ROTATEQ Reexamination Study (V260-037): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for ROTATEQ Reexamination Study (V260-037) (NCT01074242), a registered phase not stated study. The primary outcome is Percentage of Participants With Any Adverse Experience.

2. Clinical Question

The study’s stated purpose was to collect safety information for re-examination of ROTATEQ and to reconfirm its clinical usefulness under the applicable re-examination framework. The endpoint is therefore framed around events occurring in usual practice, not around a direct estimate of comparative benefit against a control group. The record identifies Gastroenteritis Rotavirus as the condition and Merck Sharp & Dohme LLC as sponsor. Its stated time window is up to 42 days after any vaccination; it does not provide a more detailed account of how event observation or reporting was organized.

3. Trial Design

NCT01074242, titled ROTATEQ Reexamination Study (V260-037), is recorded as completed. The study start is listed as 2007-09 and primary completion as 2013-06. It is described as a re-examination study of ROTATEQ safety in usual practice, conducted among Korean infants vaccinated with the product. The registry enrollment is 3798. Enrollment is not interchangeable with the primary analysis population: that population is defined as enrolled participants who received at least 1 dose, and the adverse-experience figures list 3395 participants at risk.

The described vaccine regimen consists of 3 ready-to-use oral doses. The first dose was to be administered at age 6-12 weeks, with later doses administered at 4 to 10-week intervals. This describes the intended regimen; the registry record does not report how many participants received each dose, the distribution of actual dosing intervals, or adherence to the regimen.

The study is not a randomized comparison. The allocation field is not stated, and the record warns that the arms are not a like-for-like control comparison. The available adverse-experience group is ROTATEQ; a concurrent control group or comparator outcome is not reported. The design information therefore supports describing safety observations in the treated group, but not attributing differences between groups to vaccination.

The primary endpoint is the percentage of participants with any adverse experience up to 42 days after any ROTATEQ vaccination. The record lists 2 outcome measures but supplies detailed primary endpoint information for this safety measure. It records 0 analyses. That means no analyses are entered in the registry record; it does not establish whether analyses were performed elsewhere. Details of recruitment, site structure, data collection procedures, monitoring, and the statistical analysis plan are not reported in 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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: All enrolled participants who received at least 1 dose of study vaccine were included in the analysis

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: Baseline characteristics were reported for all enrolled participants who received at least 1 dose of study vaccine

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Participants With Any Adverse Experience, measured over Up to 42 days after any Rotateq vaccination.

The primary endpoint is the percentage of participants with any adverse experience up to 42 days after any ROTATEQ vaccination. The registry defines an adverse experience as an unfavorable and unintended change in body structure, function, or chemistry that is temporally associated with use of the study vaccine. The event counts whether or not it is considered related to the product. Worsening of a preexisting condition also qualifies when it is temporally associated with vaccination.

This broad definition is useful in a safety re-examination because it captures events occurring after vaccination without requiring a judgment that the vaccine caused them. That approach can describe the range of events observed during the stated period, while preserving the distinction between timing and causation. An event occurring after vaccination is not, from timing alone, evidence that vaccination caused it.

As a binary percentage endpoint, the measure classifies each participant according to whether any qualifying event was recorded during the specified period. In general, this type of endpoint communicates how common an event was in the analyzed population, rather than how many total episodes occurred or how long an event lasted. The endpoint does not, by itself, describe severity, duration, clinical course, or causal attribution.

The primary result is not reported in the registry record. No percentage, event count for this endpoint, uncertainty interval, or inferential comparison is available in the record. The separate adverse-experience figures should not be substituted for the missing primary endpoint result unless their relationship to that endpoint is explicitly documented.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a binary participant-level measure: whether a participant had any qualifying adverse experience during the stated period. The registry expresses the outcome as a percentage of participants. In general, a percentage for a binary outcome is formed by counting participants with the event and relating that count to the defined analysis population. The registry record does not report the primary event count or percentage, so neither can be interpreted for this study from the entry.

What does the endpoint count?

The event definition is intentionally broad. It includes unfavorable and unintended changes in body structure, function, or chemistry that are temporally associated with vaccination, irrespective of whether the event is considered related to the product. It also includes worsening of a preexisting condition when temporally associated. This definition makes the endpoint a measure of recorded events after vaccination, not a direct measure of events proven to have been caused by vaccination.

For a participant-level “any event” outcome, an individual is generally counted as having the endpoint if at least one qualifying event is recorded during the observation window. Multiple events in the same person do not necessarily create multiple participants with the endpoint. That general distinction matters because a participant percentage answers a different question from a total event count. The registry does not provide the event-level rules used to combine repeated episodes, nor does it report the primary endpoint count.

How should the time window be read?

The endpoint timeframe is up to 42 days after any ROTATEQ vaccination. This defines the period relevant to the outcome as registered. It does not specify the detailed operational rules for participants receiving successive doses, such as how overlapping periods were handled, how incomplete follow-up was treated, or how events with uncertain onset dates were classified. Those procedures are not reported in the registry record, so they should not be assumed.

In general, a fixed observation window helps make an endpoint interpretable by defining which events count toward it. A window also limits the scope of the conclusion: events outside it are not captured by this particular endpoint definition. The registry’s stated period supports interpretation only for the registered post-vaccination timeframe, not for longer-term safety.

What can a confidence interval add?

In general, a confidence interval expresses the statistical uncertainty around an estimated outcome. A narrower interval indicates greater precision under the assumptions of the method; a wider interval indicates less precision. It does not remove possible bias in how participants were selected, how events were recorded, or how the analysis population was defined. No confidence interval for the primary endpoint is reported in the registry record, so its precision cannot be assessed from this entry.

For a binary percentage, the precision depends in part on the number of participants and how frequently the event occurs. The registry record supplies an at-risk count for the separate adverse-experience figures, but not the primary endpoint event count or estimate. It would therefore be inappropriate to reconstruct a primary interval or substitute another outcome’s count. No such recalculation is reported.

Why does the design affect statistical interpretation?

The study is described as a usual-practice re-examination and not a randomized comparison. In general, random allocation can support a more direct comparison of outcomes between study groups because it helps balance measured and unmeasured participant characteristics on average. Without a randomized, like-for-like comparator, a descriptive event frequency cannot isolate the effect of vaccination from other explanations. The record does not state allocation and does not provide a control comparison.

The registry identifies 3395 participants at risk for both serious and other adverse-experience counts in the ROTATEQ group. Those figures can be reported as recorded, but they do not by themselves provide a comparative effect estimate. No adjustment model, covariate set, or method for handling confounding is reported in the registry record. The record’s 0 analyses entry also means no analysis entries appear in the registry; it does not demonstrate that no analyses were conducted outside that record.

What do the planning assumptions mean?

The registry’s planning description characterizes the sample-size values as illustrations based on the observed effect, not as the trial’s own design. It describes a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is described as a stated fraction of the observed effect. These assumptions explain the nature of a planning calculation, not the study’s actual enrollment rationale or analysis plan. The registry record does not report a protocol-based sample-size justification, and the planning illustrations must not be read as observed power or as evidence that the study was designed around those assumptions.

In general, a planning calculation estimates the sample size that would be needed under specified assumptions. It is not a measure of the probability that a completed study has found a real effect, and it does not replace estimates and uncertainty intervals for the observed outcome. Because the primary result is not reported, the interpretation of any planning illustration cannot supply the missing endpoint estimate.

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("Rotateq")
n      <- c(3395)
events <- c(751)
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  Rotateq  3395  751  22.1  20.7  23.6  20.8  23.5  20.8  23.5

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists 2 outcome measures and 0 analyses. It provides the primary endpoint title, definition, population, and timeframe, but does not report the primary endpoint result. The details of the other listed outcome measure are not reported in the registry record. No analysis entries are recorded, so there is no documented set of statistical comparisons from which to assess the analysis hierarchy or the relationship between primary and secondary findings.

Multiplicity refers, in general, to the increased chance of at least one false-positive finding when many statistical hypotheses are tested. It can be addressed through prespecified hierarchies or adjustment methods, among other approaches. The registry record does not report whether any multiplicity adjustment was planned or used, whether there were interim analyses, or which analyses were prespecified. No claim about those procedures is supported by the record.

Missing-data handling is also not reported in the registry record. The primary population is defined as enrolled participants who received at least 1 dose, but there is no participant flow describing outcome availability, withdrawals, incomplete follow-up, or exclusions from analysis. The record does not state how missing event information was treated or whether any sensitivity analyses were conducted.

These omissions matter because the analysis population and the handling of unavailable outcomes can affect the meaning of a participant percentage. The difference between enrollment of 3798 and the 3395 at-risk count in the adverse-experience figures is not explained. It should not be interpreted as a specific type of exclusion or loss without further documentation. The record also does not report confidence intervals or an inferential method for the primary endpoint.

12. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: pneumonia (0.1%), urinary tract infection (0.1%), gastroenteritis (0.0%), laryngitis (0.0%), enteritis (0.0%).

The ROTATEQ group has 8 serious adverse experiences among 3395 participants at risk. The separate count for other adverse experiences is 210 among 3395 participants at risk. These are the counts recorded; no percentages should be calculated from them. The registry record does not report deaths, so death information is not reported in the registry record.

The displayed serious-event terms are Pneumonia at 0.1%, Urinary tract infection at 0.1%, Gastroenteritis at 0.0%, Laryngitis at 0.0%, Enteritis at 0.0%, and Pyrexia at 0.0%. These are rounded percentages, and term-specific counts are not reported alongside them. A listed term’s displayed percentage is not a measure of causation. The event definition includes temporal association whether or not an event is considered related to the vaccine.

The serious and other counts are descriptive figures for the ROTATEQ group, not a comparative estimate. The record does not give a randomized control group or enough detail to determine whether the listed terms cover every event. The primary endpoint, which concerns any adverse experience, has no reported result in the registry record; the serious-event counts do not fill that gap.

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

The record documents a completed usual-practice safety re-examination of ROTATEQ among Korean infants. It states the vaccination regimen, defines a broad post-vaccination adverse-experience endpoint, and reports some adverse-experience counts for the ROTATEQ group. It also lists selected serious-event terms with rounded percentages. Those details allow a reader to understand what the study set out to describe and which safety figures were entered in the registry.

The record does not report the primary endpoint result: the percentage of participants with any adverse experience up to 42 days after any vaccination. Therefore, the primary question cannot be answered numerically from the registry entry. There is no reported confidence interval to show how precisely that endpoint was estimated, and no p-value or inferential analysis is entered.

The adverse-experience counts do not establish that vaccination caused the events. The study definition includes events that are temporally associated with vaccination whether or not considered related to the product. Because the registry does not describe a randomized, like-for-like control comparison, the ROTATEQ group’s observed events cannot be interpreted as an estimate of the difference between vaccination and an alternative condition.

The findings also have a defined scope. The primary endpoint period is up to 42 days after vaccination, and the study population is described as enrolled participants who received at least 1 dose. The record does not detail longer-term follow-up or provide a complete participant flow. It does not report how missing outcome information was handled or explain why the adverse-experience figures list 3395 participants at risk while enrollment is 3798.

Accordingly, the entry is best read as a limited registry record of a safety-focused study, with descriptive adverse-experience information and substantial gaps in reported analysis. It does not establish a causal effect, quantify the primary endpoint, or support a comparative conclusion. Those boundaries reflect the information recorded, rather than a conclusion that an unreported analysis was or was not performed elsewhere.

14. Why This Trial Matters Statistically

This study illustrates why a clearly defined endpoint and a reported result are both necessary for statistical interpretation. The registry defines “any adverse experience” broadly and specifies a post-vaccination observation period. Those details clarify what the primary measure is intended to capture. But without the endpoint’s event count or percentage, readers cannot assess the observed frequency or its precision. A well-described measure cannot substitute for a missing estimate.

It also illustrates the importance of distinguishing event descriptions from causal comparisons. The adverse-experience definition includes events based on temporal association, regardless of whether they are considered related to the product. In a usual-practice study without a stated randomized comparator, recorded events can describe what was observed in the vaccinated group, but they do not alone identify what would have occurred under a different exposure.

Denominators also require context. Enrollment is recorded as 3798, while the adverse-experience figures use 3395 participants at risk. The record does not explain the relationship between these numbers. A statistical reader should not silently treat enrollment as the endpoint denominator or assume a reason for the difference. Clear participant flow and endpoint-specific analysis populations are important for understanding how a percentage was formed.

Finally, the entry shows the difference between study-design information and post hoc planning illustrations. The planning description gives assumptions for sample-size illustrations, while explicitly distinguishing them from the trial’s own design. Such calculations are not observed power and cannot compensate for absent outcome estimates, uncertainty intervals, or analysis details. The registry’s statistical value depends not only on study intent, but also on complete reporting of how participants and outcomes were analyzed.

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 main limitation for interpreting this specific record is the absence of the primary endpoint result. Although the registry defines the outcome and its timeframe, it gives no event count or percentage for participants with any adverse experience. It also reports no confidence interval or inferential analysis for that endpoint. The record therefore does not allow assessment of the primary outcome’s magnitude or precision.

The design does not provide a stated randomized comparison. Allocation is not stated, and the record cautions that the arms are not a like-for-like control comparison. The reported ROTATEQ safety figures should consequently be treated as descriptive rather than as a comparative treatment effect. The registry does not report methods for adjustment or control of confounding.

The registry enrollment of 3798 differs from the 3395 participants at risk listed for the adverse-experience figures, and the reason is not reported in the registry record. There is no complete participant flow, detail on outcome availability, or explanation of exclusions. Missing-data methods and the handling of incomplete follow-up are not reported. The primary population definition refers to participants who received at least 1 dose, but the record does not describe the number receiving each dose or how the regimen was followed in practice.

Further limitations include the absence of documented statistical methods, a multiplicity strategy, interim-analysis information, and a protocol-based sample-size justification. The entry lists 0 analyses, but this refers to registry analysis entries and does not establish what may have been conducted outside the registry. The selected serious-event terms lack term-specific counts, and death information is not reported in the registry record. These gaps constrain both safety characterization and assessment of statistical uncertainty.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: ROTATEQ Reexamination Study (V260-037) — NCT01074242.
• Registry record last updated 2017-04-13; status last verified 2017-03.
• Results first posted 2014-03-27.
• 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

NCT01074242 is the ROTATEQ Reexamination Study (V260-037), sponsored by Merck Sharp & Dohme LLC and recorded as completed. It concerns Gastroenteritis Rotavirus and describes usual-practice vaccination of Korean infants. Enrollment is 3798; the study start is 2007-09 and primary completion is 2013-06.

The primary endpoint is the percentage of participants with any adverse experience up to 42 days after any vaccination. Its definition includes events temporally associated with vaccination whether or not considered related, including worsening of a preexisting condition. The primary population is enrolled participants who received at least 1 dose. The endpoint result is not reported in the registry record.

For the ROTATEQ group, the registry lists 8 serious adverse experiences and 210 other adverse experiences, each with 3395 participants at risk. It describes the study as not a randomized comparison and provides no analysis entries. Details of the primary result, statistical methods, missing-data handling, and explanation of the enrollment and at-risk counts are not reported in the registry record.