Clinical Performance of a Vaginal Pessary (pHyph) in Bacterial Vaginosis: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Clinical Performance of a Vaginal Pessary (pHyph) in Bacterial Vaginosis (NCT03762083), a na na study. The primary outcome is Clinical Cure Rate.

2. Clinical Question

The primary question is a within-group description of the endpoint after treatment, not a test of whether the pessary performs better than an alternative. Without a comparator, changes from study inclusion to follow-up cannot by themselves distinguish a treatment effect from other explanations, such as the natural course of BV or measurement variation.

The study also planned to assess individual Amsel criteria, usability by questionnaire, recurrence, and safety. Those outcomes can add context about symptoms and patient experience, but the registry record does not report their results. Its description says patients who were not cured at the first assessment would receive an additional week of treatment, with telephone follow-up up to 29 days after last treatment. The reported primary endpoint is specifically tied to Day 7, so later treatment and follow-up are distinct from that endpoint.

3. Trial Design

This was an open-label, single-group, multi-center study of Gedea Pessary in adult women with bacterial vaginosis. The registry lists the study as completed, with a start date of 2019-01-07 and a primary completion date of 2019-10-22. The enrollment is listed as 24. The primary endpoint description states that 22 patients were included in its analysis.

At study inclusion, participants were to have a gynecological examination and vaginal samples taken. The study description says participants had confirmed BV according to fulfillment of at least 3 of the 4 Amsel criteria. Participants received the investigational product for self-administration. At Day 7, they were to be assessed using 3 Amsel criteria; the vaginal-fluid pH criterion was used at study inclusion for diagnosis and was not part of the Day 7 cure definition.

Participants who were not cured at the Day 7 assessment were to receive prolonged treatment for an additional week. Follow-up by telephone was planned up to 29 days after the last treatment. Vaginal samples were intended to confirm diagnosis and support microbiome analyses, while questionnaires were intended to assess BV symptoms, usability, and adverse events.

The study had no randomized allocation and no masking. No separate control arm is described. Consequently, the design can characterize observations in the treated group but does not provide a randomized treatment contrast. The registry record does not report a detailed protocol, the rationale for the enrollment target, or a statistical analysis plan. The record also does not report whether every planned assessment was completed for every participant.

The primary endpoint is a participant count at Day 7, based on meeting a composite clinical definition. The registry names additional outcome measures, but their results are not reported in the registry record. The distinction between planned assessments and reported results matters: a listed objective does not establish that a result was available, analyzed, or reported.

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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Number of patients included in analysis = 22.

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: A total of 24 participants were enrolled, and all 24 participants received study treatment.

6. Primary Endpoint

The registry lists the primary outcome as Clinical Cure Rate, measured over Day 7.

The primary endpoint is titled Clinical Cure Rate, with the unit recorded as participants and the measure defined as a count. At Day 7, a participant was classified as clinically cured if all 3 specified Amsel criteria were absent: thin, white, yellow, homogenous discharge; clue cells on microscopy, defined in the record as more than 20% of epithelial cells; and release of fishy odor in a positive whiff test after potassium hydroxide solution was added.

A composite endpoint combines several clinical observations into one classification. Here, requiring absence of all specified signs makes the endpoint a measure of the joint clinical definition rather than a measure of any one sign alone. It gives a clear rule for counting participants who meet the study’s stated definition at the assessment time.

The endpoint is used to describe clinical status at Day 7. The registry record says the primary analysis included 22 patients, but does not report how many met the cure definition. Therefore, the cure count and rate are not reported in the registry record. The endpoint definition also should not be confused with the study’s entry criteria: the description uses at least 3 of the 4 Amsel criteria to confirm BV at inclusion, while the Day 7 endpoint uses the absence of the specified 3 criteria. Those are different rules applied at different stages of the study.

As a general statistical point, a binary endpoint reduces a participant’s status to one of two categories under a stated rule. This can aid interpretation, but it does not convey the degree of change in each sign, the timing of any change, or patient experience beyond what the separate outcome measures assess.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Several statistical ideas help clarify what the study design and endpoint can show. The distinction between observed counts, estimates, uncertainty, and comparisons is especially important when a trial has one group and the result itself is not reported in the registry record.

What does a single-group design estimate?

In a single-group study, the direct descriptive quantity is the outcome observed among participants receiving the intervention. For this trial, the primary endpoint is a count of participants meeting a Day 7 clinical definition. If a count and denominator were reported, a rate could describe the proportion of the analyzed group meeting that definition. The registry record gives the primary analysis population as 22 but does not report the cure count or rate.

General statistical context: an observed outcome in one group is not the same as a treatment contrast. A contrast requires outcomes under different conditions, such as an intervention group and a comparator group. Without a separate comparator, differences from baseline or a clinical threshold cannot isolate the effect of treatment from other factors. This is why the study’s results, if reported, would primarily describe outcomes in the treated group rather than establish superiority or non-inferiority relative to another option.

What does a binary endpoint capture?

The primary endpoint is a binary clinical classification summarized as a participant count. The definition requires absence of all 3 specified criteria at Day 7. Composite definitions can be useful when several clinical signs together represent the outcome of interest. They also mean that a participant’s classification depends on each component and on how each is assessed. A participant who does not meet the composite definition may still have improved on some components; the binary endpoint alone would not describe that pattern.

General statistical context: binary outcomes are often summarized with a count and a proportion, and uncertainty can be expressed with a confidence interval. The interval’s width depends on the observed data and the method used. It describes uncertainty in an estimate, not a guarantee that the true value lies within any particular realized interval. No endpoint estimate or interval is reported in the registry record, so neither can be interpreted for this trial.

Why does the analysis population matter?

The primary endpoint description states that 22 patients were included in the analysis, while the enrollment is listed as 24. The record does not explain the difference. Analysis populations can be defined in different ways, for example by whether participants were enrolled, received treatment, or had an evaluable outcome. These are general possibilities, not descriptions of the population used in this trial beyond the registry’s statement that 22 patients were included.

Missing outcome data can affect interpretation if the patients without an observed endpoint differ from those with an endpoint. Statistical approaches vary in their assumptions about missingness and how to handle it. The registry record does not report the reasons for missing data, whether there were any missing Day 7 assessments, or a method for handling missing outcomes. It is therefore not possible to judge whether the reported analysis population would represent all enrolled participants.

How should the planning illustrations be understood?

The sample-size illustrations use the observed effect as their starting point and are not the trial’s own design calculations. Their stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. For time-to-event illustrations, the stated quantity is a total number of events; other illustrations use participants per arm for 80% power or another stated power level.

General statistical context: sample-size planning asks how much information a future study might need under chosen assumptions. These calculations are conditional on the assumed effect, variability, allocation, significance level, and statistical method. When the effect is based on an observed result, the illustration is not an independent validation of that result. It is not observed power, and it does not show that the current study was adequately powered. The registry record does not report that these planning assumptions were used to design this trial.

The stated illustrations assume two arms, whereas this trial is single-group. They should therefore be read as planning scenarios for a hypothetical comparative study, not as evidence that the current design included a comparator or that the illustrations describe its enrollment target.

What does multiplicity mean in this setting?

Multiplicity arises when several outcomes or statistical tests are considered. If multiple hypotheses are tested, the chance of at least one apparently noteworthy result can increase unless the analysis accounts for the number and structure of tests. This is general statistical context; it does not establish that multiplicity adjustment was or was not appropriate for this study. The registry record lists multiple secondary outcomes and six outcome measures and six analyses, but does not report a multiplicity procedure or a hierarchy of confirmatory hypotheses.

Without the actual results and analysis details, a reader cannot assess the precision of the primary endpoint, the role of any secondary findings, or the impact of missing observations. The appropriate interpretation is limited to the endpoint definition, analysis population statement, study design, and adverse-event counts 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("pHyph, Gedea Pessary")
n      <- c(22)
events <- c(18)
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  pHyph, Gedea Pessary  22  18  81.8  59.7  94.8  61.5  92.7  61.2  92.5

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists the primary clinical cure endpoint alongside secondary outcomes covering each of the 3 Amsel criteria, questionnaire-based usability, and BV recurrence. It reports six outcome measures and six analyses. The record does not describe a testing hierarchy, identify which secondary outcomes were confirmatory, or report a correction for multiple comparisons. It is therefore not reported in the registry record whether any multiplicity strategy was planned or applied.

Multiplicity is a general statistical concern when interpreting several tests: the more results examined, the greater the opportunity for chance findings to appear noteworthy. Whether adjustment is needed depends on the purpose and structure of the analyses. The listed outcomes alone do not establish how the investigators treated them statistically. As the numerical results for these outcomes are not reported in the registry record, their findings and relationship to the primary endpoint cannot be assessed.

The primary endpoint description says 22 patients were included in analysis, while the enrollment is 24. Reasons for the difference, the number of missing endpoint observations, and any method used to handle missing data are not reported in the registry record. The record does not describe whether the analysis population was defined before data were examined, or whether any sensitivity analyses were conducted.

These omissions limit assessment of the analysis population and potential bias. General statistical context: when outcome availability is related to participants’ clinical status or experience, an analysis restricted to observed outcomes can differ from the result that would have been obtained if outcomes were available for everyone. The registry record does not provide enough information to determine whether this concern applies or how it was addressed. The reported population count should therefore be treated as a description of the analysis set, not as an explanation of missingness.

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 5% reporting threshold.

Most frequent non-serious adverse event terms

The registry record lists 24 participants at risk for serious adverse events and reports 0 participants affected by serious adverse events. It also lists 24 participants at risk for other adverse events and reports 11 participants affected. These are participant counts in the pHyph, Gedea Pessary group. The record does not list any serious adverse-event terms.

These figures should be read as separate serious and other adverse-event summaries. The 11 participants affected by other adverse events does not describe how many events occurred, what the events were, how severe they were, or whether they were considered related to treatment; those details are not reported in the registry record. Likewise, a serious adverse-event count of 0 means no affected participants are recorded in this summary, not that the study establishes an absence of risk.

General statistical context: safety counts are descriptive and their interpretation depends on the observation period, event definitions, completeness of reporting, and the number of participants observed. The registry record describes telephone follow-up up to 29 days after last treatment, but the adverse-event summary does not specify the event collection window or provide further detail. These counts cannot be compared with a control group because none is described.

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

The registry record establishes that the study evaluated Gedea Pessary in adult women with confirmed BV and defined a Day 7 clinical cure endpoint using the absence of 3 specified Amsel criteria. It also reports that 22 patients were included in the primary analysis and provides a summary of serious and other adverse events. These details describe the planned clinical question, the endpoint rule, and selected safety counts.

However, the record does not report the primary cure count or rate. It therefore does not say how many analyzed patients met the clinical cure definition at Day 7, or how precisely that result was estimated. The listed secondary outcomes also lack numerical results in the registry record. Without those outcomes, the registry entry cannot support conclusions about individual signs, usability, recurrence, or the broader pattern of clinical response.

Even a reported cure proportion from this study would be a description of outcomes in one treated group. Because the study is single-group and has no separate comparator, it cannot provide a randomized estimate of how outcomes would differ under another treatment. An observed outcome after treatment is not, by itself, proof that treatment caused the outcome.

The safety summary records 0 participants affected by serious adverse events and 11 affected by other adverse events. These are useful descriptive figures, but the registry does not report the terms or further characteristics of the other events. The summary also does not establish that no unrecorded events occurred.

General statistical context: estimates are more informative when accompanied by uncertainty measures and a transparent account of analysis populations and missing data. The record does not report a confidence interval or a method for handling missing outcomes. As a result, the evidence described in the registry is limited to study conduct, endpoint definitions, and the specified counts—not a quantified comparative treatment effect or a complete account of benefit and risk.

14. Why This Trial Matters Statistically

This study raises several important statistical interpretation issues in a compact clinical setting. First, its endpoint is a composite clinical definition. Requiring absence of all 3 specified Amsel criteria provides a clear rule for classifying Day 7 status, but the result would not show how each sign changed on its own. Separate component outcomes are listed, yet their results are not reported in the registry record.

Second, the study is single-group and open-label. Those design features mean that a clinical cure count, if available, would describe observations in the treated group without a concurrent control for comparison. This is different from estimating a treatment contrast in a randomized trial. The absence of a comparator is central to what the results can and cannot establish, rather than a minor technical detail.

Third, the endpoint population count is 22, while enrollment is 24. The registry record does not explain the difference or state how missing observations were handled. This makes transparency about the analysis population particularly relevant: readers need to know who contributed endpoint data and why any enrolled participants were not included.

Finally, the record lists multiple secondary outcomes and reports safety counts, but does not provide the clinical outcome results or detail the statistical analysis. This illustrates why an endpoint definition is not the same as an endpoint finding, and why descriptive adverse-event counts should not be mistaken for a complete safety assessment. Taken together, these features make careful separation of design, planned measurement, and reported results essential for interpreting the registry entry.

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 most immediate limitation for interpretation is that the registry record does not report the primary clinical cure count or rate. It also does not report numerical results for the listed secondary outcomes. As a result, the clinical outcomes cannot be quantified from this record, and no endpoint estimate or confidence interval can be assessed.

The single-group design has no separate comparator, so it cannot establish how outcomes would compare with another treatment or with no treatment. The study is also open-label, with no masking. The registry record does not describe procedures to limit potential influence on outcome assessment or participant-reported measures.

The primary analysis population is reported as 22 patients, compared with an enrollment of 24, but the reason for the difference is not reported in the registry record. The record does not describe missing endpoint data, the handling of missing observations, or sensitivity analyses. This limits assessment of how the analysis set relates to the enrolled group.

The primary endpoint uses a composite rule based on absence of 3 clinical criteria. The record does not report component-level results, so it is not possible to determine which criterion contributed to endpoint classifications. The described schedule also includes an additional week of treatment for participants not cured at Day 7, followed by telephone follow-up up to 29 days after last treatment. Later outcomes may therefore reflect different treatment durations, but those results and their analysis are not reported in the registry record.

Finally, the adverse-event summary gives counts but does not report the non-serious event terms, severity, relatedness, or detailed observation period. These limitations do not show that an outcome was favorable or unfavorable; they constrain what can be concluded from the registry record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Clinical Performance of a Vaginal Pessary (pHyph) in Bacterial Vaginosis — NCT03762083.
• Registry record last updated 2025-07-25; status last verified 2025-07.
• Results first posted 2025-07-25.
• 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

NCT03762083 is a completed, open-label, single-group, multi-center study of pHyph generation I, also described as Gedea Pessary, in adult women with bacterial vaginosis. The registry lists enrollment of 24 and a primary analysis population of 22. The study dates are 2019-01-07 for start and 2019-10-22 for primary completion.

The primary endpoint is a participant count meeting the Day 7 clinical cure definition, which requires absence of 3 specified Amsel criteria. The cure result and numerical results for the listed secondary outcomes are not reported in the registry record. The record reports 0 participants affected by serious adverse events and 11 affected by other adverse events, with 24 at risk in each category. It does not describe the other adverse-event terms.

Because the study has no separate comparator, it provides no randomized treatment contrast. The registry record also does not report the reasons for the difference between enrollment and the primary analysis population, or how missing outcomes were handled.