Efavirenz (EFV) Intensification: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Efavirenz (EFV) Intensification (NCT07193875), a na phase 4 study. The primary outcome is Safety as Measured by Adverse Events.

2. Clinical Question

The record frames the investigation around whether adding EFV to cART is safe and well tolerated and whether reservoir size changes after intensification. These are distinct questions. An adverse-event count addresses a safety outcome; it does not measure reservoir reduction. Similarly, a pre/post change in a reservoir measure, if reported, would describe change over time in the enrolled participants, but by itself would not provide the same comparison as a concurrent control group.

The single-arm structure matters when interpreting any apparent change. Participants serve as their own reference for the stated pre/post reservoir comparison, but changes over time can have explanations other than the intervention. The registry record does not describe a control condition that could help separate those explanations. It also does not report the reservoir measurements or an analysis of them. Consequently, the registry record supports describing the study questions and design, but not drawing a conclusion about reservoir reduction.

3. Trial Design

This is a completed phase 4 study with a single-group model and no masking. The registry record lists allocation as not applicable and describes only one arm, “Efavirenz intensification.” The listed intervention is Efavirenz 600mg. The study summary describes intensification of participants’ baseline cART and a comparison of reservoir size before and after intensification. Enrollment was 9.

The registry record reports a start date of 2023-02-09 and a primary completion date of 2024-12-16. Its status is completed. The primary safety outcome’s timeframe is from enrollment until study completion, described as an average of 5 months. That timeframe is attached to the safety measure; the record does not give additional visit schedules or specify the timing of individual assessments.

With one group and no masking, this is not a randomized, blinded comparison of EFV intensification against a control treatment. Its stated pre/post approach can compare observations within participants, but there is no parallel group in the record to show what would have happened over the same period without intensification. This distinction is important: the design can describe observed changes, but the registry information does not establish that a change was caused by the intervention.

The record names Washington University School of Medicine as sponsor. It lists two outcome measures and zero analyses. Detailed protocol information such as eligibility criteria, the planned statistical analysis, sample-size justification, interim analyses, and handling of deviations is not reported in the registry record. The posted page also contains calculated tables, plots, and a sample-size section; those displays should be read as presentations of the posted information, not as extra outcomes or design features.

The sample-size section is a planning illustration, not a record of the original design rationale and not observed power. Its stated assumptions describe a two-arm illustration, whereas this study has one arm. It therefore should not be mistaken for evidence that the actual trial was designed or powered for that two-arm comparison. The registry record does not report the study’s own sample-size justification.

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.

6. Primary Endpoint

The registry lists the primary outcome as Safety as Measured by Adverse Events, measured over From time of enrollment until completion of study on average 5 months.

The primary endpoint is titled “Safety as Measured by Adverse Events.” It counts participants, rather than counting the total number of separate events. The endpoint description includes participants with serious adverse events, adverse events that lead to study discontinuation, or adverse events considered clinically significant. The timeframe runs from enrollment through study completion, described as an average of 5 months.

Counting participants with an event is a way to summarize how many people experienced at least one event within the outcome’s definition and timeframe. It is useful for a safety description because it focuses on the number of participants affected, rather than allowing a participant with repeated events to contribute many times to a participant count. The registry summary does not provide a separate count for each component of the combined endpoint, so the components should not be treated as individually quantified.

The endpoint is relevant to the study’s stated safety and tolerability question, but it is not a measure of HIV reservoir size. Nor does the label alone specify how investigators judged clinical significance, attributed events, or handled events with incomplete information; those operational details are not reported in the registry record. The safety count should therefore be interpreted according to the posted endpoint definition, without assuming further rules.

The outcome is reported over the study period, rather than as an event rate per unit of follow-up. The record does not give individual follow-up durations or a time-to-event analysis. This limits what can be inferred about when events occurred or how their timing compared across participants.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a single-group design show?

This study has one arm and no masking. The registry summary describes comparing each participant’s reservoir size before and after EFV intensification. In general, a within-participant comparison uses measurements from the same person at different times. This can describe whether the measured outcome changed in the observed participants. It does not, on its own, distinguish an intervention effect from other changes over time, measurement variation, or changes in care that are not described in the record.

A concurrent comparison group can help provide context for changes over the same period, but this record does not describe such a group. Allocation is listed as not applicable, and the study model is single group. Consequently, analyses should not be described as randomized treatment comparisons. The registry record does not report a specific statistical model for the intended pre/post reservoir comparison.

What does the safety count represent?

The primary outcome is a participant count for a composite safety definition. It includes serious adverse events, events leading to study discontinuation, or events considered clinically significant. A participant count is distinct from an event count: a participant who experiences more than one event may still contribute as one participant to a count of participants with an event. This is a general distinction; the record does not provide separate component counts or a detailed event-level analysis.

The reported safety summary gives 1 serious event among 7 participants at risk. It also lists 0 for other adverse events in the displayed category and 0 deaths. The record’s term listing names hepatotoxicity at 14.3%. These are registry summaries, not results from a comparative model. The at-risk denominator should not be silently replaced by enrollment of 9; the record does not explain why the figures differ.

How should uncertainty be understood?

In general, a point estimate summarizes an observed result, while a confidence interval describes uncertainty around that estimate under specified assumptions. The registry information does not provide a confidence interval for the safety counts or an inferential analysis for the reservoir question. That means the precision of any estimated event frequency or reservoir change cannot be evaluated from a reported interval.

For a small study, counts can be informative as a record of what was observed, while still providing limited information about the range of outcomes that might occur in a larger population. This general principle does not justify generating an interval or estimate that the registry record does not report. It also does not establish that the study’s original analysis lacked such calculations; the appropriate statement is that they are not reported in the registry record.

What do the planning illustrations mean?

The sample-size section is described as a planning illustration computed from an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The section states that the effect to detect is a specified fraction of the observed effect; it also distinguishes participant counts per arm from total events for time-to-event tables. These are assumptions for an illustration, not reported design decisions for this trial.

This study is single group, so a two-arm, equal-allocation illustration does not reproduce its design. The illustration should not be read as the number enrolled, as an assessment of whether this study had adequate power, or as observed power. Observed power is not a substitute for interpreting the estimate and its uncertainty, and the registry does not report a trial-specific sample-size justification. The posted results also do not provide a reservoir effect estimate that can be used to interpret the biological question.

What can be said about multiplicity and analysis?

The registry lists two outcome measures and zero analyses. It does not report a statistical analysis plan, a hierarchy among outcomes, an adjustment for multiple comparisons, or the handling of missing measurements. In general, multiplicity refers to the increased chance of a false-positive finding when many hypotheses are tested. Whether and how that issue was addressed cannot be determined from the registry record.

Likewise, an analysis population specifies which participants are included in a particular analysis, and missing-data methods describe how unavailable measurements are handled. Neither is specified in the information. The difference between enrollment of 9 and the safety table’s 7 participants at risk makes it especially important not to infer a denominator or analysis population beyond what each posted result states.

These limitations concern what is documented in the registry record; they do not establish what investigators may have done outside the posted record. A cautious reading separates recorded counts and design details from unreported methods, estimates, and conclusions.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists two outcome measures and zero analyses. It does not report a statistical analysis plan explaining how outcomes were prioritized, whether multiple statistical tests were planned, or whether any multiplicity adjustment was used. In general, testing multiple outcomes can increase the chance of a false-positive result if the testing strategy is not accounted for. The record does not contain enough information to assess whether that issue arose or how it was handled.

The primary outcome is described as a composite safety measure, but separate results for each component are not reported in the summary. The study description also raises the reservoir question, yet no reservoir estimates or analyses are posted in the information. Neither the number of outcome measures nor the stated scientific questions establishes which results were available to investigators or how analyses were selected.

Missing-data rules and analysis populations are not reported in the registry record. The safety table lists 7 participants at risk, whereas enrollment is 9, and the reason for this difference is not reported. The record does not describe whether this reflects follow-up availability, eligibility for a particular analysis, or another reason, so none should be assumed. It also does not explain how missing pre/post measurements, if any, were handled.

In general, missingness can affect interpretation when participants without a measurement differ from those with one. Without a reported account of missing observations and the analysis population, readers cannot determine whether this concern applies or how it was addressed. These are gaps in the posted reporting, not proof that the investigators did not conduct additional analyses.

11. Safety Results

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

Deaths

Other (non-serious) adverse events

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

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: hepatotoxicity (14.3%).

The registry’s safety summary reports 1 serious adverse event among 7 participants at risk in the single-arm group. It lists 0 for other adverse events in the displayed category and 0 deaths. The serious-event term listing reports hepatotoxicity at 14.3%. Read these as the posted descriptive safety figures, not as a comparison with a control group.

The primary outcome definition combines serious events, adverse events leading to discontinuation, and events considered clinically significant. The summary does not give separate counts for each component. The category-level count therefore should not be taken as a full breakdown of every type of event covered by the endpoint. The registry record also does not give further detail about event timing or attribution.

Enrollment is 9, but the adverse-event table reports 7 participants at risk. The registry record does not explain this difference. The denominator of 7 belongs to the posted safety summary and should not be replaced by enrollment when describing that table. Nor can the displayed counts establish how often events would occur in a larger or different population.

In general, safety counts describe what was recorded within a study’s defined group and timeframe. With a single arm, these figures do not show what would have occurred under a separate comparator condition, and they do not by themselves establish causation. The record states an average safety timeframe of 5 months from enrollment until study completion.

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

The posted record can support a limited, descriptive account of this completed study: it enrolled 9 participants, used a single-group EFV intensification design, and reports a safety table with 7 participants at risk. The table records 1 serious adverse event, 0 other adverse events in the listed category, and 0 deaths. The term listing identifies hepatotoxicity at 14.3%. These results describe the registry entries; they do not amount to a controlled estimate of comparative safety.

The results do not show whether reservoir size changed. Although the study description identifies blood and tissue reservoir reduction as a question and describes a pre/post comparison, no corresponding measurements or analysis are reported in the registry information. Therefore, the record cannot establish the direction or magnitude of any reservoir change, nor its precision.

The study has no separate control arm, so even a posted pre/post change would need careful interpretation. In general, change over time in a single group is not sufficient by itself to attribute that change to an intervention. The record does not describe a randomized or otherwise concurrent comparator that could address this limitation.

The absence of a posted analysis does not show that no analysis was performed outside the registry. It means that readers of this record cannot inspect such an analysis or its assumptions. The record also does not report the trial’s sample-size justification, missing-data methods, or statistical analysis plan. Those omissions limit assessment of how the study was intended to quantify uncertainty and handle incomplete observations.

Accordingly, neither a claim that EFV intensification reduced the reservoir nor a claim that it did not reduce the reservoir follows from the information. Similarly, the adverse-event entries do not establish causation or predict an individual’s experience. The sound interpretation is confined to the recorded study design, stated outcome, and posted safety figures, with the reservoir result and important analytical details not reported in the registry record.

13. Why This Trial Matters Statistically

This trial is statistically instructive because its scientific questions and its design need to be kept distinct. The study description asks about both tolerability and HIV reservoir reduction, but the primary endpoint is a safety measure. Safety counts cannot stand in for measurements of reservoir change. The registry record does not post a reservoir analysis, so the central biological question remains unanswered by these results.

The single-group pre/post design also illustrates the difference between describing change and estimating a causal effect. A within-participant comparison can use each person’s baseline observation as a reference, but without a concurrent control group it cannot by itself account for other changes over time. The record’s allocation field is not applicable, and its model is single group; language suggesting a randomized comparison would be inaccurate.

Denominators are another central interpretive issue. Enrollment is reported as 9, while the safety table reports 7 participants at risk. The registry does not explain the difference. Keeping those figures attached to their correct contexts avoids implying that the safety analysis included every enrolled participant or inventing an explanation for who contributed to it.

Finally, the record lists two outcome measures and zero analyses, with no statistical analysis plan or sample-size justification. This makes it important to distinguish posted descriptive counts from estimates supported by a documented inferential method. The planning illustrations may help explain assumptions, but they are not observed power, do not document the original design rationale, and do not turn the single-arm trial into a two-arm study.

14. Limitations

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

The most important trial-specific limitation is the single-group design. The registry describes a pre/post reservoir comparison but no separate control arm. Without a concurrent comparator, observed change over time cannot be separated confidently from other time-related influences. This limitation applies to interpretation of any pre/post findings; in the information, reservoir findings are not reported at all.

The enrollment is 9, while the adverse-event table identifies 7 participants at risk. The registry record does not explain the difference. This leaves uncertainty about how the safety denominator relates to the enrolled group and prevents readers from inferring the reason for the discrepancy. The safety figures should be reported with the denominator shown in that table.

The primary endpoint combines serious adverse events, events leading to study discontinuation, and clinically significant adverse events. Separate counts for these components are not reported in the summary here, limiting interpretation of which component contributes to the outcome. The record also does not give further detail on event timing, assessment procedures, attribution, or the operational definition of clinical significance.

The registry lists two outcome measures but zero analyses. It does not report the statistical analysis plan, missing-data methods, analysis populations, or the study’s sample-size justification. These omissions limit assessment of how the intended analyses handled uncertainty and incomplete observations. The registry’s safety timeframe is described as an average of 5 months, but individual follow-up durations are not reported.

These are limits of the record available for interpretation. They should not be expanded into claims that particular procedures were absent or that unposted analyses were never conducted. The appropriate conclusion is that those details are not reported in the registry record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Efavirenz (EFV) Intensification — NCT07193875.
• Registry record last updated 2026-07-17; status last verified 2026-06.
• Results first posted 2026-07-17.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

NCT07193875 is a completed phase 4, single-group study of Efavirenz 600mg intensification in people living with HIV. The registry lists enrollment of 9, no masking, and Washington University School of Medicine as sponsor. The study description frames questions about safety, tolerability, and changes in blood and tissue HIV reservoir after intensification.

The primary outcome is a participant count covering serious adverse events, adverse events leading to discontinuation, or clinically significant adverse events, from enrollment until study completion, described as an average of 5 months. The adverse-event summary reports 1 serious event among 7 participants at risk, 0 other adverse events in the displayed category, and 0 deaths; hepatotoxicity is listed at 14.3%.

The registry lists two outcome measures and zero analyses. Reservoir results, a trial-specific sample-size justification, and detailed statistical methods are not reported in the registry record. The safety counts are descriptive, and the single-arm design does not provide a concurrent control comparison.