Precision Approach to PPI Therapy in Gastroesophageal Reflux Disease: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Precision Approach to PPI Therapy in Gastroesophageal Reflux Disease (NCT03619811), a na na study. The primary outcome is Patient-reported Symptom Response to Treatment Measured by the Reflux Symptom Index (RSI) Score.

2. Clinical Question

In practical terms, the study is framed around symptom reporting after use of the assist device in the context of proton-pump inhibitor therapy. Because there is no listed control arm, the design does not provide a randomized between-group estimate of how outcomes compare with an alternative treatment or with no device. The clinical question is consequently narrower than a comparative treatment question: it concerns symptom response among participants in the study group. The registry record does not report enough outcome data to quantify that response or its precision.

3. Trial Design

This is a completed, single-group study sponsored by the University of California, San Diego. The registry lists enrollment of 43 participants, no masking, and allocation as not applicable. The study is not assigned a clinical-trial phase. Its start date is 2018-07-13, and its primary completion date is 2021-06-30. The listed conditions are Gastroesophageal Reflux and Laryngopharyngeal Reflux.

The single arm is called Symptomatic. Its description says the study examines the efficacy of the upper esophageal sphincter assist device as an adjunct to proton-pump inhibitors in symptomatic subjects. The device is named as the Reflux Band® Upper Esophageal Sphincter Assist Device and is classified as a diagnostic test in the registry. That classification and the arm description are both part of the record; further detail about the rationale for the classification is not reported in the registry record.

A single-group design describes outcomes within one study group. It is not a randomized comparison, and the registry explicitly notes that its arms should not be read as a like-for-like control comparison. With no separate control group described, differences between the study group and an external or hypothetical alternative cannot be attributed to the device using a randomized contrast. The record also does not report a masking procedure.

The registry lists two outcome measures, but the available description identifies the primary outcome as patient-reported symptom response measured by the Reflux Symptom Index score at week 8, or completion. The endpoint population is described as participants who completed phase 1 and phase 2. The number in that analysis population, the handling of participants who did not complete those phases, and details of follow-up beyond the stated timeframe are not reported in the registry record. Although the study is marked completed, the endpoint’s numerical result and its statistical analysis 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: This analysis includes the participants that completed phase 1 \& 2 of the 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 Patient-reported Symptom Response to Treatment Measured by the Reflux Symptom Index (RSI) Score, measured over Week 8 (Completion).

The primary endpoint concerns patient-reported reflux-related symptoms measured with the Reflux Symptom Index (RSI). The record describes the scale as ranging from 0 to 45 and states that lower scores indicate fewer reported symptoms, while higher scores indicate more reported symptoms. The assessment time is week 8, identified as completion.

The endpoint description combines two forms of reporting. The title identifies a mean RSI score, a continuous summary that describes the average score in a group. The description also defines a binary response: positive or negative, with a positive response requiring a post-treatment RSI score at most 13 and a 33% change from comparator RSI. The registry record does not explain how the binary response definition relates to the mean-score endpoint, or clarify the comparator used for the stated change. No mean, standard deviation, response count, or response proportion is reported in the registry record.

General: Patient-reported symptom scales are used to capture the experience of symptoms that may not be fully represented by an examination or laboratory measure. A continuous score can retain information across the scale, while a binary responder definition can make a threshold-based outcome easier to interpret. Each approach also has limits: a mean can obscure variation between participants, and a threshold converts a range of scores into categories. Neither summary alone describes every participant’s experience.

Here, the endpoint’s stated purpose is to assess symptom response after treatment. Without numerical results and clarification of the relationship between the continuous and binary definitions, the extent and precision of any change cannot be determined from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary endpoint is described using a continuous measure, the mean RSI score, with standard deviation as the stated measure of dispersion. Its description also includes a binary response definition. These are distinct statistical summaries, and interpretation depends on which one was analyzed and how the definition was applied. The registry record does not report an analysis entry or numerical result clarifying that point.

What does a mean and standard deviation describe?

General: A mean is the arithmetic average of a set of measurements. For a symptom score, it gives a group-level summary, but it does not show whether individual participants had similar scores or very different ones. The standard deviation describes how spread out measurements are around the mean. A larger standard deviation indicates greater variability within the group; it is not the same as the uncertainty in the estimated mean.

The RSI is described as having a minimum value of 0 and a maximum value of 45. The record says that lower scores represent fewer reported symptoms and higher scores represent more reported symptoms. The mean therefore needs to be read in the context of the scale’s direction and range. However, no mean or standard deviation is reported in the registry record, so no group score or variability can be interpreted.

How does a binary responder definition differ?

General: A binary endpoint classifies each participant into one of two categories, such as meeting or not meeting a prespecified response criterion. It can communicate the proportion meeting a clinically defined threshold, but it discards distinctions among scores within each category. A participant just meeting a threshold and one with a larger change may both be counted as responders. The continuous score preserves more gradation, but a group mean does not directly show how many participants crossed a threshold.

The registry describes a positive response as requiring a post-treatment RSI score at most 13 and a 33% change from comparator RSI. It does not report the number who met both criteria, and it does not explain the comparator used in that definition. The title’s mean-score wording and the binary response description are both present; the record does not make their analytical relationship clear.

What would uncertainty measures add?

General: A confidence interval gives a range of values compatible with the data and the method used to calculate it. Its width reflects statistical precision: narrower intervals indicate more precise estimation under the assumptions of the analysis, while wider intervals indicate more uncertainty. A p-value addresses the compatibility of the data with a specified null hypothesis under a statistical model; it does not measure the size or importance of an effect. Neither quantity replaces the estimate itself.

No confidence interval, p-value, or numerical endpoint estimate is reported in the registry record. Thus, neither the magnitude of an RSI result nor its statistical uncertainty can be evaluated. A result cannot be inferred from the endpoint definition, enrollment figure, or completed status of the study.

What is over-dispersion, in general?

General: Over-dispersion occurs when variation in observed data exceeds what a chosen statistical model assumes. It matters because a model that understates variability can produce uncertainty estimates that are too small. It is especially discussed for count and categorical data models, where the assumed relationship between the mean and variance may not fit the observed data. The registry record does not report an analysis model or data diagnostics, so there is no basis to say whether over-dispersion was relevant to this study.

How should the planning assumptions be read?

The record describes a sample-size illustration using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. For time-to-event outcomes, the illustration is described as using a total event count; for other outcomes, it is described in participants per arm. These are planning conventions, not results from participants.

General: Sample-size calculations estimate how many observations may be needed to detect an effect under specified assumptions. Their output depends on the assumed effect, variability, significance level, allocation, and statistical model. A planning calculation is not observed power and does not describe how precise an actual study result is. In this case, the design assumptions describe equal allocation between two arms, whereas the registered study is single-group. The observed effect used in the illustration and any calculated planning values are not reported in the registry record. The illustration should therefore not be treated as evidence about the study’s realized precision or as confirmation of its original design rationale.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Symptomatic")
n   <- c(31)
m   <- c(15.5)
sp  <- c(10.3)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Symptomatic  31  15.500  10.300  11.722  19.278

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists two outcome measures, but only the primary outcome is described in detail in the available record. It contains no analysis entries. An adjustment for multiple outcomes, a hierarchy for interpreting outcomes, or a strategy for selecting among analyses is not reported in the registry record. Without that information, the effect of multiplicity on any statistical claims cannot be assessed. The absence of an analysis entry does not establish what analyses may have been conducted outside the registry.

The stated primary endpoint population includes participants who completed phase 1 and phase 2. The registry lists enrollment of 43, but does not report how many participants completed those phases or contributed an RSI assessment at week 8. The number with missing endpoint data, reasons for missingness, and methods for handling missing values are not reported in the registry record.

General: Missing outcome data can affect both the precision and the interpretation of a study. If participants with missing assessments differ from those with observed assessments, a completer-only summary may not represent the full enrolled group. Statistical approaches such as imputation or sensitivity analyses can examine how assumptions about missing values influence results, but the record does not say whether any such methods were used.

The registry also does not report an intention-to-treat analysis population, a per-protocol population, or other analysis-population definitions beyond the stated phase-completer description. Interim analyses and any stopping rules are not reported in the registry record. These omissions mean that the analysis population, handling of incomplete data, and multiplicity strategy cannot be independently evaluated from the posted record.

12. 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 0% reporting threshold.

Most frequent non-serious adverse event terms

The registry’s adverse-event figures list 43 symptomatic participants at risk for serious adverse events and 0 affected by a serious adverse event. It lists 43 at risk for other adverse events and 1 affected. Deaths are listed as 0. No serious adverse-event terms are listed.

These counts should be read as the event figures recorded for the study group, not as a comparison between treatment groups. The study is single-group, and the registry does not provide a control group for assessing relative event frequency. The figures also do not describe the nature, severity, timing, or duration of the one other adverse event; those details are not reported in the registry record.

General: A recorded count of zero means that no events in that category are listed in the record for the stated group. It is not proof that an event is impossible, nor does it by itself establish that an intervention is safe. Interpretation depends on how events were defined, collected, and followed, as well as on the number of participants and observation time. The registry record does not provide further detail on event definitions or the observation period for these counts.

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

The registry record describes a study of a symptom-assist device used as an adjunct to proton-pump inhibitor therapy in symptomatic participants. It specifies an RSI endpoint at week 8 and defines a positive response using a score threshold and change from comparator RSI. Those details explain what the study set out to assess, but they do not supply the observed endpoint result.

No numerical mean RSI score, standard deviation, responder count, change estimate, confidence interval, or p-value is reported in the registry record. Consequently, the direction and size of observed symptom outcomes, and the precision with which they were estimated, cannot be determined from the record. The endpoint definition alone does not show whether participants met the response criteria.

The single-group design also limits what any within-group result could establish. Without a randomized comparison group, an observed change would not isolate the effect of the device from other influences on symptoms. The registry description of the arm as an adjunct to proton-pump inhibitor therapy further means the study question concerns the device in that treatment context, rather than a documented comparison of the device against a separate alternative regimen.

General: Statistical evidence is strongest when the estimate, its uncertainty, the analysis population, and the study design are considered together. A point estimate without an interval does not convey precision; a statistical test without the estimate does not convey magnitude. A result in one group does not by itself establish a causal treatment effect. These principles are relevant to interpreting the design, but the numerical information needed to apply them to the RSI outcome is not reported in the registry record.

The adverse-event figures list no serious adverse events and no deaths, with one other adverse event recorded. These counts describe the registry entries and should not be taken as a complete characterization of safety in other populations or settings. In sum, the record makes the study question and several design features clear, while leaving the principal numerical efficacy result and detailed safety context unreported. It supports neither a claim of benefit nor a claim of no benefit.

14. Why This Trial Matters Statistically

This study is statistically informative as an example of the distinction between defining an endpoint and reporting its result. The registry identifies a patient-reported RSI outcome, a specific assessment time, a score direction, and a response threshold. Those features help readers understand what was intended to be measured. Yet without an outcome estimate and its uncertainty, the central quantitative question remains unanswered in the registry record.

The endpoint description also illustrates why clear specification matters. It names a mean score while describing a binary positive-or-negative response. A mean and a responder classification answer different questions: one summarizes average score level, while the other counts participants meeting a criterion. The record does not explain how these summaries are connected in the analysis. Clarifying that relationship would help readers understand which result is primary and how it should be interpreted.

Design is equally important. A single-group study can describe outcomes among enrolled participants, but it cannot offer the same protection against confounding as a randomized control comparison. This is particularly relevant when a study aims to assess an intervention alongside existing therapy. The registry’s explicit identification of the design makes it important not to interpret any within-group change as a controlled estimate of the device’s effect.

The record further distinguishes planning from observation. A sample-size illustration can show how assumptions relate to a hypothetical target, but it is not a report of observed response or actual precision. Its stated two-arm allocation assumptions do not match the registered single-group design. Keeping those concepts separate is essential to avoid treating planning calculations as evidence about study outcomes.

Finally, the stated phase-completer population makes reporting the number analyzed and the handling of missing assessments especially relevant. These details are not reported. Together, endpoint clarity, design-aware interpretation, and transparent reporting of analysis populations are central statistical considerations for reading this study.

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 principal limitation for interpreting the primary outcome is that the registry record does not report numerical RSI results. Without the mean, standard deviation, binary response count, or an estimate of change, the observed symptom outcomes cannot be quantified. No confidence interval or statistical test result is reported to show the uncertainty around an estimate.

The endpoint description contains both a mean-score framing and a binary responder definition. It does not explain how these relate analytically. The definition refers to a change from comparator RSI, but the comparator is not described further, and no separate comparison group is listed. This leaves the change criterion difficult to interpret as a study contrast.

The design is single-group, with allocation listed as not applicable and no masking. There is no randomized control group described. As a result, the registered design does not support a like-for-like treatment comparison, and any within-group symptom change would have to be interpreted without a concurrent randomized control estimate.

The primary analysis population is described as participants who completed phase 1 and phase 2, but the number of completers and the number contributing endpoint data are not reported in the registry record. The record also does not report reasons for missing assessments, missing-data methods, or sensitivity analyses. This prevents evaluation of how incomplete follow-up may affect the endpoint summary.

Other limitations of the available record include the absence of analysis entries, details about the second outcome measure, a multiplicity strategy, and information about interim analyses. The registry’s sample-size illustration uses assumptions for two-arm allocation, while the registered study is single-group; no calculated planning values or original design justification are reported. These are limitations of what can be interpreted from the registry record, and do not establish what information may exist outside it.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Precision Approach to PPI Therapy in Gastroesophageal Reflux Disease — NCT03619811.
• Registry record last updated 2021-09-20; status last verified 2021-08.
• Results first posted 2021-09-20.
• 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

NCT03619811 is a completed, single-group study sponsored by the University of California, San Diego, with enrollment of 43. It evaluates the Reflux Band® Upper Esophageal Sphincter Assist Device in symptomatic participants, described as an adjunct to proton-pump inhibitor therapy. The registered primary endpoint is patient-reported RSI symptom response at week 8, or completion.

The registry describes both a mean RSI score and a binary response definition, with a positive response requiring a post-treatment score at most 13 and a 33% change from comparator RSI. The endpoint population is described as participants who completed phase 1 and phase 2. Numerical efficacy results, analysis details, and the number of endpoint completers are not reported in the registry record.

The adverse-event figures list 0 serious adverse events, 1 other adverse event, and 0 deaths. The study has no registered randomized control group, so the record does not provide a between-group treatment comparison.