Chemo/XRT +/- Amifostine to Assess Outcomes Related to Xerostomia, Mucositis, & Dysphagia: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Chemo/XRT +/- Amifostine to Assess Outcomes Related to Xerostomia, Mucositis, & Dysphagia (NCT00503776), a randomized phase 2 study. The primary outcome is Number of Patients With Each Degree of Swallowing Dysfunction.

2. Clinical Question

3. Trial Design

This was a randomized, parallel-group phase II pilot trial with no masking reported. The registry record lists enrollment of 41 participants and status as terminated. The start date is recorded as 2006-01 and primary completion as 2008-08. A reason for termination is not reported in the registry record.

Four arms combined the interventions in different ways. Arm IA received specialized nutrition therapy, including dietitian counseling and calorie goal instruction. Arm IB received the same nutrition therapy plus low weight resistance training. Arm IIA received subcutaneous amifostine before intensity-modulated radiotherapy and specialized nutrition therapy. Arm IIB received amifostine, nutrition therapy, and low weight resistance training. Thus, nutrition therapy was included in all arm descriptions, while amifostine and exercise varied across the combinations.

The registry record describes randomization but does not report the sequence-generation method, allocation concealment, or whether assignment was balanced across the four arms. It also does not state whether the study was planned as a factorial design or describe a primary statistical contrast among the combinations. Those design details are not reported in the registry record and should not be inferred from the arm structure alone.

The trial assessed swallowing dysfunction as well as secondary outcomes involving salivary production, oral mucositis, and dietary intake. The primary endpoint was assessed 6 months after concurrent chemotherapy and radiation. One participant in Arm IIB did not undergo that study. The registry does not report the reason for that missing assessment or how it was handled analytically.

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: 43 patients consented, one was ineligible for a total of 42 patients on study.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: One patient (Arm 2B) did not undergo the 6-month 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 Number of Patients With Each Degree of Swallowing Dysfunction, measured over 6 months after concurrent chemotherapy and radiation.

The primary endpoint was the number of participants with each degree of swallowing dysfunction, assessed 6 months after concurrent chemotherapy and radiation. Swallowing was evaluated using the modified barium swallow score. The listed categories progress from grade 1, normal, and grade 2, within functional limits, to grade 3, mild impairment; grade 4, mild to moderate impairment; grade 5, moderate impairment; grade 6, moderate to severe impairment; and grade 7, severe impairment.

This outcome is clinically relevant to the trial's focus on dysphagia and treatment-related effects on swallowing. Recording participants in each category preserves the distinctions among levels of impairment rather than reducing the outcome to a single yes-or-no classification. In general, an ordinal scale can convey an ordered pattern of severity, but the distance between adjacent categories is not necessarily equal. The registry record does not describe an analysis that treats the grades as a continuous score or specify a statistical model for the categories.

The record names the endpoint and assessment time but does not report the number of participants in each grade, by arm or overall. Consequently, the posted results do not establish the distribution of swallowing dysfunction at the assessment or quantify differences between the intervention combinations.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does an ordinal endpoint show?

General statistical explanation: an ordinal outcome has categories that can be ranked, while the spacing between categories is not assumed to be equal. The modified barium swallow grades in this trial have a stated order from normal swallowing to severe impairment. Reporting the number of participants in each category can show how observations are distributed across that ordered scale. An analysis might instead use a method designed for ordinal outcomes, but the registry record does not report an analysis method for the primary endpoint. It would be inappropriate to assume that the grade numbers were treated as equally spaced measurements.

The registry endpoint is a count in each degree of dysfunction, not a single binary outcome. Collapsing grades into impaired versus not impaired would require a threshold choice, and no such threshold is stated in the registry record. A summary score would also require a defined method. Neither should be inferred from the endpoint title.

What do arm-level event counts mean?

General statistical explanation: a count of participants with an event describes how many people in a group experienced the event during the recorded period. The corresponding number at risk gives the group size used for that count. These counts are descriptive; by themselves they do not account for chance variation or establish whether groups differ. A comparative analysis would need a defined contrast and an appropriate method, with uncertainty quantified where possible. The registry record does not report such a comparative analysis for the adverse-event counts.

For a binary outcome, a confidence interval can express the uncertainty around an estimated event frequency or contrast. In general, narrower intervals indicate greater precision, while wider intervals indicate less precision. No confidence intervals for the listed adverse-event counts are reported in the registry record. No treatment-effect estimate or interval for the primary swallowing outcome is reported either.

Why does the choice of comparison matter?

The four arms differ in the combination of interventions. Comparisons could concern amifostine, LWRT, or combinations of these interventions, but each question corresponds to a different contrast. A contrast should be defined before interpreting results because choosing among several comparisons after seeing outcomes can make an apparent pattern misleading. The registry record describes randomization and the arm combinations but does not report the intended primary contrast or a statistical plan for comparing them.

In general, a randomized design supports comparison of assigned groups, but interpretation still depends on how assignment was conducted, how outcomes were collected, and how missing observations were handled. The registry record does not report the randomization procedure or allocation concealment. It also does not report whether outcome assessors were masked. Masking is listed as none, but the record does not explain which study roles this refers to.

What does the sample-size illustration represent?

General statistical explanation: a planning calculation estimates the group size that might be needed to detect a specified effect under stated assumptions. The registry's planning assumptions describe 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. The record explicitly characterizes these calculations as planning illustrations rather than the trial's own design. Such illustrations are not observed power and do not show the probability that this completed trial detected an effect.

The stated illustration uses an observed effect as its reference, but the registry does not report a primary-endpoint result or a single primary contrast from which to interpret that effect. The trial itself had four arm combinations, whereas the illustration assumptions refer to two arms. The illustration should not be mistaken for evidence that the original trial was designed with those assumptions or that its design had a particular power.

How should multiplicity and uncertainty be viewed?

General statistical explanation: evaluating multiple outcomes or multiple contrasts creates multiple opportunities for an apparently notable finding. A prespecified analysis plan can identify primary comparisons and describe whether and how multiplicity will be addressed. The registry lists a primary swallowing outcome and secondary outcomes, but does not report a multiplicity strategy or statistical analysis plan. It is therefore not possible to determine whether any adjustment was planned.

The registry record reports no analyses for the outcomes. Without estimates, intervals, or a stated model, the statistical evidence for the primary endpoint cannot be evaluated. Descriptive adverse-event counts remain useful for understanding what was recorded, but they do not replace a prespecified comparative analysis.

10. Multiplicity, Missing Data and Analysis Populations

The registry identifies one primary outcome, the number of participants with each degree of swallowing dysfunction, and lists secondary outcomes for salivary production, oral mucositis, and changes in food amount, texture, and dietary intake. It also reports five outcome measures. The registry record does not report a statistical analysis plan or a strategy for handling multiplicity across outcomes, categories, or possible arm comparisons. It does not identify a single primary contrast among the four arms.

The record reports zero analyses. Accordingly, it does not provide an analysis population, a method for handling missing observations, or a description of whether participants were analyzed according to randomized assignment. The primary outcome description notes that one participant in Arm IIB did not undergo the 6-month study. The reason for this missing assessment and its treatment in any analysis are not reported in the registry record. No imputation method or sensitivity analysis is reported.

General statistical explanation: missing outcome data can affect interpretation when the participants without measurements differ from those with measurements. The extent and direction of any effect depend on the reasons for missingness and the analytic approach. With no reported reason or handling method for the missed assessment, the implications cannot be evaluated from this record.

The randomization method, allocation concealment, sample-size justification, interim analyses, and detailed analysis populations are not reported in the registry record. The planning assumptions described for sample-size illustrations do not establish the trial's original sample-size justification or a prespecified analysis plan.

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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: mucositis/stomatitis-oral cavity (33.3%), nausea (22.2%), pain - larynx (16.7%), accute hearing loss (11.1%), muscle weakness - lower extremity (11.1%).

The serious adverse-event figures are counts of participants at risk and participants affected in each arm. Arm IA had 0 serious adverse events among 8 participants at risk; Arm IB had 0 among 12; Arm IIA had 2 among 12; and Arm IIB had 4 among 9. These figures describe what the registry records for each arm. They do not, by themselves, establish that the differences among arms are statistically meaningful or caused by a particular intervention.

The registry also reports other adverse events for 7 of 8 participants in Arm IA, 12 of 12 in Arm IB, 10 of 12 in Arm IIA, and 8 of 9 in Arm IIB. Serious and other adverse-event counts are distinct entries in the record and should not be combined into a new total. The record does not report a comparative safety analysis, confidence intervals, or a causal attribution for these events.

Listed serious adverse-event terms include mucositis/stomatitis-oral cavity at 33.3%, nausea at 22.2%, pain - larynx at 16.7%, accute hearing loss at 11.1%, muscle weakness - lower extremity at 11.1%, and pain - oral cavity at 11.1%. The registry record does not specify the denominator behind these term percentages or explain whether participants could contribute to more than one term. They should be interpreted as listed event summaries, not as arm-specific risks or a basis for ranking the arms.

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

The record documents a randomized phase II pilot trial with four combinations of specialized nutrition therapy, low weight resistance training, and amifostine. It specifies swallowing dysfunction at 6 months as the primary outcome and describes the modified barium swallow categories. It also includes counts of participants affected by serious and other adverse events. These details identify the outcomes and interventions recorded, but they do not constitute a comparative result for swallowing dysfunction.

The registry record does not provide the numbers of participants in each swallowing grade, an effect estimate, a confidence interval, or a p-value. It is therefore not possible to describe how the primary outcome was distributed or to quantify a difference among arms. The record does not report an analysis comparing the intervention combinations, so the posted data do not establish whether any combination changed the measured outcome.

The adverse-event counts show that serious events were recorded in some arms and that other adverse events were recorded across all four arms. They are descriptive, not proof of a difference in safety between interventions. Without a comparative analysis and further detail about attribution and follow-up, the counts should not be used to make a causal claim.

General statistical explanation: a trial result is best understood through an estimate of the contrast of interest and its uncertainty, alongside the design and analysis methods. A trial's randomized label alone does not supply the missing estimate or establish which comparison answers the research question. Here, the registry record does not identify a primary arm-to-arm contrast, and it reports no outcome analyses.

The record can therefore support a description of the trial structure, endpoint definition, missing 6-month assessment, and posted adverse-event counts. It cannot support a conclusion about the magnitude or precision of an intervention effect on swallowing dysfunction. The absence of a reported primary-outcome analysis should not be interpreted as evidence of either benefit or lack of benefit.

13. Why This Trial Matters Statistically

This trial is statistically informative as an example of why intervention structure and outcome reporting need to be considered together. Four arms combine specialized nutrition therapy, low weight resistance training, and amifostine, while the primary endpoint is an ordered set of swallowing dysfunction categories. The design raises distinct potential questions about each intervention and their combinations. Without a reported primary contrast, readers cannot tell which comparison was intended to carry the main inference.

The endpoint definition is more detailed than a simple event indicator: it distinguishes grades from normal swallowing through severe impairment. That detail can preserve clinically relevant differences, but it also calls for clear reporting of category counts and a suitable analysis approach. The registry record gives the grading descriptions but no category results or analytic method, leaving the main statistical question unresolved.

The study also illustrates the difference between descriptive safety information and comparative evidence. Arm-level adverse-event counts communicate what was recorded, but they do not quantify uncertainty or isolate the effects of individual interventions. Clear denominators and a defined comparison are important to interpreting such information.

Finally, a pilot designation and a planning illustration should not be confused with a completed test of efficacy or with observed power. The record describes a planning framework, but does not report the trial's own sample-size justification or a primary outcome analysis. For clinical researchers and biostatisticians, the central lesson is that transparent reporting of prespecified contrasts, missing-data handling, analysis populations, and outcome estimates is essential for interpreting randomized studies.

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 specific to this trial are apparent from the registry record. The primary outcome is defined, but its category counts and analysis are not reported. The result is therefore not interpretable as a comparison of swallowing dysfunction among the four arms. The record also does not identify a primary contrast, making it unclear which intervention question was intended to be central.

The enrollment was 41 participants across four arms. The registry does not report a sample-size justification for the trial, so the intended precision or ability to detect a difference cannot be assessed. Planning illustrations are not the trial's original design justification and are not observed power. The reason the study was terminated is not reported in the registry record.

One participant in Arm IIB did not undergo the 6-month study. The reason, missing-data method, and any sensitivity analysis are not reported. The randomization procedure, allocation concealment, detailed analysis populations, and statistical methods are also not reported. These gaps limit assessment of how assignment and missing outcome data may have affected interpretation.

The safety information is descriptive and does not include a reported comparative analysis or confidence intervals. The registry does not explain the denominator for the percentages attached to serious adverse-event terms. It is therefore not possible to interpret those percentages as arm-specific event risks or use them to make direct safety comparisons.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Chemo/XRT +/- Amifostine to Assess Outcomes Related to Xerostomia, Mucositis, & Dysphagia — NCT00503776.
• Registry record last updated 2017-06-20; status last verified 2017-05.
• Results first posted 2011-12-08.
• 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

The registry describes NCT00503776 as a randomized, unmasked, parallel-group phase II pilot trial with enrollment of 41. It lists a start date of 2006-01, primary completion of 2008-08, and status as terminated. The study concerned patients undergoing chemotherapy and radiation for stage III or stage IV head and neck cancer and included four combinations of specialized nutrition therapy, low weight resistance training, and amifostine.

The primary endpoint was the number of participants in each degree of swallowing dysfunction 6 months after concurrent chemotherapy and radiation, measured with the modified barium swallow score. The registry does not report the primary category counts or an analysis. One participant in Arm IIB missed the 6-month study, with no reason or handling method reported. Arm-level serious and other adverse-event counts are recorded, but no comparative safety analysis is reported. The reason for termination and the trial's detailed statistical plan are not reported in the registry record.