Home Assessment and Initiation of Antiretroviral Therapy for HIV in Malawi: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Home Assessment and Initiation of Antiretroviral Therapy for HIV in Malawi (NCT01414413), a randomized na study. The primary outcome is ART Initiation.

2. Clinical Question

3. Trial Design

This was a randomized, parallel-group trial in Blantyre, Malawi, with a cluster-randomized design. Clusters, rather than individual participants, were assigned to the study arms. The registry lists masking as none, so the design was open-label. The record gives a total enrollment of 16660 and a completed status. The listed study start is 2012-01, and primary completion is 2012-11.

The comparison was between home assessment and initiation of ART and clinic-based ART assessment and initiation. The study description places this comparison within a home-based HIV testing and counseling strategy. Its stated interest was whether home assessment and initiation added to that strategy in relation to entry into, adherence with, and retention in HIV care. The primary endpoint was broader than people who tested positive or took part in home testing: it counted ART initiation among all resident adults in the study clusters.

The registry lists HIV as the condition and does not list a clinical-trial phase beyond NA. The available arm descriptions are incomplete, so details of procedures and eligibility should not be inferred from their names. The record lists secondary outcomes concerning uptake of home-based HIV testing, reporting of HIV-positive results, loss to retention, adherence to ART, and adult mortality. It does not give a fuller account of how these outcomes were defined or analyzed.

Cluster assignment matters to interpretation. Adults within the same cluster may share circumstances, services, or exposure to the assigned strategy. In general, observations within a cluster can therefore be more alike than observations from different clusters. An analysis that treats every adult as independently randomized can misrepresent the uncertainty around an arm comparison. The registry record explicitly cautions that a simple individual-level re-analysis would be misleading.

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

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: The 14 clusters included in the study had a combined adult population of 16660, with 8194 adults resident in 3213 households in the OHC arm and 8466 adults resident in 3397 households in the FCO arm. Socio-demographic characteristics assessed in the baseline enumeration were well balanced between intervention groups.

6. Primary Endpoint

The registry lists the primary outcome as ART Initiation, measured over First six months following introduction of home-based HIV testing.

The primary endpoint is ART initiation during the first six months following introduction of home-based HIV testing. It compares the proportion of all resident adults in each study arm who initiated ART. The denominator is defined per capita and includes adults irrespective of HIV status or participation in the home-based testing intervention.

This endpoint addresses a population-level question about whether the assigned approach was associated with ART initiation across the resident adult population, rather than only among people who received a positive HIV test or attended a particular service. In general, an outcome with a clearly specified population and time window helps define what an arm comparison represents. Here, the stated time window also distinguishes the primary outcome from longer-term questions such as adherence and retention.

The endpoint is described as a comparison of proportions, while the registry’s outcome type indicates counts of participants with an event. These are compatible ways of describing a binary outcome: each adult either did or did not initiate ART within the stated window, and the arm-level comparison concerns the proportion with the event. The registry record does not report the event counts, arm-specific proportions, effect estimate, confidence interval, or statistical test for this primary endpoint. Its result therefore cannot be quantified from the posted record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes random allocation in a parallel design and identifies the trial as cluster-randomized. It does not report the statistical model, variance estimator, cluster-level adjustment, covariates, or inferential procedure used for the primary outcome. Those analysis details are not reported in the registry record. The interpretation should therefore separate the design information that is recorded from analysis methods that are not documented.

Why cluster assignment affects uncertainty

In general, cluster randomization assigns groups of people rather than each person separately. People in a group can share local conditions or services, which may make their outcomes more alike. Statistical methods for cluster trials account for that within-cluster similarity when estimating uncertainty. If an analysis treats all people as independent, it can understate uncertainty. The registry record specifically cautions that a simple individual-level re-analysis would be misleading. It indicates that only the sponsor’s own analysis is shown, but a numerical primary-outcome analysis is not reported in the registry record.

The number of enrolled adults does not by itself reveal the number of clusters, the distribution of enrollment across clusters, or the degree of within-cluster similarity. Those design details are not reported in the registry record. Without them, and without the sponsor’s analysis, the uncertainty around the primary comparison cannot be reconstructed from enrollment alone. No new individual-level calculation should be treated as a substitute for the cluster-aware analysis.

What the endpoint comparison represents

The primary outcome is a binary participant event: ART initiation within the stated six-month period. The planned comparison is between arm-level proportions among all resident adults, regardless of HIV status or home-testing participation. In general, an effect estimate for a binary outcome may be expressed in different ways, such as a difference in proportions or a relative measure. The registry record does not report which effect measure was used, so none should be attributed to the trial’s analysis.

A confidence interval, in general, describes the range of effect values reasonably compatible with the data and the analysis assumptions. Its width conveys precision; it does not remove the need to consider the design or the outcome definition. The registry record does not report a confidence interval for ART initiation. It is therefore not possible to assess the precision of the primary estimate from the posted results.

Planning illustrations are not trial results

The registry describes a planning illustration based on the observed effect, rather than the trial’s own design calculation. It specifies a two-sided significance level of 0.05, equal allocation between the two arms, a normal approximation, and an effect to detect expressed as a stated fraction of the observed effect. The resulting planning values are not reported in the registry record.

Such calculations are planning illustrations, not observed power. In general, a sample-size calculation asks what scale of study would be needed under stated assumptions to detect a target effect. It does not show that the trial actually had that power, and it does not establish whether the observed data support an effect. A calculation based on an observed effect is especially dependent on that effect estimate; here, the registry does not report the primary estimate needed to evaluate the illustration’s numerical results.

The registry’s planning description also distinguishes time-to-event calculations, which use a total number of events, from other calculations, which use participants per arm. That general convention does not provide a primary outcome analysis for this trial. The primary endpoint is described as ART initiation within a fixed period, not as a time-to-event result in the available record.

Multiplicity and model details

Multiplicity arises when multiple outcomes or statistical comparisons are examined: the chance of at least one apparently unusual result can increase as the number of tests increases. In general, analysts may prespecify a primary outcome and a strategy for interpreting secondary outcomes. The registry lists six outcome measures, including the primary outcome and secondary outcomes, but a multiplicity adjustment or testing hierarchy is not reported in the registry record.

The record reports zero analysis entries. This does not establish what analyses were conducted outside the posted record; it means the registry does not provide analysis entries from which to assess modeling, adjustment, or uncertainty procedures. The statistical plan, any interim analyses, and any sample-size justification for the trial are 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("Home Assessment and Initiation of ART", "Clinic-based ART Assessment and Initiation")
n      <- c(8194, 8466)
events <- c(181, 63)
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  Home Assessment and Initiation of ART  8194  181  2.2  1.9  2.6  1.9  2.6  1.9  2.6
ARM  Clinic-based ART Assessment and Initiation  8466  63  0.7  0.6  1.0  0.6  1.0  0.6  1.0

11. Multiplicity, Missing Data and Analysis Populations

The registry lists six outcome measures. The primary outcome is ART initiation; the listed secondary outcomes concern uptake of home-based HIV testing, reporting of HIV-positive results, loss to retention, adherence to ART, and adult mortality. The record does not describe a hierarchy among these outcomes, a family of planned comparisons, or a method for controlling the chance of false-positive findings across multiple tests. A multiplicity strategy is not reported in the registry record.

In general, examining several outcomes can make isolated results harder to interpret unless the analysis plan specifies how they will be handled. This is particularly relevant when a primary outcome is distinguished from secondary outcomes. The listed outcome names identify areas of interest, but they do not establish which analyses were planned, which were performed, or whether any adjustments were used.

Missing-data methods and the extent of missing outcome information are not reported in the registry record. The record does not state how adults with unknown ART initiation status were handled, whether outcome ascertainment was complete, or how loss to follow-up affected the primary analysis. Analysis populations, such as the precise population included in the sponsor’s primary analysis, are not reported in the registry record.

The registry lists zero analysis entries. This is not evidence that no analysis occurred; it means the record does not document the analyses in entries that can be reviewed. It also does not provide information about interim analyses or the statistical analysis plan. As a result, the posted record cannot establish how missing observations, multiple outcomes, or analysis populations were addressed.

12. 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 5% reporting threshold.

The registry’s adverse-event entries list 0 serious events and 0 other events for home assessment and initiation of ART, with 8194 at risk. For clinic-based ART assessment and initiation, the entries list 0 serious events and 0 other events, with 8466 at risk. These are the figures recorded for the listed event categories and arm denominators.

Zero recorded events should be read as a registry count, not as a general guarantee that no adverse experiences occurred. The record does not describe the event collection process, the definition of each category, reporting completeness, or the period over which the figures were collected. The death counts are not reported in the registry record; the death entries are not numeric zeroes.

These safety entries are separate from the primary outcome of ART initiation. They do not establish the primary outcome result and should not be treated as a comparison of treatment effectiveness. The available figures permit only a description of what was entered in the adverse-event record, not a broader conclusion about safety.

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

The record establishes that a cluster-randomized comparison was registered between home assessment and initiation of ART and clinic-based ART assessment and initiation. It defines the primary question as a comparison of ART initiation among all resident adults during the first six months following the introduction of home-based HIV testing. It also records total enrollment of 16660 and a completed study status.

The record does not report the primary outcome results. No event counts, arm-specific proportions, effect estimate, confidence interval, or p-value for ART initiation are given. It is therefore not possible to determine from the posted results how large the difference was, which arm had the higher recorded initiation proportion, or how precise an estimated difference would be. The absence of a reported result is not evidence that the arms had equal outcomes.

The trial’s cluster design also limits what can be inferred from aggregate enrollment or adverse-event denominators. In general, valid uncertainty estimates depend on accounting for the grouped allocation. The registry record cautions against a simple individual-level re-analysis, and it does not provide the sponsor’s numerical primary analysis for independent review.

The listed adverse-event figures are zero for both serious and other events in each arm, but they do not answer the primary efficacy question, and the death entries are not reported. The registry also does not report how missing outcome data or multiple outcomes were handled. The evidence available in this record is therefore sufficient to describe the trial question and design, but insufficient to characterize the primary result or its precision.

14. Why This Trial Matters Statistically

This trial raises a statistical question that is both population-based and dependent on grouped assignment. Its primary endpoint concerns ART initiation among all resident adults, not only people who tested positive or participated in home-based testing. That definition makes clear that the target comparison is about the reach of the assigned approach across the adult population in the study clusters.

The cluster-randomized design is central to the analysis. In general, people sharing a cluster may have more similar outcomes than people from different clusters. An analysis must account for that structure to represent uncertainty appropriately. The registry record explicitly warns that a simple individual-level re-analysis would be misleading, underscoring why the unit of randomization should guide statistical interpretation.

The record also illustrates the difference between a clearly stated question and a reportable result. It describes the endpoint and the comparison, but provides no numerical primary estimate or uncertainty interval. Without those quantities, readers cannot judge the observed magnitude or precision. Enrollment and study completion alone do not fill that gap.

Finally, the listed secondary outcomes, planning assumptions, and adverse-event entries answer different questions from the primary comparison. Distinguishing design, outcome definition, analysis, and reporting is essential when interpreting a trial record, particularly when the primary result is not reported.

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 for interpretation is that the registry record does not report a numerical result for the primary endpoint. It gives no arm-specific ART initiation counts or proportions, effect estimate, confidence interval, or p-value. The primary comparison’s direction and precision therefore cannot be assessed from the posted results.

Although the record identifies a cluster-randomized design, it does not report the number of clusters, cluster sizes, or analysis methods. Those details matter because outcomes within a cluster may be correlated. The registry cautions against simple individual-level re-analysis, but does not provide the sponsor’s numerical analysis of the primary endpoint for review.

The available arm descriptions are incomplete. The record does not provide enough detail to reconstruct all intervention procedures or establish how consistently the approaches were delivered. It also does not report the primary outcome’s arm-specific denominators, completeness of ascertainment, or methods for handling missing data. The statistical analysis plan, interim analyses, and trial-specific sample-size justification are not reported in the registry record.

The record lists six outcome measures but does not describe how multiplicity was handled or define analysis populations. The adverse-event entries include zero counts in the listed serious and other categories, but the collection and reporting methods are not described, and deaths are not reported. These limitations constrain interpretation of the posted record; they do not by themselves establish what occurred outside the information recorded.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Home Assessment and Initiation of Antiretroviral Therapy for HIV in Malawi — NCT01414413.
• Registry record last updated 2014-04-07; status last verified 2014-02.
• Results first posted 2014-04-07.
• 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 a completed, open-label, parallel cluster-randomized trial in Blantyre, Malawi, comparing home assessment and initiation of ART with clinic-based ART assessment and initiation. Total enrollment is 16660. The listed study start is 2012-01, and primary completion is 2012-11.

The primary endpoint is the proportion of all resident adults who initiated ART during the first six months after home-based HIV testing was introduced, regardless of HIV status or participation in home testing. The registry lists secondary outcomes related to HIV testing, reporting of positive results, retention, adherence, and adult mortality.

The primary result and its statistical uncertainty are not reported in the registry record. The record cautions against a simple individual-level re-analysis because of cluster randomization. Its adverse-event entries list zero serious and zero other events in each arm; death counts are not reported.