent HIV infection. The registry lists Northwestern University as sponsor and records the study as completed. Its start date is 2021-04-15, and its primary completion date is 2024-08-30.

Clusters were randomized to one of 3 sequences, which determined when the intervention began. Sequence A received the intervention from 0 to 48 weeks, followed by a post-intervention period from 49-72 weeks. Sequence B had a pre-intervention period from 0 to 24 weeks, an intervention period from 25 - 72 weeks, and a post-intervention period from 73 - 96 weeks. Sequence C had a pre-intervention period from 0 to 48 weeks, followed by intervention from 49 - 96 weeks. The primary outcome description frames the analysis as a change before and after 48 weeks of exposure.

In a stepped-wedge design, clusters cross from a comparison condition into an intervention condition at different scheduled times. This makes intervention timing central to interpretation: outcomes may reflect both the intervention and changes over calendar time. Random allocation of sequence can help balance such influences, but the validity of an estimate depends on the analysis accounting appropriately for cluster assignment and time. The registry record does not report the specific model, covariates, or treatment of time effects used by the sponsor. It also does not report a detailed masking procedure beyond “none,” or explain whether outcome assessors were masked.

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.

Week 0 - 24

Week 25 - 48

Week 49 - 72

Week 72 - 96

Analysis population for the primary outcome, as defined in the registry: Baseline: Proportion with virologic suppression (HIV-1 RNA \<200 copies/ml)

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: Number of baseline participants in each cluster

6. Primary Endpoint

The registry lists the primary outcome as Proportion of Participants With Viral Load Suppression, (Plasma HIV-1 RNA <200 Copies/ml), measured over Clusters randomized to 1 of 3 sequences, which determined timing of the intervention: Sequence 1 (intervention at visit 1=0 weeks(at baseline), 2 (intervention at visit 2: 24 weeks post baseline) or 3 (intervention at visit 3: 48 weeks post baseline).

The primary endpoint is the proportion of participants with viral-load suppression, defined as plasma HIV-1 RNA below 200 copies/ml. Viral load measures HIV-1 RNA in plasma; the endpoint classifies participants according to whether their measurement meets the stated threshold. The registry describes the primary outcome as the proportion with virologic suppression at baseline and says the study assessed change in that proportion before and after exposure to 48 weeks of the iCARE intervention.

In general, a proportion translates individual outcome classifications into a group-level summary. It can describe how common suppression was in a defined population and period, while a change in proportions can describe how that summary differs across assessment periods. Interpreting such a change requires knowing who contributed outcome measurements at each period, how missing measurements were handled, and how the design’s clustering and sequence timing were addressed.

The endpoint is clinically relevant to HIV treatment outcomes because it records whether viral load is below a prespecified threshold. The registry record does not report the observed proportions, the number assessed at each time, or the estimated change. It also does not report an uncertainty interval or test result for this endpoint. Thus, the outcome definition is available, but the size and precision of the primary result are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies a randomized, stepped-wedge, sequential cluster design, but does not report the sponsor’s statistical model or estimates. The concepts below describe general considerations for interpreting such a design; they are not claims about the specific analysis used in this trial.

Why does cluster assignment matter?

In cluster randomization, groups rather than individuals are assigned to a study condition or intervention sequence. Participants within the same cluster may share settings, services, or other influences, so their outcomes may be more alike than outcomes from participants in different clusters. In general, this within-cluster similarity reduces the amount of independent information in the data compared with an analysis that treats every participant as unrelated. A valid analysis generally needs to account for the clustering; otherwise, standard errors may be too small and confidence intervals may be too narrow. The registry specifically cautions that a simple individual-level re-analysis would be misleading and says that only the sponsor’s own analysis is shown.

What does stepped-wedge timing add?

In a stepped-wedge trial, clusters enter the intervention at different times. That structure allows outcomes from periods before and after implementation to contribute to the evaluation, but it also means intervention exposure is linked to calendar time. Outcomes could change over time for reasons unrelated to the intervention, such as changes in service delivery or the surrounding context. In general, an analysis should distinguish intervention exposure from time-period effects and account for the way clusters move between conditions. The registry provides the sequence windows but does not report whether or how the sponsor modeled calendar time, period effects, or within-cluster correlation.

How should the primary proportion be understood?

The endpoint classifies participants according to whether plasma HIV-1 RNA is below 200 copies/ml, then summarizes the result as a proportion. In general, an analysis of a binary outcome can estimate proportions or compare them across periods, with the exact interpretation depending on the model and its link function. A proportion can be reported for each assessment period, while a model-based contrast may adjust for design features or other variables. The registry does not report the observed proportions, the model, the contrast definition, or whether estimates were adjusted. It is therefore not possible to identify a particular statistical estimand or reproduce the sponsor’s primary analysis from the record.

What does uncertainty quantify?

In general, a confidence interval gives a range of values compatible with the data under the specified model and its assumptions. Its width reflects statistical precision: narrower intervals indicate greater precision, while wider intervals indicate less. A p-value summarizes how unusual data at least as incompatible with a null hypothesis would be if that hypothesis and the model assumptions held. It does not measure the probability that the intervention is effective, and it does not convey the size or practical importance of an effect. The registry record does not report a primary estimate, confidence interval, or p-value, so the precision and test evidence cannot be assessed.

What can the planning illustrations tell readers?

The stated planning assumptions describe an illustration calculated from the observed effect, not the trial’s own design. The assumptions specify a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is expressed as a stated fraction of the observed effect. In general, such calculations ask what sample size might be needed under specified assumptions to detect a target effect. They are planning illustrations, not observed power and not a measure of how likely the completed trial was to detect an effect. Their interpretation depends on the effect used, the model assumptions, and whether the trial design matches the simplified calculation. The registry record does not report the numerical observed effect or provide the sponsor’s power calculation or sample-size justification.

The planning description also distinguishes time-to-event calculations, which give a total number of events, from other calculations, which give participants per arm. No numerical planning result or detailed input values beyond the stated assumptions are reported in the registry record. The illustrations cannot replace the cluster-aware analysis of the completed study.

What analysis details remain unknown?

The registry records 2 analyses but does not describe their statistical methods. It does not report the model family, link function, variance estimator, covariate adjustment, handling of repeated measurements, or method for constructing uncertainty intervals. Those details can affect interpretation, particularly in cluster-randomized stepped-wedge studies. The record also does not state how incomplete outcome measurements were treated. These omissions do not establish that a method was absent from the full study materials; they mean that the method is not reported in the registry record.

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("Sequence A (Cluster 1): HIV Treatment Intervention", "Sequence B (Cluster 2): HIV Treatment Intervention", "Sequence C (Cluster 3): HIV Treatment Intervention")
n      <- c(59, 302, 167)
events <- c(37, 182, 108)
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  Sequence A (Cluster 1): HIV Treatment Intervention  59  37  62.7  49.1  75.0  50.0  73.9  49.9  73.9
ARM  Sequence B (Cluster 2): HIV Treatment Intervention  302  182  60.3  54.5  65.8  54.7  65.6  54.6  65.6
ARM  Sequence C (Cluster 3): HIV Treatment Intervention  167  108  64.7  56.9  71.9  57.2  71.5  57.2  71.5

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 6 outcome measures and 2 analyses. Secondary outcomes include antiretroviral adherence and adherence at or above 90%. It does not report a multiplicity strategy, such as a prespecified hierarchy, adjustment across hypotheses, or designation of which comparisons were confirmatory. Without that information, readers cannot determine whether reported tests, if available elsewhere, were interpreted with a plan for the number of outcomes and analyses. The record does not provide outcome-specific results for these secondary measures.

Missing-data handling is not reported in the registry record. The record does not state how participants with absent viral-load measurements were treated, whether any imputation was used, or what assumptions were made about why measurements might be missing. It also does not report the number assessed at each outcome time point. In general, estimates can be affected if outcome availability is related to participants’ characteristics or outcomes; the direction and extent of any such effect depend on the data and analysis assumptions.

The analysis populations are also not reported in the registry record. It does not specify whether the primary analysis followed assignment to randomized sequence regardless of intervention receipt, or whether another population was used. Nor does it describe exclusions, protocol deviations, or the handling of participants who changed or missed intervention periods. These details matter for understanding which participants and measurements contribute to an estimate. Their absence prevents a full assessment of analysis completeness and robustness from the registry record alone.

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.

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: death (2.9%), hospitalization (1.7%).

The registry records serious adverse event entries by intervention sequence. The listed at-risk counts are 60 for Sequence A, 309 for Sequence B, and 172 for Sequence C. The corresponding serious adverse event counts are 1, 6, and 5, and the death counts are also listed as 1, 6, and 5, respectively. These are descriptive entries; the registry does not report a comparative safety analysis or explain the period covered by each count.

The registry lists Death at 2.9% and Hospitalization at 1.7% among the top serious terms. It does not report the denominators or additional detail needed to interpret those percentages, such as whether they refer to participants, events, or a particular observation period. The sequence-level at-risk counts should not automatically be treated as denominators for these terms.

In general, serious adverse event counts do not by themselves establish whether an event was caused by an intervention. Comparisons require consistent definitions, observation periods, denominators, and an analysis that accounts for the study design. The registry record does not provide those comparative details, so the entries should be read as reported safety counts rather than as evidence of a causal difference between sequences.

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

The record establishes that a randomized, stepped-wedge study evaluated peer navigation and SMS text messaging for HIV treatment outcomes among adolescents in Nigeria. Its primary outcome was the proportion with viral-load suppression, defined as plasma HIV-1 RNA below 200 copies/ml, and the intended primary comparison concerned change before and after 48 weeks of intervention exposure. The record also describes the timing of the intervention across assigned sequences and identifies secondary adherence outcomes.

Those design and outcome details do not show what the trial found. The primary outcome estimate, observed proportions, uncertainty interval, and statistical test are not reported in the registry record. Therefore, the record alone does not establish whether suppression changed, how large any change was, or how precisely it was estimated. The completed status does not answer those questions.

In general, an estimated effect and its uncertainty need to be considered together. A small estimated change with a narrow interval and a similar change with a wide interval have different implications for precision, even if a test result were similar. Statistical evidence also does not by itself establish the practical or clinical importance of an effect. No numerical effect or interval is available to support those distinctions.

The record’s design requires attention to cluster assignment and the staggered intervention timing. A simple individual-level re-analysis could misrepresent uncertainty, as the registry itself cautions. The record says only the sponsor’s own analysis is shown, but does not include that analysis’s result or method details in the registry record. The appropriate conclusion is therefore limited: the registered study and its intended endpoint can be described, but its primary result cannot be interpreted from this registry record.

Safety counts are also not a substitute for efficacy estimates. They describe serious adverse events and deaths by sequence, but the record does not provide a comparative safety analysis or details sufficient to attribute events. Neither efficacy nor safety conclusions should be inferred beyond the information actually reported.

14. Why This Trial Matters Statistically

This trial is statistically notable because the intervention was introduced at different times across randomized clusters. That stepped-wedge arrangement makes timing part of the comparison: observations before and after intervention exposure occur in different periods, and clusters may contribute data under more than one condition. An analysis must therefore address both cluster-level dependence and changes over time. The registry’s warning against simple individual-level re-analysis highlights why design-aware inference matters.

The endpoint is a binary classification based on a viral-load threshold, summarized as a proportion. The registry frames the primary question as change in the proportion suppressed after 48 weeks of exposure. That wording makes the estimand, assessment period, and denominator important: a change in a proportion is interpretable only when readers know which participants and time points contribute and how the design was handled. Those analysis details and the primary estimate are not reported in the registry record.

The record also illustrates a distinction between a completed trial and a fully interpretable result. Registration contains useful information about allocation, sequence timing, intervention components, and outcome definitions, but does not provide the sponsor’s primary result or statistical method. The registry lists 2 analyses and 6 outcome measures without describing their analyses or reporting their numerical results. That limits assessment of precision, multiplicity, missingness, and consistency across endpoints.

Finally, the planning assumptions are explicitly described as illustrations based on the observed effect rather than as the trial’s own design. Keeping planning calculations separate from observed results prevents a common interpretive error: treating a modeled sample-size scenario as evidence about the completed trial’s actual statistical power. Together, these features make the study a useful example of why design, analysis reporting, and outcome estimates must be read together.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The main limitation of the available registry record is the absence of numerical primary outcome results. It does not report the observed suppression proportions, estimated change, confidence interval, or p-value. Although the study is marked completed, that status does not indicate the magnitude, direction, or precision of the primary finding.

The statistical analysis is insufficiently described for independent interpretation. The record identifies a randomized stepped-wedge cluster design and notes that a simple individual-level re-analysis would be misleading, but does not report the sponsor’s model, adjustment for time, method for accounting for clustering, or construction of uncertainty intervals. It says that only the sponsor’s own analysis is shown, yet no numerical sponsor result is included in the record.

Important data-handling details are not reported in the registry record. These include missing-outcome methods, analysis populations, exclusions, and the number of participants assessed at each period. The record also does not describe a multiplicity plan despite listing multiple outcomes and analyses. These gaps prevent assessment of how incomplete measurements or multiple comparisons may affect interpretation.

The intervention description names peer navigation and SMS text messaging but does not report delivery intensity, participant uptake, or fidelity. The record does not provide sequence-specific primary outcome results or a comparative safety analysis. Serious adverse event and death entries are descriptive, and their observation periods and relationship to intervention exposure are not detailed. Consequently, the registered information supports description of the design and outcomes, but not a full appraisal of efficacy, precision, or causal safety differences.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Intensive Combination Approach to Rollback the Epidemic in Nigerian Adolescents: UH3 Phase — NCT04950153.
• Registry record last updated 2026-04-21; status last verified 2026-04.
• Results first posted 2026-04-21.
• 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

The registry record describes NCT04950153, “Intensive Combination Approach to Rollback the Epidemic in Nigerian Adolescents: UH3 Phase,” sponsored by Northwestern University. The study is listed as randomized, sequential, unmasked, and completed, with enrollment of 541. Its recorded start date is 2021-04-15 and primary completion date is 2024-08-30.

The interventions are peer navigation and SMS text messaging. Clusters were randomized to 1 of 3 sequences with different intervention start times. The primary endpoint is the proportion of participants with plasma HIV-1 RNA below 200 copies/ml, assessed as change before and after 48 weeks of exposure. Secondary outcomes concern antiretroviral adherence.

The registry record does not report the primary outcome estimate, its uncertainty, or the sponsor’s analysis method. It records serious adverse event counts and deaths by sequence, along with Death at 2.9% and Hospitalization at 1.7% among top serious terms. The available entries support a description of the registered design and outcomes, but not a numerical interpretation of the primary result.