Gynaecological Follow-up of a Subset of 580299/008 (NCT00122681) Study Subjects: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Gynaecological Follow-up of a Subset of 580299/008 (NCT00122681) Study Subjects (NCT00937950), a na phase 3 study. The primary outcome is Number of Subjects With HPV DNA in Cervical Samples by Hybrid Capture 2 Test (HCII).

2. Clinical Question

3. Trial Design

This completed Phase 3 study followed a subset of participants from HPV-008 (NCT00122681). Its stated purpose was to provide annual oncogenic HPV DNA testing and cervical cytology examination for up to four years. The follow-up was intended for participants whose last HPV-008 visit showed normal cervical cytology with a positive oncogenic HPV result, and also for participants who were pregnant at that visit and therefore had no cervical sample collected.

The design is recorded as single group, with no allocation and no masking. The intervention is named gynaecological follow-up. These features describe an observational follow-up structure rather than a randomized comparison of treatment groups. The registry record lists enrollment of 2022, but this does not establish how many participants had evaluable cervical samples at each later visit. The analysis population is described as the Total HPV-052 cohort, comprising participants with available data at the considered time points who met the stated eligibility circumstances at their last HPV-008 visit.

The primary endpoint is a count of participants with oncogenic HPV DNA in cervical samples, determined using the Hybrid Capture 2 test. It is assessed at Months 12, 24, 36, and 48. The primary objectives and outcome measures of the parent study, HPV-008, are posted separately under NCT00122681; they should not be treated as results of this follow-up study. The registry record marks this study completed, but does not report its statistical analysis plan or primary endpoint results.

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: Out of the 2022 subjects enrolled in this study, 19 were excluded for reasons of non-eligibility, hence only 2003 started the study.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The analysis was based on the Total HPV-052 cohort, which included subjects with available data at the considered time points and who at their last HPV-008 (NCT00122681) study visit displayed normal cervical cytology but tested positive for oncogenic HPV infection or were pregnant so that no cervical sample could be collected at that visit.

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 Number of Subjects With HPV DNA in Cervical Samples by Hybrid Capture 2 Test (HCII), measured over At Months 12, 24, 36, 48.

The primary endpoint counts participants with oncogenic HPV DNA detected in cervical samples by the Hybrid Capture 2 (HCII) test at Months 12, 24, 36, and 48. The test is described as detecting HPV DNA types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, and 68. The recorded outcome is a participant count, not a measure of viral quantity or a comparison between randomized groups.

In general, repeated assessment of a biological marker can describe whether it is detected at scheduled follow-up points. Such measurements can help characterize the observed pattern over time among participants who contribute data. They do not, by themselves, establish why a result changed or what would have happened under a different intervention. For this endpoint, interpretation also depends on how many participants had an evaluable sample at each time point and how missing or insufficient samples were handled.

The registry record notes that some results were missing when the sample quantity was not sufficient (QNS). It does not report the observed endpoint counts, denominators at each visit, or a method for handling missing results. The endpoint definition is therefore available, but its numerical results and precision cannot be assessed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the endpoint count?

The primary outcome is a count of participants whose cervical sample tested positive for oncogenic HPV DNA using HCII. The test is described as detecting the listed oncogenic HPV DNA types. This is a binary classification for each assessed sample: DNA is detected or it is not detected, subject to the possibility of an insufficient sample. The endpoint is specified at Months 12, 24, 36, and 48.

In general, a count is easier to interpret when accompanied by its denominator: the number of participants assessed and eligible to have the outcome at that time point. A count without that denominator does not show the proportion of assessed participants with a positive result. No visit-specific denominators or endpoint counts are reported in the registry record, so no proportion or comparison across time points can be described.

What does a single-group design allow?

The design is recorded as single group, with allocation listed as NA and masking listed as none. No comparator group is described. This structure can document measurements in the followed cohort, but it does not provide a randomized contrast between groups. In general, a randomized comparison helps separate the effect of an assigned intervention from other explanations for differences between groups. Without such a comparison, a change across follow-up visits cannot be attributed to the follow-up procedure or to any other cause on the basis of this record alone.

The study is a follow-up of a selected subset from HPV-008, rather than a report of all participants in that parent study. Eligibility for this follow-up was tied to findings or pregnancy status at the last HPV-008 visit. That selection defines the population to which the endpoint relates. It does not warrant extending the interpretation to people outside the described cohort. The primary objectives and outcomes of HPV-008 are posted separately under NCT00122681.

How should estimates and uncertainty be understood?

In general, an estimate summarizes the observed data, while a confidence interval communicates uncertainty around that estimate under the assumptions of the analysis. The interval’s width depends in part on the amount and variability of usable data and on the method used. The registry record does not report a confidence interval, standard error, or statistical model for the primary endpoint. It also does not report a test of a statistical hypothesis. As a result, the precision and inferential strength of the endpoint cannot be evaluated from the posted results.

Statistical significance and clinical importance are different ideas. A result can be statistically compatible with a difference while its practical importance remains unclear; conversely, an imprecise estimate may not rule out effects of interest. In this study, no estimated difference or uncertainty measure is reported, and there is no stated comparator for a treatment effect. These general distinctions therefore explain how results should be read if available, but do not supply a conclusion about this study’s endpoint.

What does the planning illustration represent?

In general, sample-size calculations are planning exercises based on chosen assumptions about the effect to detect, the statistical test, and the allocation structure. They do not describe the observed number of outcomes or establish that a study had adequate power after completion. The registry record’s stated illustration uses a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect expressed as a fraction of the observed effect. For time-to-event settings, its stated approach uses a total event count; other settings are expressed as participants per arm.

Those assumptions do not describe the recorded single-group follow-up design, which has no two-arm allocation or comparator. Any planning illustration based on a two-arm structure must therefore be read as hypothetical, not as the design justification for this study. The registry record does not report the protocol’s sample-size justification. The posted record also lists zero analyses, and does not provide primary endpoint effect estimates from which a reader could assess the underlying assumptions. A planning calculation is not observed power and cannot substitute for results or an analysis plan.

Why can insufficient samples matter?

The endpoint description states that some results were missing when sample quantity was not sufficient (QNS). In general, missing data reduce the information available for an analysis. More importantly, the interpretation can depend on why values are missing and whether the chance of missingness is related to participant characteristics or the outcome. If missingness differs across follow-up visits or is associated with the underlying HPV status, the participants with evaluable samples may not represent everyone eligible for follow-up.

These are general concerns, not claims that such a pattern occurred in this study. The registry record does not report the number of QNS results, the full missing-data pattern, or an approach for handling missing results. It also does not report sensitivity analyses. Without those details, the effect of missing samples on the reported endpoint cannot be assessed.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists 13 outcome measures and identifies the participant count with oncogenic HPV DNA by HCII as the primary outcome. The primary outcome is assessed at Months 12, 24, 36, and 48. It lists zero analyses, and does not report whether or how statistical testing was conducted across these assessments or across the other outcome measures. A multiplicity adjustment or a prespecified hierarchy of tests is not reported in the registry record.

In general, evaluating several outcomes or time points can increase the chance of obtaining at least one apparently notable result by chance if each is tested separately. Statistical plans may address this through prespecified primary outcomes, adjustment procedures, or a clearly defined descriptive focus. These are general options; the record does not establish that any particular approach was used. Since no tests or endpoint results are reported, the impact of multiplicity on this study’s conclusions cannot be assessed.

The analysis population is described as the Total HPV-052 cohort with available data at the considered time points and the relevant prior HPV-008 findings or pregnancy status. The registry record notes missing results for some samples with quantity not sufficient (QNS). It does not report the number missing at each visit, how many participants contributed to each assessment, or the rules used to include or exclude records from analyses. The missing-data method, any imputation, and any sensitivity analyses are not reported in the registry record. Consequently, the extent to which incomplete sample data may affect interpretation is unknown.

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 5% reporting threshold.

The registry record lists one safety group, HPV-052 Study Subjects Group, with 2003 participants at risk for serious adverse events and 0 affected. It also records 0 deaths. No serious adverse event terms are listed. These are the figures reported for this group; they should not be read as evidence that no adverse events of any kind occurred.

The figures concern serious adverse events, not necessarily all adverse events, symptoms, or laboratory abnormalities. The registry record does not report the definition used for a serious adverse event, the period or method of safety surveillance, or detailed event narratives. It also does not provide a comparison group. Thus, the counts describe the posted safety record but do not support a comparative safety estimate or a causal conclusion.

In general, a zero count means that no event was recorded in the stated category for the recorded group and reporting period. It does not establish that the risk is zero, particularly when event definitions, ascertainment, and follow-up completeness are not available. The record’s safety figures should therefore be interpreted narrowly as reported serious-event and death counts.

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

The record establishes that this was a completed single-group follow-up study of a selected subset from HPV-008. Its primary endpoint was defined as the count of participants with oncogenic HPV DNA detected in cervical samples by HCII at scheduled follow-up points. It also specifies that the follow-up was intended to include annual testing and cervical cytology for up to four years. These design and endpoint details describe what the study set out to measure.

The registry record does not report the observed primary endpoint counts at Months 12, 24, 36, or 48. It does not provide visit-specific denominators, estimates of uncertainty, or results of statistical tests. Therefore, it does not allow readers to determine the frequency of positive samples at those visits, assess a pattern over time, or judge the precision of any estimate. Completion status and enrollment do not fill this results gap.

The single-group structure also limits what the study can establish. In general, follow-up observations can describe a cohort, but without a comparator they do not estimate a randomized difference between groups. A finding at a later visit, if available, would not by itself identify the cause of that finding. The registry record does not report a treatment-effect estimate or a statistical plan for causal inference.

The record notes that some test results were missing because sample quantity was not sufficient. The number and distribution of these missing results, and the method used to handle them, are not reported. This limits assessment of how representative the analyzed samples may be. The safety listing reports 0 serious adverse events affected and 0 deaths in the recorded group, but it does not describe all adverse events or provide comparative safety data.

In short, the record supports a description of the study’s design, eligibility context, measurement, and posted safety counts. It does not support a numerical conclusion about the primary endpoint, its precision, or a comparative effect.

13. Why This Trial Matters Statistically

This study is statistically informative as an example of the distinction between defining an outcome and reporting its results. The registry record gives a clear primary measurement: participants with oncogenic HPV DNA detected in cervical samples by HCII, assessed at scheduled follow-up points. Yet it does not report the counts or denominators needed to interpret that measurement numerically. A well-specified endpoint is important, but it is not a substitute for an estimate and its uncertainty.

The record also illustrates why the analysis population matters. This was not a general sample of all participants from HPV-008; it was a subset selected according to findings or pregnancy status at the last parent-study visit. The endpoint therefore pertains to a particular follow-up cohort. Interpreting counts requires knowing who was assessed at each visit, especially when some samples were reported as insufficient.

Its single-group design makes the distinction between descriptive follow-up and comparative evidence especially important. A set of repeated measurements can describe outcomes in the observed cohort. Without a comparator, however, those observations do not estimate how a different group would have fared under an alternative condition. This is a design limitation rather than a defect in the endpoint itself.

Finally, the record demonstrates why numerical safety listings need context. The recorded serious adverse event and death counts are useful descriptors, but their meaning depends on event definitions, ascertainment, and reporting periods, details not reported in the registry record. Statistical interpretation depends not only on numerical values, but also on the population, design, missingness, and analysis methods that give those values their meaning.

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 primary limitation for interpreting this registry entry is that it does not report the primary endpoint results. Counts with HPV DNA detected, visit-specific denominators, and measures of precision are not reported in the registry record. The enrollment figure does not show how many participants had usable samples at each assessment. Therefore, the endpoint’s frequency and variation over follow-up cannot be evaluated.

The analysis population is selected from a parent study based on cervical cytology, oncogenic HPV status, or pregnancy at the last HPV-008 visit. The results, if available, would describe this specified follow-up cohort rather than an unselected population. The record does not provide additional detail about how eligibility was applied or how many eligible participants entered each assessment.

Some test results were missing because sample quantity was not sufficient. The number of such results, their distribution across visits, and the method used to handle them are not reported. The record also does not report sensitivity analyses assessing the possible effect of missing data. This leaves uncertainty about the role of incomplete samples in the endpoint summaries.

The single-group design has no randomized comparator, so it cannot provide a randomized between-group estimate. The registry record does not report a statistical analysis plan, confidence intervals, hypothesis tests, or a sample-size justification. The listed planning assumptions use a two-arm allocation structure, which does not match the recorded single-group follow-up design; those assumptions should not be interpreted as evidence of the study’s original design or observed power. The primary objectives of the parent study are separate, and are not reported as outcomes of this follow-up entry.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Gynaecological Follow-up of a Subset of 580299/008 (NCT00122681) Study Subjects — NCT00937950.
• Registry record last updated 2019-10-29; status last verified 2019-10.
• Results first posted 2015-01-15.
• 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

NCT00937950 is a completed Phase 3, single-group follow-up study sponsored by GlaxoSmithKline. It followed a subset of participants from HPV-008 (NCT00122681) who had normal cervical cytology and oncogenic HPV infection at their last parent-study visit, or were pregnant and could not provide a sample at that visit. Participants were 15-25 years old at first study vaccination.

The primary endpoint is the number of participants with oncogenic HPV DNA detected in cervical samples by HCII at Months 12, 24, 36, and 48. The registry record reports the endpoint definition but not its observed counts, denominators, or statistical analyses. It notes some missing results due to insufficient sample quantity. The safety listing records 0 serious adverse events affected and 0 deaths in the group, without further safety detail or a comparator.