Patient Acceptance and Preference Among Screening Modalities for Detection of Barrett's Esophagus: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Patient Acceptance and Preference Among Screening Modalities for Detection of Barrett's Esophagus (NCT04301986), a non-randomized na study. The primary outcome is 7 Days Post-EGD Impact of Events Score (IES).

2. Clinical Question

3. Trial Design

NCT04301986 is a completed, non-randomized, parallel study sponsored by the University of North Carolina, Chapel Hill. The registry lists an enrollment of 24 and identifies the study as not applicable for phase. The recorded start date is 2020-08-11, and the primary completion date is 2022-05-10. The listed status is completed.

The study concerns patient acceptance and preference among three screening modalities for Barrett's esophagus: Cytosponge, TNE, and EGD. According to the brief description, participants underwent Cytosponge and TNE before a scheduled, clinically indicated upper endoscopy performed under routine standard of care. The arm descriptions distinguish a TNE-followed-by-EGD sequence from a Cytosponge-then-TNE-followed-by-EGD sequence. A follow-up phone call was planned to collect questionnaire measures and adverse events related to study participation.

Because allocation was non-randomized, the groups are not exchangeable by design. The record itself cautions that the arms are not a like-for-like control comparison. Their different procedure sequences also mean that a contrast between arms would not isolate the effect of one modality under otherwise identical conditions. The registry record does not report the allocation process, baseline characteristics, or an analysis adjusting for differences between groups.

The primary outcome is the Impact of Events Score measured seven days after EGD in the arm completing all three maneuvers. Other registered outcomes concern a Visual Analog Scale score, willingness to repeat, ranking and reporting of a preferred screening modality, and factors influencing preference. The record lists six outcome measures and zero analyses. Outcome values and analysis results 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

Analysis population for the primary outcome, as defined in the registry: All participants enrolled into the arm completing all 3 maneuvers (i.e., Cytosponge, Then TNE, Followed by EGD).

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: All participants enrolled into the arm completing all 3 maneuvers (i.e., Cytosponge, Then TNE, Followed by EGD).

6. Primary Endpoint

The registry lists the primary outcome as 7 Days Post-EGD Impact of Events Score (IES), measured over 7 days post-EGD.

The primary endpoint is the Impact of Events Score (IES) seven days after EGD. It is described as a measure of distress associated with a specific life event. The registry identifies the outcome as a mean on a scale and specifies standard deviation as its measure of dispersion. The stated population is participants in the arm completing Cytosponge, then TNE, followed by EGD.

The IES is used to quantify a participant's self-reported distress related to an event. The registry describes a range from 0-75, with higher scores indicating more severe distress associated with an event. It states that scores ≥ 44 indicate an event has a severe impact on self-reported distress, while scores ≤ 25 indicate that the event may have an effect on distress. These descriptions provide context for interpreting scores; they do not establish a diagnosis or measure the performance of a screening modality.

For a mean outcome, the group average describes the central level of scores, while the standard deviation describes how dispersed individual scores are around that average. Both are needed to understand a reported mean. However, the registry record does not report the observed IES mean or standard deviation, nor does it report an interval estimate. The endpoint's actual level and precision therefore cannot be characterized from the posted registry results.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Reading a mean and standard deviation

The primary outcome is defined as a mean IES score with standard deviation. In general, a mean summarizes the center of a set of numerical observations. The standard deviation describes how spread out those observations are around the mean. A mean alone does not reveal whether most scores were close to it or whether individual responses varied widely. The standard deviation is descriptive; it is not the same as the uncertainty in the estimated mean.

In general, a confidence interval expresses the uncertainty around an estimate under a specified statistical method. A narrower interval indicates greater precision for that estimate, while a wider interval indicates less precision. The registry record does not report a confidence interval or other uncertainty estimate for the IES mean. No interval can therefore be interpreted from the posted outcome information.

Understanding the scale

The IES is described as a scale for distress associated with a specific event, with a range from 0-75. Higher values indicate more severe distress associated with the event. The registry also gives interpretive thresholds: scores ≥ 44 indicate a severe impact on self-reported distress, and scores ≤ 25 indicate the event may have an effect on distress. Such thresholds help contextualize scale values, but they do not replace reporting the score distribution. A group mean cannot show how many individual participants crossed either threshold. The registry record does not report individual scores or counts above or below these thresholds.

Interpreting a non-randomized parallel design

In general, random allocation helps balance measured and unmeasured participant characteristics between groups, on average. In a non-randomized design, that protection is absent. Differences in outcomes between groups can reflect the procedures being compared, differences in who entered each group, or both. Here, the registry explicitly cautions that the arms are not a like-for-like control comparison. The sequences also differ: one includes Cytosponge before TNE and EGD, while the other includes TNE followed by EGD. A simple difference between their outcomes would not, by itself, identify the separate contribution of each modality.

Procedure order can matter in general because an earlier procedure may affect a participant's experience of a later procedure or how the participant reports that experience. This is a possible design consideration, not a finding about participants in this study. The registry record does not report an analysis of order effects or other factors that could influence responses.

What the sample-size assumptions mean

The registry describes sample-size calculations as planning illustrations based on the observed effect, not as the trial's own design. The stated assumptions are a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. The effect to detect is described as a stated proportion of the observed effect. For non-time-to-event outcomes, the calculations are expressed as participants per arm; time-to-event calculations would use total events. These are planning conventions, not observed trial outcomes and not evidence that a study had a particular probability of detecting an effect.

The registry record does not report a sample-size justification for the actual study, nor does it provide the observed effect needed to interpret such planning illustrations. The record also lists zero analyses, so no trial analysis result is available to evaluate. Planning calculations must not be read as observed power or as evidence that an outcome difference was present.

Over-dispersion and other model considerations

In general, over-dispersion occurs when observed variation is greater than a statistical model expects. It can make standard errors too small if the model does not accommodate that extra variation, leading to overconfident inferences. This concept is especially relevant to certain count outcomes; it is not a reported feature of this study. The primary endpoint is a continuous scale summarized by a mean and standard deviation, and the registry record does not describe a model, a distributional assessment, or an over-dispersion check.

More broadly, a statistical analysis plan would clarify how outcomes were summarized, how missing observations were handled, whether any covariates were included, and how uncertainty was calculated. Those details are not reported in the registry record. It is therefore not possible to determine whether analyses were adjusted, whether model assumptions were checked, or which inferential procedures would have been used.

Interpreting the absence of posted estimates

The absence of a reported estimate is not an estimate of zero and does not show that participants had no distress or no preference. It means the registry record does not provide the numerical outcome result needed for that interpretation. The same applies to the listed secondary outcomes: their names indicate what the study intended to assess, but do not reveal the responses or their uncertainty.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists six outcome measures: the primary IES outcome and secondary measures concerning a Visual Analog Scale score, willingness to repeat, preferred-modality ranking, the number of participants reporting a preferred modality, and factors influencing preference. Considering multiple outcomes raises a general statistical issue: when many hypotheses are tested, the chance of at least one apparently notable result can increase. A prespecified strategy may address this, for example by identifying a primary outcome or adjusting interpretation across tests.

The record identifies the primary IES outcome, but does not report a multiplicity strategy, a hierarchy among secondary outcomes, or which comparisons were planned. It lists zero analyses, and outcome results are not reported in the registry record. It is therefore not possible to determine how multiplicity was handled or to assess the evidence across the outcome set.

The record defines the primary population as participants in the arm completing all three maneuvers. It does not report the number with complete outcome data, the handling of missing responses, or whether any participants were excluded from analyses. Missing-data methods can affect interpretation when outcome availability differs across participants or relates to their experience. Without the relevant counts and methods, the completeness and representativeness of the primary endpoint cannot be evaluated.

The registry record does not report a statistical analysis plan, an intention-to-treat approach, adjustment for baseline characteristics, or a method for accounting for the non-randomized allocation. These omissions do not establish what analyses were or were not conducted outside the registry; they limit what can be learned from the posted record.

11. Safety Results

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

Deaths

Other (non-serious) adverse events

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

Most frequent non-serious adverse event terms

The registry records zero serious adverse events and zero deaths in both listed arm records. For the Cytosponge-then-TNE-then-EGD arm, 24 participants are listed as at risk for other adverse events, with 3 affected. The registry does not identify the specific other adverse-event terms in the information.

The TNE-followed-by-EGD arm lists zero participants at risk for serious and other adverse events, with zero affected in each category. Because the at-risk denominator is zero, those entries cannot be interpreted as an observed event rate among participants. They do not demonstrate that no participants in that arm experienced an event; the record provides no at-risk population with which to interpret the counts.

Adverse-event counts describe what is recorded, not whether a procedure is safe in general. Interpretation also depends on how events were defined, solicited, monitored, and attributed, as well as the duration of follow-up. The brief description says adverse events related to study participation were collected during a follow-up phone call. Further monitoring details, event descriptions, severity classifications beyond the serious category, and causal assessments are not reported in the registry record. The small enrollment and non-randomized design also limit how broadly these counts can be interpreted.

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

The registry record documents a study designed to assess acceptance, preference, distress, and adverse events associated with screening modalities for Barrett's esophagus. It specifies a primary distress measure collected seven days after EGD and lists secondary outcomes addressing willingness to repeat and modality preference. These details clarify the study's focus: participant experience rather than a direct comparison of diagnostic accuracy.

The record does not report the primary IES mean or standard deviation, secondary outcome values, or statistical analyses. As a result, it does not show the level of reported distress, the variability in responses, which modality participants preferred, or how precisely any outcome was estimated. The lack of posted estimates should not be interpreted as a finding of no effect, no distress, or equal preference.

The study's non-randomized arms do not provide a like-for-like control comparison. Their procedure sequences differ, and only one includes Cytosponge. Even if group results were available, an unadjusted contrast would not isolate a single modality's effect from sequence differences and possible participant differences. The registry record does not report an analysis designed to address those issues.

The posted adverse-event figures record zero serious adverse events and zero deaths in the arm with 24 participants listed at risk, and 3 participants affected by other adverse events. The other arm has zero listed at risk, so its zeros cannot be interpreted as a rate among participants. These counts are limited to the registry's reporting and do not establish general safety.

Overall, the registry describes what the study set out to measure and provides limited safety counts, but it does not supply outcome estimates for evaluating participant responses. It also does not report diagnostic performance, long-term outcomes, or evidence that one modality is preferable on clinical grounds. Those questions cannot be answered from the posted registry results.

13. Why This Trial Matters Statistically

This study is statistically notable because its central outcomes concern participants' experience of screening procedures. Acceptance, preference, willingness to repeat, and distress are distinct constructs. A study can define measures for these constructs without the measures being interchangeable: a preference ranking, for example, is not the same as a distress score. Clear outcome definitions matter when interpreting what a study can address.

The design also illustrates why allocation matters. A non-randomized comparison of procedure sequences can be affected by differences between the groups, and the sequences do not vary only by one isolated feature. The registry's caution that the arms are not a like-for-like control comparison is therefore important to interpretation. Describing the design accurately prevents a group contrast from being mistaken for a randomized estimate of a modality's effect.

Another statistical issue is the distinction between an outcome definition and an outcome result. The registry specifies a scale, its range, and interpretive thresholds, but does not report observed scores. Those definitions help explain how results could be read; they do not reveal the participants' actual responses. Likewise, listing secondary outcomes does not establish what participants preferred.

Finally, the record illustrates the value of complete reporting. Means, variability, uncertainty, analysis populations, missing-data handling, and methods for non-randomized comparisons would all contribute to a more informative statistical account. Their absence limits precision and interpretability, even though the study's purpose and planned measurements are described.

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 this registry record is that outcome estimates and analyses are not reported. The primary IES mean and standard deviation are absent, as are results for the listed secondary outcomes. No confidence intervals or other measures of uncertainty are reported. The registry record therefore cannot support an assessment of the magnitude or precision of participant responses.

The allocation is non-randomized, and the registry explicitly warns that the arms are not a like-for-like control comparison. The arms also differ in sequence and in whether Cytosponge is included. Potential differences in participant characteristics, order, or procedure exposure could complicate comparisons. These are design concerns; the record does not show that any one of them altered the results.

The stated primary population is limited to participants in the arm completing all three maneuvers. The number meeting that definition and the completeness of their outcome data are not reported. Eligibility criteria, baseline characteristics, and details of the recruitment and allocation process are also not reported in the registry record. These gaps make it difficult to assess who the findings would represent even if estimates were available.

The registry lists adverse-event counts but provides limited detail about event types and assessment. The TNE-followed-by-EGD arm has zero listed at risk, preventing interpretation of its zero event counts as a participant-level rate. The record also does not report the statistical analysis plan, multiplicity handling, missing-data methods, or adjustments for group differences. These limitations concern what can be concluded from the registry record and do not establish whether further information exists elsewhere.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Patient Acceptance and Preference Among Screening Modalities for Detection of Barrett's Esophagus — NCT04301986.
• Registry record last updated 2023-05-08; status last verified 2022-09.
• Results first posted 2023-05-08.
• 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

NCT04301986 is a completed, non-randomized, parallel study sponsored by the University of North Carolina, Chapel Hill, with an enrollment of 24. It examines acceptance and preference among Cytosponge, TNE, and clinically indicated EGD. The listed sequences are TNE followed by EGD, and Cytosponge followed by TNE and EGD. The primary outcome is the IES mean, with standard deviation, seven days after EGD in the arm completing all three maneuvers.

The registry lists secondary outcomes concerning a Visual Analog Scale score, willingness to repeat, preferred-modality ranking and reporting, and factors influencing preference. It records zero analyses, and outcome results are not reported in the registry record. The safety record lists zero serious adverse events and zero deaths in both arms; the Cytosponge-then-TNE-then-EGD arm lists 3 participants affected by other adverse events among 24 at risk. The other arm lists zero at risk, so its event counts do not provide a participant-level rate.