This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Effect of Valacyclovir in the Reduction of HSV-2 Recurrence and Shedding (NCT00803543), a randomized na study. The primary outcome is Herpes Simplex Virus Type 2 Recurrence.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00803543 |
| Phase | NA |
| Condition | HIV, HIV Infections |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Triple |
| Enrollment | 103 |
| Arms in the primary outcome | 2 |
| Lead sponsor | University of Alabama at Birmingham |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns people with HIV. Its brief summary describes an additional aim of assessing how common herpes is among people with HIV who do not know they have it. The precise eligibility criteria and the population included in the recurrence analysis are not reported in the registry record.
Intervention
Valacyclovir is the active intervention. The official title describes daily valacyclovir, and the trial arms identify valacyclovir as the study drug. The dose, schedule details beyond daily use, and adherence information are not reported in the registry record.
Comparator
The comparator is placebo. The registry identifies placebo as the control arm. Details about how placebo was matched to valacyclovir are not reported in the registry record.
Primary question
The primary endpoint counts genital herpes recurrences during 24 Weeks. The statistical question is whether the posted recurrence counts differ between the valacyclovir and placebo arms. No participants in either arm were reported to have a recurrence, and the registry does not provide an estimable two-arm comparison for this count outcome.
The broader study purpose also includes estimating herpes prevalence among people with HIV and assessing effects on the amount of HIV in blood and HSV in bodily secretions. Those aims provide context, but the posted primary outcome is specifically a count of genital herpes recurrences. Results for other outcomes are not reported in the registry record.
3. Trial Design
The registry describes a randomized, triple-masked, parallel-group study comparing valacyclovir with placebo. The record lists University of Alabama at Birmingham as the sponsor, phase as NA, and status as completed. The study start is recorded as 2009-01 and primary completion as 2014-04. Enrollment is recorded as 103.
The outcome-specific arm records list 45 participants for valacyclovir and 22 for placebo. These endpoint records should not be treated as a reconciliation of the overall enrollment figure: why the outcome-specific group counts differ from the enrollment figure, and which participants were included or excluded from this endpoint, are not reported in the registry record. The record does not describe the allocation sequence, concealment procedures, or the roles of the people masked.
A parallel-group design compares groups assigned to different interventions rather than comparing each participant with themself. Randomization is intended, in general, to make treatment groups comparable at assignment, while masking can limit certain influences on care, reporting, and assessment. Those are general design principles; the registry does not describe implementation details that would establish how these safeguards operated in this trial.
The stated study purpose reaches beyond the primary recurrence endpoint, including herpes prevalence and measures related to HIV and HSV. However, the registry lists no posted secondary results and no posted analyses. Consequently, the available result does not answer every aim in the study summary, and details of the analysis populations and procedures cannot be reconstructed from the registry record.
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
| Stage | Valacyclovir | Placebo |
|---|---|---|
| STARTED | 69 | 34 |
| COMPLETED | 45 | 22 |
| NOT COMPLETED | 24 | 12 |
Analysis population for the primary outcome, as defined in the registry: No participants reported genital herpes recurrence during the 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.
| Characteristic | Unit | Valacyclovir | Placebo | Total |
|---|---|---|---|---|
| Participants analysed | 45 | 22 | 67 | |
| Age, Continuous | years | 45 (23 to 68) | 43 (27 to 61) | 45 (23 to 68) |
| Sex: Female, Male: Female | Participants | 8 | 1 | 9 |
| Sex: Female, Male: Male | Participants | 37 | 21 | 58 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 | 0 | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 45 | 22 | 67 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 25 | 9 | 34 |
| Race (NIH/OMB): White | Participants | 20 | 13 | 33 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Region of Enrollment: United States | participants | 45 | 22 | 67 |
| Absolute CD4 (cluster of differentiation 4) Count | cell/ml | 528 (165 to 1135) | 693 (198 to 1272) | 582 (165 to 1272) |
| Number with Undetectable Viral Load | participants | 40 | 19 | 59 |
6. Primary Endpoint
The registry lists the primary outcome as Herpes Simplex Virus Type 2 Recurrence, measured over 24 Weeks.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Recurrence |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the number of genital herpes recurrences during 24 Weeks. A recurrence count captures repeated episodes over a defined observation period, rather than simply recording whether a participant ever had an episode. In general, this type of outcome can describe the frequency of recurrent disease activity and may be useful when the research question concerns how often episodes occur.
For this endpoint, however, the registry reports no participants with a genital herpes recurrence during the study. The recorded count is 0 in the valacyclovir arm and 0 in the placebo arm. The number of recurrences is therefore zero in both reported groups, and the registry marks the two-arm count comparison as not estimable. It provides no comparative effect estimate or uncertainty interval for this primary endpoint.
The distinction between an endpoint definition and its observed result matters. A recurrence count is the intended measurement; the absence of reported recurrences does not itself establish that the interventions have identical effects in other settings, or that recurrence risk is absent outside the recorded observation. Information about how recurrences were confirmed, whether follow-up was complete, and how missing observations were handled is not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted primary outcome is a count of genital herpes recurrences over 24 Weeks. The registry reports 0 recurrences in the valacyclovir arm and 0 in the placebo arm, with no participants reported to have a recurrence. These values describe what is recorded for this endpoint; they do not provide a measurable contrast between the groups.
The registry specifically indicates that values are missing or not estimable for a two-arm comparison of this count outcome. There is no posted estimate of a treatment effect, confidence interval, or inferential test for the primary comparison. The record also lists no posted analyses. It is therefore not possible to use the registry result to quantify how much the groups differed, or how precisely such a difference was estimated.
In general, a confidence interval expresses the uncertainty around an estimated effect under a statistical model. When a comparison cannot be estimated, there is no interval to interpret as evidence for either a meaningful difference or close similarity. A result with zero observed counts in both groups is not a formal demonstration of equivalence. Equivalence or non-inferiority requires a defined statistical question and an analysis capable of assessing it; those details are not reported in the registry record.
The endpoint arm counts are 45 for valacyclovir and 22 for placebo, whereas overall enrollment is recorded as 103. These figures refer to different registry entries, and the record does not explain the relationship between them. The analysis population, the number with complete endpoint follow-up, and reasons for any difference are not reported in the registry record. The outcome-specific counts should therefore be read as the group counts attached to this endpoint, not as a complete account of participant disposition.
The study's wider aims include herpes prevalence and effects on HIV in blood and HSV in bodily secretions. No results for those outcomes are posted in the registry record. The recurrence result cannot be used to infer findings about prevalence, viral amounts, or other outcomes that are not reported.
In short, the record documents zero reported recurrences in each arm but supplies no estimable between-arm comparison. This is a descriptive result, not a basis for claiming either benefit or lack of benefit. Interpretation is further limited by the absence of analysis details, uncertainty estimates, outcome ascertainment information, and explanations for the difference between enrollment and endpoint group counts.
9. Statistical Methods Explained
The endpoint is a count, meaning that it records the number of recurrence events rather than a continuous measurement such as a laboratory concentration. Count outcomes can be analysed in different ways depending on their distribution, follow-up, and scientific question. The registry identifies the endpoint as a number of recurrences, but it does not report a statistical model or a method for comparing the arms.
Why do zero counts matter?
When no events are observed in either group, the data offer no observed separation in event counts. For some count models and effect measures, zero observations in both groups can prevent an ordinary comparative estimate from being obtained. Other methods may be considered in particular settings, but the registry does not name or report one for this endpoint. The posted comparison is explicitly not estimable, so an alternative method should not be assumed to have been used.
In general, count data may show over-dispersion: the observed variation can exceed what a simple model expects. Over-dispersion matters because a model that understates variability can produce uncertainty estimates that are too narrow. It is not possible to assess this feature from the registry entry because the endpoint has no reported recurrence events and the dispersion field is empty. The record does not report a model, a dispersion estimate, or a diagnostic assessment.
What can randomization and masking contribute?
Randomization is a design approach intended to reduce systematic differences between groups at assignment. Masking is intended, in general, to reduce the influence of knowledge about assignment on participant experience, clinical decisions, or outcome assessment. Here the record identifies randomized allocation, triple masking, a parallel model, valacyclovir, and placebo. It does not describe the randomization process, the people masked, or whether masking was maintained. The design labels alone do not show whether those procedures were implemented successfully.
Why is there no effect estimate to interpret?
An effect estimate summarizes a contrast between groups in a defined scale, such as a difference in counts or a ratio of rates. A confidence interval accompanies an estimate to represent its statistical uncertainty. Neither an estimate nor an interval is posted for the primary recurrence comparison. With the recorded count of 0 in each arm, the registry marks the two-arm comparison as not estimable. There is consequently no posted estimate to recalculate from summary statistics.
In general, a nonsignificant test and an unestimable comparison are not interchangeable. A test result concerns evidence under a specified model and hypothesis; an unestimable comparison means the record does not give a usable comparative estimate. No test statistic or p-value for this primary endpoint is reported, so the result should not be described as statistically significant, nonsignificant, or proof of no difference.
How should planning calculations be read?
Any sample-size planning illustrations associated with the posted results are not observed power and are not evidence about the trial's design justification. The stated illustration assumptions are a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. For time-to-event outcomes, the stated convention is to report total events; for other outcomes, it is participants per arm. The registry does not report the trial's own sample-size justification. Because the observed recurrence comparison is not estimable, planning values based on an observed effect should not be treated as an informative assessment of power for this endpoint.
More broadly, a statistical plan would ordinarily specify the primary comparison, analysis population, handling of missing data, model assumptions, and approach to uncertainty or multiplicity. Those procedures are not reported in the registry record. Without them, the posted zero counts can be described, but the analysis cannot be independently reconstructed or evaluated for sensitivity to modelling choices.
10. Multiplicity, Missing Data and Analysis Populations
The study summary names several aims, including herpes prevalence and possible effects on outbreaks, HIV in blood, and HSV in bodily secretions. The registry identifies the recurrence count as the primary outcome, but it does not report a statistical plan for managing multiple outcomes or multiple comparisons. No secondary outcome results or analyses are posted. It is therefore not possible to determine whether any multiplicity adjustment was planned or used, or how the primary endpoint was prioritized relative to the broader aims.
Missing-data procedures and analysis populations are also not reported in the registry record. The overall enrollment is recorded as 103, while the endpoint arm records list 45 for valacyclovir and 22 for placebo. The record does not explain this difference, describe participant flow, or indicate whether endpoint data were unavailable for some participants. The listed group counts should not be interpreted as proof of complete follow-up or as an explanation for missing observations.
The registry states that no participants reported genital herpes recurrence during the study. It does not explain whether this means all participants were assessed throughout the observation period, whether recurrence information was missing for any participants, or how incomplete follow-up was treated. Such details affect how a zero-event result should be interpreted. They cannot be inferred from the recorded outcome values.
The record also does not report interim analyses or stopping rules. Their presence or absence should not be guessed from the completed status. Without a published analysis plan or further registry detail, the available account supports a description of the posted outcome, but not a full assessment of multiplicity control, missingness, or the analysis population.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Valacyclovir | 0 | 45 | 0.0% |
| Placebo | 0 | 22 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Valacyclovir | 0 of 45 |
| Placebo | 0 of 22 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Valacyclovir | 0 of 45 |
| Placebo | 0 of 22 |
The safety records list 45 participants at risk in the valacyclovir group and 22 in the placebo group. For serious adverse events, the recorded affected count is 0 in each group, and recorded deaths are also 0 in each group. The other adverse-event affected count is recorded as 0 in both groups. No top serious-event terms are listed.
These are the safety figures reported in the registry, not evidence that no event could have occurred outside the captured records or observation period. The record does not describe adverse-event definitions, collection procedures, severity grading, follow-up duration for safety, or whether events were judged related to study treatment. It also does not explain the relationship between the safety groups and overall enrollment. The figures should therefore be read as the registry's recorded counts, without extending them to claims about broader safety.
Zero reported serious events is a descriptive count. It does not by itself establish that the treatments have the same safety profile, nor does it quantify the uncertainty around uncommon harms. No comparative safety estimate or confidence interval is reported in the registry record.
12. What the Result Does, and Does Not, Mean
The result establishes a narrow descriptive point: the registry records no genital herpes recurrence in either trial arm during the stated 24 Weeks. It does not establish a comparative treatment effect. With a count of 0 in both groups, the registry reports that the two-arm comparison is not estimable, and no effect estimate or confidence interval is available.
This distinction is important because identical observed counts do not prove that the underlying event rates are identical. In general, observed data are limited by the participants, follow-up, outcome ascertainment, and analysis methods captured in a study. The registry does not provide enough detail to assess those factors fully for this endpoint. The result is not a formal equivalence finding and does not answer whether a clinically meaningful difference could be ruled out.
The broader study purpose includes estimating herpes prevalence and assessing HIV and HSV amounts in bodily measures. Those questions cannot be answered from the posted recurrence result. Results for the secondary outcomes are not reported in the registry record, and the record lists no analyses. It would be inappropriate to treat the recurrence count as a proxy for findings on viral amounts or prevalence.
The safety record also lists zero affected counts for serious and other adverse events and zero deaths in the two groups. Those figures describe what is recorded; they do not resolve questions about event ascertainment, follow-up, or safety precision, none of which is reported in detail.
Accordingly, the most defensible interpretation is limited: no recurrences were reported in either arm, and a comparative estimate for the primary count outcome is unavailable. The registry does not support a claim that valacyclovir reduced recurrences, that it had no effect, or that the groups were equivalent. Additional outcome and analysis information would be needed to address those questions.
13. Why This Trial Matters Statistically
This trial illustrates a core distinction in clinical statistics: an observed group result is not the same as an estimable treatment comparison. The registry records zero recurrences in both arms, but it does not report an effect estimate or an uncertainty interval. When the comparison cannot be estimated, matching observed counts cannot be translated into a conclusion that the interventions are equivalent.
The record also makes clear why outcome-specific denominators and analysis populations matter. Overall enrollment is recorded as 103, while the primary endpoint records list 45 for valacyclovir and 22 for placebo. Without participant flow or an explanation of this difference, readers cannot tell how the endpoint counts relate to the full enrolled group. This limits assessment of follow-up and of the scope of the observed zero counts.
More generally, count outcomes require analysis choices suited to the event distribution and observation process. The registry does not report a model, an approach to missing data, or a detailed analysis plan. Those omissions do not invalidate the descriptive values, but they constrain what can be concluded from them and prevent independent reconstruction of a comparative analysis.
The record's broader goals also demonstrate the importance of distinguishing a primary endpoint from other research questions. Recurrence counts do not answer questions about herpes prevalence or measured HIV and HSV amounts. With no secondary results posted, the available evidence is especially narrow. The statistical lesson is not a claim about treatment efficacy; it is that clear endpoint reporting, analysis details, and uncertainty estimates are essential for interpreting clinical results.
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.
Several trial-specific limitations of interpretation arise from the registry record. First, the primary endpoint is not accompanied by a comparative estimate, confidence interval, or inferential test. The record reports zero recurrences in both arms and marks the two-arm count comparison as not estimable. The result therefore supports description of the reported counts but not a quantified treatment contrast.
Second, overall enrollment is listed as 103, whereas the endpoint arm records list 45 for valacyclovir and 22 for placebo. Participant flow, the endpoint analysis population, and the reason for the difference are not reported in the registry record. It is not possible to determine whether the outcome counts represent everyone enrolled, a subset with observed endpoint data, or another analysis population.
Third, the recurrence ascertainment process is not described. The registry does not report how recurrences were defined or confirmed, how often they were assessed, whether follow-up was complete, or how missing observations were handled. These omissions limit evaluation of what the zero counts represent over the stated observation period.
Fourth, no statistical model or analysis plan is reported. Details of randomization, masking roles, adherence, dose, and treatment discontinuation are also not reported in the registry record. The record lists no secondary analyses or results, so the broader study aims cannot be assessed from the posted outcome. These limitations concern the information available in the record and do not establish what procedures may or may not have occurred.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Effect of Valacyclovir in the Reduction of HSV-2 Recurrence and Shedding — NCT00803543.
- Registry record last updated 2017-07-13; status last verified 2017-06.
- Results first posted 2017-07-13.
- 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.
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18. Record Summary
The registry record describes NCT00803543, titled “Effect of Valacyclovir in the Reduction of HSV-2 Recurrence and Shedding.” It identifies a randomized, triple-masked, parallel-group study sponsored by University of Alabama at Birmingham, with status completed and phase recorded as NA. The study start is 2009-01, primary completion is 2014-04, and enrollment is 103.
The primary endpoint is the number of genital herpes recurrences during 24 Weeks. The registry reports 0 in the valacyclovir arm and 0 in the placebo arm, with no participants reported to have a recurrence. A two-arm comparison is not estimable, and no analyses or secondary results are posted. The endpoint arm records list 45 for valacyclovir and 22 for placebo; the reason these counts differ from overall enrollment is not reported in the registry record.
Safety records list zero serious adverse-event affected counts, zero other adverse-event affected counts, and zero deaths in each group. The available record supports a description of these posted counts, but not an estimated treatment effect or a broader conclusion about the study's other aims.