Symptomatic Relief of Acute Dyspeptic Pain in Emergency Department With Pantoprazole: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Symptomatic Relief of Acute Dyspeptic Pain in Emergency Department With Pantoprazole (NCT01281501), a randomized phase 4 study. The primary outcome is Pain Scores on the 100-millimeter Visual Analog Scale (VAS) at 1 Hour After Treatment.

2. Clinical Question

The central contrast is the addition of intravenous pantoprazole to the listed conventional treatment. Both groups received oral antacid and intravenous hyoscine butylbromide; the registry record distinguishes the groups by the intravenous pantoprazole versus normal saline component. The outcome focuses on pain at a prespecified time after treatment rather than on pain over a longer follow-up period.

The registry record also defines responder status using change from pretreatment pain and the post-treatment score. A responder had at least a 50% decrement between pretreatment and 1-hour scores and a post-treatment score of 40 millimeters or less. A non-responder had less than a 50% decrement or a post-treatment score greater than 40 millimeters. These definitions provide a categorical complement to the primary comparison of mean scores.

The question is about the recorded pain outcome and the pattern of estimates, not a recommendation about treatment. The registry record does not report the clinical threshold for a meaningful difference in the mean VAS score.

3. Trial Design

The registry record describes a completed, randomized, triple-masked, parallel-group Phase 4 trial sponsored by Chulalongkorn University. Enrollment was 87. The recorded start was 2011-01, and primary completion was 2011-10. The study title and summary describe an evaluation of adding intravenous pantoprazole to conventional treatment for immediate relief of severe acid-related dyspeptic pain in an emergency-department setting.

The conventional-treatment arm included oral antacid, 20 mg of intravenous hyoscine butylbromide, and normal saline. The pantoprazole arm included oral antacid, 20 mg of intravenous hyoscine butylbromide, and 80 mg of intravenous pantoprazole. The registry record labels allocation as randomized, masking as triple, and the model as parallel. It does not identify which roles were masked or describe the randomization procedure.

The posted primary outcome was the pain score on a 100-millimeter visual analog scale at 1 hour after treatment. VAS measurements were described as being taken consecutively every 15 minutes until 1 hour; the 1-hour score was the primary measurement. The primary outcome was analyzed under intention-to-treat principles in all enrolled patients. The record does not report details of adherence, treatment discontinuation, or how any missing outcome measurements were handled.

Four secondary outcomes are posted: responder count, non-responder count, adverse-effect count, and overall satisfaction count. The registry record lists five outcome measures in total and one analysis. Details of the original design assumptions, including the intended sample-size justification and any interim analyses, 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: We analyzed the data for all enrolled patients with the intention-to-treat principles.

Overall Study

Analysis population for the primary outcome, as defined in the registry: All enrolled patients were analyzed with the intention-to-treat principles.

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 Pain Scores on the 100-millimeter Visual Analog Scale (VAS) at 1 Hour After Treatment, measured over 1 hour after treatment.

The primary endpoint is the mean pain score on the 100-millimeter visual analog scale at 1 hour after treatment. The scale runs from 0 to 100 millimeters, with the registry record describing the minimum and maximum scores. The endpoint summarizes pain at a fixed time after treatment and allows a comparison of average scores between the randomized groups.

The registry record says that VAS scores were measured every 15 minutes until the 1-hour assessment, but identifies the 1-hour score as the primary outcome measurement. A lower score indicates less pain reported on the scale at that assessment. The posted arm summaries are means with standard deviations, so they describe both the average score and the spread of individual scores around that average.

The record additionally defines responders and non-responders by combining the change from pretreatment with a threshold for the 1-hour score. That binary classification may be easier to interpret as a participant count, but it is not the primary endpoint. It also discards some of the detail retained by the continuous score: people with different scores can fall into the same category, while people near a cutoff can be classified differently despite similar scores.

The registry record does not report a threshold for deciding whether a difference in mean VAS scores is clinically important. Statistical estimates therefore describe the observed contrast and its uncertainty, but do not by themselves establish the importance of that contrast to patients.

7. Results Posted in the Registry

• Pantoprazole: mean 19.00 versus 17.00 on control; difference 2.00 (95% CI -7.88 to 11.88), standardized effect d = 0.09; z-test p = 0.691.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Number of Participants in the Predefined "Responders"

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Pantoprazole: 74.4% (32/43) versus 81.8% (36/44) on control; risk difference -7.4 percentage points (95% CI -24.7 to 9.9), risk ratio 0.91 (0.73–1.14); unadjusted two-proportion z-test p = 0.404.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Pantoprazole and the control. The interval gives the range of effects that remain compatible with the data.

Number of Participants in the Predefined "Non-responders"

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Pantoprazole: 25.6% (11/43) versus 18.2% (8/44) on control; risk difference 7.4 percentage points (95% CI -9.9 to 24.7), risk ratio 1.41 (0.63–3.16); unadjusted two-proportion z-test p = 0.404.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Pantoprazole and the control. The interval gives the range of effects that remain compatible with the data.

Number of Participants That Have Overall Satisfaction on the Treatment

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Pantoprazole: 79.1% (34/43) versus 77.3% (34/44) on control; risk difference 1.8 percentage points (95% CI -15.6 to 19.2), risk ratio 1.02 (0.82–1.28); unadjusted two-proportion z-test p = 0.839.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Pantoprazole and the control. The interval gives the range of effects that remain compatible with the data.

Across the posted secondary outcomes, the estimates do not indicate a clear separation between the treatment groups. The responder and non-responder outcomes are complementary classifications based on the registry's stated pain-score criteria, while satisfaction captures a different participant-reported aspect of the treatment experience. These outcomes add context to the primary mean-score comparison, but they do not change what the primary endpoint measures.

The re-calculated intervals for the secondary risk differences include zero. This means the posted counts do not precisely establish a difference for these outcomes. The pattern is broadly consistent with the primary result in that neither the continuous endpoint nor the posted categorical comparisons show a clearly separated effect. It should not be read as proof that all outcomes are equivalent or that no difference exists.

Secondary outcomes are generally interpreted with more caution when several outcomes are assessed. Examining multiple results increases the opportunity for an apparently notable finding to occur by chance, especially when no adjustment or hierarchy is specified. The registry record does not report a multiplicity adjustment, a prespecified order for interpreting the secondary outcomes, or a detailed analysis plan for them.

The posted secondary results are therefore best treated as supportive descriptive evidence rather than independent confirmation of the primary result. They do not warrant a stronger conclusion than the primary outcome's estimate and uncertainty permit. Their interpretation should also respect their distinct meanings: response classification, non-response classification, and satisfaction are not interchangeable with the mean 1-hour VAS score.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Number of Participants in the Predefined "Responders"
• Number of Participants in the Predefined "Non-responders"
• Number of Participants With Adverse Effect
• Number of Participants That Have Overall Satisfaction on the Treatment

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is continuous: each participant's 1-hour VAS score is measured on a millimeter scale, and the posted arm summaries are means and standard deviations. A mean difference expresses the contrast between the average scores in the two groups. The re-calculated contrast is unadjusted and uses the posted summary statistics. Its sign depends on the order used for subtraction; the estimate described as pantoprazole versus conventional treatment is 2.0.

What does the confidence interval describe?

A confidence interval expresses the uncertainty around an estimated effect under the assumptions of the method used. The re-calculated 95% interval for the mean difference ranges from -7.877 to 11.88. Since it includes zero, the posted summary statistics are compatible with no mean difference as well as with differences in either direction. The interval is not a range containing 95% of individual patients' scores, and it does not assign a 95% probability to a particular fixed value of the effect.

What does the p-value contribute?

The unadjusted p-value for the re-calculated primary comparison is 0.691. In general, a p-value describes how compatible the observed data are with a null hypothesis under the specified statistical model. It is not the probability that the null hypothesis is true, and it does not measure the size or clinical importance of an effect. A non-small p-value does not demonstrate equivalence or prove that there is no difference.

Why does variation matter?

The posted standard deviations, 24.0 and 23.0, describe the spread of scores within their respective groups. When individual measurements vary considerably, a difference between group means may be estimated less precisely unless the sample provides enough information to distinguish the average contrast from that variation. The standard deviation is not the same as the standard error: the standard error concerns the uncertainty in an estimated mean or contrast, rather than the spread of individual scores. The re-calculated standard errors for the arm means are 3.618 and 3.507.

How do the binary comparisons differ?

Responder, non-responder, and satisfaction outcomes are posted as counts. A risk difference compares the proportion meeting an outcome in one group with the proportion in the other. The re-calculated risk-difference estimates are unadjusted. For the responder comparison, for example, the estimate is -0.074 with an interval from -0.247 to 0.099; the interval includes zero. The non-responder and satisfaction intervals also include zero. These comparisons answer questions about category frequencies, not the average VAS score.

What does masking and randomization tell us?

The record identifies the design as randomized, triple-masked, and parallel. Random allocation is intended to support a fair comparison between assigned groups, while masking can reduce some forms of bias when participants, care teams, or outcome assessors do not know group assignment. The registry record does not specify the allocation method or which parties were masked, so those procedural details cannot be assessed from the record.

The primary analysis population is described as all enrolled patients under intention-to-treat principles. In general, intention-to-treat analysis aims to retain participants in their assigned groups, preserving the comparison created by randomization. The registry record does not give further details on analysis implementation, missing-data handling, or deviations from assigned treatment.

11. Confidence Intervals and Precision

The re-calculated mean difference for pantoprazole versus conventional treatment is 2.0 millimeters, with a 95% confidence interval from -7.877 to 11.88. The interval is wide enough to include both a negative contrast and a positive contrast, as well as zero. Thus, the point estimate alone should not be treated as a precise description of the effect that would be expected beyond this sample.

The interval's width reflects uncertainty in the estimated mean contrast, not the range of scores among individual participants. The posted standard deviations are 24.0 and 23.0, showing that individual scores varied substantially within both groups. The standard errors of the group means are 3.618 and 3.507. These quantities describe different aspects of the data: standard deviations describe within-group spread, while standard errors describe the uncertainty in estimated means.

The sponsor-reported result is a mean difference in final values of -2.6, with a 95% confidence interval from -12.7 to 7.4. Its interval also includes zero. The registry record does not report enough detail to reconcile the difference between that estimate and the simple re-calculation. The two estimates should be kept distinct rather than combined.

Neither interval establishes equivalence. A conclusion of equivalence would require an acceptable difference range specified in advance and evidence that the interval is contained within that range. No such range is reported in the registry record. The available precision therefore supports a cautious reading: the posted results do not clearly distinguish the groups, but they also do not tightly bound the possible mean difference.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning figures are participants per arm, not total events. They are illustrative calculations based on the observed effect, not the trial's original design assumptions. The registry record does not report the original sample-size justification or the assumptions used to plan enrollment.

The stated planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is set to a stated fraction of the observed effect: 100%, 75%, or 50%. The displayed values give the number of participants per arm for 80% power and for 90% power under those assumptions.

In general, power is the chance that a study using a specified design would reject the null hypothesis if the assumed effect were the true effect. The 80% and 90% columns describe different planning targets: the higher target aims for a greater chance of detecting the assumed effect, and therefore requires more participants under the stated calculation. Smaller effects need more participants because they are harder to distinguish from random variation.

These calculations are not observed power. They do not say how much power the completed trial had after the results were known, and they do not establish whether the original trial was planned using these assumptions. They are conditional illustrations using the re-calculated observed effect as their starting point. If the true effect differs from the observed estimate, the planning figures would not necessarily correspond to the sample size needed for that true effect.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = 2.000; pooled standard deviation σ = 23.511.
2. n = 2 × (1.96 + 0.842)² × 23.511² / 2.000² = 2,169.3, rounded up to 2,170 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- 2                      # observed difference in means
sigma <- 23.5111988334971                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(1281501)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 2,170 (80% power), 2,905 (90% power)
 75% of observed effect: n per arm = 3,857 (80% power), 5,163 (90% power)
 50% of observed effect: n per arm = 8,678 (80% power), 11,617 (90% power)
power.t.test: 2170.3 
Simulated power at n = 2,170 per arm: 0.797 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Analyses Reported by the Sponsor

The registry record reports a two-sided t-test for the final-value mean difference. The sponsor-reported estimate is -2.6, with a 95% confidence interval from -12.7 to 7.4 and p = 0.6. The simple unadjusted re-calculation from the posted arm summaries gives a mean difference of 2.0, a 95% confidence interval from -7.877 to 11.88, and an unadjusted p-value of 0.691.

Both analyses have confidence intervals that include zero, and neither gives a precise estimate confined to one direction. Their point estimates and interval limits are not identical. The registry record does not explain how the sponsor's reported final-value analysis relates to the calculation from the posted means and standard deviations, or whether the analyses use different conventions or data handling. No reconciliation should be inferred from the record.

The sponsor-reported analysis is the trial's reported inferential result; the re-calculation is a simple unadjusted check based on the posted summary statistics. The latter should not be represented as a replacement for the sponsor's analysis. Both are consistent with substantial uncertainty about the mean difference, while the record leaves the numerical difference between the estimates unexplained.

15. Multiplicity, Missing Data and Analysis Populations

The registry record lists five outcome measures and posts four secondary outcomes alongside the primary pain-score outcome. It reports one analysis for the primary comparison. The secondary results include responder count, non-responder count, adverse-effect count, and overall satisfaction count. The record does not report a multiplicity adjustment or a prespecified hierarchy for interpreting the outcomes.

Multiplicity matters because the more outcomes or comparisons examined, the greater the chance that at least one result may appear unusual through random variation alone. Without a reported adjustment or clear outcome hierarchy, secondary p-values and intervals should not be treated as if each were the sole confirmatory test. This does not make the outcomes unusable; it limits how strongly isolated findings can support a claim.

The primary outcome population is described as all enrolled patients analyzed with intention-to-treat principles. This identifies the intended analysis population, but the registry record does not report whether every participant had an observed 1-hour VAS score or how missing values were handled. Missing-data procedures, sensitivity analyses, and reasons for any unavailable outcomes are not reported in the registry record.

The registry record also does not report the original sample-size justification, interim analyses, the full statistical analysis plan, or details of the randomization procedure. These omissions do not establish that such procedures were absent; they mean their methods and consequences cannot be evaluated from the registry record. The stated intention-to-treat approach is useful context, but it does not answer questions about missingness, adherence, or analysis choices in detail.

16. 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 non-serious adverse event terms

The posted serious adverse event count is 0 in the conventional-treatment group among 44 at risk and 0 in the pantoprazole group among 43 at risk. These figures describe the serious adverse events recorded for the groups during the period covered by the registry results. They do not establish that the risk of a serious event is zero, because a trial of this size can provide limited information about uncommon events.

The record separately lists other adverse effects for 31 participants in the conventional-treatment group and 30 participants in the pantoprazole group. These are not the serious adverse event counts and should not be conflated with them. The registry record does not provide further detail in the posted summary about the nature, severity, timing, or attribution of these other effects.

Death counts are not reported in the registry record. Safety counts should be interpreted descriptively: they record what was reported in the study groups, but do not by themselves establish a causal relationship to treatment or precisely estimate uncommon risks.

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

The results describe the average 1-hour pain scores and other posted outcomes among participants enrolled in this randomized trial. The primary re-calculated mean difference is 2.0 millimeters, with a 95% confidence interval from -7.877 to 11.88. The sponsor-reported estimate is -2.6, with a 95% confidence interval from -12.7 to 7.4. Both intervals include zero, and the registry record does not explain why the two estimates differ numerically.

These findings do not establish that the treatments are equivalent, that there is no effect, or that one treatment is superior. The estimates remain compatible with differences in either direction, and no equivalence margin is reported. The results also do not establish whether any possible difference is important to patients; a threshold for clinical importance is not reported in the registry record.

The study's endpoint is a pain score at 1 hour after treatment. It does not, by itself, describe pain relief beyond that assessment time, recurrence, later care, or longer-term outcomes. The registry record's responder definition adds a categorical assessment at the same time point, but does not resolve the uncertainty in the mean-score comparison.

The safety figures are limited as well. No serious adverse events were recorded in either group in the posted results, but these counts do not rule out uncommon harms. The record's other adverse-effect counts are descriptive and do not establish which treatment caused them.

Overall, the record supports a cautious account of the observed data: group mean scores were close, while the confidence intervals were broad enough to leave meaningful uncertainty about the underlying contrast. Conclusions beyond that require information not reported in the registry record.

18. Why This Trial Matters Statistically

This trial illustrates why an estimated effect should be read together with its uncertainty. The primary point estimate is small on the 0-to-100-millimeter VAS scale, but the 95% confidence interval extends on both sides of zero. Focusing only on the point estimate could overstate how precisely the study determines the difference; focusing only on whether a p-value crosses a conventional threshold would also lose information about the range of effects compatible with the data.

The example also shows the distinction between a continuous endpoint and a threshold-based classification. The mean VAS score uses the measured values, whereas responder status applies the record's combined change and final-score criteria. These approaches can offer complementary summaries, but neither automatically substitutes for the other. Thresholds can make outcomes easier to categorize while reducing detail about the size of individual changes.

Comparing a sponsor-reported analysis with a simple unadjusted re-calculation is another useful statistical exercise. The analyses are not numerically identical, and the registry record does not explain the difference. Reporting each estimate with its method and uncertainty avoids silently treating distinct calculations as the same result.

Finally, the planning illustration emphasizes that enrollment needs depend on the effect a study aims to detect and the desired power. Its figures are not a retrospective verdict on the trial's design. Because the original design assumptions are not reported, the illustration cannot show whether the enrollment target was selected using the same assumptions.

19. 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 registry record describes a randomized, triple-masked design, but does not specify the randomization procedure, which parties were masked, or how masking was maintained. These omissions limit assessment of those design features. The record also does not report the original sample-size justification, so the adequacy of the enrollment target against a prespecified effect cannot be evaluated from the posted information.

The primary outcome is measured at 1 hour after treatment. The registry record does not provide a longer-term pain outcome in the posted results, so the findings are limited to the specified early assessment. Although scores were described as being measured every 15 minutes until that point, the primary comparison is the score at 1 hour.

The mean-difference re-calculation and the sponsor-reported analysis have different point estimates and interval limits. The registry record does not explain this discrepancy in the numerical results. The reported analysis is identified as a two-sided t-test of final values, but details needed to reconcile it with the simple calculation from the posted summaries are not reported in the registry record.

Missing-data handling, reasons for missing measurements, treatment adherence, and sensitivity analyses are not reported in the registry record. The intention-to-treat population is stated, but those details remain important for understanding how the analysis was implemented. A multiplicity adjustment or hierarchy for the secondary outcomes is also not reported, which limits confirmatory interpretation of those results.

Finally, the record does not report a threshold for clinical importance on the VAS or an equivalence margin. Statistical uncertainty can therefore be described, but the clinical importance of a possible difference cannot be determined from the posted information alone.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Symptomatic Relief of Acute Dyspeptic Pain in Emergency Department With Pantoprazole — NCT01281501.
• Registry record last updated 2013-09-18; status last verified 2013-09.
• Results first posted 2012-07-27.
• 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.

23. Record Summary

NCT01281501 is a completed, randomized, triple-masked, parallel-group Phase 4 trial sponsored by Chulalongkorn University. Enrollment was 87; the recorded start was 2011-01 and primary completion was 2011-10.

The trial compared oral antacid and intravenous hyoscine butylbromide with normal saline against the same conventional treatment with intravenous pantoprazole added. The primary outcome was mean pain score on a 100-millimeter VAS at 1 hour after treatment, analyzed under intention-to-treat principles.

The primary re-calculation estimates a mean difference of 2.0 millimeters, with a 95% confidence interval from -7.877 to 11.88. The sponsor-reported analysis estimates -2.6, with a 95% confidence interval from -12.7 to 7.4. Both intervals include zero; the registry record does not explain the numerical difference between the analyses. The posted results are uncertain and do not establish equivalence or a clinically important difference.