Enhanced Virologic Monitoring for Pregnant and Postpartum Women With HIV: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Enhanced Virologic Monitoring for Pregnant and Postpartum Women With HIV (NCT05845619), a non-randomized na study. The primary outcome is Plasma HIV RNA >50 Copies/mL.

2. Clinical Question

The research question links a practical support strategy to a laboratory measure of viremia after participation. Viral-load feedback and counseling are intended to support adherence, while the endpoint captures whether a participant’s measured plasma HIV RNA exceeds the stated threshold during the follow-up window. The endpoint is recorded from clinical records, rather than through participant interaction for outcome collection.

The distinction between the intervention group and controls matters for interpreting the question. The study is nonrandomized, and the controls are described through different routes of enrollment: prospective enrollment and abstraction from records. Those groups may not be directly comparable to the pilot participants. The registry itself flags that the arms are not a like-for-like control comparison. Consequently, even if an outcome contrast were posted, it would need to be read as an observational comparison rather than as a randomized estimate of the intervention’s effect.

The record gives the study’s purpose and endpoint definition, but not the observed primary outcome counts or an estimate comparing groups. It therefore does not answer whether viral suppression differed after the intervention. Feasibility findings are also not reported in the registry record.

3. Trial Design

This is a completed, nonrandomized, parallel-model study of enhanced virologic monitoring for pregnant and postpartum women with HIV. The registry lists the allocation as nonrandomized and masking as none. The recorded enrollment is 550. The study is listed as phase not applicable, and the sponsor is the University of California, San Francisco.

The intervention is named enhanced virologic monitoring and classified as behavioral. The study summary describes peer counseling about viral load levels and rapid delivery of viral-load results as parts of the pilot. Its stated aim is to learn about adherence support and evaluate feasibility, while assessing viral suppression after the intervention compared with historical controls. More detailed descriptions of the arms are not reported in the registry record.

The record lists a Pilot group, Controls - Prospectively Enrolled, and Controls - Abstracted From Records. It does not describe random assignment, and its own note warns that this is not a like-for-like control comparison. The use of prospective controls alongside controls identified through record abstraction also means that the comparison groups arise through different processes. The registry record does not provide enough detail to characterize how those processes affected comparability or the analyses.

The study began on 2023-05-08, reached primary completion on 2024-06-30, and is listed as completed. The primary endpoint timeframe is within 6 months after study engagement for the pilot, after the enrollment visit for prospectively enrolled controls, and after the date of eligibility for controls from records. This group-specific description defines when outcome information was sought, but does not establish that the groups had equivalent follow-up or equivalent opportunities for measurement.

The registry record reports no rationale for the enrollment target, no detailed statistical analysis plan, and no explanation of how the control groups were selected or adjusted in comparisons. Those design details are important to assessing the strength of any treatment-effect interpretation, and should not be inferred from the study’s stated purpose.

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.

Before assignment: There was no pre-assignment procedure

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: All 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 Plasma HIV RNA >50 Copies/mL, measured over Within 6 months after study engagement (i.e., after pilot study participation; after the enrollment visit for prospectively enrolled controls; after the date of eligibility for controls from records).

The primary endpoint is the count of participants whose plasma HIV RNA is above 50 copies/mL during the specified follow-up period. It is a binary outcome at the participant level: a participant either has a qualifying result in the window or does not, based on the endpoint definition. The record identifies the endpoint unit as participants and the population as all participants.

The timeframe differs according to group. For the pilot, it is within 6 months after study engagement, described as after pilot participation. For prospectively enrolled controls, it is after the enrollment visit. For controls abstracted from records, it is after the eligibility date. If more than one viral load is collected during the relevant timeframe, the first is used. The endpoint description says data are collected from clinical records only, with no participant interaction for this outcome collection.

A threshold-based viral-load measure offers a concrete way to describe viremia during follow-up. It is related to the study’s interest in viral suppression, but the posted endpoint is specifically the count above the stated threshold; it is not a direct measure of adherence, counseling engagement, or feasibility. The registry record does not report the group-specific endpoint counts, denominators used in an analysis, or a comparative estimate. Thus the endpoint definition is available, but its observed results 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 participant-level count outcome: the number of participants whose plasma HIV RNA is above 50 copies/mL in the defined timeframe. Although the endpoint is expressed as a count, its underlying classification is binary for each participant. A group count alone does not show the probability of the outcome unless its denominator is also known. The posted registry information does not include primary outcome counts or analysis denominators, so an observed group rate cannot be interpreted from this record.

What does a confidence interval communicate?

In general, a confidence interval describes the precision of an estimated effect under the assumptions of the analysis. A narrow interval indicates greater statistical precision, while a wide interval indicates less precision. Its interpretation depends on the estimate, the method used to construct the interval, and the design that produced the data. No primary-outcome confidence interval is reported in the registry record, so neither the precision nor the range of plausible comparative effects can be assessed.

Even when a confidence interval or significance test is available, it does not remove design limitations. For a nonrandomized study, statistical uncertainty and potential systematic differences between groups are separate issues. An interval can quantify uncertainty under an analysis model without accounting for unmeasured confounding, selection into groups, or differences in outcome ascertainment. The registry identifies the study as nonrandomized and cautions that the arms are not like-for-like; detailed adjustment methods are not reported.

Why does allocation matter?

Random allocation is a design method intended to balance measured and unmeasured factors across groups on average. This study is listed as nonrandomized, so that protection cannot be presumed. Comparisons may be affected by who entered the pilot, how controls were identified, or the circumstances in which clinical records were available. These are general concerns for nonrandomized comparisons, not claims that a specific bias occurred in this study. The registry does not report enough information to judge their extent.

The parallel model indicates that the study organizes groups in parallel rather than describing a crossover arrangement. The named groups are the Pilot, prospectively enrolled controls, and controls abstracted from records. The registry record does not report detailed group procedures, allocation mechanisms, or the exact comparison used in the two listed analyses. It is therefore not possible to reconstruct the analysis from the design labels alone.

How should the endpoint timing be understood?

The outcome window is tied to different reference points for the groups: study engagement for the pilot, the enrollment visit for prospectively enrolled controls, and the eligibility date for controls abstracted from records. The first viral-load result in the relevant timeframe is used if more than one is collected. These rules define which observation is intended to represent the endpoint. They do not indicate how frequently testing occurred, whether test timing was similar across groups, or how absent measurements were handled. Those details are not reported in the registry record.

In general, differing opportunities to obtain measurements can affect comparisons based on clinical records. If outcome availability varies with participant characteristics or group, the analyzed participants may not represent the same underlying populations. This is why reporting the number with available measurements, missing-data procedures, and analysis population is important. The registry lists the endpoint population as all participants, but further analysis-population and missing-data details are not reported.

What do the planning assumptions mean?

The registry’s planning note describes an illustration based on the observed effect, not the trial’s own design. It specifies 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. Such calculations are planning illustrations, not observed power and not evidence that a study had a particular chance of detecting its actual effect. The note also distinguishes participant-per-arm illustrations from total-event illustrations for time-to-event outcomes. The primary endpoint in this study is a participant count, not a time-to-event endpoint.

The assumptions should not be mistaken for the study’s actual design. The registry describes three named groups and a nonrandomized allocation, whereas the planning illustration uses equal allocation between two arms. No numerical planning outputs, chosen effect fraction, original sample-size justification, or protocol-based power calculation are reported in the registry record. The planning note therefore cannot be used to infer what effect the study was designed to detect.

What can a recalculation establish?

In general, a recalculation from posted summary statistics can check an unadjusted contrast under specified assumptions. It cannot reproduce an adjusted sponsor analysis without the underlying model and inputs, and it cannot address unmeasured confounding. In this record, the primary outcome summary statistics and comparative estimates are not reported, so no primary-outcome recalculation can be interpreted from the posted information. No recalculated primary result is available to compare with a sponsor analysis.

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("Pilot", "Controls - Prospectively Enrolled", "Controls - Abstracted From Records")
n      <- c(273, 123, 149)
events <- c(34, 13, 15)
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  Pilot  273  34  12.5  8.8  17.0  9.1  16.9  9.1  16.9
ARM  Controls - Prospectively Enrolled  123  13  10.6  5.7  17.4  6.3  17.2  6.3  17.3
ARM  Controls - Abstracted From Records  149  15  10.1  5.7  16.1  6.2  15.9  6.2  16.0

11. Multiplicity, Missing Data and Analysis Populations

The registry lists two analyses, but their individual hypotheses, group contrasts, outcome assignments, and statistical methods are not reported in the registry record. It also does not report whether a multiplicity adjustment was planned or used. When several outcomes or comparisons are tested, multiplicity can increase the chance of obtaining an apparently noteworthy result by chance. General methods for addressing this include prespecifying a primary contrast or adjusting interpretation for multiple testing, but the record does not say which approach applied.

Missing-data handling is not reported. The primary endpoint relies on clinical records, and the record specifies which viral-load result to use when more than one is collected. It does not state how participants with no recorded viral load during the relevant timeframe were handled, whether the amount of missing outcome information differed by group, or whether any imputation or sensitivity analysis was performed. These omissions limit interpretation because outcome availability can affect both the analyzed population and the apparent group contrast.

The endpoint population is labeled all participants. This does not provide a full analysis-population definition or establish that every enrolled participant had an observed outcome. The registry record does not report exclusions, adherence to the intervention, or whether analyses followed an intention-to-treat, per-protocol, or other principle. Those analysis choices should not be inferred from the population label.

These reporting gaps matter alongside the nonrandomized design. Without defined comparisons and information about missingness and analysis populations, readers cannot judge whether the analyses preserve the intended comparison or how robust the findings would be to alternative assumptions. Primary outcome findings themselves are not reported in 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 serious adverse event entries report zero affected participants in the Pilot group, with 273 listed as at risk. For Controls - Prospectively Enrolled, the record lists 123 at risk and 0 affected. For Controls - Abstracted From Records, it lists 149 at risk and 0 affected. These are the registry’s reported serious adverse event counts for the named groups.

A zero count means that the registry entry records no affected participants for that category; it does not establish that the study had no safety concerns of any kind. Interpretation also depends on the event definition, observation period, completeness of reporting, and the way events were collected. Further detail on those matters is not reported in the registry record. The empty list of top serious terms does not add information about the primary endpoint.

These safety figures should be kept separate from the primary viral-load outcome. They do not show whether the intervention changed the number of participants with plasma HIV RNA above 50 copies/mL, and they do not provide evidence about feasibility. The registry record also does not report a comparative safety analysis. The counts are descriptive entries, not a basis for drawing broader conclusions about safety or effectiveness.

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

The record documents a completed pilot study focused on enhanced virologic monitoring and adherence support for pregnant and postpartum women living with HIV. It specifies a primary outcome based on plasma HIV RNA above 50 copies/mL within 6 months after engagement, with group-specific reference dates and a rule to use the first viral-load result when multiple measurements fall in the window. It also reports serious adverse event counts for the named groups.

What it does not report is the primary outcome result. No outcome count by group, comparative effect estimate, confidence interval, or significance result is included in the posted registry information. The record therefore does not show whether the groups differed, how large a difference might have been, or how precisely any difference was estimated. The study summary’s stated intent to assess improvement is not itself evidence that improvement occurred.

The design also limits what a comparison could establish. Allocation was nonrandomized, and the registry warns that the arms are not a like-for-like control comparison. The prospectively enrolled controls and record-abstracted controls have different descriptions, and the details needed to evaluate their comparability are not reported. Even with outcome estimates, a between-group association would not automatically establish that the intervention caused the difference.

Nor does the posted record establish whether the intervention was feasible. Although feasibility is named as a study objective, feasibility measures and findings are not reported. The serious adverse event counts are a distinct kind of information and do not fill that gap.

The appropriate conclusion is limited: the registry identifies the intervention concept, study structure, endpoint, and selected safety counts, but does not report the primary result or feasibility findings. It cannot support a claim that the intervention did or did not change viral suppression, and it does not establish a causal effect.

14. Why This Trial Matters Statistically

This study illustrates why a registry entry must be read in two layers: the question and design, and the results available to answer that question. The record gives a clinically meaningful outcome definition and a follow-up framework, but does not report the primary outcome data. Clear endpoint wording cannot substitute for outcome counts, effect estimates, or uncertainty intervals.

It also highlights the statistical importance of control-group construction. The record distinguishes prospectively enrolled controls from controls abstracted from records and explicitly notes that the comparison is not like-for-like. Those details are not incidental: group formation influences what a contrast can mean. Without reported information on comparability, adjustment, and outcome availability, readers cannot determine how much of a possible difference might reflect the intervention rather than other group differences.

The endpoint illustrates another practical issue: clinical-record measures depend on the availability and timing of measurements. The record specifies the first result in the timeframe, which makes the selection rule explicit. Still, the frequency of testing and handling of missing results are not reported. A well-defined measurement rule is useful, but a complete statistical interpretation also needs information about who contributed an observed result and how missing measurements were addressed.

Finally, the record’s planning note distinguishes planning illustrations from the trial’s own design. This distinction is important because a calculation based on an observed effect is not the same as a prospective design justification, and it is not observed power. The record does not provide numerical planning outputs or an original sample-size rationale. Taken together, these features make the study a useful example of how registry transparency shapes the limits of statistical interpretation.

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 principal limitation for interpreting this record is that primary outcome results are not reported. The endpoint is defined, but group-specific outcome counts, denominators, and comparative estimates are absent. Feasibility findings are also not reported, despite feasibility being a stated study objective.

The comparison is nonrandomized, and the registry explicitly cautions that the arms are not a like-for-like control comparison. The record names prospectively enrolled controls and controls abstracted from records, but does not provide details sufficient to assess their selection, baseline comparability, or the analysis used to compare them. Masking is listed as none. Whether or how these design features affected results cannot be determined from the registry record.

Outcome ascertainment uses clinical records, with group-specific reference dates and the first viral-load result used when multiple results occur in the window. The registry does not report measurement availability, missing-data procedures, or whether testing opportunities were comparable across groups. The endpoint population is labeled all participants, but the analysis population and any exclusions are not described.

The record lists two analyses without describing their methods or contrasts, and does not report whether multiplicity was addressed. It also gives no original sample-size justification or detailed statistical plan. These gaps prevent assessment of the intended estimand, the role of adjustment, and the robustness of any result. The posted safety counts are limited to the reported serious adverse event entries and do not resolve these efficacy and design uncertainties.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Enhanced Virologic Monitoring for Pregnant and Postpartum Women With HIV — NCT05845619.
• Registry record last updated 2025-08-14; status last verified 2025-07.
• Results first posted 2025-08-14.
• 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

NCT05845619 is a completed, nonrandomized, parallel-model study titled “Enhanced Virologic Monitoring for Pregnant and Postpartum Women With HIV.” Its official title describes implementing a risk score to facilitate enhanced adherence support for pregnant and postpartum women at risk of viremia. The sponsor is the University of California, San Francisco; the record lists enrollment of 550, phase not applicable, and no masking.

The behavioral intervention is enhanced virologic monitoring. The primary endpoint counts participants with plasma HIV RNA above 50 copies/mL within 6 months after the group-specific reference point. The study began on 2023-05-08 and reached primary completion on 2024-06-30.

The registry names a Pilot group and two control groups, and warns that this is not a like-for-like control comparison. Primary endpoint results, feasibility findings, detailed analysis methods, and missing-data procedures are not reported in the registry record. Serious adverse event entries list 0 affected participants in each group.