Impact of Symbiotic Administration on Intestinal Function of Head and Neck Patients Surgically Treated: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Impact of Symbiotic Administration on Intestinal Function of Head and Neck Patients Surgically Treated (NCT02654652), a randomized na study. The primary outcome is Serum DAO Enzyme Concentration.

2. Clinical Question

The central question concerns a short-term biological measurement after surgical treatment, rather than a direct assessment of long-term outcomes. The study also recorded infection rate over 7 days as a secondary outcome. That outcome offers another perspective on the postoperative period, but it does not replace the primary endpoint or establish what caused any difference between groups.

The comparison is between the two assigned supplement regimens as described in the record. No further details about background nutrition therapy, adherence, or other care received by participants are reported in the registry record. Those details would help readers understand the context in which the interventions were used, but should not be inferred from the intervention names alone.

3. Trial Design

The registry record describes a randomized, triple-masked, parallel study sponsored by the Federal University of Minas Gerais. Its status is completed. The recorded start is 2014-10 and the primary completion is 2016-01. The listed enrollment is 40. The registry identifies the phase as NA, rather than reporting a numbered phase.

Participants were assigned to a symbiotic or maltodextrin arm. The symbiotic arm description names LactoFos and specifies twice-daily administration for seven days after surgery, via nasoenteric tube. The maltodextrin arm is described as 6g twice daily for seven days after surgery. Although the record labels masking as triple, it does not explain which people were masked, how masking was maintained, or whether it was assessed.

The parallel design means the two arms are presented as separate groups, with the listed outcomes measured in each. Randomization is intended, in general, to support a fair comparison by assigning participants without choosing their group based on expected outcome. It does not by itself show that the groups were balanced in every characteristic, especially in a study of this size. Baseline characteristics and the details of the allocation procedure are not reported in the registry record.

The primary endpoint is serum DAO enzyme concentration at 7 days. The registry reports a median and full range for each arm. Each arm has 18 participants in the posted primary results. The secondary outcome is infection rate at 7 days, also reported for 18 participants per arm. The record lists two outcome measures, but a detailed schedule of all measurements and the handling of missing observations are not reported in the registry record.

The planned sample-size rationale, allocation ratio, and statistical analysis plan are not reported in the registry record. Nor does the record describe interim analyses, stopping criteria, or analysis populations. These omissions limit what can be concluded about the original design choices and how closely the posted results reflect a prespecified analysis.

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: Of the 40 patients screened, six were ineligible: esophageal cancer (1), cirrhosis (1) and four were inoperable. Forty were randomized (19 - symbiotic group and 21 - control)

Overall Study

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Serum DAO Enzyme Concentration, measured over 7 days.

The primary endpoint is serum DAO enzyme concentration, measured in ng/mL at 7 days. The registry describes this measurement as an assessment of intestinal permeability. Concentration was determined using a sandwich enzyme-linked immunosorbent assay kit, identified as SEA656Hu, according to the manufacturer specifications named in the record.

This endpoint is a laboratory measurement rather than a count of symptoms or clinical events. As a general point, a biomarker can provide a quantitative way to examine a biological process of interest. Its usefulness depends on how well the measurement reflects that process and how the result relates to outcomes that matter to patients. The registry record identifies the intended relationship to intestinal permeability, but does not report validation details, assay performance characteristics, or a clinically meaningful threshold for interpreting a particular concentration.

The posted primary results are descriptive: the symbiotic arm has a median concentration of 3.0 ng/mL with a full range from 0.0 to 7.0, and the maltodextrin arm has a median of 2.5 ng/mL with a full range from 0.0 to 6.0. These summaries describe the observed values in the two groups. They do not, on their own, quantify uncertainty in the difference between groups or establish whether any observed separation is compatible with chance variation.

A comparative analysis of this primary endpoint, including an estimate of the between-arm contrast and its uncertainty, is not reported in the registry record. The posted medians therefore should be read as group summaries, not as a complete inferential answer to the trial's primary question.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What do the primary summaries describe?

The primary endpoint is summarized with a median and a full range in each arm. A median describes the central position of ordered observations: half the observations are at or below it and half are at or above it, allowing for ties. A full range gives the lowest and highest observed values. These summaries are useful for describing a distribution, but the range is particularly sensitive to extreme observations and does not convey how values are distributed between its endpoints.

The posted medians and ranges do not give an estimate of uncertainty for the difference between arms. A general inferential comparison would usually state the contrast being estimated and a measure of its uncertainty. Neither a comparative primary-endpoint estimate nor its interval is reported in the registry record. A p-value for the primary endpoint is not reported either. The registry record does not state which statistical test or model was planned for this endpoint.

How should the infection comparison be read?

Infection rate is reported as a participant count in each arm, and the comparison is expressed as a risk difference. A risk difference is a contrast between the proportions experiencing an outcome in two groups; its sign depends on the order of the groups used to define the contrast. The posted comparison identifies maltodextrin relative to symbiotic and reports an estimate of -0.222, with an interval from -0.541 to 0.096. Keeping the comparison order in view is important: reversing the order would reverse the sign of the difference.

As a general statistical concept, an interval estimate describes a range of values compatible with the observed data under the method used to construct it. Its width conveys precision: wider intervals leave more uncertainty about the size and direction of an effect. The registry record does not specify the confidence level or method used for the posted interval, so those details should not be assumed. Because the reported interval includes zero, the posted data do not exclude a no-difference value for this risk-difference comparison.

The unadjusted p-value is 0.182. In general, a p-value describes how unusual data at least as extreme as those observed would be under a specified null model and its assumptions. It is not the probability that the null hypothesis is true, nor does it measure the clinical importance of an effect. The registry record labels this value unadjusted. No correction for multiple comparisons is reported, and the record does not give the full statistical analysis plan or the assumptions behind this calculation.

Why do small counts matter?

The infection comparison is based on 18 participants in each arm. With a limited number of observations, each outcome can have substantial influence on the estimated group proportions. As a general point, uncertainty is often considerable for binary outcomes in small samples, particularly when the number of events is limited. The interval helps communicate that uncertainty; the point estimate alone would give an incomplete impression.

General statistical methods for binary outcomes may use risk differences, risk ratios, or odds ratios. These are distinct measures and can convey different numerical contrasts. The registry record posts a risk-difference comparison and associated unadjusted p-value. It does not report a sponsor-authored analysis for this endpoint, so the available result should be read as the posted comparison, not as evidence of an unreported prespecified model.

What do the planning illustrations mean?

The sample-size illustrations are explicitly described as planning calculations based on the observed effect, not as the trial's own design justification. They assume a two-sided significance level of 0.05, equal allocation, and a normal approximation. The illustrations give participants per arm for 80% power and participants per arm for 90% power, at planning for 100%, 75%, and 50% of the observed effect. For 100% of the observed effect, the stated values are 79 participants per arm for 80% power and 105 participants per arm for 90% power. For 75% of the observed effect, they are 140 and 187. For 50% of the observed effect, they are 313 and 419.

These figures are prospective planning illustrations, not observed power and not evidence that the original trial was designed around those assumptions. The original sample-size justification is not reported in the registry record. In general, planning for a smaller effect requires more participants than planning for a larger effect, because a smaller contrast is harder to distinguish from random variation under otherwise similar assumptions. The illustrated estimates also depend on the observed effect and the stated approximation; they should not be treated as definitive sample-size recommendations.

What analysis details remain unknown?

The registry record reports zero analyses in its analysis listing and does not provide a primary statistical test, a model, or an analysis population. It also does not report how missing observations were handled, whether all randomized participants were included in the analyses, or whether adjustments for baseline characteristics were planned. As general principles, these choices can affect estimates and their uncertainty, so their absence limits reproducibility and interpretation. No interim analyses or prespecified stopping rules are reported. The posted descriptive summaries and secondary comparison therefore support a restricted reading of the available results, rather than reconstruction of a full analysis plan.

10. Multiplicity, Missing Data and Analysis Populations

The registry record does not report a multiplicity strategy. It identifies serum DAO concentration as the primary endpoint and infection rate as a secondary outcome, but does not describe a testing hierarchy, an adjustment to account for testing multiple outcomes, or which findings were intended to be confirmatory. The infection p-value is unadjusted. This matters because, as a general statistical principle, repeated testing across outcomes can increase the chance of obtaining a nominally unusual result even when there is no true effect. The record does not provide enough information to determine whether any formal multiplicity control was planned or applied.

Missing-data procedures are also not reported. The registry lists an enrollment of 40, while the posted primary and infection results each report 18 participants in each arm. The reasons that outcome counts are not the same as the enrollment figure are not stated. The record does not indicate whether participants were excluded after randomization, whether any measurements were unavailable, or how such cases were handled. No imputation method or sensitivity analysis is described.

The analysis population is not reported. In particular, the record does not say whether the analyses included all randomized participants, only participants who completed the assigned regimen, or another defined group. These are distinct approaches, and the distinction can affect the interpretation of randomized comparisons. The registry also does not report a participant-flow account that would clarify the numbers at each stage.

These absences do not prove that no multiplicity, missing-data, or population decisions were made; they mean the relevant details are not reported in the registry record. Readers cannot assess whether analysis choices were prespecified, how robust the results are to missing observations, or whether the posted counts correspond to a particular analysis set. Such uncertainty is especially important when interpreting a secondary result as exploratory rather than confirmatory.

11. 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 0% reporting threshold.

The posted safety figures report zero serious adverse events among 18 participants at risk in the symbiotic group and zero among 18 participants at risk in the maltodextrin group. The record also reports zero other adverse events among 18 participants at risk in each group. These figures describe what was recorded for the stated groups and follow-up; they should not be interpreted as proof that no adverse events could occur.

The deaths field is null for both groups. A null entry does not establish that there were no deaths; the deaths information is not reported in the registry record. The record lists no leading serious adverse-event terms, but it does not give further detail about event definitions, collection procedures, severity assessment, or the duration of safety monitoring beyond what can be understood from the posted study timeframe. The intervention descriptions specify seven days of administration, but a separate safety follow-up period is not reported.

With 18 participants in each group, the safety counts are limited observations. As a general point, an absence of recorded events in a small group does not exclude uncommon events or establish comparative safety. The figures should be read as descriptive registry reporting, not as a comprehensive safety assessment or a basis for clinical advice.

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

The primary results establish the observed median and full range of serum DAO concentration in each arm at 7 days. They do not provide a direct statistical comparison of those distributions. Without a reported primary-endpoint effect estimate and uncertainty measure, the extent and precision of any between-group difference cannot be assessed from the registry record.

The infection results provide a secondary comparison, but the reported interval is broad and includes zero, and the p-value is unadjusted. This means the posted data leave considerable uncertainty about the size and direction of the risk difference. It is not appropriate to translate that uncertainty into a claim that the regimens are equivalent, or into a claim that one regimen is superior. Failure to distinguish a result from zero is not proof that the true effect is zero.

The posted summaries also do not establish a causal explanation for observed differences in a particular outcome. Randomization is an important design feature for causal comparisons, but interpretation still depends on the conduct of the trial, the completeness of outcome data, the analysis population, and the analysis methods. Details on these matters are not reported in the registry record. The record also does not supply baseline characteristics or a participant-flow account to help assess group comparability and outcome availability.

The results concern short-term measurements after surgery, with outcomes recorded at 7 days. They do not report longer-term outcomes, and they should not be generalized beyond the population and setting described without additional evidence. The registry record's brief description states the purpose as determining the impact of symbiotic use on intestinal function after surgical treatment; the posted results do not by themselves answer every aspect of that broad purpose.

In practical statistical terms, the most defensible reading is limited: the registry reports descriptive primary-endpoint data and an uncertain, unadjusted secondary infection comparison. It does not report enough primary analysis detail to quantify a primary treatment contrast, and it does not support medical advice or a conclusion about whether either regimen works.

13. Why This Trial Matters Statistically

This trial illustrates why a randomized design and a complete statistical report are both important. Randomization is intended to reduce systematic differences in how participants enter comparison groups, while masking can reduce some forms of bias in treatment delivery or outcome assessment. The record identifies the study as randomized and triple-masked, but does not explain allocation procedures or who was masked. Those labels describe design intentions; they do not replace information about implementation.

The primary endpoint is a continuous laboratory measurement, reported using medians and ranges. This is a useful reminder that descriptive summaries and inferential comparisons answer different questions. The summaries show the observed values in each arm, while an estimate of the contrast and its uncertainty would help assess how precisely the groups differ. That primary comparison is not reported in the registry record.

The secondary infection result also shows why estimates should be read together with uncertainty. A risk-difference estimate gives a direction and magnitude for the comparison, but its interval indicates that a range of interpretations remains compatible with the data. An unadjusted p-value alone cannot describe that uncertainty or establish clinical importance. The posted planning illustrations further demonstrate that assumptions about the effect to detect materially shape the number of participants needed; they are not evidence of observed power or the trial's original planning rationale.

Finally, the enrollment figure and outcome counts make transparent reporting of participant flow important. The registry record does not explain the relationship between enrollment and the numbers included in the posted results. Without analysis-population and missing-data information, readers cannot fully assess how representative the results are of all randomized participants. These are general lessons in interpreting clinical trial evidence, not conclusions about unreported events in this particular study.

14. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

Several limitations are specific to the available registry record. The primary endpoint has descriptive medians and ranges but no reported inferential comparison. The primary analysis method, effect estimate, and measure of uncertainty are not reported, preventing a direct assessment of the precision of the primary contrast.

The posted outcome counts are 18 participants per arm, while enrollment is listed as 40. The registry record does not explain the participant flow or the relationship between these figures. It does not report whether all randomized participants were analyzed, whether outcomes were missing, or how any missing data were handled. This limits assessment of selection and attrition effects.

The infection comparison is secondary and unadjusted. The record does not report a multiplicity strategy, outcome definition details, or a hierarchy of confirmatory analyses. Its interval is wide and includes zero, leaving substantial uncertainty. The registry also does not report baseline characteristics, so the observed balance of groups cannot be evaluated from the posted information.

Implementation details are limited. The record states that allocation was randomized and masking was triple, but does not identify the masked parties, allocation procedure, adherence, or whether the treatment assignment was successfully concealed. The symbiotic arm description is truncated at its final phrase, so no additional administration detail should be inferred from that text. The record does not report assay performance information or a threshold for clinical interpretation of serum DAO concentration.

Finally, the outcomes are recorded at 7 days, and longer-term results are not reported. The sample-size rationale and original analysis plan are not reported in the registry record. These limitations concern the information available for interpretation and should not be mistaken for proof that the corresponding procedures or data did not exist.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Impact of Symbiotic Administration on Intestinal Function of Head and Neck Patients Surgically Treated — NCT02654652.
• Registry record last updated 2019-06-05; status last verified 2019-02.
• Results first posted 2019-06-05.
• 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

NCT02654652 is a completed randomized, triple-masked, parallel study sponsored by the Federal University of Minas Gerais. The registry lists enrollment of 40 and records a start of 2014-10 and primary completion of 2016-01. The listed phase is NA.

The study compares symbiotic administration after surgery with maltodextrin. Its primary endpoint is serum DAO enzyme concentration in ng/mL at 7 days, reported as a median and full range for 18 participants in each arm. Infection rate at 7 days is the posted secondary outcome, also reported for 18 participants in each arm.

The registry provides an unadjusted comparison for infection but does not report a comparative primary-endpoint analysis. The statistical analysis plan, sample-size rationale, analysis populations, and missing-data procedures are not reported in the registry record. The planning illustrations are not the trial's original design justification.