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 Study to Gather Information on the Acceptability of a New Flavor System With Increasing Levels of 2, 4, 6 g or Higher of Mannitol for PEG 3350 in Subjects Having Infrequent Bowel Movements. (NCT04534465), a non-randomized phase 4 study. The primary outcome is Number of Participants With the Opinion of the Products' Flavor.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04534465 |
| Phase | Phase 4 |
| Condition | Constipation |
| Allocation | Non-Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 50 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Bayer |
| Results posted | Yes |
2. Clinical Question
The study asked how participants with occasional constipation rated the flavor of PEG 3350 preparations containing a flavor blend and increasing amounts of mannitol. The primary measure was the number of participants with an opinion of the products’ flavor, assessed on a seven-point scale ranging from “1-extremely dislike” to “7-extremely like.” The registry record does not report the counts for the individual ratings or a summary of participants’ opinions, so the flavor-acceptability findings cannot be characterized from the posted results.
Population
Participants with occasional constipation or infrequent bowel movements. The study enrolled 50 participants. Further eligibility details and characteristics of the enrolled population are not reported in the registry record.
Intervention
Each formulation contained a 17g MiraLAX sachet and flavor blend, with total mannitol levels of 2g, 4g, 6g, 8g, or 10g across the five dosing arms.
Comparator
The arms represent different mannitol levels, not a randomized control comparison. Allocation was non-randomized, and the registry explicitly notes that the arms are not a like-for-like control comparison.
Primary question
What flavor opinions did participants report for the formulations after the one-day assessment period? The registry record describes the rating scale but does not report the observed rating counts or an analysis comparing arms.
3. Trial Design
This was a completed, single-center, open-label, parallel-arm, phase 4 study sponsored by Bayer. The registry reports an enrollment of 50 and lists constipation as the condition. The study began on 2013-02-13, reached primary completion on 2013-03-19, and has completed status.
Five dosing arms were described. All included a MiraLAX Sachet (17g) and flavor blend. The total mannitol amounts were 2g in Dosing Arm 1, 4g in Dosing Arm 2, 6g in Dosing Arm 3, 8g in Dosing Arm 4, and 10g in Dosing Arm 5. These are ascending formulation levels, rather than a treatment-versus-placebo structure. Although the intervention is described as a flavor-acceptability study, the record lists polyethylene glycol and mannitol as drug interventions.
The study was not randomized and had no masking. Those features matter when interpreting differences between arms: treatment assignment may be related to participant or study characteristics, and participants knew which formulation they received. The registry specifically warns that the arms are not a like-for-like control comparison. An observed difference, if reported, would therefore not by itself establish that the mannitol level caused the difference.
The primary outcome concerned participants’ opinions of the products’ flavor during a one-day timeframe. The record also lists secondary measures covering bowel movements, time to bowel movements, symptom ratings, and treatment-emergent adverse events. It does not report the allocation procedure, arm-specific enrollment outside the safety listings, detailed eligibility criteria, or a statistical analysis plan. Those design details 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.
Before assignment: Sixty-two (62) subjects was screened and fifty (50) subjected completed the study.
Overall Study
| Stage | Dosing Arm 1 | Dosing Arm 2 | Dosing Arm 3 | Dosing Arm 4 | Dosing Arm 5 |
|---|---|---|---|---|---|
| STARTED | 10 | 10 | 10 | 10 | 10 |
| COMPLETED | 10 | 10 | 10 | 10 | 10 |
| NOT COMPLETED | 0 | 0 | 0 | 0 | 0 |
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 | All Population |
|---|---|---|
| Participants analysed | 50 | |
| Age, Continuous | Years | 43.9 (28 to 60) |
| Sex: Female, Male: Female | Participants | 40 |
| Sex: Female, Male: Male | Participants | 10 |
| Race/Ethnicity, Customized: African American | participants | 25 |
| Race/Ethnicity, Customized: Asian | participants | 1 |
| Race/Ethnicity, Customized: Caucasian | participants | 24 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With the Opinion of the Products' Flavor, measured over 1 day.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is described as the number of participants with an opinion of the products’ flavor. Opinion was assessed using a seven-point rating scale: “1-extremely dislike, 2-moderately dislike, 3-dislike somewhat, 4-neither like nor dislike, 5-like somewhat, 6-moderately like, 7-extremely like.” The assessment timeframe was 1 day.
A rating scale is useful for recording a participant’s subjective response in an ordered format. Its categories convey direction and degree of expressed liking or disliking, while retaining a neutral response option. Counting participants at the rating levels can show how responses are distributed across the categories. That distribution may be more informative than a single summary value when responses differ among participants.
The registry record does not provide the number of participants at each rating level, a combined acceptability definition, a mean or median rating, or an arm comparison. It also does not explain how the rating counts were intended to be summarized. Consequently, the endpoint definition identifies what was assessed, but the posted results do not show the observed flavor opinions or their precision. The recorded endpoint should not be interpreted as evidence of acceptability in the absence of those results.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies the study question and the flavor-rating instrument, but it does not report the primary endpoint results. There are no posted counts of participants by rating category and no arm-level summary of flavor opinions. The record lists 0 analyses. As a result, there is no reported statistical estimate or uncertainty measure with which to describe how participants rated the formulations or whether ratings differed across mannitol levels.
The safety listings report 10 participants at risk in each dosing arm. They record zero serious adverse events in each arm. The counts of participants with other adverse events are 6, 3, 4, 7, and 6 across Dosing Arms 1 through 5, respectively. These are descriptive counts; the record does not provide an analysis that compares adverse-event frequency among arms. The absence of serious events in these listings is a statement about the recorded observations, not proof that serious events cannot occur.
Any cross-arm interpretation also needs to account for the non-randomized, open-label design. In a randomized comparison, random allocation is intended to reduce systematic differences between groups. Here, the registry says allocation was non-randomized and cautions that the arms are not like-for-like controls. Participant expectations may also affect subjective flavor ratings when masking is absent. These design features limit causal interpretation, even if arm-level ratings were available.
The sample-size assumptions described for planning illustrations are not the trial’s design rationale. They refer to a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and detecting a stated fraction of the observed effect. Such assumptions are used to illustrate planning under specified conditions; they do not establish the study’s original sample-size justification or observed power. The protocol’s sample-size justification is not reported in the registry record.
Overall, the posted information supports a description of the study structure and the listed safety counts, but not a conclusion about the primary flavor outcome. Statistical significance, effect size, confidence intervals, and comparative efficacy results are not reported in the registry record. The distinction is important: a defined endpoint is not itself an outcome finding.
9. Statistical Methods Explained
What the endpoint scale captures. The primary measure uses ordered categories for participants’ opinions of flavor. An ordinal scale preserves the ranking of responses, from stronger dislike through a neutral category to stronger liking. The distance between adjacent categories is not necessarily equal in the way that units on a physical measurement scale are equal. For that reason, a statistical summary should match the question and the structure of the response data. The registry record names the scale but does not report its category counts or the method used to summarize them.
Why the arm structure affects comparisons. The study used parallel arms, with a different total mannitol level in each formulation. Parallel-arm designs place participants in one formulation group for the comparison, rather than having every participant receive each formulation. In this study, however, allocation was non-randomized. Without random allocation, differences among groups may reflect differences in who entered or was assigned to each arm as well as any difference associated with the formulation. Open-label status means participants knew the formulation they received, which can influence a subjective outcome such as flavor opinion. These are general design considerations; the registry record does not report an adjustment strategy to address them.
Counts, estimates, and uncertainty. A count reports how many participants fell into a category or experienced an event. A count alone does not describe how precisely a broader population value has been estimated. A confidence interval is a range of values compatible with the data under a specified statistical procedure. Its width reflects uncertainty, and its interpretation depends on the model and assumptions used. No confidence intervals for flavor ratings or arm comparisons are reported in the registry record. The posted adverse-event counts are descriptive and are not accompanied by comparative estimates or uncertainty intervals.
For an outcome expressed as a participant count, an analysis might compare proportions or model the event counts, depending on how the endpoint is defined and how data are collected. The registry labels the primary outcome as a participant count, but it does not define a binary event for the flavor endpoint. A rating scale has multiple ordered categories, so reducing it to a single event count would require a stated rule for which responses qualify. No such rule is reported. It would therefore be inappropriate to infer a favorable-rating threshold or treat the endpoint as a binary success outcome.
Multiplicity and outcome selection. The registry lists 15 outcome measures, including the primary flavor measure and secondary measures related to bowel movements, timing, symptom ratings, and adverse events. When many outcomes or comparisons are examined, the chance of obtaining an apparently notable result by chance can increase. Statistical approaches can address multiplicity, but the approach depends on which outcomes and comparisons were prespecified. The registry record does not report a multiplicity procedure, a hierarchy for secondary outcomes, or analysis results. It lists 0 analyses, so no inferential findings can be reviewed in the registry record.
Over-dispersion as a general concept. Count data sometimes vary more than a simple model assumes. This is called over-dispersion, and ignoring it can make uncertainty appear smaller than it is. Whether it is relevant depends on the outcome’s data structure and the model used. The posted primary endpoint is described as a number of participants, but the record does not provide the underlying observations or identify a count model. The dispersion field is empty, and no model choice or assessment of model fit is reported. It is therefore not possible to determine whether over-dispersion was assessed or whether it would apply to the actual analysis.
Planning illustrations are not trial results. The recorded planning assumptions describe illustrations based on an observed effect, with 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 how a planning illustration may be framed, but they do not show what effect was observed in this trial or establish the trial’s original design assumptions. The registry record does not report its sample-size justification. A planning sample size is not observed power, and it cannot substitute for the missing endpoint estimate and its uncertainty.
What can be concluded about the method. The record documents a subjective, ordered flavor-rating endpoint in an open-label, non-randomized parallel-arm study. Those details help readers understand what the study set out to measure and why causal comparisons require caution. But the endpoint values, statistical procedures, missing-data handling, and analysis population are not reported in the registry record. Without those details and the underlying outcome results, the methods cannot be independently evaluated beyond the design features that are recorded.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists 15 outcome measures and 0 analyses. It identifies the flavor opinion measure as primary and lists secondary outcomes that include no bowel movement, time to first bowel movement, ratings for gas, bloating and abdominal discomfort, no successful bowel movement, time to first successful bowel movement, and treatment-emergent adverse events. The record does not describe a strategy for controlling multiplicity, such as a prespecified hierarchy or adjustment across comparisons. Because multiple outcomes may generate multiple statistical tests, the absence of a reported strategy limits interpretation of any selective finding; no such findings are reported in the registry record in any case.
Missing-data handling is not reported in the registry record. The record does not say whether participants missed assessments, how incomplete rating forms were handled, or whether any imputation or other missing-data method was used. The analysis population is also not reported: there is no description of which participants were included in each endpoint analysis or how deviations from the intended assessment were handled.
These omissions matter because outcome estimates can depend on how incomplete observations and analysis populations are defined. They also affect whether results can be reproduced or assessed for potential bias. The record identifies enrollment of 50, but does not provide a primary endpoint analysis population or outcome-level denominators for the flavor ratings. The safety listings report 10 participants at risk in each arm, which does not supply the missing details for the primary endpoint.
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 |
|---|---|---|---|
| Dosing Arm 1 | 0 | 10 | 0.0% |
| Dosing Arm 2 | 0 | 10 | 0.0% |
| Dosing Arm 3 | 0 | 10 | 0.0% |
| Dosing Arm 4 | 0 | 10 | 0.0% |
| Dosing Arm 5 | 0 | 10 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Dosing Arm 1 | 0 of 10 |
| Dosing Arm 2 | 0 of 10 |
| Dosing Arm 3 | 0 of 10 |
| Dosing Arm 4 | 0 of 10 |
| Dosing Arm 5 | 0 of 10 |
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 |
|---|---|
| Dosing Arm 1 | 6 of 10 |
| Dosing Arm 2 | 3 of 10 |
| Dosing Arm 3 | 4 of 10 |
| Dosing Arm 4 | 7 of 10 |
| Dosing Arm 5 | 6 of 10 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Dosing Arm 1 | Dosing Arm 2 | Dosing Arm 3 | Dosing Arm 4 | Dosing Arm 5 |
|---|---|---|---|---|---|---|
| Increased Gas | Gastrointestinal disorders | 3 of 10 | 2 of 10 | 2 of 10 | 6 of 10 | 5 of 10 |
| Watery Stool | Gastrointestinal disorders | 1 of 10 | 0 of 10 | 3 of 10 | 2 of 10 | 1 of 10 |
| Increased Bloating | Gastrointestinal disorders | 1 of 10 | 0 of 10 | 4 of 10 | 0 of 10 | 1 of 10 |
| Increased Abdominal Discomfort | Gastrointestinal disorders | 2 of 10 | 1 of 10 | 0 of 10 | 0 of 10 | 1 of 10 |
| Nausea | Gastrointestinal disorders | 1 of 10 | 0 of 10 | 0 of 10 | 0 of 10 | 0 of 10 |
The registry safety listings report serious adverse-event counts separately for each dosing arm. Each arm lists 10 participants at risk and zero participants affected by a serious adverse event. The death count is also zero in each arm. These figures describe the events recorded in the registry for the listed groups.
The listings also give counts for participants with other adverse events: 6 in Dosing Arm 1, 3 in Dosing Arm 2, 4 in Dosing Arm 3, 7 in Dosing Arm 4, and 6 in Dosing Arm 5. The record does not provide event terms, severity details, timing, or a statistical comparison of these counts. The figures should therefore be read as descriptive arm-level counts, not as evidence that one formulation has a different safety profile.
Zero recorded serious events does not establish that the risk is absent. It means only that no serious events are listed for these groups in the posted record. The study’s enrollment and brief observation context also do not answer questions about events outside the recorded assessment period. Further detail about safety ascertainment is not reported in the registry record.
12. What the Result Does, and Does Not, Mean
The study record establishes that investigators evaluated flavor opinions for five PEG 3350 formulations containing increasing mannitol levels. It identifies a seven-point rating scale and a one-day timeframe. That is useful information about the question the study was designed to address. However, the registry record does not report the participants’ flavor ratings, category counts, or a comparative analysis. The posted data therefore do not establish how acceptable participants found any formulation or whether their opinions varied by mannitol level.
The record also does not establish a causal effect of mannitol level. The study was open-label and non-randomized, and the registry cautions that the arms are not a like-for-like control comparison. Even if outcome differences were reported, the design would require careful interpretation because group differences could be related to allocation or expectations as well as formulation. No adjusted or unadjusted comparison is reported in the registry record.
The safety listings show zero serious adverse events in each arm and give counts for participants with other adverse events. These are observations from the listed groups, not proof of safety or a comparative safety conclusion. The record does not include event descriptions or inferential analyses of the safety counts.
In general, a study’s results are most informative when the endpoint values, analysis methods, uncertainty, missing-data procedures, and analysis population are all clear. Several of those elements are not reported in the registry record. The available information supports a description of the study design and recorded safety counts, but it does not support a conclusion about flavor acceptability, comparative effects, or the precision of an estimated effect.
13. Why This Trial Matters Statistically
This trial is statistically notable because its central question concerns a subjective outcome: participants’ opinions of flavor. The scale retains ordered levels of dislike, neutrality, and liking, but the registry record does not say how those responses were summarized or report the response distribution. For subjective outcomes, the exact endpoint definition and presentation of category-level results are important to interpretation.
The five formulations form a graded set of mannitol levels, which may invite readers to look for a pattern across arms. But a sequence of dose levels does not itself make the comparison causal. Allocation was non-randomized, masking was absent, and the registry warns that the arms are not a like-for-like control comparison. These design features illustrate why the direction of a numerical pattern, if available, should not be confused with evidence that the formulation caused it.
The registry’s distinction between a primary endpoint and secondary outcomes also matters. The study lists 15 outcome measures, yet no analysis results are recorded. Without a reported analysis plan, multiplicity handling, and missing-data procedures, readers cannot assess how outcomes were selected, compared, or interpreted. The study therefore offers a useful example of the difference between registering a question and reporting evidence that answers it.
Finally, safety counts need context. A zero serious-event count in the posted groups is a description of recorded events, not a guarantee of no risk. Counts of other adverse events are also not comparisons unless their definitions, follow-up, and analysis are clear. The record’s main statistical lesson is the need to interpret endpoint definitions, study design, and result completeness together.
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 main limitation for interpreting the primary question is that the registry record describes the flavor scale but does not report the actual ratings. There are no category counts, summary statistics, arm-specific results, or confidence intervals for the primary endpoint. The record lists 0 analyses, so it is not possible to assess the size or precision of any difference in flavor opinions.
The design also limits comparisons. This was a non-randomized, open-label study, and the registry explicitly states that its arms are not a like-for-like control comparison. The record does not explain how participants were allocated to arms, whether baseline characteristics differed, or whether any adjustment was planned. Since flavor is a subjective assessment, lack of masking is particularly relevant to how responses may be interpreted.
Additional limitations include the absence of reported eligibility details, participant characteristics, primary endpoint denominators, missing-data methods, analysis populations, and multiplicity procedures. The registry lists 15 outcome measures but does not describe a statistical analysis plan. It is also unclear from the record how the one-day timeframe relates to assessment of each secondary endpoint. These details are not reported in the registry record.
The safety information is limited to counts. The record does not give the terms or severity of other adverse events, or comparative safety estimates. The listed zero serious events should not be generalized beyond the recorded groups and assessment. Finally, the sample-size justification is not reported in the registry record, and planning illustrations do not fill that gap.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Study to Gather Information on the Acceptability of a New Flavor System With Increasing Levels of 2, 4, 6 g or Higher of Mannitol for PEG 3350 in Subjects Having Infrequent Bowel Movements. — NCT04534465.
- Registry record last updated 2020-11-12; status last verified 2020-10.
- Results first posted 2020-11-12.
- 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
NCT04534465 is a completed, single-center, open-label, non-randomized, parallel-arm, phase 4 study sponsored by Bayer. The registry reports enrollment of 50 participants with constipation. Five formulations combined a MiraLAX Sachet (17g) and flavor blend with total mannitol levels of 2g, 4g, 6g, 8g, and 10g.
The primary endpoint was the number of participants with an opinion of product flavor, assessed on a seven-point scale over 1 day. The registry record does not report the flavor-rating results or statistical analyses. It lists 15 outcome measures and 0 analyses.
The safety listings show 10 participants at risk in each arm, zero serious adverse events in each arm, and other-adverse-event participant counts of 6, 3, 4, 7, and 6 across the arms. The registry cautions that the non-randomized arms are not like-for-like control groups. Missing-data handling, analysis populations, and the sample-size justification are not reported in the registry record.